[Objectives] This study was conducted to verify the field application effect of slow-release nitrogen fertilizer on summer maize in Shajiang black soil area by simultaneous sowing and fertilization, and explore the ap...[Objectives] This study was conducted to verify the field application effect of slow-release nitrogen fertilizer on summer maize in Shajiang black soil area by simultaneous sowing and fertilization, and explore the application scope and nitrogen metabolism mechanism, so as to lay a foundation for fertilizer reduction and efficiency improvement. [Methods] With maize variety Beiqing 340 and sulfur-coated urea as experimental materials, five nitrogen application levels were set, namely, control (C0), slow-release nitrogen 70 kg/hm^(2) (C70), slow-release nitrogen 140 kg/hm^(2) (C140), slow-release nitrogen 210 kg/hm^(2) (C210) and slow-release nitrogen 280 kg/hm^(2) (C280). The phosphorus and potassium fertilizers were all in accordance with the unified standard. [Results] With the application rate of slow-release nitrogen increasing, the nitrogen accumulation in organs increased first and then decreased after tasseling stage of maize. In order to reduce the fertilizing amount and increase efficiency, 210 kg/hm^(2) of slow-release nitrogen fertilizer was the best fertilizing amount for summer maize in Shajiang black soil area. [Conclusions] This study provides reference for fertilizer reduction, efficiency improvement and sustainable development of summer maize in Shajiang black soil area.展开更多
Nitrogen(N)fertilization affects grain quality in common buckwheat(Fagopyrum esculentum Moench).But the effects of N fertilizer on various buckwheat protein parameters are not fully understood.This study aimed to inve...Nitrogen(N)fertilization affects grain quality in common buckwheat(Fagopyrum esculentum Moench).But the effects of N fertilizer on various buckwheat protein parameters are not fully understood.This study aimed to investigate the synthesis,accumulation,and quality of buckwheat protein under four N application rates in the Loess Plateau,China.Optimal N application(180 kg N ha-1)improved yield,agronomic traits,and N transport and increased protein yield and protein component accumulation.Prolamin and glutelin accumulation first increased and then decreased with increasing N application.The relationships between the contents of protein components and the amount of applied N generally followed quadratic functions.Nitrate reductase and glutamine synthetase activities first increased and then decreased with increasing N levels.Optimal N fertilizer increased the waterholding capacity and thermal stability of buckwheat protein and reduced its emulsification capacity,but negligibly changed its oil-absorption capacity.Hydrophobic amino acids and glutelin content were the main factors affecting protein quality.展开更多
Field experiments were carried out on roselle (Hibiscus sabdariffa L) during the 2019 and 2020 cropping seasons at the CSIR-SARI Research Station at Manga in the Upper East Region of Ghana. The aim of the experiment w...Field experiments were carried out on roselle (Hibiscus sabdariffa L) during the 2019 and 2020 cropping seasons at the CSIR-SARI Research Station at Manga in the Upper East Region of Ghana. The aim of the experiment was to study the response of roselle to cowdung, nitrogen fertilizer and their interaction on the growth and yield of roselle. The treatments consisted of factorial combination of five rates of cowdung (0, 1.5, 2.5, 3.5 and 4.5 t/ha) and five levels of nitrogen (0, 20, 40, 60 and 80 kgN/ha) laid out in a randomized complete block design and replicated three times. Data were collected on days to 50% flowering, plant height, number of leaves per plant and dry calyx yield. The results indicated that differences in dry calyx yield due to the manure and nitrogen fertilizer effects were highly significant (P 0.01). Application rate of 2.5 t/ha manure recorded the highest yield of 340 kg/ha and 308.1 kg/ha in 2019 and 2020 respectively. Increasing manure rate from 2.5 - 3.5 t/ha did not result in significant increases in dry calyx yield. The four rates differed significantly from the control which had the least calyx yield of 190.3 kg/ha and 180 kg/ha in 2019 and 2020 respectively. Nitrogen rate of 60 kg/ha recorded the highest dry calyx yield of 510.5 kg/ha and 370.4 kg/ha in 2019 and 2020 respectively which were significantly different from calyx yields recorded by other treatments. The trend on partial budget analysis was consistent in both seasons with the highest yielding treatments (2.5 t/ha cowdung manure and 60 kg/ha) recording the highest net benefit while the control (0 kg/ha) ranked last. The application rate of 2.5 t/ha of cowdung and 60 kg/ha of Nitrogen is thus recommended for optimum roselle production and productivity in the study area.展开更多
[Objectives]In response to the issue of soil improvement in Yuanmou County,the effects of combined application of biochar-based organic fertilizer and reduced nitrogen fertilizer on soil nutrients,soil enzyme activity...[Objectives]In response to the issue of soil improvement in Yuanmou County,the effects of combined application of biochar-based organic fertilizer and reduced nitrogen fertilizer on soil nutrients,soil enzyme activity,and yield of purple cabbage(Brassica oleracea var.capita rubra)were investigated in the field base of Institute of Thermal Zone Ecological Agriculture,Yunnan Academy of Agricultural Sciences in Yuanmou County.[Methods]A total of 13 treatments were set up by applying biochar-based organic fertilizer at three levels of 15,30 and 45 t/hm^(2)(T_(1),T_(2),T_(3)),combined with top application of nitrogen fertilizer(urea)at four levels:375(N_1),300(N_(2)),225(N_(3))and 0 kg/hm^(2),with non-fertilizing treatment as control check(CK),in order to explore the optimal ratio for the combined application of biochar-based organic fertilizer with nitrogen fertilizer.[Results]The application of biochar-based organic fertilizer could significantly improve soil nutrients,enzyme activity,and purple cabbage yield.The improvement effect of combined application with nitrogen fertilizer was higher than that of single application of biochar-based organic fertilizer,and the improvement effect was enhanced with the application amount of biochar-based organic fertilizer increasing.The contents of organic matter and total nitrogen were the highest in treatment T_(3)N_(3),of which the values increased by 81.39%and 56.09%compared with the CK,respectively.The contents of soil hydrolyzable nitrogen,available phosphorus,and available potassium were all the highest under treatment T_(3)N_(2),with increases of 92.76%,171.01%and 235.50%,respectively.There was a significant positive correlation between the activity of soil catalase,urease,and sucrase and organic matter,total nitrogen,and available nutrients.The overall soil enzyme activity was relatively higher in treatment T_(3)N_(2).The yield of purple cabbage treated with biochar-based organic fertilizer combined with nitrogen fertilizer could reach 85750 kg/hm^(2),which was 94.78%higher than that treated with biochar-based organic fertilizer alone.Based on comprehensive analysis,the optimal combination ratio was 45 t/hm^(2)of biochar-based organic fertilizer and 300 kg/hm^(2)of urea(T_(3)N_(2)).[Conclusions]This study provides data support for the promotion of biochar-based organic fertilizers and reduced fertilizer in agricultural soil in the Dam area of Yuanmou County.展开更多
Machine transplanting and the application of slow-release nitrogen(N) fertilizer(SRNF) have played vital roles in the modernization of rice production. We aimed to determine the effects of potted-seedling transplantin...Machine transplanting and the application of slow-release nitrogen(N) fertilizer(SRNF) have played vital roles in the modernization of rice production. We aimed to determine the effects of potted-seedling transplanting—a new machine-transplanting method—and SRNF on hybrid rice yields. A 2-year splitplot experiment(2016–2017) was conducted in Meishan, Sichuan province, China, using two machinetransplanting methods(potted-seedling and blanket-seedling) and three N treatments. Total green leaf area, high-effective leaf area and its rate at heading, net photosynthetic rate of flag leaves 7 days after heading, glutamate synthase(GOGAT) and glutamine synthase(GS) activity after heading, dry matter production, and N accumulation at heading and maturity increased under the potted-seedling method or 70% SRNF as a base + 30% urea application at the panicle initiation stage(SBUP). Stem diameter and number of small and of all vascular bundles at the neck–panicle node in potted-seedling plants increased as a result of increasing numbers of effective panicles, secondary branches, and spikelets. In pottedseedling plants, treatment with SBUP increased the number of large and total vascular bundles at the panicle–neck internode and the number of differentiated and surviving secondary branches and spikelets and decreased the number of ineffective tillers and degenerated secondary branches and spikelets. We conclude that the potted-seedling machine transplanting method and SRNF combined with urea topdressing can strengthen the source–sink relationship in rice, resulting in higher yields.展开更多
The effects of different timing of N fertilizer application at the same rate on grain β-amylase activity, protein con- centration, weight and malt quality of barley were studied. Grain β-amylase activity and protein...The effects of different timing of N fertilizer application at the same rate on grain β-amylase activity, protein con- centration, weight and malt quality of barley were studied. Grain β-amylase activity and protein concentration were significantly higher in treatments where all top-dressed N fertilizer was applied at booting stage only or equally applied at two-leaf stage and booting stage than in the treatment where all top-dressed N fertilizer was applied at two-leaf age stage only. On the other hand, grain weight and malt extract decreased with increased N application at booting stage. There were obvious differences between barley varieties and experimental years in the grain and malt quality response to the timing of N fertilizer application. It was found that grain protein concentration was significantly and positively correlated with β-amylase activity, but significantly and nega- tively correlated with malt extract and Kolbach index. The effect of grain protein concentration on malt quality was predominant over the effect of grain β-amylase activity.展开更多
In order to screen suitable high hybrid wheat seed production technology,the split-plot experiment design was adopted and study was carried out about the effects of the different row ratios of male and female parents ...In order to screen suitable high hybrid wheat seed production technology,the split-plot experiment design was adopted and study was carried out about the effects of the different row ratios of male and female parents and application amount of nitrogen fertilizer on hybrid wheat seed production and its component factors. The results showed that the seed production increased with the increase in the number of female parent row. When the row ratio of male and female parents was 2 ∶ 6,the seed production was 3 683. 8 kg/ha; when the application amount of nitrogen fertilization was 50 kg/ha,the seed production was 3 649. 4 kg/ha; the interaction between the row ratio of male and female parents and the application amount of nitrogen fertilizer indicated that when the row ratio of male and female parents was 2∶ 6 and the application amount of nitrogen fertilizer was 300 kg/ha,the seed production reached the highest( 4160. 6 kg/ha). The row ratio of male and female parents and application amount of nitrogen fertilizer had significant effect on the component factors of seed production,including the number of grains per spike,spike weight and setting percentage. When the row ratio of male and female parents was 2∶ 5,the number of grains per spike,spike weight and setting percentage were the highest at 26. 7 grains,1. 12 g,and 62. 6% respectively; when application amount of nitrogen fertilizer was 450 kg/ha,the number of grains per spike,spike weight and setting percentage were the highest at 26. 0 grains,1. 08 g,and59. 2% respectively; the interaction of row ratio of male and female parents and application amount of nitrogen fertilizer had significant effect on the number of grains per spike,spike weight and setting percentage; when the row ratio of male and female parents was 2∶ 5 and the application amount of nitrogen fertilizer was 300 kg/ha,the number of grains per spike,spike weight and setting percentage were the highest at 29. 6grains,1. 24 g,and 71. 6% respectively. The number of grains per spike is the largest component factor for seed production. Increasing the number of grains per spike can increase the seed production. According to the effects of row ratio of male and female parents and application amount of nitrogen fertilizer on the component factors of seed production,the optimal condition was 2∶ 5-2∶ 6 for row ratio of male and female parents and 300-450 kg/ha for application amount of nitrogen fertilizer.展开更多
To find proper nitrogen fertilizer application mode of rapeseed( Brassica napus L.),promote the high and stable yield of rapeseed,field experiment was carried out to study the effect of nitrogen fertilizer application...To find proper nitrogen fertilizer application mode of rapeseed( Brassica napus L.),promote the high and stable yield of rapeseed,field experiment was carried out to study the effect of nitrogen fertilizer application modes on the yield and economic traits of Fengyou 10 rapeseed planted in two different fertility soils,and characteristics and differences of responses of different fertility soils to nitrogen fertilizer application modes were compared and analyzed. The results showed that the yield and related economic traits of rapeseed treated by nitrogen fertilizer were higher than the control group; in the nitrogen fertilizer treatment group,when the nitrogen fertilizer was applied as the base fertilizer and wintering fertilizer at the ratio of 7∶ 3,the rapeseed yield was higher than the control group and reached the highest; when the nitrogen fertilizer was applied as the base fertilizer,wintering fertilizer,and bud fertilizer at the ratio of 5∶ 3∶ 2,the rapeseed yield was significantly higher than the control group but was the lowest. These indicate that sufficient nitrogen supply is the basis for normal growth and development of rape seedlings. When the pure nitrogen fertilizer was at 192 kg/ha and the ratio of base fertilizer and wintering fertilizer was 7∶ 3,it can better coordinate the high yield of rapeseed and overall use of nitrogen fertilizer,and obtain higher rapeseed yield.展开更多
Nitrogen fertilizer application is an important means to promote cotton production in saline-alkali land.A metaanalysis and regression analysis of 49 peer-reviewed studies were conducted using yield data(373 data poin...Nitrogen fertilizer application is an important means to promote cotton production in saline-alkali land.A metaanalysis and regression analysis of 49 peer-reviewed studies were conducted using yield data(373 data points),dry matter accumulation(114 data points),and water use efficiency(157 data points)to quantify the effect of nitrogen fertilizer on the yield,dry matter accumulation,and water use efficiency of cotton in saline-alkali land in China for different planting management practices and different growing environments.The results showed that the nitrogen application significantly improved the yield,dry matter accumulation,and water use efficiency by 34.11%,36.27%,and 33.87%,respectively,compared with no nitrogen application.The largest improvements in the yield,dry matter accumulation,and water use efficiency occurred in areas where saline-alkali land had been improved for many years,in Eastern China,South Central China,and Northwest China(areas with annual average precipitation≤200 mm or>800 mm,and annual average evaporation≤800 mm or>2400 mm),in areas with trickle irrigation,and fields with a planting density of 100000 to 250000 plants/hm2.Cotton exhibited the optimal response to nitrogen application at a rate of 300-375 kg/hm2,a basal application ratio of 20%-40%,and top-dressing in the cotton bud,flowering boll,and full boll stages.The effect of nitrogen application increased as the salinity increased.A suitable nitrogen application rate,top-dressing ratio,and top-dressing period are crucial for increasing cotton production in saline-alkali land,although environmental differences and planting measures have to be considered.This study provided information on the correct application of nitrogen fertilizer to maximize its benefits and suggests controlling nitrogen fertilizer inputs in agriculture to protect the soil environment and ensure sustainable agricultural development.展开更多
In recent years,in order to improve nutrient use efficiency,especially nitrogen use efficiency,fertilizer valueadded technology has been developed rapidly.However,the mechanism of the effect of synergistic fertilizer ...In recent years,in order to improve nutrient use efficiency,especially nitrogen use efficiency,fertilizer valueadded technology has been developed rapidly.However,the mechanism of the effect of synergistic fertilizer on plant nitrogen utilization is not clear.A study was,therefore,conducted to explore the activities and gene expression of key enzymes for nitrogen assimilation and the gene expression of nitrogen transporters in wheat after the application of synergistic fertilizer.Soil column experiment was set up in Qingdao Agricultural University experimental base from October 2018 to June 2019.Maleic acid and itaconic acid were copolymerized with acrylic acid as cross-linking monomer to make a fluid gel,which was sprayed on the fertilizer surface to make nitrogen and phosphorus synergistic fertilizer.A total of 6 treatments was set according to different nitrogen and phosphorus fertilizer ratios:(1)100%common nitrogen fertilizer+100%common phosphate fertilizer(2)70%nitrogen synergistic fertilizer+100%phosphorus synergistic fertilizer;(3)100%nitrogen synergistic fertilizer+70%phosphorus synergistic fertilizer;(4)100%nitrogen synergistic fertilizer+100%phosphorus synergistic fertilizer;(5)70%nitrogen synergistic fertilizer+70%phosphorus synergistic fertilizer;(6)100%commercial nitrogen synergistic fertilizer+100%commercial phosphorus synergistic fertilizer.The results are as follows:(1)the enzyme activities of wheat plants under synergistic fertilizer condition were higher than those under ordinary fertilizer,except under the treatment that nitrogen and phosphorus synergistic fertilizer were both reduced;(2)the expression level of the genes under the treatment“100%nitrogen synergistic fertilizer+100%phosphorus synergistic fertilizer”was significantly higher than those in other treatments.Combined with the higher performance of nitrogen concentration in various parts of the plant under the condition of applying synergistic fertilizer,this study indicated that the application of synergistic fertilizer can improve the nitrogen metabolism of the plant by increasing the nitrogen level in the rhizosphere soil,inducing the expression of nitrogen transporter genes and key assimilation enzymes genes.展开更多
Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the act...Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.展开更多
Modelling of the effects of water and different levels of nitrogen on evapotranspiration and water productivity of rainfed soybeans is very important in optimising resource use in the production of the crop.The object...Modelling of the effects of water and different levels of nitrogen on evapotranspiration and water productivity of rainfed soybeans is very important in optimising resource use in the production of the crop.The objective of the study was to model evapotranspiration,soil water storage and water productivity of rainfed soybeans under different levels of nitrogen fertilizer by using the FAO AquaCrop model.Field experiments were conducted at the Teaching and Research Farms of Obafemi Awolowo University,Nigeria in the rainy seasons of 2015 and 2016.There were five levels of nitrogen,which are 00,25,50,75 and 100%of the recommended nitrogen applications and two varieties of soybeans,which produced a 2 by 5 factorial experimental design.The data of the wetter year 2015,were used for calibration of the AquaCrop model because AquaCrop is water driven.The 2016 data were used for the validation.The AquaCrop model simulated canopy cover with R2 and EF>0.90,d-in-dex>0.99.The model captured the trend of the soil water storage well,R2 and EF>0.70.The AquaCrop model simulated soil water storage below wilting point for seasonal rainfall less than 600 mm,and it did not overestimate it.The model predicted evapotranspirationwith R and EF>0.89,d-index=1.00.Above ground biomass was overestimated even though R2>0.98.Although,nitrogen stress reduced seed yield and water productivity,there was no under or over estimation of the seed yields.They were predicted with low error under the different levels of nitrogen fertilizer,R>0.99,EF and d-index>0.99.The AquaCrop model is suitable for simulating canopy cover,soil water storage,evapotranspiration,and seed yieldof rainfed soybeans with different levels of nitrogen fertilizer under temporal distribution of seasonal rainfall.Therefore,it can serve as a useful tool for smallholder farmers in predicting productivity of soybeans and optimising resource allocation,land and water use in the tropical farming systems.We recommend simulation of the effects of pest on biomass,seed yield and water produc-tivity by subsequent versions of the AquaCrop model.In addition,incorporating an eco-nomic sub-unit in the model will enable users to make financial decisions.展开更多
[Objectives]To study the effect of nitrogen(N)on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers,and to carry out experiments on nitrogen fertilizer control of summer ...[Objectives]To study the effect of nitrogen(N)on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers,and to carry out experiments on nitrogen fertilizer control of summer peanuts.[Methods]Four treatments were set up in the experiment:no-nitrogen plot(N 0P_(4)K_(4)),optimized nitrogen plot(N_(7)P_(4)K_(4)),70%optimized nitrogen plot(N_(5)P_(4)K_(4)),130%optimized nitrogen plot(N 9P 4K 4),repeated 3 times,and arranged in random blocks.The area of the plot was 42 m^(2),ridges were set between the plots,and protective rows of more than 1 m were set around the experimental site.The types of fertilizers were urea,superphosphate,and imported potassium chloride,and the variety of peanuts was Linhua 5.Except for the level of fertilization,other agricultural operations were the same,and soil sampling tests,field records,and yield testing were carried out according to the requirements of the plan.[Results]On the basis of 60 kg/ha of phosphorus and potassium fertilizer application,the optimum economical fertilizer application rate and the highest application rate of pure nitrogen were about 115.20 and 131.25 kg/ha,respectively.[Conclusions]This study is expected to provide a certain basis for the high-quality and high-yield summer peanuts in southern Shandong area.展开更多
A water-saving cultivation technique of supplementary irrigation based on soil moisture levels has been adopted for winter wheat production in the Huang-Huai-Hai Plain of China,due to the enhanced water-use efficiency...A water-saving cultivation technique of supplementary irrigation based on soil moisture levels has been adopted for winter wheat production in the Huang-Huai-Hai Plain of China,due to the enhanced water-use efficiency.However,appropriate split nitrogen management may further improve crop growth and grain yield.Here,we conducted a 2-year field experiment to determine if split nitrogen management might improve wheat productivity by enhancing ^(13)C photosynthate mobilization and the antioxidant defense system under water-saving conditions.Split nitrogen management involved a constant total nitrogen rate(240 kg ha^(−1))split in four different proportions between sowing and jointing stage,i.e.,10:0(N1),7:3(N2),5:5(N3),and 3:7(N4).The N3 treatment significantly enhanced“soil-plant analysis development”values,superoxide dismutase antioxidant activity,soluble protein content,sucrose content,and sucrose phosphate synthetase activity,although it reduced the accumulation of malondialdehyde(MDA).The N3 treatment ultimately increased the amount of dry matter assimilation after anthesis significantly.In addition,the ^(13)C isotope tracer experiment revealed that the N3 treatment promoted the assimilation of carbohydrates after anthesis and their partitioning to the developing grains.Compared to the unequal ratio treatments(N1,N2,and N4),the equal ratio treatment(N3)increased grain yield by 5.70–16.72%via increasing 1000-grain weight and number of grains per spike in both growing seasons.Therefore,we recommend the use of a 5:5 basal-topdressing split nitrogen fertilizer application under water-saving irrigation conditions to promote antioxidant enzyme activity and the remobilization of photosynthate after anthesis for improving wheat grain yield.展开更多
Background:Native warm-season grass(NWSG)mixtures may provide a lownitrogen(N)-input summer perennial forage option to extensively managed forage-livestock systems.Methods:Mixed pastures of big bluestem(Andropogon ger...Background:Native warm-season grass(NWSG)mixtures may provide a lownitrogen(N)-input summer perennial forage option to extensively managed forage-livestock systems.Methods:Mixed pastures of big bluestem(Andropogon gerardii Vitman),little bluestem(Schizachyrium scoparium Michx.),and indiangrass(Sorghastrum nutans L.)fertilized with 0 or 67 kgNha−1 were continuously stocked with beef heifers and cows.Forage mass,nutritive value,and canopy heights were determined every 2 weeks during the grazing season.Stand persistence measures included the canopy cover and leaf area index(LAI)and plant crown density at spring emergence following 3 years of grazing management.Results:Forage mass,canopy height,and stocking densities were greater for N-fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3-year study.Forage NWSG fertilized with N had a greater decrease in LAI during the growing season(51%decrease)than unfertilized NWSG.Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.Conclusions:Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low-level N than zero-N-input systems and may provide a low-N-input alternative for improved species use in southeastern US forage-livestock systems.展开更多
To address the relationships between the amount of nitrogen fertilizer application and the yield of double cropping rice systems,we investigated the effects of a cultivation pattern of strong seedlings with increased ...To address the relationships between the amount of nitrogen fertilizer application and the yield of double cropping rice systems,we investigated the effects of a cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application(SDN)on the morphological and physiological characteristics of double cropping rice.Our results indicated that the effects of SDN on the morphological characteristics of the single plant roots of double cropping rice were not significant,but the morphological characteristics of the population roots were largely different.Specifically,SDN significantly increased the morphological indexes of the root population such as root fresh weight,root volume,root number,root length and root dry weight.The effects of SDN on the total root absorption areas and root active absorption areas of the single plants were non-significant,but it dramatically enhanced the total root absorption areas and root active absorption areas of the plant population during the tillering,heading and mature stages.In addition,SDN significantly increased the root bleeding intensity and elevated the soluble sugar and free amino acid contents of root bleeding sap.Compared to the traditional cultivation pattern(CK),SDN significantly increased root bleeding intensity at the heading stage by 4.37 and 8.90% for early and late rice,respectively.Meanwhile,SDN profoundly enhanced the soluble sugar contents of root bleeding sap by 12.85 and 10.41% for early and late rice,respectively.In addition,SDN also significantly enhanced free amino acid content of root bleeding sap by 43.25% for early rice and by 37.50% for late rice systems compared to CK.Furthermore,SDN increased the actual yield of double cropping rice mainly due to the higher effective panicle number and the larger seedsetting rate.The actual yields of early rice under SDN were higher than CK by 9.37 and 5.98% in 2016 and 2017,and the actual yields of late rice under SDN were higher than CK by 0.20 and 1.41% in 2016 and 2017,respectively.Correlation analysis indicated that the significant positive correlations were observed between the majority of the root indexes and the actual yield across the four different growth stages.展开更多
Research on the effect of the nitrogen application rate on the balance of the nitrogen utilization, yield and quality of rice is common in South China but is relatively lacking in Northeast China, especially in the Li...Research on the effect of the nitrogen application rate on the balance of the nitrogen utilization, yield and quality of rice is common in South China but is relatively lacking in Northeast China, especially in the Liaohe Delta. In this study, Yanfeng 47 rice was planted in Panjin city, China, to explore the effect of six nitrogen rates (0, 160, 210, 260, 315 and 420 kg N/ha) on the nitrogen use efficiency, rice quality and grain yield of rice plants. The results showed that the application of an appropriate nitrogen rate (210-260 kg N/ha) remarkably increased the nitrogen use efficiency of rice plants, grain yield, rice milling quality and nutritional quality and resulted in a moderate rice eating quality. Although low nitrogen rates (160 kg N/ha) maintained a high rice eating quality, they decreased grain yield and other rice qualities, and excessive nitrogen (315 kg N/ha) increased rice appearance quality but significantly reduced the nitrogen use efficiency (p < 0.05), yield and eating quality of rice. Therefore, to produce rice in the Liaohe Delta <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">by</span></span></span><span><span><span> an environmentally friendly method and guarantee rice with high quality and yield, the recommended nitrogen application rate is 210 kg N/ha.</span></span></span>展开更多
We conducted a pot experiment to examine the feasibility of applying a reaction-finished solution of hydrochar(HRFS)to enhance rice production in a saline soil.With this purpose,HRFS was applied(0,10,20,40,60,80 and 1...We conducted a pot experiment to examine the feasibility of applying a reaction-finished solution of hydrochar(HRFS)to enhance rice production in a saline soil.With this purpose,HRFS was applied(0,10,20,40,60,80 and 100 mL/pot)and rice yield and nitrogen(N)use efficiency(NUE)were determined.HRFS application significantly(P<0.05)increased rice grain yield by 19.6%-30.0%compared to the control treatment(CKU,with N but without HRFS addition).Moreover,HRFS application promoted plant height and straw biomass of rice.Increases of rice yield were mainly achieved by increases in the number of panicles and grains per panicle.Compared with the CKU treatment,the NUE of HRFS amendments significantly(P<0.05)increased by 56.3%-71.7%.This indicated that the improvement of NUE was one of the mechanisms to improve rice grain yield with HRFS amendment.The results of regression analysis showed that there was a positive relationship(R^(2)=0.8332)between rice yield and HRFS application rate within an appropriate range.The highest rice yield was recorded with the HRFS application of 40 mL/pot,but a further increase in HRFS application rate appeared to reduce rice yield.Based on the results of this pot study,HRFS application can increase rice yield in a saline soil by regulating its yield components and enhancing NUE.However,impact of HRFS on these variables showed a“dose effect”.展开更多
Soil microbial biomass nitrogen(MBN)contains the largest proportion of biologically active nitrogen(N)in soil,and is considered as a crucial participant in soil N cycling.Agronomic management practices such as crop ro...Soil microbial biomass nitrogen(MBN)contains the largest proportion of biologically active nitrogen(N)in soil,and is considered as a crucial participant in soil N cycling.Agronomic management practices such as crop rotation and monocropping systems,dramatically affect MBN in agroecosystems.However,the influence of crop rotation and monocropping in agroecosystems on MBN remains unclear.A meta-analysis based on 203 published studies was conducted to quantify the effect of crop rotation and mono-cropping systems on MBN under synthetic N fertilizer application.The analysis showed that crop rotation significantly stimulated the response ratio(RR)of MBN to N fertilization and this parameter reached the highest levels in upland-fallow rotations.Upland mono-cropping did not change the RR of MBN to N application,however,the RR of MBN to N application in paddy mono-cropping increased.The difference between crop rotation and mono-cropping systems appeared to be due to the various cropping management scenarios,and the pattern,rate and duration of N addition.Crop rotation systems led to a more positive effect on soil total N(TN)and a smaller reduction in soil pH than mono-cropping systems.The RR of MBN to N application was positively correlated with the RR of mineral N only in crop rotation systems and with the RR of soil pH only in mono-cropping systems.Combining the results of Random Forest(RF)model and structural equation model showed that the predominant driving factors of MBN changes in crop rotation systems were soil mineral N and TN,while in mono-cropping systems the main driving factor was soil pH.Overall,our study indicates that crop rotation can be an effective way to enhance MBN by improving soil N resources,which promote the resistance of MBN to low pH induced by intensive synthetic N fertilizer application.展开更多
Faced with the scarcity of water resources and irrational fertilizer use,it is critical to supply plants with water and fertilizer in a coordinated pattern to improve yield with high water use efficiency(WUE).One such...Faced with the scarcity of water resources and irrational fertilizer use,it is critical to supply plants with water and fertilizer in a coordinated pattern to improve yield with high water use efficiency(WUE).One such method,alternate partial root-zone irrigation(APRI),has been practiced worldwide,but there is limited information on the performance of different irrigation regimes and nitrogen(N)rates under APRI.The objectives of this study were to investigate the effects of varying irrigation regimes and N rates on shoot growth,grain yield and WUE of maize(Zea mays L.)grown under APRI in the Hexi Corridor area of Northwest China in 2014 and 2015.The three N rates were 100,200 and 300 kg N ha–1,designated N1,N2 and N3,respectively.The three irrigation regimes of 45–50%,60–65%and 75–80%field capacity(FC)throughout the maize growing season,designated W1,W2 and W3,respectively,were applied in combination with each N rate.The results showed that W2 and W3 significantly increased the plant height,stem diameter,crop growth rate,chlorophyll SPAD value,net photosynthetic rate(Pn),biomass,grain yield,ears per ha,kernels per cob,1000-kernel weight,harvest index,evapotranspiration and leaf area index(LAI)compared to W1 at each N rate.The N2 and N3 treatments increased those parameters compared to N1 in each irrigation treatment.Increasing the N rate from the N2 to N3 resulted in increased biomass and grain yield under W3 while it had no impact on those under the W1 and W2 treatments.The W3 N3 and W2 N2 and W2 N3 treatments achieved the greatest and the second-greatest biomass and grain yield,respectively.Increasing the N rate significantly enhanced the maximum LAI(LAI at the silking stage)and Pn under W3,suggesting that the interaction of irrigation and fertilizer N management can effectively improve leaf growth and development,and consequently provide high biomass and grain yield of maize.The W2 N2,W2 N3 and W3 N3 treatments attained the greatest WUE among all the treatments.Thus,either 60–65%FC coupled with 200–300 kg N ha–1 or 75–80%FC coupled with 300 kg N ha–1 is proposed as a better pattern of irrigation and nitrogen application with positive regulative effects on grain yield and WUE of maize under APRI in the Hexi Corridor area of Northwest China and other regions with similar environments.These results can provide a basis for indepth understanding of the mechanisms of grain yield and WUE to supply levels of water and nitrogen.展开更多
基金Supported by National Key Research and Development Program of China(2017FYD0101406)Zhoukou Comprehensive Test Station of Henan Provincial Corn Industry Technology System(HARS-22-02-Z5)。
文摘[Objectives] This study was conducted to verify the field application effect of slow-release nitrogen fertilizer on summer maize in Shajiang black soil area by simultaneous sowing and fertilization, and explore the application scope and nitrogen metabolism mechanism, so as to lay a foundation for fertilizer reduction and efficiency improvement. [Methods] With maize variety Beiqing 340 and sulfur-coated urea as experimental materials, five nitrogen application levels were set, namely, control (C0), slow-release nitrogen 70 kg/hm^(2) (C70), slow-release nitrogen 140 kg/hm^(2) (C140), slow-release nitrogen 210 kg/hm^(2) (C210) and slow-release nitrogen 280 kg/hm^(2) (C280). The phosphorus and potassium fertilizers were all in accordance with the unified standard. [Results] With the application rate of slow-release nitrogen increasing, the nitrogen accumulation in organs increased first and then decreased after tasseling stage of maize. In order to reduce the fertilizing amount and increase efficiency, 210 kg/hm^(2) of slow-release nitrogen fertilizer was the best fertilizing amount for summer maize in Shajiang black soil area. [Conclusions] This study provides reference for fertilizer reduction, efficiency improvement and sustainable development of summer maize in Shajiang black soil area.
基金supported by the National Key Research and Development Program of China(2020YFD1000805-03)National Natural Science Foundation of China(31671631)。
文摘Nitrogen(N)fertilization affects grain quality in common buckwheat(Fagopyrum esculentum Moench).But the effects of N fertilizer on various buckwheat protein parameters are not fully understood.This study aimed to investigate the synthesis,accumulation,and quality of buckwheat protein under four N application rates in the Loess Plateau,China.Optimal N application(180 kg N ha-1)improved yield,agronomic traits,and N transport and increased protein yield and protein component accumulation.Prolamin and glutelin accumulation first increased and then decreased with increasing N application.The relationships between the contents of protein components and the amount of applied N generally followed quadratic functions.Nitrate reductase and glutamine synthetase activities first increased and then decreased with increasing N levels.Optimal N fertilizer increased the waterholding capacity and thermal stability of buckwheat protein and reduced its emulsification capacity,but negligibly changed its oil-absorption capacity.Hydrophobic amino acids and glutelin content were the main factors affecting protein quality.
文摘Field experiments were carried out on roselle (Hibiscus sabdariffa L) during the 2019 and 2020 cropping seasons at the CSIR-SARI Research Station at Manga in the Upper East Region of Ghana. The aim of the experiment was to study the response of roselle to cowdung, nitrogen fertilizer and their interaction on the growth and yield of roselle. The treatments consisted of factorial combination of five rates of cowdung (0, 1.5, 2.5, 3.5 and 4.5 t/ha) and five levels of nitrogen (0, 20, 40, 60 and 80 kgN/ha) laid out in a randomized complete block design and replicated three times. Data were collected on days to 50% flowering, plant height, number of leaves per plant and dry calyx yield. The results indicated that differences in dry calyx yield due to the manure and nitrogen fertilizer effects were highly significant (P 0.01). Application rate of 2.5 t/ha manure recorded the highest yield of 340 kg/ha and 308.1 kg/ha in 2019 and 2020 respectively. Increasing manure rate from 2.5 - 3.5 t/ha did not result in significant increases in dry calyx yield. The four rates differed significantly from the control which had the least calyx yield of 190.3 kg/ha and 180 kg/ha in 2019 and 2020 respectively. Nitrogen rate of 60 kg/ha recorded the highest dry calyx yield of 510.5 kg/ha and 370.4 kg/ha in 2019 and 2020 respectively which were significantly different from calyx yields recorded by other treatments. The trend on partial budget analysis was consistent in both seasons with the highest yielding treatments (2.5 t/ha cowdung manure and 60 kg/ha) recording the highest net benefit while the control (0 kg/ha) ranked last. The application rate of 2.5 t/ha of cowdung and 60 kg/ha of Nitrogen is thus recommended for optimum roselle production and productivity in the study area.
基金Supported by Key R&D Program of the Ministry of Science and Technology of China(2017YFC0505102-4)。
文摘[Objectives]In response to the issue of soil improvement in Yuanmou County,the effects of combined application of biochar-based organic fertilizer and reduced nitrogen fertilizer on soil nutrients,soil enzyme activity,and yield of purple cabbage(Brassica oleracea var.capita rubra)were investigated in the field base of Institute of Thermal Zone Ecological Agriculture,Yunnan Academy of Agricultural Sciences in Yuanmou County.[Methods]A total of 13 treatments were set up by applying biochar-based organic fertilizer at three levels of 15,30 and 45 t/hm^(2)(T_(1),T_(2),T_(3)),combined with top application of nitrogen fertilizer(urea)at four levels:375(N_1),300(N_(2)),225(N_(3))and 0 kg/hm^(2),with non-fertilizing treatment as control check(CK),in order to explore the optimal ratio for the combined application of biochar-based organic fertilizer with nitrogen fertilizer.[Results]The application of biochar-based organic fertilizer could significantly improve soil nutrients,enzyme activity,and purple cabbage yield.The improvement effect of combined application with nitrogen fertilizer was higher than that of single application of biochar-based organic fertilizer,and the improvement effect was enhanced with the application amount of biochar-based organic fertilizer increasing.The contents of organic matter and total nitrogen were the highest in treatment T_(3)N_(3),of which the values increased by 81.39%and 56.09%compared with the CK,respectively.The contents of soil hydrolyzable nitrogen,available phosphorus,and available potassium were all the highest under treatment T_(3)N_(2),with increases of 92.76%,171.01%and 235.50%,respectively.There was a significant positive correlation between the activity of soil catalase,urease,and sucrase and organic matter,total nitrogen,and available nutrients.The overall soil enzyme activity was relatively higher in treatment T_(3)N_(2).The yield of purple cabbage treated with biochar-based organic fertilizer combined with nitrogen fertilizer could reach 85750 kg/hm^(2),which was 94.78%higher than that treated with biochar-based organic fertilizer alone.Based on comprehensive analysis,the optimal combination ratio was 45 t/hm^(2)of biochar-based organic fertilizer and 300 kg/hm^(2)of urea(T_(3)N_(2)).[Conclusions]This study provides data support for the promotion of biochar-based organic fertilizers and reduced fertilizer in agricultural soil in the Dam area of Yuanmou County.
基金supported by the National Key Research and Development Program of China(2017YFD0301701 and 2017YFD0301706)National Natural Science Foundation of China(31660369)。
文摘Machine transplanting and the application of slow-release nitrogen(N) fertilizer(SRNF) have played vital roles in the modernization of rice production. We aimed to determine the effects of potted-seedling transplanting—a new machine-transplanting method—and SRNF on hybrid rice yields. A 2-year splitplot experiment(2016–2017) was conducted in Meishan, Sichuan province, China, using two machinetransplanting methods(potted-seedling and blanket-seedling) and three N treatments. Total green leaf area, high-effective leaf area and its rate at heading, net photosynthetic rate of flag leaves 7 days after heading, glutamate synthase(GOGAT) and glutamine synthase(GS) activity after heading, dry matter production, and N accumulation at heading and maturity increased under the potted-seedling method or 70% SRNF as a base + 30% urea application at the panicle initiation stage(SBUP). Stem diameter and number of small and of all vascular bundles at the neck–panicle node in potted-seedling plants increased as a result of increasing numbers of effective panicles, secondary branches, and spikelets. In pottedseedling plants, treatment with SBUP increased the number of large and total vascular bundles at the panicle–neck internode and the number of differentiated and surviving secondary branches and spikelets and decreased the number of ineffective tillers and degenerated secondary branches and spikelets. We conclude that the potted-seedling machine transplanting method and SRNF combined with urea topdressing can strengthen the source–sink relationship in rice, resulting in higher yields.
基金Project supported by the National Natural Science Foundation of China (No. 30270779) and the Special Research Foundation for Doctor Discipline of Chinese Universities (No. 20020335028)
文摘The effects of different timing of N fertilizer application at the same rate on grain β-amylase activity, protein con- centration, weight and malt quality of barley were studied. Grain β-amylase activity and protein concentration were significantly higher in treatments where all top-dressed N fertilizer was applied at booting stage only or equally applied at two-leaf stage and booting stage than in the treatment where all top-dressed N fertilizer was applied at two-leaf age stage only. On the other hand, grain weight and malt extract decreased with increased N application at booting stage. There were obvious differences between barley varieties and experimental years in the grain and malt quality response to the timing of N fertilizer application. It was found that grain protein concentration was significantly and positively correlated with β-amylase activity, but significantly and nega- tively correlated with malt extract and Kolbach index. The effect of grain protein concentration on malt quality was predominant over the effect of grain β-amylase activity.
基金Supported by State Key Research and Development Program of Ministry of Science and Technology(2016YFD0101603)Fundamental Research Funds for the Central Universities in 2016(XDJK2016A020)
文摘In order to screen suitable high hybrid wheat seed production technology,the split-plot experiment design was adopted and study was carried out about the effects of the different row ratios of male and female parents and application amount of nitrogen fertilizer on hybrid wheat seed production and its component factors. The results showed that the seed production increased with the increase in the number of female parent row. When the row ratio of male and female parents was 2 ∶ 6,the seed production was 3 683. 8 kg/ha; when the application amount of nitrogen fertilization was 50 kg/ha,the seed production was 3 649. 4 kg/ha; the interaction between the row ratio of male and female parents and the application amount of nitrogen fertilizer indicated that when the row ratio of male and female parents was 2∶ 6 and the application amount of nitrogen fertilizer was 300 kg/ha,the seed production reached the highest( 4160. 6 kg/ha). The row ratio of male and female parents and application amount of nitrogen fertilizer had significant effect on the component factors of seed production,including the number of grains per spike,spike weight and setting percentage. When the row ratio of male and female parents was 2∶ 5,the number of grains per spike,spike weight and setting percentage were the highest at 26. 7 grains,1. 12 g,and 62. 6% respectively; when application amount of nitrogen fertilizer was 450 kg/ha,the number of grains per spike,spike weight and setting percentage were the highest at 26. 0 grains,1. 08 g,and59. 2% respectively; the interaction of row ratio of male and female parents and application amount of nitrogen fertilizer had significant effect on the number of grains per spike,spike weight and setting percentage; when the row ratio of male and female parents was 2∶ 5 and the application amount of nitrogen fertilizer was 300 kg/ha,the number of grains per spike,spike weight and setting percentage were the highest at 29. 6grains,1. 24 g,and 71. 6% respectively. The number of grains per spike is the largest component factor for seed production. Increasing the number of grains per spike can increase the seed production. According to the effects of row ratio of male and female parents and application amount of nitrogen fertilizer on the component factors of seed production,the optimal condition was 2∶ 5-2∶ 6 for row ratio of male and female parents and 300-450 kg/ha for application amount of nitrogen fertilizer.
基金Supported by Special Project for Construction of Modern Agricultural Industrial Technology System(CARS-12)Key Special Scientific and Technological Research Project of Henan Province(151100111200)+1 种基金Key Scientific and Technological Planning Project of Henan Province(162102110011)Planning Project for National Key Research and Development(2016YFD0101300)
文摘To find proper nitrogen fertilizer application mode of rapeseed( Brassica napus L.),promote the high and stable yield of rapeseed,field experiment was carried out to study the effect of nitrogen fertilizer application modes on the yield and economic traits of Fengyou 10 rapeseed planted in two different fertility soils,and characteristics and differences of responses of different fertility soils to nitrogen fertilizer application modes were compared and analyzed. The results showed that the yield and related economic traits of rapeseed treated by nitrogen fertilizer were higher than the control group; in the nitrogen fertilizer treatment group,when the nitrogen fertilizer was applied as the base fertilizer and wintering fertilizer at the ratio of 7∶ 3,the rapeseed yield was higher than the control group and reached the highest; when the nitrogen fertilizer was applied as the base fertilizer,wintering fertilizer,and bud fertilizer at the ratio of 5∶ 3∶ 2,the rapeseed yield was significantly higher than the control group but was the lowest. These indicate that sufficient nitrogen supply is the basis for normal growth and development of rape seedlings. When the pure nitrogen fertilizer was at 192 kg/ha and the ratio of base fertilizer and wintering fertilizer was 7∶ 3,it can better coordinate the high yield of rapeseed and overall use of nitrogen fertilizer,and obtain higher rapeseed yield.
基金supported by a start-up from the National Natural Science Foundation of China(Grant No.52069026)Xinjiang Production and Construction Corps“strong base”science and technology leading talent project(Grant No.2022CB013-02)the Xinjiang Production and Construction Crops International Science and Technology Cooperation Project(Grant No.2021BC003).
文摘Nitrogen fertilizer application is an important means to promote cotton production in saline-alkali land.A metaanalysis and regression analysis of 49 peer-reviewed studies were conducted using yield data(373 data points),dry matter accumulation(114 data points),and water use efficiency(157 data points)to quantify the effect of nitrogen fertilizer on the yield,dry matter accumulation,and water use efficiency of cotton in saline-alkali land in China for different planting management practices and different growing environments.The results showed that the nitrogen application significantly improved the yield,dry matter accumulation,and water use efficiency by 34.11%,36.27%,and 33.87%,respectively,compared with no nitrogen application.The largest improvements in the yield,dry matter accumulation,and water use efficiency occurred in areas where saline-alkali land had been improved for many years,in Eastern China,South Central China,and Northwest China(areas with annual average precipitation≤200 mm or>800 mm,and annual average evaporation≤800 mm or>2400 mm),in areas with trickle irrigation,and fields with a planting density of 100000 to 250000 plants/hm2.Cotton exhibited the optimal response to nitrogen application at a rate of 300-375 kg/hm2,a basal application ratio of 20%-40%,and top-dressing in the cotton bud,flowering boll,and full boll stages.The effect of nitrogen application increased as the salinity increased.A suitable nitrogen application rate,top-dressing ratio,and top-dressing period are crucial for increasing cotton production in saline-alkali land,although environmental differences and planting measures have to be considered.This study provided information on the correct application of nitrogen fertilizer to maximize its benefits and suggests controlling nitrogen fertilizer inputs in agriculture to protect the soil environment and ensure sustainable agricultural development.
基金supported by the Program of Shandong Modern Agricultural Technology and Industry System–Cultivation and Soil Fertilizer(SDAIT0107)the Major Application Technology Innovation Projects in Shandong Province and the Key Research and Development Projects of Shandong Province.
文摘In recent years,in order to improve nutrient use efficiency,especially nitrogen use efficiency,fertilizer valueadded technology has been developed rapidly.However,the mechanism of the effect of synergistic fertilizer on plant nitrogen utilization is not clear.A study was,therefore,conducted to explore the activities and gene expression of key enzymes for nitrogen assimilation and the gene expression of nitrogen transporters in wheat after the application of synergistic fertilizer.Soil column experiment was set up in Qingdao Agricultural University experimental base from October 2018 to June 2019.Maleic acid and itaconic acid were copolymerized with acrylic acid as cross-linking monomer to make a fluid gel,which was sprayed on the fertilizer surface to make nitrogen and phosphorus synergistic fertilizer.A total of 6 treatments was set according to different nitrogen and phosphorus fertilizer ratios:(1)100%common nitrogen fertilizer+100%common phosphate fertilizer(2)70%nitrogen synergistic fertilizer+100%phosphorus synergistic fertilizer;(3)100%nitrogen synergistic fertilizer+70%phosphorus synergistic fertilizer;(4)100%nitrogen synergistic fertilizer+100%phosphorus synergistic fertilizer;(5)70%nitrogen synergistic fertilizer+70%phosphorus synergistic fertilizer;(6)100%commercial nitrogen synergistic fertilizer+100%commercial phosphorus synergistic fertilizer.The results are as follows:(1)the enzyme activities of wheat plants under synergistic fertilizer condition were higher than those under ordinary fertilizer,except under the treatment that nitrogen and phosphorus synergistic fertilizer were both reduced;(2)the expression level of the genes under the treatment“100%nitrogen synergistic fertilizer+100%phosphorus synergistic fertilizer”was significantly higher than those in other treatments.Combined with the higher performance of nitrogen concentration in various parts of the plant under the condition of applying synergistic fertilizer,this study indicated that the application of synergistic fertilizer can improve the nitrogen metabolism of the plant by increasing the nitrogen level in the rhizosphere soil,inducing the expression of nitrogen transporter genes and key assimilation enzymes genes.
基金financially supported by the National Key Research and Development Program of China(2022YFD190160304)Natural Science Foundation of Sichuan Province(2022NSFSC0013)+1 种基金Sichuan Maize Innovation Team Construction Project(SCCXTD-2022-02)National Key Research and Development Program of China(2018YFD0301206)。
文摘Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.
文摘Modelling of the effects of water and different levels of nitrogen on evapotranspiration and water productivity of rainfed soybeans is very important in optimising resource use in the production of the crop.The objective of the study was to model evapotranspiration,soil water storage and water productivity of rainfed soybeans under different levels of nitrogen fertilizer by using the FAO AquaCrop model.Field experiments were conducted at the Teaching and Research Farms of Obafemi Awolowo University,Nigeria in the rainy seasons of 2015 and 2016.There were five levels of nitrogen,which are 00,25,50,75 and 100%of the recommended nitrogen applications and two varieties of soybeans,which produced a 2 by 5 factorial experimental design.The data of the wetter year 2015,were used for calibration of the AquaCrop model because AquaCrop is water driven.The 2016 data were used for the validation.The AquaCrop model simulated canopy cover with R2 and EF>0.90,d-in-dex>0.99.The model captured the trend of the soil water storage well,R2 and EF>0.70.The AquaCrop model simulated soil water storage below wilting point for seasonal rainfall less than 600 mm,and it did not overestimate it.The model predicted evapotranspirationwith R and EF>0.89,d-index=1.00.Above ground biomass was overestimated even though R2>0.98.Although,nitrogen stress reduced seed yield and water productivity,there was no under or over estimation of the seed yields.They were predicted with low error under the different levels of nitrogen fertilizer,R>0.99,EF and d-index>0.99.The AquaCrop model is suitable for simulating canopy cover,soil water storage,evapotranspiration,and seed yieldof rainfed soybeans with different levels of nitrogen fertilizer under temporal distribution of seasonal rainfall.Therefore,it can serve as a useful tool for smallholder farmers in predicting productivity of soybeans and optimising resource allocation,land and water use in the tropical farming systems.We recommend simulation of the effects of pest on biomass,seed yield and water produc-tivity by subsequent versions of the AquaCrop model.In addition,incorporating an eco-nomic sub-unit in the model will enable users to make financial decisions.
基金Supported by the Project of Peanut Innovation Team of Shandong Province Modern Agricultural Industry Technology System(SDAIT-05-022).
文摘[Objectives]To study the effect of nitrogen(N)on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers,and to carry out experiments on nitrogen fertilizer control of summer peanuts.[Methods]Four treatments were set up in the experiment:no-nitrogen plot(N 0P_(4)K_(4)),optimized nitrogen plot(N_(7)P_(4)K_(4)),70%optimized nitrogen plot(N_(5)P_(4)K_(4)),130%optimized nitrogen plot(N 9P 4K 4),repeated 3 times,and arranged in random blocks.The area of the plot was 42 m^(2),ridges were set between the plots,and protective rows of more than 1 m were set around the experimental site.The types of fertilizers were urea,superphosphate,and imported potassium chloride,and the variety of peanuts was Linhua 5.Except for the level of fertilization,other agricultural operations were the same,and soil sampling tests,field records,and yield testing were carried out according to the requirements of the plan.[Results]On the basis of 60 kg/ha of phosphorus and potassium fertilizer application,the optimum economical fertilizer application rate and the highest application rate of pure nitrogen were about 115.20 and 131.25 kg/ha,respectively.[Conclusions]This study is expected to provide a certain basis for the high-quality and high-yield summer peanuts in southern Shandong area.
基金The National Natural Science Foundation of China(31771715,31771717)Project of Technology System in Modern Wheat Industry,Ministry of Agriculture,China(CARS-3-1-19)Field Station Union Project of Chinese Academy of Sciences(KFJ-SW-YW035).
文摘A water-saving cultivation technique of supplementary irrigation based on soil moisture levels has been adopted for winter wheat production in the Huang-Huai-Hai Plain of China,due to the enhanced water-use efficiency.However,appropriate split nitrogen management may further improve crop growth and grain yield.Here,we conducted a 2-year field experiment to determine if split nitrogen management might improve wheat productivity by enhancing ^(13)C photosynthate mobilization and the antioxidant defense system under water-saving conditions.Split nitrogen management involved a constant total nitrogen rate(240 kg ha^(−1))split in four different proportions between sowing and jointing stage,i.e.,10:0(N1),7:3(N2),5:5(N3),and 3:7(N4).The N3 treatment significantly enhanced“soil-plant analysis development”values,superoxide dismutase antioxidant activity,soluble protein content,sucrose content,and sucrose phosphate synthetase activity,although it reduced the accumulation of malondialdehyde(MDA).The N3 treatment ultimately increased the amount of dry matter assimilation after anthesis significantly.In addition,the ^(13)C isotope tracer experiment revealed that the N3 treatment promoted the assimilation of carbohydrates after anthesis and their partitioning to the developing grains.Compared to the unequal ratio treatments(N1,N2,and N4),the equal ratio treatment(N3)increased grain yield by 5.70–16.72%via increasing 1000-grain weight and number of grains per spike in both growing seasons.Therefore,we recommend the use of a 5:5 basal-topdressing split nitrogen fertilizer application under water-saving irrigation conditions to promote antioxidant enzyme activity and the remobilization of photosynthate after anthesis for improving wheat grain yield.
文摘Background:Native warm-season grass(NWSG)mixtures may provide a lownitrogen(N)-input summer perennial forage option to extensively managed forage-livestock systems.Methods:Mixed pastures of big bluestem(Andropogon gerardii Vitman),little bluestem(Schizachyrium scoparium Michx.),and indiangrass(Sorghastrum nutans L.)fertilized with 0 or 67 kgNha−1 were continuously stocked with beef heifers and cows.Forage mass,nutritive value,and canopy heights were determined every 2 weeks during the grazing season.Stand persistence measures included the canopy cover and leaf area index(LAI)and plant crown density at spring emergence following 3 years of grazing management.Results:Forage mass,canopy height,and stocking densities were greater for N-fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3-year study.Forage NWSG fertilized with N had a greater decrease in LAI during the growing season(51%decrease)than unfertilized NWSG.Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.Conclusions:Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low-level N than zero-N-input systems and may provide a low-N-input alternative for improved species use in southeastern US forage-livestock systems.
基金financially supported by the National Key Research and Development Program of China(2017YFD0300106,2018YFD0301103,and 2016YFD0300108)the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2013BAD07B12)the National Natural Science Foundation of China(31601263)。
文摘To address the relationships between the amount of nitrogen fertilizer application and the yield of double cropping rice systems,we investigated the effects of a cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application(SDN)on the morphological and physiological characteristics of double cropping rice.Our results indicated that the effects of SDN on the morphological characteristics of the single plant roots of double cropping rice were not significant,but the morphological characteristics of the population roots were largely different.Specifically,SDN significantly increased the morphological indexes of the root population such as root fresh weight,root volume,root number,root length and root dry weight.The effects of SDN on the total root absorption areas and root active absorption areas of the single plants were non-significant,but it dramatically enhanced the total root absorption areas and root active absorption areas of the plant population during the tillering,heading and mature stages.In addition,SDN significantly increased the root bleeding intensity and elevated the soluble sugar and free amino acid contents of root bleeding sap.Compared to the traditional cultivation pattern(CK),SDN significantly increased root bleeding intensity at the heading stage by 4.37 and 8.90% for early and late rice,respectively.Meanwhile,SDN profoundly enhanced the soluble sugar contents of root bleeding sap by 12.85 and 10.41% for early and late rice,respectively.In addition,SDN also significantly enhanced free amino acid content of root bleeding sap by 43.25% for early rice and by 37.50% for late rice systems compared to CK.Furthermore,SDN increased the actual yield of double cropping rice mainly due to the higher effective panicle number and the larger seedsetting rate.The actual yields of early rice under SDN were higher than CK by 9.37 and 5.98% in 2016 and 2017,and the actual yields of late rice under SDN were higher than CK by 0.20 and 1.41% in 2016 and 2017,respectively.Correlation analysis indicated that the significant positive correlations were observed between the majority of the root indexes and the actual yield across the four different growth stages.
文摘Research on the effect of the nitrogen application rate on the balance of the nitrogen utilization, yield and quality of rice is common in South China but is relatively lacking in Northeast China, especially in the Liaohe Delta. In this study, Yanfeng 47 rice was planted in Panjin city, China, to explore the effect of six nitrogen rates (0, 160, 210, 260, 315 and 420 kg N/ha) on the nitrogen use efficiency, rice quality and grain yield of rice plants. The results showed that the application of an appropriate nitrogen rate (210-260 kg N/ha) remarkably increased the nitrogen use efficiency of rice plants, grain yield, rice milling quality and nutritional quality and resulted in a moderate rice eating quality. Although low nitrogen rates (160 kg N/ha) maintained a high rice eating quality, they decreased grain yield and other rice qualities, and excessive nitrogen (315 kg N/ha) increased rice appearance quality but significantly reduced the nitrogen use efficiency (p < 0.05), yield and eating quality of rice. Therefore, to produce rice in the Liaohe Delta <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">by</span></span></span><span><span><span> an environmentally friendly method and guarantee rice with high quality and yield, the recommended nitrogen application rate is 210 kg N/ha.</span></span></span>
基金The Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21-0926)the National Natural Science Foundation of China(31972518)and the Qing Lan Project of Jiangsu Province financially supported this work.
文摘We conducted a pot experiment to examine the feasibility of applying a reaction-finished solution of hydrochar(HRFS)to enhance rice production in a saline soil.With this purpose,HRFS was applied(0,10,20,40,60,80 and 100 mL/pot)and rice yield and nitrogen(N)use efficiency(NUE)were determined.HRFS application significantly(P<0.05)increased rice grain yield by 19.6%-30.0%compared to the control treatment(CKU,with N but without HRFS addition).Moreover,HRFS application promoted plant height and straw biomass of rice.Increases of rice yield were mainly achieved by increases in the number of panicles and grains per panicle.Compared with the CKU treatment,the NUE of HRFS amendments significantly(P<0.05)increased by 56.3%-71.7%.This indicated that the improvement of NUE was one of the mechanisms to improve rice grain yield with HRFS amendment.The results of regression analysis showed that there was a positive relationship(R^(2)=0.8332)between rice yield and HRFS application rate within an appropriate range.The highest rice yield was recorded with the HRFS application of 40 mL/pot,but a further increase in HRFS application rate appeared to reduce rice yield.Based on the results of this pot study,HRFS application can increase rice yield in a saline soil by regulating its yield components and enhancing NUE.However,impact of HRFS on these variables showed a“dose effect”.
基金Financial supports were received from the Agro-scientific Research in the Public Interest of China(201503122)。
文摘Soil microbial biomass nitrogen(MBN)contains the largest proportion of biologically active nitrogen(N)in soil,and is considered as a crucial participant in soil N cycling.Agronomic management practices such as crop rotation and monocropping systems,dramatically affect MBN in agroecosystems.However,the influence of crop rotation and monocropping in agroecosystems on MBN remains unclear.A meta-analysis based on 203 published studies was conducted to quantify the effect of crop rotation and mono-cropping systems on MBN under synthetic N fertilizer application.The analysis showed that crop rotation significantly stimulated the response ratio(RR)of MBN to N fertilization and this parameter reached the highest levels in upland-fallow rotations.Upland mono-cropping did not change the RR of MBN to N application,however,the RR of MBN to N application in paddy mono-cropping increased.The difference between crop rotation and mono-cropping systems appeared to be due to the various cropping management scenarios,and the pattern,rate and duration of N addition.Crop rotation systems led to a more positive effect on soil total N(TN)and a smaller reduction in soil pH than mono-cropping systems.The RR of MBN to N application was positively correlated with the RR of mineral N only in crop rotation systems and with the RR of soil pH only in mono-cropping systems.Combining the results of Random Forest(RF)model and structural equation model showed that the predominant driving factors of MBN changes in crop rotation systems were soil mineral N and TN,while in mono-cropping systems the main driving factor was soil pH.Overall,our study indicates that crop rotation can be an effective way to enhance MBN by improving soil N resources,which promote the resistance of MBN to low pH induced by intensive synthetic N fertilizer application.
基金The study was funded by the National Natural Science Foundation of China(51809006 and 51079124).
文摘Faced with the scarcity of water resources and irrational fertilizer use,it is critical to supply plants with water and fertilizer in a coordinated pattern to improve yield with high water use efficiency(WUE).One such method,alternate partial root-zone irrigation(APRI),has been practiced worldwide,but there is limited information on the performance of different irrigation regimes and nitrogen(N)rates under APRI.The objectives of this study were to investigate the effects of varying irrigation regimes and N rates on shoot growth,grain yield and WUE of maize(Zea mays L.)grown under APRI in the Hexi Corridor area of Northwest China in 2014 and 2015.The three N rates were 100,200 and 300 kg N ha–1,designated N1,N2 and N3,respectively.The three irrigation regimes of 45–50%,60–65%and 75–80%field capacity(FC)throughout the maize growing season,designated W1,W2 and W3,respectively,were applied in combination with each N rate.The results showed that W2 and W3 significantly increased the plant height,stem diameter,crop growth rate,chlorophyll SPAD value,net photosynthetic rate(Pn),biomass,grain yield,ears per ha,kernels per cob,1000-kernel weight,harvest index,evapotranspiration and leaf area index(LAI)compared to W1 at each N rate.The N2 and N3 treatments increased those parameters compared to N1 in each irrigation treatment.Increasing the N rate from the N2 to N3 resulted in increased biomass and grain yield under W3 while it had no impact on those under the W1 and W2 treatments.The W3 N3 and W2 N2 and W2 N3 treatments achieved the greatest and the second-greatest biomass and grain yield,respectively.Increasing the N rate significantly enhanced the maximum LAI(LAI at the silking stage)and Pn under W3,suggesting that the interaction of irrigation and fertilizer N management can effectively improve leaf growth and development,and consequently provide high biomass and grain yield of maize.The W2 N2,W2 N3 and W3 N3 treatments attained the greatest WUE among all the treatments.Thus,either 60–65%FC coupled with 200–300 kg N ha–1 or 75–80%FC coupled with 300 kg N ha–1 is proposed as a better pattern of irrigation and nitrogen application with positive regulative effects on grain yield and WUE of maize under APRI in the Hexi Corridor area of Northwest China and other regions with similar environments.These results can provide a basis for indepth understanding of the mechanisms of grain yield and WUE to supply levels of water and nitrogen.