Effects of Panicle Fertilizer Application on Source-Sink Characteristics and Nitrogen Fertilizer Use Efficacy of Ganxin688

[Objective]The paper was to explore the effect of postponing application of N fertilizer on source-sink characteristics of super hybrid rice Ganxin688.[Method] With super hybrid rice Ganxin688 as test material,the source organ traits（leaf area index,leaf weight,chlorophyll content,photosynthetic rate of flag leaf,stem and sheath dry matter accumulation and output） and yield were measured,the effects of nitrogen application on source-sink relationship,yield and N fertilizer use efficiency were also studied.[Result] Appropriate postponing of N fertilizer was benefit for optimizing population quality,harmonizing source-sink relation,enhancing leaf function,prolonging leaf function period and increasing N fertilizer use efficiency.After heading,the leaves area index（LAI） and chlorophyll content increased with the increasing application amount of panicle fertilizer,and their reduction rate slowed down with the increased application amount of panicle fertilizer.Appropriate increased application of panicle fertilizer could prolong the function period of leaves in lower position,increase storage amount of stem and sheath matter,total sink capacity and sink capacity per unit leaf area during heading stage,improve panicle rate and seed setting rate,reduce the demand of grain sink on stem and sheath matter,and increase lodging resistance of plant,which could also increase dry matter productivity and rice productivity of N fertilizer,and increase absorption and application ratio and total accumulation amount of N fertilizer.For Ganxin 688,when N application amount was 175-205 kg/hm2,the proportion of panicle fertilizer in total nitrogen application should be better as 40%-45%.[Conclusion] The study provided basis for making reasonable and efficient N application strategy to establish a coordinated huge sink and strong source relationship for super rice.

Optimum Application Rate of Nitrogen in Summer Peanut in Southern Shandong Area

[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.

Production Benefits of Double-Cropping Rice Under Optimized Application of Nitrogen and Potassium Fertilizers Combined with Chinese Milk Vetch and Straw Co-Returning to Fields

In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.

Optimum Application Time and Application Rate of Nitrogen Fertilizer in Brassica napus L.

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.

Effects of Postponing N Application on Metabolism,Absorption and Utilization of Nitrogen of Summer Maize in SuperHigh Yield Region

[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a super-high yielded region of summer maize, field experiment was conducted to research effects of N fertilizer postponing on key enzymes of N metabolism, yield of maize and N fertilizer use. [Result] After application of N fertilizer was postponed, NR, SPS and GS activities of ear-leaf of summer maize increased by 11.99%-34.87%, 8.25%-10.64% and 10.00%- 16.81% on the 28^th d of silking; content of soluble sugar in leaves enhanced signifi- cantly and accumulated nitrogen increased by 5.00%-9.74% in mature stage. The postponing fertilization of ＂30% of fertilizer in seedling stage＋30% of fertilizer in flare- opening stage＋40% of fertilizer in silking stage meets N demands of summer maize in late growth period. Compared with conventional fertilization, the maize yield, agro- nomic efficiency and use of N fertilizer all improved by 5.05%, 1.75 kg/kg and 6.87%, respectively, after application postponed. [Conclusion] Application postponing of N fertilizer maintains activity of NR, GS and SPS higher and coordinates metabolism of C and N in late growth period, to further improve yield of maize.

Effect Models of Nitrogen,Phosphorus and Potassium Fertilizer Formulation in Banana

[Objective] The aim was to modify the application amount of N,P and K fertilizer so as to provide a reference for establishing balanced fertilization index system of banana.[Method]The N,P and K fertilizer ＂3414＂ test was carried out on banana,and then regression analysis was performed on the fertilizer effect.Ternary quadratic,binary quadric and one-variable quadratic regression equations for the fertilizer effect on the banana yield were constructed.[Result]Suitable amount of N,P and K fertilizer had significant yield improving effect,whereas overdose of fertilizer application led to decreasing of utilization rate of fertilizer.Therefore,suitable amount of N,P and K fertilizer should be selected in production.It could be concluded that one-variable quadratic regression equations was the best model to calculate the suitable fertilizer amount.The best yield range of banana in the tested field was 44.193-45.904 t/hm2,while the corresponding optimum application amount of N,P2O5 and K2O was 795.1,262.3 and 1 236.9 kg/hm2 respectively,and the ratio among nitrogen,phosphorus and potassium are 1∶0.33∶1.55.[Conclusion]The result in this study could provide references for the soil types similar to the tested field.

Effects of Nitrogen Application on Chlorophyll Fluorescence Parameters and Leaf Gas Exchange in Naked Oat

Naked oat（Avena nuda L.） was originated from China,where soil nitrogen（N） is low availability.The responses of chlorophyll（Chl.） fluorescence parameters and leaf gas exchange to N application were analysed in this study.After the N application rate ranged from 60 to 120 kg ha-1,variable fluorescence（F v）,the maximal fluorescence（F m）,the maximal photochemical efficiency（F v /F m）,quantum yield（Φ PS II） of the photosynthetic system II（PS II）,electron transport rate（ETR）,and photochemical quenching coefficient（qP） increased with N application level,however,non-photochemical quenching coefficient（qN） decreased.Moreover,there was no difference in initial fluorescence（F o） with further more N enhancement.The maximum net photosynthetic rate（P max）,apparent dark respiration rate（R d） and light saturation point（LSP） were improved with 40-56 kg N ha-1as basal fertilizer and 24-40 kg N ha-1as top dressing fertilizer applied at jointing stage.Initial quantum yield（α） was decreased with 24 kg N ha-1as basal fertilizer and 56 kg N ha-1as top dressing fertilizer.Flag-leaf net photosynthetic rate（P n） was significantly enhanced at the jointing and heading stages with 40-56 kg N ha-1as basal fertilizer; in addition,increased at grain filling stage of naked oat with 40-56 kg N ha-1as top dressing fertilizer.90 kg N ha-1（50-70% as basal fertilizer and 30-50% as top dressing fertilizer） application is recommended to alleviate photodamage of photosystem and improve the photosynthetic rate in naked oat.

Effects of Nitrogen Application Rate and Ratio on Lodging Resistance of Super Rice with Different Genotypes

The objective of this study was to determine the morphology mechanism of nitrogen （N） fertilizer rates and ratio on lodging resistance through analying its effects among lodging index （LI）, lodging-related morphological traits and physical strength in basal intemodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels （0, 150 and 300 kg ha-L） and two ratios of basal to topdressing （8：2 and 5：5） with two super rice cultivars （Yliangyou 2 and Wuyunjing 23）, were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal intemodes and culm＇s physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was significant greater than that of Wuyunjing 23 due to larger bending moment by whole plant （WP） with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no significant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength （M） in basal intemodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress （BS） of Wuyunjing 23 and section modulus （Z） of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction ofBS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, influencing their M indirectly. These results suggested that breaking strength was the key factor influencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of japonica super rice influenced breaking strength, as well as lodging index, respectively.

Effects of Nitrogen Application Time on Caryopsis Development and Grain Quality of Rice Variety Yangdao 6

A pot experiment was conducted to study the effects of different nitrogen application time （during the tillering or the booting stages） with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6. The increased nitrogen fertilizer （urea）, especially applied during the booting stage, could evidently increase the milled rice rate, head rice rate and protein content in rice grains compared with the control （no nitrogen application）, and decrease chalky grain rate and amylose content. Moreover, the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages, especially during the booting stage. During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents, but not obviously for the amylopectin content in rice grain. Increased topdressing of nitrogen fertilizer, especially applied during the booting stage, had significant effect on the development and structures of amyloplasts and proteinoplasts. That is, it could change the distribution, number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen, Compared with the control the arrangements of amyloplasts and proteinoplasts were closer, with more numbers, higher density and less interspaces each ohter. Furthermore, most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.

Interactions of Water Management and Nitrogen Fertilizer on Nitrogen Absorption and Utilization in Rice

The interactions of water management and nitrogen fertilizer on nitrogen absorption and utilization were studied in rice with Wuxiangjing9 (japonica). The results showed that the nitrogen uptake and remaining in straw increased and the percentage of nitrogen translocation (PNT) from vegetative organs, nitrogen dry matter production efficiency (NDMPE) and nitrogen grain production efficiency (NGPE) decreased with nitrogen increasing. The nitrogen uptake and NGPE decreased when severe water stressed. However, rice not only decreased the nitrogen uptake but also increased the PNT from vegetative organs, NDMPE and NGPE when mild water stressed. There were obvious interactions between nitrogen fertilizer and water management, such as with water stress increasing the effect of nitrogen on increasing nitrogen uptake was reduced and that on decreasing NDMPE was intensified.

Effects of Increased Planting Density with ReducedNitrogen Application on Yield Formation and NitrogenUtilization of Autumn Maize

With the change of cropping system in the middle reaches of the Yangtze River,the planting area of autumn maize is gradually increasing.However,the cultivation techniques are still under improvement for higher yield and nitrogen efficiency of autumn maize.Increase in planting density with reduced nitrogen fertilizer application is one of the important paths to achieve high yield and high nitrogen utilization efficiency.Meanwhile,the effect needs to be verified for autumn maize.The semi-compact autumn maize variety Qinyu 58 was planted under different planting densities and nitrogen fertilizer amounts with the split plot design.Different nitrogen application rates were arranged in the main plots,including the conventional nitrogen application(N300,300 kg/hm^2),30%reduction from the conventional treatment(N210,210 kg/hm^2)and no nitrogen application(N0).Different planting densities were arranged in the sub-split plots,including the conventional planting density(D60,60000 plants/hm2),medium density(D78,78000 plants/hm^2)and high density(D93,93000 plants/hm2).The effects of nitrogen fertilizer,planting density and their interaction effects on canopy structure,dry matter accumulation,yield and nitrogen use efficiency of autumn maize were studied.The nitrogen application rate and planting density had obvious interaction effects on the yield formation of autumn maize.Compared with the conventional cultivation(N300D60),increasing the planting density with 30%reduction in nitrogen application(N210)can obviously increase the canopy light interception rate,LAI,dry matter accumulation and yield.However,there was no significant change in canopy light interception rate,LAI,dry matter accumulation,grain weight and yield between D93 and D78.Compared with N300D60,nitrogen translocation efficiency and nitrogen contribution proportion to grain nitrogen did not change significantly in autumn maize grown under N210 and D78 treatments,whereas nitrogen partial productivity,nitrogen agronomic efficiency and recovery and utilization efficiency of nitrogen fertilizer increased significantly.Moreover,high density(D93)planting at N210 plots significantly improved nitrogen transport efficiency and utilization efficiency in autumn maize.Therefore,the suitable planting density of the autumn maize variety Qinyu 58 in Hubei Province is recommended a value of 78000 plants/hm^2,with the nitrogen application rate of 210 kg/hm2,which can achieve the target of higher yield by increasing density and reducing nitrogen.

Effects of Nitrogen Application Amount during Various Periods on Yield of High Grade Hybrid Rapeseed

[Objective] The paper was to study the nitrogen application amount and nitrogen application model for high grade hybrid rapeseed （Brassica napus L.） to get high yield. [Method] With ＂Youyan 599＂ and ＂Sanbei 98＂ as materials, using quadratic regression orthogonal gyration combination design, the impact of nitrogen application amount during various periods on rapeseed yield was studied. [Result] The combinations of factors to obtain the highest yield index （2 898.211 kg / hm 2 ） of ＂Youyan 599＂ were as follows： living rape fertilizer 89.27 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 101.12 kg / hm 2 , total nitrogen application amount 310.39 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12th lunar month fertilizer were 28.76%, 38.66% and 32.58%, respectively. The combinations of factors to obtain the highest yield index （2 870.14 kg/hm 2 ） of ＂Sanbei 98＂ were as follows： living rape fertilizer 120 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 37.55kg / hm 2 , total nitrogen application amount 277.55 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 43.24%, 43.24% and 13.53%, respectively. The combinations of factors to obtain the highest yield index of two combined varieties （2 813.82 kg/hm 2 ）were as follows： living rape fertilizer 120 kg/hm 2 , opening fertilizer 120 kg/hm 2 , 12 th lunar month fertilizer 76.23 kg/hm 2 , total nitrogen application amount 316.23 kg/hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 37.95% , 37.95% and 24.11% , respectively. [Conclusion] The paper provided theoretical basis for high yield cultivation of high grade hybridized rapeseed.

Effects of different ration of NPK fertilizer on the grain yield and protein content in forage rice

Different ratios of NPK were adopted in this research to study its effects on the objective traits of 2 early forage-rice varieties, and to obtain the optimum ratio to further improve the application technique in theory. At the same time, the possibility of increasing yield and protein content in the grain through cultivation technique was also studied. The conclusions were：

Revising Nitrogen Recommendations for Wheat in Response to the Need for Support of Variable-Rate Nitrogen Application

Sampling studies in North Dakota conducted from 1994 to 2003 showed that variable-rate N application could be practically directed with zone soil sampling. Results from variable-rate N studies using zone soil sampling were often less than rewarding due in part to the use of a whole-field predicted yield-based formula for developing the N recommendation in each zone. Nitrogen rate studies on spring wheat and durum were established in 2005 through 2009 with the objective to reexamine N recommendations and construct a new system if necessary. The results of the study and archived wheat N response data showed that the state should be divided into three separate N response regions. Within each region historic yields from low to high productivity were defined. The gross N rate was determined using the return-to-N concept developed in the US corn-belt states but with additional consideration for wheat protein value The gross N rate is then modified by credits for previous crop, soil test N from zone soil sampling, tillage systems, excessive straw from the previous year, relative susceptibility to nitrate leaching or denitrification. Finally, the user is encouraged to use common sense and consider whether particular fields have characteristics that require more or less N fertilizer than suggested by the recommendation formulas.

Effects of nitrogen fertilizer application on saline-alkali land cotton in China quantified using meta-analysis and regression analysis

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.

Characterization of Soil Available Nitrogen in the Major Vegetable Production Areas of Pearl River Delta,China

A macro scale survey was performed to investigate the content of soil available nitrogen (N) and its spatial distribution in the main vegetable production areas of the Pearl River Delta.Preliminary enrichment-deficient index of available N was then developed,which was a base for increasing fertilizer application efficiency and vegetable yield as well as for constructing soil testing and fertilizing formula.In general,most of the vegetable growth areas in Pearl River Delta were N-deficient or medium-N-deficient.There was 30%-62% increase in yield of Chinese cabbage on the N-deficient soil after application of N; when soil available N content was less than 145 mg/kg,the yield increased with application of N fertilizer at a rate of 60-70 kg/hm2.

氮磷配施和化肥减施对小麦生长、养分利用及产量性状的影响

为明确氮磷配施和化肥减施对小麦生长、养分利用及产量性状的影响,以8个晋南主栽品种为材料,于2019—2021年开展水培和大田定位试验,水培试验设置4个氮磷水平(N 0.2 mmol·L^(-1)+P 0.1 mmol·L^(-1)、N 0.2 mmol·L^(-1)+P 2.5 mmol·L^(-1)、N 4 mmol·L^(-1)+P 0.1 mmol·L^(-1)、N 4 mmol·L^(-1)+P 2.5 mmol·L^(-1)),对不同小麦品种苗期性状进行初步考察筛选;大田试验设置常规施肥(CF)、化肥减施(FR)和不施肥(CK)3个处理,研究不同年型下化肥减施对小麦生长发育、养分利用及产量的影响。结果表明,水培条件下,不同氮磷水平品育8161株高、根长、植株干重、根干重及根冠比均最低;良星67在低磷时正常氮较低氮植株干重增幅仅为17.07%,根干重反而降低,且在正常氮磷时根冠比较低。大田生产条件下,2019—2020年度(丰水年)化肥减施处理下以品育8012、济麦22产量较高,二者差异不显著,邯农1412产量最低,仅为7520.18 kg·hm^(-2)。其中,山农20、中麦4072和邯农1412产量均表现为化肥减施显著低于常规施肥。2020—2021年度(干旱年)化肥减施处理下济麦22产量为6191.53 kg·hm^(-2),显著高于品育8012和石农086,其籽粒氮素积累量和磷素吸收效率均最高,分别为130.35 kg·hm^(-2)和0.79 kg·kg^(-1)。干旱年减施化肥导致小麦生育后期叶片早衰,显著降低成熟期干物质积累,但对茎秆形态特征影响较小。综上,晋南小麦-玉米轮作区小麦生育期基施纯N 180.0 kg·hm^(-2)、P_(2)O_(5)105.0 kg·hm^(-2)、K_(2)O34.5 kg·hm^(-2),拔节期追施纯N 60.0 kg·hm^(-2)时,丰水年品育8012和济麦22产量较高,干旱年济麦22产量最高,且化肥减施有利于提高济麦22开花前营养器官干物质贮藏再转运量及其对籽粒的贡献率和第3节间厚度。单纯的连年化肥减施在干旱年份会导致小麦产量的稳定性和可持续性降低。本研究结果为晋南麦区小麦稳产高效栽培提供了技术参考。

小麦玉米间作氮肥后移利于减少土壤蒸发提高水分利用效率

【目的】针对绿洲灌区小麦玉米间作水分高效利用潜力挖掘不足,制约多熟种植稳定发展的问题,拟通过探明不同氮肥后移比例对小麦玉米间作耗水特性及水分利用的影响,为绿洲灌溉区水分高效利用麦玉间作模式创建提供理论依据。【方法】试验于2020—2021年在甘肃农业大学绿洲农业综合试验站开展,设小麦玉米间作、单作小麦和单作玉米3种种植模式,针对玉米设不施氮(N0)、氮肥后移20%(N1)、氮肥后移10%(N2)和传统施氮氮肥不后移(N3)4个处理,间作玉米和单作玉米各施氮处理下总施氮量分别为210和360kg·hm^(-2),研究不同种植制度及氮肥后移比例对小麦和玉米的土壤蒸发、耗水特性及水分利用的影响。【结果】小麦、玉米独立生长阶段间作处理的棵间蒸发量大于单作,间作小麦棵间蒸发较单作小麦增大15.9%—16.7%,间作玉米棵间蒸发较单作玉米增大5.4%—14.7%,麦玉共生期间作棵间蒸发量较单作加权降低4.6%—6.1%;全生育期棵间蒸发总量表现为:小麦玉米间作最大、单作玉米次之、单作小麦最小,在间作模式中,氮肥后移20%处理棵间蒸发量较传统施氮降低6.5%,且小麦带棵间蒸发量较玉米带增大12.6%—17.3%,是间作系统棵间蒸发的主要来源。间作系统中氮肥后移20%和后移10%处理全生育期耗水量较传统施氮分别降低34.3和18.9 mm,E/ET与传统施氮差异不显著。间作系统籽粒产量较单作加权平均提高21.1%—39.0%,间作系统氮肥后移20%处理籽粒产量较传统施氮提高28.8%,其中间作小麦、间作玉米氮肥后移20%处理较传统施氮分别提高24.3%、30.8%。间作种植模式氮肥后移处理水分利用效率较单作加权平均显著提高15.0%、12.3%,其中氮肥后移20%处理较传统施氮提高35.9%,氮肥后移10%处理较之提高19.3%。【结论】小麦玉米间作种植模式结合氮肥后移20%能减少土壤蒸发和全生育期耗水量,提高产量和水分生产力,是绿洲灌区小麦玉米间作高产高效生产可采用的施氮制度。

氮、磷、钾配施对葛根生长及品质的影响

为探明氮、磷、钾肥配施对葛根生长及品质的影响,为葛根高效栽培提供合理的施肥技术支撑和理论依据,采用L_(9)(3~4)正交试验设计,研究氮、磷、钾配施对葛根产量和主要功能成分的影响,明确研究区葛根氮、磷、钾的最佳施用量。结果表明,不同施肥方案对葛根产量和功能成分的影响显著,其中以N_(3)P_(1)K_(2)(N 270kg/hm^(2),P_(2)O_(5)45 kg/hm^(2),K_(2)O 90 kg/hm^(2))处理的产量和总黄酮含量最高,分别为2.13 kg/株和83.10 mg/g;N_(1)P_(3)K_(2)(N 90 kg/hm^(2),P_(2)O_(5)135 kg/hm^(2),K_(2)O 90 kg/hm^(2))的葛根素含量最高,为24.85 mg/g,N_(1)P_(2)K_(3)(N 90 kg/hm^(2),P_(2)O_(5)90 kg/hm^(2),K_(2)O 135 kg/hm^(2))处理的大豆苷和大豆苷元含量均为最高,分别为22.96和2.55 mg/g。氮、磷、钾肥配施对葛根产量和葛根素含量影响的大小顺序为氮肥>钾肥>磷肥。以葛根产量为目标的最佳施肥量为N 270 kg/hm^(2)、P_(2)O_(5)135 kg/hm^(2)、K_(2)O 90 kg/hm^(2),以葛根品质提升为目标的最佳施肥量为N 180 kg/hm^(2)、P_(2)O_(5)135 kg/hm^(2)、K_(2)O 90 kg/hm^(2)。

推荐施肥量下控释肥替代普通尿素提高高粱产量和氮肥生产力

【目的】高粱生产中氮肥施用不合理,氮肥利用效率低,研究适宜重庆地区高粱种植的控释氮肥减施比例,在减少氮肥用量的同时,确保高粱稳产高产,提高肥料利用效率。【方法】田间定位试验于2021、2022年在重庆永川进行,供试高粱品种为晋渝糯3号和金糯粱1号。设置6个处理,分别为不施氮肥(CK);习惯尿素施肥量(U,N 180 kg/hm^(2));尿素推荐施用量(U1,减N 20%,N 144 kg/hm^(2));控释氮肥减施氮量20%(C1,N144 kg/hm^(2));控释氮肥减施氮量30%(C2,N 126 kg/hm^(2));控释氮肥减施氮量40%(C3,N 108 kg/hm^(2))。在高粱开花期和成熟期,调查干物质积累量和转运量,成熟期调查植株和籽粒氮素含量、生物量、产量及产量构成因素。【结果】开花期和成熟期高粱干物质积累量均以C1和U1处理最高,C1处理成熟期干物质积累量又显著高于U1。C1处理叶片花前干物质转运量显著高于U。花后干物质积累量C1处理显著高于其他处理,U1和C2处理显著高于U处理。C1处理晋渝糯3号和金糯粱1号花后干物质积累量对籽粒的贡献率较U分别显著提高了11.54%和12.41%。C1处理的高粱产量最高(晋渝糯3号6611 kg/hm^(2),金糯粱1号5690 kg/hm^(2)),较其他施氮处理显著提高了5.40%~18.66%;其次为C2和U1处理,二者的产量均显著高于U和C3处理。各施氮处理的氮肥生理利用率(NPE)差异不显著;减氮处理间氮肥农学利用率(NAE)无显著差异,氮肥偏生产力(NPFP)差异显著,其NAE和NPFP均显著高于习惯施氮处理U;控释肥各减氮处理的NPFP显著高于普通氮肥推荐量处理U1。C1处理较U处理大幅提高了NAE、NPFP和氮肥利用率(NUE),晋渝糯3号分别提高了58.54%、39.61%和59.28%,金糯粱1号分别提高了80.97%、48.30%和63.08%;与U1处理相比,晋渝糯3号的NPFP、NUE分别提高了5.38%和22.19%,金糯粱1号分别提高了5.82%和4.42%。【结论】推荐施氮量下,用控释肥替代普通氮肥增加了高粱开花期和成熟期干物质积累量,提高了叶片花前干物质转运量和花后干物质积累量及其对籽粒的贡献率,提升了高粱产量和氮肥利用效率,可作为西南地区高粱生产的推荐氮肥施用方式。