Effects of Cultivation Density,Fertilizer Type and Fertilizer Amount on Yield of Jicaidou No.1

[Objectives]This study was conducted to explore the effects of planting density,fertilizer type and fertilizer amount on yield of Jicaidou No.1.[Methods]Three treatments of plant spacing,fertilizer type and fertilizer amount of Jicaidou No.1 were set up respectively to screen out the best combination mode.[Results]The best combination mode was:plant spacing 50 cm,fertilizer amount 1800 kg/hm^(2),and any one of the two fertilizers,as the difference between the two kinds of fertilizers was not significant.[Conclusions]This study provides a scientific basis for the standardized cultivation of kidney beans in Jilin Province.

Repositioning fertilizer manufacturing subsidies for improving food security and reducing greenhouse gas emissions in China

China removed fertilizer manufacturing subsidies from 2015 to 2018 to bolster market-oriented reforms and foster environmentally sustainable practices.However,the impact of this policy reform on food security and the environment remains inadequately evaluated.Moreover,although green and low-carbon technologies offer environmental advantages,their widespread adoption is hindered by prohibitively high costs.This study analyzes the impact of removing fertilizer manufacturing subsidies and explores the potential feasibility of redirecting fertilizer manufacturing subsidies to invest in the diffusion of these technologies.Utilizing the China Agricultural University Agri-food Systems model,we analyzed the potential for achieving mutually beneficial outcomes regarding food security and environmental sustainability.The findings indicate that removing fertilizer manufacturing subsidies has reduced greenhouse gas(GHG)emissions from agricultural activities by 3.88 million metric tons,with minimal impact on food production.Redirecting fertilizer manufacturing subsidies to invest in green and low-carbon technologies,including slow and controlled-release fertilizer,organic-inorganic compound fertilizers,and machine deep placement of fertilizer,emerges as a strategy to concurrently curtail GHG emissions,ensure food security,and secure robust economic returns.Finally,we propose a comprehensive set of government interventions,including subsidies,field guidance,and improved extension systems,to promote the widespread adoption of these technologies.

Combined application of organic fertilizer and chemical fertilizer alleviates the kernel position effect in summer maize by promoting post-silking nitrogen uptake and dry matter accumulation

Adjusting agronomic measures to alleviate the kernel position effect in maize is important for ensuring high yields.In order to clarify whether the combined application of organic fertilizer and chemical fertilizer(CAOFCF)can alleviate the kernel position effect of summer maize,field experiments were conducted during the 2019 and 2020 growing seasons,and five treatments were assessed:CF,100%chemical fertilizer;OFCF1,15%organic fertilizer+85%chemical fertilizer;OFCF2,30%organic fertilizer+70%chemical fertilizer;OFCF3,45%organic fertilizer+55%chemical fertilizer;and OFCF4,60%organic fertilizer+40%chemical fertilizer.Compared with the CF treatment,the OFCF1 and OFCF2 treatments significantly alleviated the kernel position effect by increasing the weight ratio of inferior kernels to superior kernels and reducing the weight gap between the superior and inferior kernels.These effects were largely due to the improved filling and starch accumulation of inferior kernels.However,there were no obvious differences in the kernel position effect among plants treated with CF,OFCF3,or OFCF4 in most cases.Leaf area indexes,post-silking photosynthetic rates,and net assimilation rates were higher in plants treated with OFCF1 or OFCF2 than in those treated with CF,reflecting an enhanced photosynthetic capacity and improved postsilking dry matter accumulation(DMA)in the plants treated with OFCF1 or OFCF2.Compared with the CF treatment,the OFCF1 and OFCF2 treatments increased post-silking N uptake by 66.3 and 75.5%,respectively,which was the major factor driving post-silking photosynthetic capacity and DMA.Moreover,the increases in root DMA and zeatin riboside content observed following the OFCF1 and OFCF2 treatments resulted in reduced root senescence,which is associated with an increased post-silking N uptake.Analyses showed that post-silking N uptake,DMA,and grain yield in summer maize were negatively correlated with the kernel position effect.In conclusion,the combined application of 15-30%organic fertilizer and 70-85%chemical fertilizer alleviated the kernel position effect in summer maize by improving post-silking N uptake and DMA.These results provide new insights into how CAOFCF can be used to improve maize productivity.

Coupling of reduced inorganic fertilizer with plant-based organic fertilizer as a promising fertilizer management strategy for colored rice in tropical regions

Colored rice is a type of high-quality,high-added-value rice that has attracted increasing attention in recent years.The use of large amounts of inorganic nitrogen fertilizer in rice fields results in low fertilizer use efficiency and high environmental pollution.Organic fertilizer is a promising way to improve soil quality and sustain high yields.However,most studies focus on the effect of animal-based organic fertilizers.The effects of different ratios of plantbased organic fertilizer and inorganic fertilizer on the grain yield and quality of colored rice have rarely been reported.Therefore,a two-year field experiment was conducted in 2020 and 2021 to study the effects of replacing inorganic N fertilizers with plant-based organic fertilizers on the yield,nitrogen use efficiency(NUE),and anthocyanin content of two colored rice varieties in a tropical region in China.The experimental treatments included no nitrogen fertilization(T1),100% inorganic nitrogen fertilizer(T2),30%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T3),60%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T4),and 100% plantbased organic fertilizer(T5).The total nitrogen provided to all the treatments except T1 was the same at 120 kg ha-1.Our results showed that the T3 treatment enhanced the grain yield and anthocyanin content of colored rice by increasing nitrogen use efficiency compared with T2.On average,grain yields were increased by 9 and 8%,while the anthocyanin content increased by 16 and 10% in the two colored rice varieties under T3 across the two years,respectively,as compared with T2.Further study of the residual effect of partial substitution of inorganic fertilizers showed that the substitution of inorganic fertilizer with plant-based organic fertilizer improved the soil physiochemical properties,and thus increased the rice grain yield,in the subsequent seasons.The highest grain yield of the subsequent rice crop was observed under the T5 treatment.Our results suggested that the application of plantbased organic fertilizers can sustain the production of colored rice with high anthocyanin content in tropical regions,which is beneficial in reconciling the relationship between rice production and environmental protection.

Application of organic fertilizer for improving soybean production under acidic stress

The presence of acidic soil in rural areas poses difficulties for agricultural production.One factor regulating soil pH is the overuse of inorganic fertilizer.The increased use of fertilizers in soybean production not only raises sustainability concerns but also contributes to soil acidity.Therefore,the use of organic fertilizer could offer a solution for addressing both issues related to soil acidity and sustainability.The purpose of this study was to investigate the manipulation of soil pH using organic fertilizer for soybean production under acidic stress.The planting medium,consisting of a mixture of topsoil,rice husk charcoal,and organic fertilizer(in a ratio of 2:1:1),was supplemented with 0.5 g of NPK fertilizer as a basal treatment in each planting medium.To regulate the soil acidity to pH 4,we added FeSO_(4) and allowed the mixture to incubate for 30 days.The results demonstrate that the application of three types of organic fertilizers chicken manure(P1),oil palm empty bunch fertilizer(P2),and vermicompost(P3)positively impacts the growth of three soybean varieties.The findings indicate that the application of P2 organic fertilizer can increase vegetative growth almost 50%in soybeans on acidic soil,including plant height,leaf count,and root length.Meanwhile,applying P3 organic fertilizer can boost reproductive growth responses in soybeans on acidic soil,such as pod number(from around 0-4 unit to 42-51 unit),grain number(from around 0-5 unit to 88-90 unit),and grain weight(from around 0-0.37 g to 12-25 g).Organic fertilizer has the potential to regulate soil pH,promoting higher yields of soybeans under acidic stress.

Analysis on Demonstration Application of Silicon Fertilizer in Field Cultivation of Rice

[Objectives]This study was conducted to investigate the scientific application of silicon fertilizer in rice cultivation,one of the staple crops.[Methods]In 2022,Yandu District carried out a special experiment and field demonstration study on the effects of foliar application of Zhengda water-soluble silicon fertilizer on rice production.[Results]The preliminary results showed that①Zhengda water-soluble silicon fertilizer could effectively improve the growth and development of rice and improve the population quality.The peak number of tillers,productive tiller percentage,number of effective panicles and number of effective grains per panicle increased by 6.7%,5.8%,5.5%,and 1.2%,respectively.②The yield and processing quality were improved.After applying silicon fertilizer,the yield per unit area increased by about 6.8%,and the unpolished rice yield,milled rice yield and head rice yield increased by 0.7%,1.94%and 2.15%respectively.[Conclusions]The demonstration application of silicon fertilizer in field cultivation of rice in Yandu District further proves previous research conclusions and has important practical significance.

Effects of Slow-release Nitrogen Fertilizer on Yield and Nitrogen Accumulation of Summer Maize in Shajiang Black Soil Area

[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.

Effect of K Fertilizer on Absorption of Mineral Elements in Greenhouse-grown Strawberry Fruits

[Objectives]The paper was to explore the effect of K fertilizer on the absorption of mineral elements in greenhouse-grown strawberry fruits.[Methods]A systematic investigation was conducted on the effects of K fertilizer dosage levels on the absorption of mineral elements in Fengxiang strawberries,an excellent variety suitable for cultivation in Anhui Province.The investigation was carried out under medium N and P conditions in a greenhouse.[Results]The N content of strawberry fruits increased as the K_(2)O dosage increased within the range of 0-250 kg/hm^(2).Similarly,the P content of strawberry fruits increased gradually with the increase of K_(2)O dosage within the range of 0-125 kg/hm^(2).[Conclusions]This study presents a basis for enhancing the absorption of mineral elements in strawberry fruit by applying K appropriately.

Effect of Biofertilizers on the Agromorphological Parameters of Three Okra Cultivars in Southern Côte d’Ivoire

Okra (Abelmoschus esculentus L.) is an herbaceous plant of the Malvaceae family. In Côte d’Ivoire, okra production is estimated to be over 193,000 tons. This low production is largely due to poor soils and hardly covers the needs of the population. To remedy this, growers systematically use mineral fertilizers. However, these fertilizers pollute the environment. To find an alternative to chemical fertilization and increase production, the effect of biofertilizers (Spaawet, Retone, Super Gro) compared with NPK mineral fertilizer was evaluated on Divo, Teriman, and Djonan F1 cultivars. The trial was set up in a factorial block design with three replications. Plant height, number of functional leaves, and crown diameter were assessed at 60 days after sowing (DAS). The time to 50% flowering, production time, and fruit yield were calculated. The results showed that the biofertilizer Retone induced the highest heights and number of functional leaves, with averages of 61.89 cm and 29.88 leaves, respectively. The diameter at the crown (17.77 mm) was highest with the NPK mineral fertilizer, and the shortest 50% flowering time, with an average of 47.61 days, was also obtained with the biofertilizer Retone. The NPK mineral fertilizer produced the longest production time, with an average of 35.25 days. The highest yields were obtained using Retone (11.07 t/ha) and NPK (9.52 t/ha) fertilizers. The “Divo*Retone” interaction produced the highest yield with an average of 12.19 t/ha. The biofertilizer Retone could therefore be used as an alternative fertilizer to chemical fertilization in okra crops, given its effect on the parameters assessed.

Determination of Egg Shell Structure and Mineral Composition Using SEM-EDS and Identification the Possibility to Produce Fertilizer

Throwing out egg shells without using them depreciates a vital source of calcium. As an egg shell contains twice the amount of calcium a person needs a day, it is considered as the richest source of calcium of natural origin. Egg shells have been traditionally and widely used in medicine, beauty science and food production for decades. In spite of that, there is a lack of new solutions that profoundly study mineral elements and beneficial components contained in egg shells for further usage as a product. Assuming we consume 2 eggs a day, the yearly consumption for a person is 730 eggs. As beneficial component, the egg shell structure and mineral elements, were determined in 3 types of samples (Mongolian eggs, Russian eggs, and iodized eggs) by SEM-EDS (Scanning electron microscopy with energy dispersive spectroscopy), a state-of-the-art research method. Consequently, it was established that egg shells consists of Ca (72.6% - 85.7%), Mg (2.7% - 4.5%), Si (0.3% - 0.6%), P (7.0% - 18.1%), S (0.5% - 2.0%), K (0.4% - 0.9%), I (2.6% - 3.0%), respectively. Additionally, the D3.8 × 120, 250, 500, and 1000 times zoomed images of shell structure (SEM) of each sample were examined, and the results were compared and evaluated. The reverse titration method examination has demonstrated that the calcium carbonate (CaCO3) content in egg shells is 91% - 92.5%, and pH is 8.41 - 8.75. Ultimately, fertilizer containing 97.7% Ca without chemical additives has been extracted by grounding the eggshells to 4.4 μm, then preparing the mixture at the rate of 20:0.5 (shell: mix, enriched with mandarin and lemon peel) and adjusting its pH to 7.5 - 8.0. Further research on the impact of fertilizer on growing process of indoor flowers has been commenced.

Required amounts of medium and fertilizer for potted culture of zucchini

In Japan, zucchini culture has yet to get underway, and the current costs of zucchini can be attributed to damage from soil-borne disease and the unstable yields due to seasonal change of female flowers. Eradication of these problems will lead to stable supply and a consequent price reduction of zucchini fruits. We previously clarified the efficacy of potted culture as a new culture method for zucchini, but potted culture can be burdensome as the weak water and nutrient retention capacity of the medium warrants its regular replacement. To solve this problem, in this study, we investigated the blend ratio for mixing rice husk charcoal with peat and the amount of fertilizer required for potted culture of zucchini. Results revealed no significant differences in the length of the largest leaf, total number of flowers, number of female flowers, and the ratio of female flowers to total flowers with different blend ratios of rice husk charcoal to peat. However, the number of harvested fruits increased with higher ratios of rice husk charcoal to peat and was highest at 80:20. The length of the largest leaf increased with increased amounts of fertilizer, with the best response was at 200 g. No significant differences were noted between the ratio of female flowers to total flowers in any treatments. In addition, the number of harvested fruits was highest with 160 g and 200 g of fertilizer. Taken together, the optimal blend ratio of rice husk charcoal to peat is 80:20, and the optimal amount of fertilizer with this ratio is 160 g.

Effects of Different Row Ratios of Male and Female Parents and Application Amount of Nitrogen Fertilizer on Hybrid Wheat Seed Production and Its Component Factors

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.

Carbon sequestration rate,nitrogen use efficiency and rice yield responses to long-term substitution of chemical fertilizer by organic manure in a rice–rice cropping system

Combined application of chemical fertilizers with organic amendments was recommended as a strategy for improving yield,soil carbon storage,and nutrient use efficiency.However,how the long-term substitution of chemical fertilizer with organic manure affects rice yield,carbon sequestration rate(CSR),and nitrogen use efficiency(NUE)while ensuring environmental safety remains unclear.This study assessed the long-term effect of substituting chemical fertilizer with organic manure on rice yield,CSR,and NUE.It also determined the optimum substitution ratio in the acidic soil of southern China.The treatments were:(i)NPK0,unfertilized control;(ii)NPK1,100%chemical nitrogen,phosphorus,and potassium fertilizer;(iii)NPKM1,70%chemical NPK fertilizer and 30%organic manure;(iv)NPKM2,50%chemical NPK fertilizer and 50%organic manure;and(v)NPKM3,30%chemical NPK fertilizer and 70%organic manure.Milk vetch and pig manure were sources of manure for early and late rice seasons,respectively.The result showed that SOC content was higher in NPKM1,NPKM2,and NPKM3 treatments than in NPK0 and NPK1 treatments.The carbon sequestration rate increased by 140,160,and 280%under NPKM1,NPKM2,and NPKM3 treatments,respectively,compared to NPK1 treatment.Grain yield was 86.1,93.1,93.6,and 96.5%higher under NPK1,NPKM1,NPKM2,and NPKM3 treatments,respectively,compared to NPK0 treatment.The NUE in NPKM1,NPKM2,and NPKM3 treatments was higher as compared to NPK1 treatment for both rice seasons.Redundancy analysis revealed close positive relationships of CSR with C input,total N,soil C:N ratio,catalase,and humic acids,whereas NUE was closely related to grain yield,grain N content,and phenol oxidase.Furthermore,CSR and NUE negatively correlated with humin acid and soil C:P and N:P ratios.The technique for order of preference by similarity to ideal solution(TOPSIS)showed that NPKM3 treatment was the optimum strategy for improving CSR and NUE.Therefore,substituting 70%of chemical fertilizer with organic manure could be the best management option for increasing CSR and NUE in the paddy fields of southern China.

Improvement of soil fertility and rice yield after long-term application of cow manure combined with inorganic fertilizers

Fertilization is an effective technique to improve soil fertility and increase crop yield.The long-term effects of different fertilizers on soil considerably vary.Over 38 consecutive years of different fertilization positioning experiments in a double cropping rice field of Qiyang Red Soil Experimental Station,seven different fertilization treatments including CK(no fertilization),NPK(nitrogen,phosphorus,and potassium fertilizer),M(cow manure),NPKM(nitrogen,phosphorus,and potassium with cow manure),NPM(nitrogen and phosphorus with cow manure),NKM(nitrogen and potassium with cow manure),and PKM(phosphorus and potassium with cow manure)were applied to study the effects on rice yield,soil fertility,and nutrient apparent balance in a paddy field.The results showed that the annual average yields of rice in NPKM,NPM,NKM,PKM,M,NPK and CK treatments ranged from 6214 to 11562 kg ha-1.Yields under long-term organic and inorganic treatments(NPKM,NPM,NKM and PKM)were 22.58,15.35,10.53 and 4.41%,respectively,greater than under the NPK treatment.Soil organic carbon(SOC),total nitrogen(TN),available nitrogen(AN)and available potassium(AK)concentration with long-term organic and inorganic treatment(NPKM,NPM,NKM and PKM)were significantly higher than in inorganic fertilizer(NPK)treatments.Soil total phosphorus(TP)and available phosphorus(AP)contentration with organic fertilizer combined with inorganic N and P fertilizer treatment(NPKM,NPM and PKM)were significantly higher than with inorganic fertilizer alone(NPK treatments).The average annual rice yield(11562 kg ha-1),SOC(20.88 g kg-1),TN(2.30 g kg-1),TP(0.95 g kg-1),TK(22.50 g kg-1)and AP(38.94 mg kg-1)concentrations were the highest in the NPKM treatment.The soil AN concentration(152.40 mg kg-1)and AK contentration(151.00 mg kg-1)were the highest in the NKM treatment.N and P application led to a surplus of nitrogen and phosphorus in the soil,but NPKM treatment effectively reduced the surplus compared with other treatments.Soils under all treatments were deficient in potassium.Correlation analysis showed that SOC,TN,AN,TP,and AP contentration was significantly correlated with rice yield;the correlation coefficients were 0.428,0.496,0.518,0.501,and 0.438,respectively.This study showed that the combined application of N,P,and K with cow manure had important effects on rice yield and soil fertility,but balanced application of N,P,and K with cow manure was required.

Effects of water and fertilizer deficit regulation with drip irrigation at different growth stages on fruit quality improvement of kiwifruit in seasonal arid areas of Southwest China

For a long time,seasonal drought occurs frequently in Southwest China,and the management of water and fertilizer in kiwifruit orchards has no quantitative standards,which seriously affects the yield and quality of kiwifruit.Therefore,the effects of water and fertilizer deficit regulation with drip irrigation(WFDRDI)on the quality of kiwifruit at different growth stages were explored to achieve water and fertilizer saving,and green and efficient production of kiwifruit.We select‘Jin Yan'kiwifruit and set two water deficit levels(W_(D20%)and W_(D40%))and three fertilizer deficit levels(F_(D15%),F_(D30%)and F_(D45%))at bud burst to leafing stage(stageⅠ),flowering to fruit set stage(stageⅡ),fruit expansion stage(stageⅢ)and fruit maturation stage(stageⅣ),respectively,with a full irrigation and fertilization as the control treatment(CK)in 2017and 2018.Results showed that the WFDRDI at stageⅡandⅢhad significant effect on fruit physical quality of kiwifruit,specifically,theⅢ-WD40%F_(D30%)andⅢ-W_(D20%)F_(D45%)treatments significantly increased fruit firmness by 13.62 and 15.59%(P<0.05),respectively;theⅡ-W_(D40%)F_(D15%)andⅢ-W_(D40%)F_(D15%)treatments significantly increased dry matter by 8.19 and 6.47%(P<0.05),respectively;theⅢ-W_(D20%)F_(D15%)treatment significantly increased single fruit weight and fruit volume by 9.33 and 12.65%(P<0.05),respectively;theⅡ-W_(D20%)F_(D15%)treatment significantly increased fruit water content by 1.99%(P<0.05).The WFDRDI had an obvious effect on fruit chemical quality of kiwifruit.TheⅢ-W_(D20%)F_(D45%),Ⅳ-W_(D40%)F_(D15%)andⅣ-W_(D20%)F_(D30%)treatments significantly increased vitamin C(Vc)content by 69.96,36.96 and 34.31%(P<0.05),respectively;theⅢ-W_(D40%)F_(D15%)andⅣ-W_(D40%)F_(D15%)treatments significantly increased total soluble solid(TSS)content by 3.79 and 17.05%(P<0.05),respectively,and significantly increased soluble sugar content by 28.61 and 34.79%(P<0.05),respectively;the contents of fructose,glucose and sucrose also had a significantly increasing trend,which was increased significantly by 5.58–19.63%,40.55–60.36%and 54.03–54.92%in theⅢ-WD40%F_(D15%)andⅣ-W_(D40%)F_(D15%)treatments(P<0.05),respectively;sugar–acid ratio was increased significantly in theⅣ-W_(D40%)F_(D15%)treatment by 64.65%(P<0.05).The degree and duration of water and fertilizer deficit had a comprehensive effect on fruit quality of kiwifruit.The WFDRDI at stageⅡandⅢcontribute to improving fruit physical quality,and the threshold of water and fertilizer deficit were 20 and 15%,respectively;stageⅢandⅣare the critical periods for improving fruit chemical quality by water and fertilizer coupling effect,and the threshold of water and fertilizer deficit were 40 and 15%,respectively.Therefore,aiming at precise water and fertilizer saving,theⅠ-W_(D20%)F_(D30%),Ⅱ-W_(D40%)F_(D15%),Ⅲ-W_(D40%)F_(D15%)andⅣ-W_(D40%)F_(D15%)treatments under WFDRDI during the whole growth period of kiwifruit were the best mode to improve quality and production of kiwifruit.

Effects of mixed fertilizers formed by the compounding of two targeted controlled-release nitrogen fertilizers on yield,nitrogen use efficiency,and ammonia volatilization in double-cropping rice

One-time application of mixed fertilizer formed by the compounding of two controlled-release nitrogen fertilizers(CRUs)with targeted N supply during the periods from transplantation(TS)to panicle initiation(PI)and from PI to heading(HS)is expected to synchronize the double-peak N demand of rice.However,its effects on the yield and N use efficiency(NUE)of labor-intensive double-cropping rice were unknown.Two targeted CRU(CRU_(A)and CRU_(B))were compounded in five ratios(CRU_(A):CRU_(B)=10:0,7:3,5:5,3:7,and 0:10)to form five mixed fertilizers(BBFs):BBF1-5.A field experiment was performed to investigate the characteristics of N supply in early and late seasons under different BBFs and their effects on N uptake,yield,and ammonia volatilization(AV)loss from paddy fields of double-cropping rice.Conventional high-yield fertilization(CK,three split applications of urea)and zero-N treatments were established as controls.The N supply dropped significantly with the increased compound ratio of CRU_(B)during the period from TS to PI,but increased during the period from PI to HS.With the exception of the period from TS to PI in the late rice season,the N uptake of early and late rice maintained close synchronicity with the N supply of BBFs during the double-peak periods.Excessive N supply(BBF1 and BBF2)in the late rice season during the period from TS to PI increased N loss by AV.The effect of BBF on grain yield increase varied widely between seasons,irrespective of year.Among the BBFs,the BBF2 treatment of early rice not only stabilized the spikelets per panicle but also ensured a high number of effective panicles by promoting N uptake during the period from TS to PI and a high grain-filling percentage by appropriately reducing the N supply at the later PI stage,resulting in the highest rice yield.While stabilizing the effective panicle number,the BBF4 treatment of late rice increased the number of spikelets per panicle by promoting N uptake during the period from PI to HS,resulting in the highest rice yield.The two-year average yield and apparent N recovery efficiency of the BBF2 treatment during the early rice season were 9.6 t ha 1 and 45.3%,while those of late rice in BBF4 were 9.6 t ha 1 and 43.0%,respectively.The yield and NUE indexes of BBF2 in early rice and BBF4 in late rice showed no significant difference from those of CK.The AVs of BBF2 during the early rice season and of BBF4 during the late rice season were 50.0%and 76.8%lower,respectively,than those of CK.BBF2 and BBF4 could effectively replace conventional urea split fertilization in early and late rice seasons,ensuring rice yield and NUE and reducing AV loss in paddy fields.

Application Effects of Stabilized Fertilizer with Reduced Amount and Frequency on Rice

The activity of microorganisms in the soil can be adjusted through the application of stabilized fertilizer.Using biochemical means,the transformation of nitrogen in the soil is controlled,synchronizing the peak of nutrient released from soil and the peak of nutrient absorption by rice.With the application of stabilized fertilizer,the fertilizer utilization rate and the income of farmers can be improved and the environmental pollution can be cut down by reducing the amount of nitrogen fertilizer and decreasing the frequency of fertilization.This paper summarizes the application effects of stabilized fertilizer on different cultivars of rice in different regions for many years,and puts forward the issues to be concerned in the application of stabilized fertilizer with reduced amount and frequency and efficiency improvement techniques.

Response of growth,metabolism and yield of Dendrocalamopsis oldhami to long-day photoperiod and fertilizer compensation

The effects of long-day photoperiod on growth,photo synthetic fluorescence,carbon and nitrogen metabolism,and yield of Dendrocalamopsis oldhami and the compensation effects of fertilization were investigated.A completely randomized design was used with two light factors(bamboo culms cultivated in solar greenhouse under long-day[Ls]and short-day[Ln]treatments);two organic nitrogen fertilizer levels(application of organic fertilizer[OF]and no organic fertilizer[NF]);and three nitrogen fertilizer levels(Low[N0],medium[N1]and high nitrogen[N2]).Leaf chlorophyll and fluorescence parameters(φPo,PIABS,and ETo/CSm)decreased and DIo/CSmincreased in Ls compared to Ln.Indole acetic acid(IAA)and gibberellic acid(GA3)levels decreased,whereas abscisic acid(ABA)increased.Leaf area decreased and leaf dry mass increased.The contents of carbon and nitrogen metabolism-related enzymes(nitrate reductase,glutamine synthetase,amylase,and sucrose synthase)and products(total nitrogen,organic carbon,soluble sugar,and starch)increased.Single bamboo shoot weight and diameter at breast height decreased,whereas shoot quantity and total yield increased.Fertilizer application significantly affected physiological growth and yield in the two light treatments,thus promoting carbon and nitrogen metabolism.TheφPo,PIABS,IAA,and GA3contents increased slightly,whereas ABA levels decreased.Shoot quantity,individual weight,and total yield improved.IA A,soluble sugar,and total yield to organic manure and light were lower than those of nitrogen levels(FN>FL,FO).Other indicators showed lower responses to different fertilization treatments than the light factor(FL>FN,FO).The ability of D.oldhami to alter its morphological and physiobiochemical traits and yield in response to variations in light applications may translate into high phenotypic plasticity.Fertilization significantly improved photoplasticity of D.oldhami.Under Ls,D.oldhami had high metabolic rates.was easily inhibited by light,and showed accelerated leaf senescence,and shoot quantity and total output increased.However,the quality of individual shoots decreased.Different fertilization treatments affected D.oldhami differently under the two light intensities.Ls sensitivity to nitrogen was higher.Fertilization could delay leaf dormancy and senescence under Ls treatment.Organic fertilizer addition could improve yield more effectively,with OFN1being the optimal fertilization level.

Growth of tandem long-mat rice seedlings using controlled release fertilizers:Mechanical transplantation can be more economical and high yielding

The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings(TLMS)are necessary for the resource-efficient cultivation of rice.In the present study,a controlled-release fertilizer(CRF)-polymer-coated compound fertilizer with 3 months release period(PCCF-3M)was applied as seedling fertilizer(SF),and five different dosages of SF(SF-0,SF-10,SF-20,SF-30,and SF-40)were compared with an organic substrate as the control(CK).Among all SF treatments,the best results were obtained with the application of 20 g/tray of SF(SF-20),as the seedling quality and machine transplanting quality were comparable to those of CK.In contrast,the lower dosages(SF-0 and SF-10)resulted in low nitrogen content and reduced shoot growth,while the higher dosages(SF-30 and SF-40)resulted in toxicity(increased malondialdehyde accumulation)and inhibited the root growth.Similarly,SF-20 increased panicle number(5.6-7.0%)and yield(4.3-5.3%)compared with CK,which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field.Moreover,SF-20 reduced the seedling block weight(53.1%)and cost of seedling production(23.5%)but increased the gross margin,indicating that it was easy to handle and economical.Taken together,our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings.To our knowledge,this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.

Fate of fertilizer nitrogen and residual nitrogen in paddy soil in Northeast China

The relationship between the fate of nitrogen (N) fertilizer and the N application rate in paddy fields in Northeast China is unclear,as is the fate of residual N.To clarify these issues,paddy field and15N microplot experiments were carried out in 2017 and 2018,with N applications at five levels:0,75,105,135 and 165 kg N ha–1(N0,N75,N105,N135 and N165,respectively).15N-labeled urea was applied to the microplots in 2017,and the same amount of unlabeled urea was applied in 2018.Ammonia (NH3) volatilization,leaching,surface runoff,rice yield,the N contents and15N abundances of both plants and soil were analyzed.The results indicated a linear platform model for rice yield and the application rate of N fertilizer,and the optimal rate was 135 kg N ha–1.N uptake increased with an increasing N rate,and the recovery efficiency of applied N (REN) values of the difference subtraction method were 45.23 and 56.98%on average in 2017and 2018,respectively.The RENwas the highest at the N rate of 135 kg ha–1in 2017 and it was insignificantly affected by the N application rate in 2018,while the agronomic efficiency of applied N (AEN) and physiological efficiency of applied N (PEN) decreased significantly when excessive N was applied.N loss through NH3volatilization,leaching and surface runoff was low in the paddy fields in Northeast China.NH3volatilization accounted for 0.81 and 2.99%of the total N application in 2017 and 2018,respectively.On average,the leaching and surface runoff rates were 4.45% and less than 1.05%,respectively,but the apparent denitrification loss was approximately 42.63%.The residual N fertilizer in the soil layer (0–40 cm) was 18.37–31.81 kg N ha–1in 2017,and the residual rate was 19.28–24.50%.Residual15N from fertilizer in the soil increased significantly with increasing N fertilizer,which was mainly concentrated in the 0–10 cm soil layer,accounting for 58.45–83.54% of the total residual N,and decreased with increasing depth.While the ratio of residual N in the 0–10 cm soil layer to that in the 0–40 cm soil layer was decreased with increasing N application.Furthermore,of the residual N,approximately 5.4%was taken up on average in the following season and 50.2%was lost,but 44.4%remained in the soil.Hence,the amount of applied N fertilizer should be reduced appropriately due to the high residual N in paddy fields in Northeast China.The appropriate N fertilizer rate in the northern fields in China was determined to be 105–135 kg N ha–1in order to achieve a balance between rice yield and high N fertilizer uptake.