Integration of natural gas and electricity transmission systems has strengthened interdependence between the two systems.Due to the close interconnection through coupling elements between the power system(PS)and natur...Integration of natural gas and electricity transmission systems has strengthened interdependence between the two systems.Due to the close interconnection through coupling elements between the power system(PS)and natural gas system(NGS)when a disturbance happens in one system,a series of complicated sequences of dependent events may follow in another system.Therefore,an integrated planning model jointing security-constrained considering cascading effects is proposed in this paper.Meanwhile,natural gas and electricity transmission systems considering stochastic failures and various operating characteristics of components can be viewed as a multistate systems.Moreover,power-to-gas(P2G),as a promising technology proposed to store surplus renewable energy,is considered in the integrated planning.First,multi-state models for different components are developed to describe realistic operating conditions in natural gas and electricity transmission systems.Furthermore,a mixed-integer linear programming(MILP)approach considers N-1 contingency and cascading effects between natural gas and the electrical power systems.Therefore,a security-constrained integrated planning model of natural gas and electricity transmission systems is represented.The proposed methods are validated using an integrated gas and power test system.展开更多
The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited im...The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited imaginary frequencies in their phonon spectra at 0 GPa.Here,we conducted a systematic investigation of P-N compounds using first-principles calculations,uncovering a series of structurally similar stable phases,C2/m-PN_(x)(x=6,8,10,12,and 14),in which N forms zigzag N chains similar to those in Ch-N.In P-N compounds,the longest zigzag N-chain,which can theoretically remain stable under ambient pressure,is the N-chain composed of 14 N atoms in C2/m-PN14.If the N-chain continues to grow,imaginary interchain vibrational frequencies arise in the system.Notably,N chains with an even number of atoms were more likely to be energetically favorable.The five C2/m-PN_(x) phases and one metastable phase(R-PN_(6))exhibited remarkable stability and excellent detonability at ambient pressure,indicating that they are promising candidates for high-energy-density materials.In addition,R-PN_(6) was the first structure to stabilize the N_(6) ring through covalent bonding,with the covalent network contributing to its high hardness(47.59 GPa).展开更多
Nitrogen(N)serves as an essential nutrient for yield formation across diverse crop types.However,agricultural production encounters numerous challenges,notably high N fertilizer rates coupled with low N use efficiency...Nitrogen(N)serves as an essential nutrient for yield formation across diverse crop types.However,agricultural production encounters numerous challenges,notably high N fertilizer rates coupled with low N use efficiency and serious environmental pollution.Deep placement of nitrogen fertilizer(DPNF)is an agronomic measure that shows promise in addressing these issues.This review aims to offer a comprehensive understanding of DPNF,beginning with a succinct overview of its development and methodologies for implementation.Subsequently,the optimal fertilization depth and influencing factors for different crops are analyzed and discussed.Additionally,it investigates the regulation and mechanism underlying the DPNF on crop development,yield,N use efficiency and greenhouse gas emissions.Finally,the review delineates the limitations and challenges of this technology and provides suggestions for its improvement and application.This review provides valuable insight and reference for the promotion and adoption of DPNF in agricultural practice.展开更多
Using phosphorus(P)fertilizers has historically increased agricultural productivity,yet the highly dissipative nature of phosphate rock and the low effciency due to soil fxation and runoff raise sustainability concern...Using phosphorus(P)fertilizers has historically increased agricultural productivity,yet the highly dissipative nature of phosphate rock and the low effciency due to soil fxation and runoff raise sustainability concerns.Algae fertilizers have emerged as a promising eco-friendly alternative.However,the potential of algae fertilizers for providing sustained P availability and their impacts on plant growth,soil microbes,and nutrient cycling remains to be explored.In this study,we developed a polyphosphate-enriched algae fertilizer(PEA)and conducted comparative experiments with chemical P fertilizers(CP)through soil and solution cultures,as well as crop growth trials.Soil cultivation experiments showed that PEA released twice as much labile P as initially available in the soil,and it functioned as a slow-release P source.In contrast,soils treated with CP initially exhibited high levels of labile P,which was gradually converted to stable forms,but it dropped to 30%of the labile P level in PEA after three months.Further tests revealed that the slow release of P from PEA was linked to increased microbial activity,and the microbial biomass P(MBP)content was about eight times higher than in soils treated with CP after three months,resulting in a 75%decline in the microbial biomass carbon(MBC)to MBP ratio.Microbial diversity analysis showed that algae fertilizers could recruit more benefcial microbes than CP,like phosphorus-solubilizing bacteria,plant growth-promoting bacteria,and stress-resistant bacteria.Crop pot experiments,along with amplicon and metagenomic analysis of tomato root-associated microbes,revealed that algae fertilizers including PEA promoted plant growth comparable to CP,and enhanced soil P cycling and overall nutrient dynamics.These data showed that algae fertilizers,especially PEA,can stabilize soil P fertility and stimulate plant growth through their slow P release and the recruitment of benefcial microbes.Our study highlights the potential of PEA to foster sustainable agriculture by mitigating the P scarcity and soil P loss associated with chemical fertilizers and improving plant growth and soil health.展开更多
The behaviour of nanofertilizers(NFs)in plant-soil systems can differ from that of conventional chemical fertilizers due to their peculiar chemical-physical properties.Their effectiveness is still poorly understood.In...The behaviour of nanofertilizers(NFs)in plant-soil systems can differ from that of conventional chemical fertilizers due to their peculiar chemical-physical properties.Their effectiveness is still poorly understood.In this study,we evaluated the P fertilization potential of a novel nanosized FePO4NF(FePNF)in a plant-soil microcosm in a pot experiment.The efficacies of FePNF and a conventional P fertilizer(triple superphosphate,TSP)in sustaining the growth of cucumber plants were evaluated.Plants were grown for 28 d on a P-deficient soil,and determinations were made of plant growth parameters,mineral nutrient concentrations in plant tissues,P availability in soil,activities of soil enzymes involved in C,N,P,and S mineralization,and soil microbial community structure.No significant differences were found in plant dry weight,leaf area,chlorophyll content,or root growth between the FePNF and TSP treatments.Conversely,P availability in soil and P concentration in plant tissues at the end of the plant growth period were significantly higher after TSP fertilization compared to FePNF fertilization,whereas no significant differences were observed for other nutrients.Among the measured soil enzyme activities,there were no significant differences in the activities of soil acid phosphatase,β-glucosidase,and arylsulfatase between the FePNF and TSP treatments,while soil alkaline phosphatase activity was higher in the TSP treatment than in the FePNF treatment and the protease activity was higher in the FePNF treatment than in the TSP treatment.The FePNF and TSP treatments showed significant differences in soil archaeal,bacterial,and fungal community structures,although the microbial community profiles generally clustered closer to each other in the two treatments.We concluded that FePNF can be an efficient alternative to the conventional P fertilizer TSP.展开更多
Corn(Zea mays L.)is a very sensitive crop to phosphorus(P)deficiency during the early development phase,which may be a limiting factor for the sustainable production of this crop in P-deficient tropical soils.However,...Corn(Zea mays L.)is a very sensitive crop to phosphorus(P)deficiency during the early development phase,which may be a limiting factor for the sustainable production of this crop in P-deficient tropical soils.However,scientific evidence indicates that inoculation with phosphate-solubilizing bacteria can improve the development,uptake,and P-use efficiency of corn plants.In the present study,two contrasting corn hybrids were investigated for their responsiveness to multiple inoculations of Bacillus subtilis,B.megaterium,B.velezencis,and Pseudomonas fluorescens and application of phosphate fertilizer rates in the sandy soil of the Brazilian Cerrado.Plants from stable(DKB 360 PRO3)and responsive(DKB 255 PRO3)corn hybrids were inoculated with 0 and 2 mL of inoculant containing multiple phosphate-solubilizing bacteria and fertilized with low(0 mg P·kg^(-1)),medium(40 mg P·kg^(-1))and high(80 mg P·kg^(-1))levels of phosphate fertilizer using triple superphosphate(46% of P_(2)O_(5)).Treatments were distributed in a randomized block design using 2×2×3 factorial scheme,with four replicates.Plants were grown in 8-L pots for 70 days under greenhouse conditions.Morphological characteristics,leaf P concentration,and P use efficiency of corn plants were evaluated.Our results showed that the multiple inoculations of Bacillus subtilis,B.megaterium,B.velezencis,and Pseudomonas fluorescens are a promising sustainable agricultural practice to be recommended for corn cultivation,especially because it improves the development and P use efficiency of plants fertilized with medium P levels,which reduces the costs associated with mineral phosphate fertilization,a non-renewable fertilizer source.In sandy tropical soilwith low P availability,applying intermediate rates of highly soluble phosphate fertilizer,such as triple superphosphate,is sufficient to maximize plant development and the nutritional status of corn crops for sustainable production with low environmental impact.展开更多
A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon（C） and total nitrogen（TN） under ploughing back o...A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon（C） and total nitrogen（TN） under ploughing back of Chinese milk vetch for 5consecutive years.Six treatments were included in the experiment,they are CK（unfertilized）,CF（100% chemical fertilizer with the amount of N,P2O5,K2 O being150,75,120 kg/hm^2respectively）,A1（22 500 kg/hm^2 Chinese milk vetch and 100%chemical fertilizer）,A2（Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer）,A3（Chinese milk vetch and 60% nitrogen and potassium fertilizer and 100% phosphate fertilizer）,A4（Chinese milk vetch and 40% nitrogen and potassium fertilizer and 100% phosphate fertilizer）.The results were as follows：application of fertilizer could increase the yield of rice,while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield.Under the condition of milk vetch application with 22 500 kg/hm^2,the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF.And the yield of treatment A3 was basically identical to or slight increase in comparison with that of CF.Decreasing amount of fertilizers cloud improve output value of rice in the case of the utilization of Chinese milk vetch.The treatment A1 increased output value of rice by 5.92% in comparison of CF,and treatment A2 was by 4.08% in the next.Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only.There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF.In general,amount of application of milk vetch with 22 500 kg/hm^2 could replace chemical fertilizer partially,it also could improve rice yield,decrease the production cost,and raise the utilization efficiency of nutrients.展开更多
[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＂ te...[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.展开更多
In order to develop organic rice and increase paddy soil fertility by cloverorganic rice rotation, the effects of N, P and K fertilizers on growth of clover nitrogen-fixing rhizobia and soil fertility after plantation...In order to develop organic rice and increase paddy soil fertility by cloverorganic rice rotation, the effects of N, P and K fertilizers on growth of clover nitrogen-fixing rhizobia and soil fertility after plantation were investigated, thereby providing certain reference for reasonable cultivation of clover and improvement of soil fertility. A two-year experiment was conducted from 2012 to 2013. The clover was cultivated after rice every year, and different levels of N, P and K fertilizers were applied before winter. In the treatment group, no fertilizer was applied. The effects of different fertilizers and different application amounts on clover yield, nitrogen-fixing rhizobia quantity, nitrogen-fixing rhizobia weight and soil fertility after plantation were analyzed. The results showed that the application of N, P and K fertilizers in the early stage had significantly effect on the growth of clover. When the application amount of N fertilizer was 75 kg/hm^2（N 46%）, the clover yield, nitrogen-fixing rhizobia quantity and nitrogen-fixing rhizobia weight were highest. The soil nitrogen content after plantation increased with the increase of the application amount of N fertilizer, while the P and K content decreased and then increased with the increased application amounts. Soil available P content increased with the increased application amounts of N and P fertilizers, but it did not change significantly with the increased application amount of K fertilizer. Soil available K content increased first and then decreased with the increased application amounts of N and P fertilizers.When the application amounts of N and P fertilizers were 150（N 46%） and 300（P_2O_5 12%） kg/hm^2, soil available K content reached the maximum. Soil organic matter content increased with the increased application amounts of N, P and K fertilizers. Therefore, in the cultivation of clover, appropriate application of N, P and K fertilizers in the early stage can improve clover yield and soil fertility.展开更多
Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze ...Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze yield. [Result] Both of N and P fertiIizers have significant effects on malze yield. When malze yield reached the highest, the quantities of N fertiIizers and P fertiIizers were 530.56 and 105.44 kg/hm2, respectiveIy. [Conclusion] Malze yield keeps growing upon N or P fertiIizers to certaln extent, and excessive quantities of N and P fertiIizer wouId reduce malze yield.展开更多
基金supported in part by the Key Projects of National Natural Science Foundation of China under Grant 51936003.
文摘Integration of natural gas and electricity transmission systems has strengthened interdependence between the two systems.Due to the close interconnection through coupling elements between the power system(PS)and natural gas system(NGS)when a disturbance happens in one system,a series of complicated sequences of dependent events may follow in another system.Therefore,an integrated planning model jointing security-constrained considering cascading effects is proposed in this paper.Meanwhile,natural gas and electricity transmission systems considering stochastic failures and various operating characteristics of components can be viewed as a multistate systems.Moreover,power-to-gas(P2G),as a promising technology proposed to store surplus renewable energy,is considered in the integrated planning.First,multi-state models for different components are developed to describe realistic operating conditions in natural gas and electricity transmission systems.Furthermore,a mixed-integer linear programming(MILP)approach considers N-1 contingency and cascading effects between natural gas and the electrical power systems.Therefore,a security-constrained integrated planning model of natural gas and electricity transmission systems is represented.The proposed methods are validated using an integrated gas and power test system.
基金supported by the Anhui Provincial Natural Science Foundation (Grant No.2508085J006)CASHIPS Director's Fund (Grant No.YZJJ202207-CX)。
文摘The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited imaginary frequencies in their phonon spectra at 0 GPa.Here,we conducted a systematic investigation of P-N compounds using first-principles calculations,uncovering a series of structurally similar stable phases,C2/m-PN_(x)(x=6,8,10,12,and 14),in which N forms zigzag N chains similar to those in Ch-N.In P-N compounds,the longest zigzag N-chain,which can theoretically remain stable under ambient pressure,is the N-chain composed of 14 N atoms in C2/m-PN14.If the N-chain continues to grow,imaginary interchain vibrational frequencies arise in the system.Notably,N chains with an even number of atoms were more likely to be energetically favorable.The five C2/m-PN_(x) phases and one metastable phase(R-PN_(6))exhibited remarkable stability and excellent detonability at ambient pressure,indicating that they are promising candidates for high-energy-density materials.In addition,R-PN_(6) was the first structure to stabilize the N_(6) ring through covalent bonding,with the covalent network contributing to its high hardness(47.59 GPa).
基金funded by grants from the National Natural Science Foundation of China(32301947,32272220 and 32172120)the China Postdoctoral Science Foundation(2023M730909).
文摘Nitrogen(N)serves as an essential nutrient for yield formation across diverse crop types.However,agricultural production encounters numerous challenges,notably high N fertilizer rates coupled with low N use efficiency and serious environmental pollution.Deep placement of nitrogen fertilizer(DPNF)is an agronomic measure that shows promise in addressing these issues.This review aims to offer a comprehensive understanding of DPNF,beginning with a succinct overview of its development and methodologies for implementation.Subsequently,the optimal fertilization depth and influencing factors for different crops are analyzed and discussed.Additionally,it investigates the regulation and mechanism underlying the DPNF on crop development,yield,N use efficiency and greenhouse gas emissions.Finally,the review delineates the limitations and challenges of this technology and provides suggestions for its improvement and application.This review provides valuable insight and reference for the promotion and adoption of DPNF in agricultural practice.
基金supported by the National Key Research and Development Program of China(2021YFF1000404)the National Natural Science Foundation of China(32472823 and 32102478)+1 种基金the Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-CSAL-202301)the China Postdoctoral Science Foundation(2021M693447,2021M693449 and 2022T150707)。
文摘Using phosphorus(P)fertilizers has historically increased agricultural productivity,yet the highly dissipative nature of phosphate rock and the low effciency due to soil fxation and runoff raise sustainability concerns.Algae fertilizers have emerged as a promising eco-friendly alternative.However,the potential of algae fertilizers for providing sustained P availability and their impacts on plant growth,soil microbes,and nutrient cycling remains to be explored.In this study,we developed a polyphosphate-enriched algae fertilizer(PEA)and conducted comparative experiments with chemical P fertilizers(CP)through soil and solution cultures,as well as crop growth trials.Soil cultivation experiments showed that PEA released twice as much labile P as initially available in the soil,and it functioned as a slow-release P source.In contrast,soils treated with CP initially exhibited high levels of labile P,which was gradually converted to stable forms,but it dropped to 30%of the labile P level in PEA after three months.Further tests revealed that the slow release of P from PEA was linked to increased microbial activity,and the microbial biomass P(MBP)content was about eight times higher than in soils treated with CP after three months,resulting in a 75%decline in the microbial biomass carbon(MBC)to MBP ratio.Microbial diversity analysis showed that algae fertilizers could recruit more benefcial microbes than CP,like phosphorus-solubilizing bacteria,plant growth-promoting bacteria,and stress-resistant bacteria.Crop pot experiments,along with amplicon and metagenomic analysis of tomato root-associated microbes,revealed that algae fertilizers including PEA promoted plant growth comparable to CP,and enhanced soil P cycling and overall nutrient dynamics.These data showed that algae fertilizers,especially PEA,can stabilize soil P fertility and stimulate plant growth through their slow P release and the recruitment of benefcial microbes.Our study highlights the potential of PEA to foster sustainable agriculture by mitigating the P scarcity and soil P loss associated with chemical fertilizers and improving plant growth and soil health.
基金supported by the Joint Project 2016 and the Joint Project 2019,developed by the University of Verona and Fabbrica Cooperativa Perfosfati Cerea,Italy。
文摘The behaviour of nanofertilizers(NFs)in plant-soil systems can differ from that of conventional chemical fertilizers due to their peculiar chemical-physical properties.Their effectiveness is still poorly understood.In this study,we evaluated the P fertilization potential of a novel nanosized FePO4NF(FePNF)in a plant-soil microcosm in a pot experiment.The efficacies of FePNF and a conventional P fertilizer(triple superphosphate,TSP)in sustaining the growth of cucumber plants were evaluated.Plants were grown for 28 d on a P-deficient soil,and determinations were made of plant growth parameters,mineral nutrient concentrations in plant tissues,P availability in soil,activities of soil enzymes involved in C,N,P,and S mineralization,and soil microbial community structure.No significant differences were found in plant dry weight,leaf area,chlorophyll content,or root growth between the FePNF and TSP treatments.Conversely,P availability in soil and P concentration in plant tissues at the end of the plant growth period were significantly higher after TSP fertilization compared to FePNF fertilization,whereas no significant differences were observed for other nutrients.Among the measured soil enzyme activities,there were no significant differences in the activities of soil acid phosphatase,β-glucosidase,and arylsulfatase between the FePNF and TSP treatments,while soil alkaline phosphatase activity was higher in the TSP treatment than in the FePNF treatment and the protease activity was higher in the FePNF treatment than in the TSP treatment.The FePNF and TSP treatments showed significant differences in soil archaeal,bacterial,and fungal community structures,although the microbial community profiles generally clustered closer to each other in the two treatments.We concluded that FePNF can be an efficient alternative to the conventional P fertilizer TSP.
基金financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nível Superior-Brasil(CAPES)-Finance Code 001financial resources from the Fundacao de Apoio ao Desenvolvimento do Ensino,Ciencia e Tecnologia do Estado de Mato Grosso do Sul—FUNDECT(Termo de Outorga:133/2023/SIAFEM:33108).
文摘Corn(Zea mays L.)is a very sensitive crop to phosphorus(P)deficiency during the early development phase,which may be a limiting factor for the sustainable production of this crop in P-deficient tropical soils.However,scientific evidence indicates that inoculation with phosphate-solubilizing bacteria can improve the development,uptake,and P-use efficiency of corn plants.In the present study,two contrasting corn hybrids were investigated for their responsiveness to multiple inoculations of Bacillus subtilis,B.megaterium,B.velezencis,and Pseudomonas fluorescens and application of phosphate fertilizer rates in the sandy soil of the Brazilian Cerrado.Plants from stable(DKB 360 PRO3)and responsive(DKB 255 PRO3)corn hybrids were inoculated with 0 and 2 mL of inoculant containing multiple phosphate-solubilizing bacteria and fertilized with low(0 mg P·kg^(-1)),medium(40 mg P·kg^(-1))and high(80 mg P·kg^(-1))levels of phosphate fertilizer using triple superphosphate(46% of P_(2)O_(5)).Treatments were distributed in a randomized block design using 2×2×3 factorial scheme,with four replicates.Plants were grown in 8-L pots for 70 days under greenhouse conditions.Morphological characteristics,leaf P concentration,and P use efficiency of corn plants were evaluated.Our results showed that the multiple inoculations of Bacillus subtilis,B.megaterium,B.velezencis,and Pseudomonas fluorescens are a promising sustainable agricultural practice to be recommended for corn cultivation,especially because it improves the development and P use efficiency of plants fertilized with medium P levels,which reduces the costs associated with mineral phosphate fertilization,a non-renewable fertilizer source.In sandy tropical soilwith low P availability,applying intermediate rates of highly soluble phosphate fertilizer,such as triple superphosphate,is sufficient to maximize plant development and the nutritional status of corn crops for sustainable production with low environmental impact.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201103005-08)National Science and Technology Support Program during the 12thFive-year Plan(2012BAD05B05-3)International Plant Nutrition Institute S&T Program(Hunan-16)~~
文摘A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon（C） and total nitrogen（TN） under ploughing back of Chinese milk vetch for 5consecutive years.Six treatments were included in the experiment,they are CK（unfertilized）,CF（100% chemical fertilizer with the amount of N,P2O5,K2 O being150,75,120 kg/hm^2respectively）,A1（22 500 kg/hm^2 Chinese milk vetch and 100%chemical fertilizer）,A2（Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer）,A3（Chinese milk vetch and 60% nitrogen and potassium fertilizer and 100% phosphate fertilizer）,A4（Chinese milk vetch and 40% nitrogen and potassium fertilizer and 100% phosphate fertilizer）.The results were as follows：application of fertilizer could increase the yield of rice,while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield.Under the condition of milk vetch application with 22 500 kg/hm^2,the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF.And the yield of treatment A3 was basically identical to or slight increase in comparison with that of CF.Decreasing amount of fertilizers cloud improve output value of rice in the case of the utilization of Chinese milk vetch.The treatment A1 increased output value of rice by 5.92% in comparison of CF,and treatment A2 was by 4.08% in the next.Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only.There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF.In general,amount of application of milk vetch with 22 500 kg/hm^2 could replace chemical fertilizer partially,it also could improve rice yield,decrease the production cost,and raise the utilization efficiency of nutrients.
基金Supported by National Science and Technology Support Program(2007BAD89B14)Science and Technology Project of Guangdong Province(2009B020201011)~~
文摘[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.
基金Science&Technology Specific Project for Enriching People and Strengthening County Economy(BN2015221)~~
文摘In order to develop organic rice and increase paddy soil fertility by cloverorganic rice rotation, the effects of N, P and K fertilizers on growth of clover nitrogen-fixing rhizobia and soil fertility after plantation were investigated, thereby providing certain reference for reasonable cultivation of clover and improvement of soil fertility. A two-year experiment was conducted from 2012 to 2013. The clover was cultivated after rice every year, and different levels of N, P and K fertilizers were applied before winter. In the treatment group, no fertilizer was applied. The effects of different fertilizers and different application amounts on clover yield, nitrogen-fixing rhizobia quantity, nitrogen-fixing rhizobia weight and soil fertility after plantation were analyzed. The results showed that the application of N, P and K fertilizers in the early stage had significantly effect on the growth of clover. When the application amount of N fertilizer was 75 kg/hm^2（N 46%）, the clover yield, nitrogen-fixing rhizobia quantity and nitrogen-fixing rhizobia weight were highest. The soil nitrogen content after plantation increased with the increase of the application amount of N fertilizer, while the P and K content decreased and then increased with the increased application amounts. Soil available P content increased with the increased application amounts of N and P fertilizers, but it did not change significantly with the increased application amount of K fertilizer. Soil available K content increased first and then decreased with the increased application amounts of N and P fertilizers.When the application amounts of N and P fertilizers were 150（N 46%） and 300（P_2O_5 12%） kg/hm^2, soil available K content reached the maximum. Soil organic matter content increased with the increased application amounts of N, P and K fertilizers. Therefore, in the cultivation of clover, appropriate application of N, P and K fertilizers in the early stage can improve clover yield and soil fertility.
基金Supported by Yantai Science and Technology Development Program(2007155)~~
文摘Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze yield. [Result] Both of N and P fertiIizers have significant effects on malze yield. When malze yield reached the highest, the quantities of N fertiIizers and P fertiIizers were 530.56 and 105.44 kg/hm2, respectiveIy. [Conclusion] Malze yield keeps growing upon N or P fertiIizers to certaln extent, and excessive quantities of N and P fertiIizer wouId reduce malze yield.
