The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducte...The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducted in Quzhou, Hebei Province, China, with MC812 maize and Jidou12 soybean varieties. Soil samples were taken from each plot to create a composite sample. The results show that nitrogen concentration varies at different depths and is higher in all treatments between 40 and 100 cm. Incorporating intercropping of maize and soybeans into farming practices can lead to more sustainable and environmentally friendly agriculture in China.展开更多
[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertiliz...[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertilizer on tobacco leaves. ln ad-dition, the effects of Mg fertilization on the absorption of K, Ca and Mg in flue-cured tobacco leaves were investigated, providing theoretical basis and production guidance for the balanced fertilization technology in the Mg-deficient flue-cured to-bacco-growing areas in Qujing City of Yunnan Province. [Method] The field plot test and randomized complete block design were adopted in this research. The group without Mg fertilization was treated as control. There were 3 treatment groups for foliar spraying of magnesium-potassium sulfate fertilizer and 2 treatment groups for soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer. The tobac-co roots, stems, lower leaves, middle leaves and upper leaves were dried and weighed. They were grinded for the determination of K, Ca and Mg content. The total K, Ca and Mg content in upper （B2F）, middle （C3F） and lower （X2F） flue-cured tobacco leaves in each plot was measured. [Result] The foliar spraying and soil application ＋ foliar spraying al increased the absorption of Mg and K in middle and lower tobacco leaves and the absorption of Ca in lower tobacco leaves, but de-creased the absorption of Mg, K and Ca in upper leaves and the absorption of Ca in middle leaves. Among the positions, the accumulated distribution of Mg, K and Ca ranked as middle leaves ＆gt; lower leaves ＆gt; upper leaves. With the application of Mg fertilizer, the Ca/Mg ratio and K/Mg ratio al decreased in middle and upper to-bacco leaves; while the Ca/Mg ratio increased in the lower tobacco leaves, and the K/Mg ratio showed no significant difference among treatment groups. [Conclusion] The foliar spraying and soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer affected the Ca/Mg ratio and K/Mg ratio in tobacco leaves mainly through affecting the absorption of Mg.展开更多
To evaluate the effect of organic manure application with chemical fertilizers on rice yield and soil fertility under long-term double-rice cropping system, a six year field experiment was conducted continually in the...To evaluate the effect of organic manure application with chemical fertilizers on rice yield and soil fertility under long-term double-rice cropping system, a six year field experiment was conducted continually in the paddy soil derived from Quaternary red clay in Hunan Province of southern China. Four different treatments, i.e., no nitrogen with chemical P and K （PK）, swine manure only （M）, N, P and K chemical fertilizers only （NPK）, and half chemical fertilizers combined with half swine manure （NPKM） with four replications were included. Each N, P and K application rate was the same at all the treatments （except the N application rate at PK） and N application rate was 150 kg N ha^-1. All fertilizers were applied to soil tillage layer with once application as baseal fertilizers. The nutrients uptake rate, grain yield, nitrogen use efficiency, and soil organic matter content at each treatment were investigated. The NPKM treatment achieved the highest mean annual yield of 12.2 t ha^-1 （68% higher than that of PK）. Higher dry matter accumulation and nutrients absorption were observed during the middle-late growth period in the NPKM treatment, with higher panicle number per unit and filled-grain number per panicle. Its average nitrogen use efficiency was 36.3% and soil organic matter increased by 18.5% during the experimental period in the NPKM treatment, which were significantly higher than those in the NPK treatment. Organic manure application with chemical fertilizers increased the yield and nitrogen use efficiency of rice, reduced the risk of environmental pollution and improved soil fertility greatly. It could be a good practical technique that protects the environment and raises the rice yield in this region.展开更多
Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed i...Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil.展开更多
The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer c...The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.展开更多
The Soil and Water Assessment Tool (SWAT) nitrogen (N) water quality model considers the artificial inputs associated with human activities, including point and nonpoint source pollution loads. Although SWAT has the a...The Soil and Water Assessment Tool (SWAT) nitrogen (N) water quality model considers the artificial inputs associated with human activities, including point and nonpoint source pollution loads. Although SWAT has the ability to simulate atmospheric N deposition and fixation, they were not considered in the modeling research. N deposition from the air is an important and considerable pathway for the input of N species into watersheds and water bodies, causing soil and water body acidification and the leaching of N into surface and groundwater, resulting in eutrophication and degraded water quality. The goal of this study is to assess the effects of atmospheric and agricultural N loads on stream water quality at the watershed scale. For a 6642 km2 Chungju dam watershed, SWAT was calibrated for 4 years (2003-2006) and validated for another 4 years (2007-2010) using daily anthropogenic N data (sewage discharge pollutants and fertilizer) and monthly measured atmospheric deposition data for NO3ˉ, NH4+, and dissolved organic N (DON). At the watershed outlet, the Nash-Sutcliffe (1970) efficiency (NSE) of daily streamflow during the validation period was 0.74. The coefficient of determination (R2) of total N was 0.69 considering atmospheric deposition, whereas it was 0.33 when removing the deposition effect. The results of this study demonstrate the potential for using the N dynamics between the atmosphere and land for SWAT assessments of nonpoint source pollution and for modeling stream water quality.展开更多
Soybean and lentil are important legume crops in southern Saskatchewan (SK) that can supply the majority of their nitrogen (N) requirement through biological N fixation (BNF). However, the onset of BNF can be slow in ...Soybean and lentil are important legume crops in southern Saskatchewan (SK) that can supply the majority of their nitrogen (N) requirement through biological N fixation (BNF). However, the onset of BNF can be slow in cold;dry prairie soils and a small amount of seed-row placed fertilizer containing both N and phosphorus (P) may benefit the crop. Nevertheless, high rates of fertilizer in close proximity to the seed can also cause injury. This study was conducted to determine the response of lentil and soybean to a starter N-P fertilizer blend applied in the seed-row. A farm field located at the boundary of the Brown and Dark Brown soil zones in south-central Saskatchewan was selected to evaluate the effect of seed-row placed N-P fertilizer blend: 50% Urea + 50% mono-ammonium phosphate (MAP) applied at 0, 10, 20 and 30 kg N and P2O5 ha-1 on emergence, yield, and nutrient uptake. The proportion of nitrogen derived from fixation (ndff) was determined in the soybean using N-15 dilution technique. The rate of 10 kg N and P2O5 ha-1 was found to be the rate that did not significantly reduce emergence, stand count or proportion of N derived from fixation, and was sufficient to maximize yield, N and P uptake for both soybean and lentil under field conditions. Rates higher than 10 kg N ha-1 in the seed row as starter 28-26-0 blend reduced emergence and decreased the proportion of ndff.展开更多
[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretic...[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretical basis for realizing the sustainable development of film mulching planting method in this area.[Methods]The effects of single application of chemical fertilizer cultivation mode under film mulching conditions on the soil organic carbon(SOC),labile organic carbon(LOC),carbon management index(CMI),extractable humus carbon(CHE),humic acid carbon(CHA),and fulvic acid carbon(CFA)in the cultivated layer(0-20 cm)were studied through three consecutive years of field experiments on dryland maize farmland in the eastern Qinghai.[Results]Under the film mulching condition,the SOC,LOC and CMI of the single application of chemical fertilizer cultivation mode were lower than that of the open field control.CHE,CHA and CFA increased with the increase of planting years,but the degree of increase was generally less than that of the open field control.With the increase of planting years,by 2020,the soil LOC/SOC value of film mulching decreased by 4.97%compared with before the start of the experiment,while the open field control increased by 1.11%;the organic carbon oxidation stability coefficient(KOS)of the film mulching was higher than that of the open field control;the soil CHA/CFA value and PQ value were higher than that of the open field control.[Conclusions]Under the condition of single application of chemical fertilizers,the continuous film mulching cultivation mode reduces the soil carbon fixation capacity,and soil organic carbon tends to be stable,which is not conducive to biological utilization and could reduce the soil fertility and degrade the soil quality,causing adverse effects on the stability of crop yield and sustainable production in the long run.展开更多
文摘The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducted in Quzhou, Hebei Province, China, with MC812 maize and Jidou12 soybean varieties. Soil samples were taken from each plot to create a composite sample. The results show that nitrogen concentration varies at different depths and is higher in all treatments between 40 and 100 cm. Incorporating intercropping of maize and soybeans into farming practices can lead to more sustainable and environmentally friendly agriculture in China.
基金Supported by National Science and Technology Support Program(2012BAD40B02)Science and Technology Plan Project of Yunnan Tobacco Company(2012YN48)~~
文摘[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertilizer on tobacco leaves. ln ad-dition, the effects of Mg fertilization on the absorption of K, Ca and Mg in flue-cured tobacco leaves were investigated, providing theoretical basis and production guidance for the balanced fertilization technology in the Mg-deficient flue-cured to-bacco-growing areas in Qujing City of Yunnan Province. [Method] The field plot test and randomized complete block design were adopted in this research. The group without Mg fertilization was treated as control. There were 3 treatment groups for foliar spraying of magnesium-potassium sulfate fertilizer and 2 treatment groups for soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer. The tobac-co roots, stems, lower leaves, middle leaves and upper leaves were dried and weighed. They were grinded for the determination of K, Ca and Mg content. The total K, Ca and Mg content in upper （B2F）, middle （C3F） and lower （X2F） flue-cured tobacco leaves in each plot was measured. [Result] The foliar spraying and soil application ＋ foliar spraying al increased the absorption of Mg and K in middle and lower tobacco leaves and the absorption of Ca in lower tobacco leaves, but de-creased the absorption of Mg, K and Ca in upper leaves and the absorption of Ca in middle leaves. Among the positions, the accumulated distribution of Mg, K and Ca ranked as middle leaves ＆gt; lower leaves ＆gt; upper leaves. With the application of Mg fertilizer, the Ca/Mg ratio and K/Mg ratio al decreased in middle and upper to-bacco leaves; while the Ca/Mg ratio increased in the lower tobacco leaves, and the K/Mg ratio showed no significant difference among treatment groups. [Conclusion] The foliar spraying and soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer affected the Ca/Mg ratio and K/Mg ratio in tobacco leaves mainly through affecting the absorption of Mg.
基金the National Key Technologies R & D Program of China (2006BAD05B09, 2006BAD02A14)the National Ba- sic Research Program of China (2007CB109308)the China-Japan Collaboration Project
文摘To evaluate the effect of organic manure application with chemical fertilizers on rice yield and soil fertility under long-term double-rice cropping system, a six year field experiment was conducted continually in the paddy soil derived from Quaternary red clay in Hunan Province of southern China. Four different treatments, i.e., no nitrogen with chemical P and K （PK）, swine manure only （M）, N, P and K chemical fertilizers only （NPK）, and half chemical fertilizers combined with half swine manure （NPKM） with four replications were included. Each N, P and K application rate was the same at all the treatments （except the N application rate at PK） and N application rate was 150 kg N ha^-1. All fertilizers were applied to soil tillage layer with once application as baseal fertilizers. The nutrients uptake rate, grain yield, nitrogen use efficiency, and soil organic matter content at each treatment were investigated. The NPKM treatment achieved the highest mean annual yield of 12.2 t ha^-1 （68% higher than that of PK）. Higher dry matter accumulation and nutrients absorption were observed during the middle-late growth period in the NPKM treatment, with higher panicle number per unit and filled-grain number per panicle. Its average nitrogen use efficiency was 36.3% and soil organic matter increased by 18.5% during the experimental period in the NPKM treatment, which were significantly higher than those in the NPK treatment. Organic manure application with chemical fertilizers increased the yield and nitrogen use efficiency of rice, reduced the risk of environmental pollution and improved soil fertility greatly. It could be a good practical technique that protects the environment and raises the rice yield in this region.
基金Project supported by the National Natural Science Foundation of China (No. 90102012).
文摘Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil.
文摘The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.
文摘The Soil and Water Assessment Tool (SWAT) nitrogen (N) water quality model considers the artificial inputs associated with human activities, including point and nonpoint source pollution loads. Although SWAT has the ability to simulate atmospheric N deposition and fixation, they were not considered in the modeling research. N deposition from the air is an important and considerable pathway for the input of N species into watersheds and water bodies, causing soil and water body acidification and the leaching of N into surface and groundwater, resulting in eutrophication and degraded water quality. The goal of this study is to assess the effects of atmospheric and agricultural N loads on stream water quality at the watershed scale. For a 6642 km2 Chungju dam watershed, SWAT was calibrated for 4 years (2003-2006) and validated for another 4 years (2007-2010) using daily anthropogenic N data (sewage discharge pollutants and fertilizer) and monthly measured atmospheric deposition data for NO3ˉ, NH4+, and dissolved organic N (DON). At the watershed outlet, the Nash-Sutcliffe (1970) efficiency (NSE) of daily streamflow during the validation period was 0.74. The coefficient of determination (R2) of total N was 0.69 considering atmospheric deposition, whereas it was 0.33 when removing the deposition effect. The results of this study demonstrate the potential for using the N dynamics between the atmosphere and land for SWAT assessments of nonpoint source pollution and for modeling stream water quality.
文摘Soybean and lentil are important legume crops in southern Saskatchewan (SK) that can supply the majority of their nitrogen (N) requirement through biological N fixation (BNF). However, the onset of BNF can be slow in cold;dry prairie soils and a small amount of seed-row placed fertilizer containing both N and phosphorus (P) may benefit the crop. Nevertheless, high rates of fertilizer in close proximity to the seed can also cause injury. This study was conducted to determine the response of lentil and soybean to a starter N-P fertilizer blend applied in the seed-row. A farm field located at the boundary of the Brown and Dark Brown soil zones in south-central Saskatchewan was selected to evaluate the effect of seed-row placed N-P fertilizer blend: 50% Urea + 50% mono-ammonium phosphate (MAP) applied at 0, 10, 20 and 30 kg N and P2O5 ha-1 on emergence, yield, and nutrient uptake. The proportion of nitrogen derived from fixation (ndff) was determined in the soybean using N-15 dilution technique. The rate of 10 kg N and P2O5 ha-1 was found to be the rate that did not significantly reduce emergence, stand count or proportion of N derived from fixation, and was sufficient to maximize yield, N and P uptake for both soybean and lentil under field conditions. Rates higher than 10 kg N ha-1 in the seed row as starter 28-26-0 blend reduced emergence and decreased the proportion of ndff.
基金Project of Natural Science Foundation of Qinghai Province(2018-ZJ-724)Major Science and Technology Program of Qinghai Province(2019-NK-A11).
文摘[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretical basis for realizing the sustainable development of film mulching planting method in this area.[Methods]The effects of single application of chemical fertilizer cultivation mode under film mulching conditions on the soil organic carbon(SOC),labile organic carbon(LOC),carbon management index(CMI),extractable humus carbon(CHE),humic acid carbon(CHA),and fulvic acid carbon(CFA)in the cultivated layer(0-20 cm)were studied through three consecutive years of field experiments on dryland maize farmland in the eastern Qinghai.[Results]Under the film mulching condition,the SOC,LOC and CMI of the single application of chemical fertilizer cultivation mode were lower than that of the open field control.CHE,CHA and CFA increased with the increase of planting years,but the degree of increase was generally less than that of the open field control.With the increase of planting years,by 2020,the soil LOC/SOC value of film mulching decreased by 4.97%compared with before the start of the experiment,while the open field control increased by 1.11%;the organic carbon oxidation stability coefficient(KOS)of the film mulching was higher than that of the open field control;the soil CHA/CFA value and PQ value were higher than that of the open field control.[Conclusions]Under the condition of single application of chemical fertilizers,the continuous film mulching cultivation mode reduces the soil carbon fixation capacity,and soil organic carbon tends to be stable,which is not conducive to biological utilization and could reduce the soil fertility and degrade the soil quality,causing adverse effects on the stability of crop yield and sustainable production in the long run.
