Phosphorus Uptake By Soybean Under Different Nitrogen Forms

In recent years,China's agricultural production has developed rapidly.Due to the higher economic value of crops and the increasing demand for food,farmers' blind application of nitrogen and phosphate fertilizers has caused a series of environmental problems.Aiming at the current problems of low fertilizer utilization rate and waste of resources caused by excessive fertilizer and unreasonable fertilization,this paper focuses on the management of red soil soil nutrients and the utilization rate of soybean fertilizer under different soil types.The results are as follows:1.Current phosphorus status of red soil in drylands and paddy fields and its loss risksBy considering the agronomic and environmental significance of soil phosphorus,the soil acidification status,phosphorus abundance and phosphorus loss of red soil paddy fields and dry land in the south were analyzed,which provided a theoretical basis for phosphorus management in the southern red soil.The results showed that most of the soil in paddy fields and drylands in Yujiang County was still acidic,but the degree of acidification was alleviated.The proportion of phosphorus deficiency sites in paddy soils was high,and the sites of high phosphorus were few.The drylands were the opposite.The risk of soil phosphorus loss indicates that the available phosphorus in the paddy soil at all the surveyed sites has not exceeded the mutation point of phosphorus loss,and the risk of phosphorus loss is low,while the available phosphorus in dryland soil exceeds the mutation point of phosphorus loss,and the risk of phosphorus loss is high.2.Soybean fertilizer utilization under different pH soilsBy planting soybeans in pots,the effects of applying nitrogen and phosphorus fertilizers under different pH soils on soybean biomass,nutrient absorption and fertilizer utilization were studied.The results showed that: in Jiangxi soil at pH 4.32,the application of nitrate nitrogen fertilizer and phosphate fertilizer increased the biomass of soybean roots,stems,leaves,and pods compared with the unfertilized treatment.After applying phosphorus fertilizer,the P and K contents of each part of the soybean increased,and the C and N contents decreased,and the corresponding C/N value increased.Each treatment showed that the C,N and P contents of the pods of each part of thesoybean were the highest,and the leaves the highest K content.Soybean nitrogen fertilizer utilization rate is 30.72% ~ 51.14%,phosphate fertilizer utilization rate is 3.10% ~ 7.21%.In the soil of pH6.52 in Jiangsu,the application of phosphate fertilizer increased the biomass of soybean roots,stems,leaves,and pods,and significantly increased the contents of C,N,and P in various parts of soybean.The content of C,N,P and K in soybean parts treated with ammonium nitrogen fertilizer was higher than that of nitrate nitrogen fertilizer.Soybean nitrogen fertilizer utilization rate is20.31% ~ 31.84%,phosphate fertilizer utilization rate is 11.82% ~ 13.37%.In the soil of Inner Mongolia pH8.02,the application of nitrogen fertilizer improves the biomass of soybean roots,stems,leaves and pods.The effect of nitrate nitrogen fertilizer is greater than that of ammonium nitrogen fertilizer.Phosphorus application significantly increased the content of P and K in various parts of soybean.Compared with the treatment without nitrogen fertilizer,the application of nitrate nitrogen reduced the content of P and K in all parts and increased the content of C.The N,P,and K contents of ammonium nitrogen treatment were higher than that of nitrate nitrogen treatment.Soybean nitrogen fertilizer utilization rate is 20.73% ~ 64.99%,phosphate fertilizer utilization rate is19.34% ~ 28.48%.3.Effect of Controlled Phosphate Fertilizer Application on Soybean Biomass under Different NitrogenBased on the preference of soybeans for different nitrogen fertilizers and the promotion effect of phosphate fertilizer on soybeans,the biomass of soybean stems and leaves and fruits were analyzed.The results showed that: in the acid soil,the biomass of soybean stems,leaves and fruits was the highest,and soybeans preferred nitrate nitrogen fertilizer.After the application of phosphorus fertilizer,the biomass of soybean stems,leaves and fruits increased after removing urea treatment.