Effect Of Organic Fertilizer Addition On Field Phosphorus Status And Yield Under Different Amounts Of Phosphorus Fertilization In Cotton Field In Xinjiang

Cotton is one of the most important economic crops in China.Rational fertilization can increase fertilizer utilization rate and cotton yield.Excessive fertilization may not only decrease the fertilizer utilization rate and cotton yield,but also cause a series of environmental problems,such as soil hardening,soil acidification.This research aimed to study the effect of different phosphorus fertilizer rates and organic fertilizer addition on soil phosphorus availability,soil alkaline phosphatase activity,microbial biomass phosphorus,plant uptake and distribution,yield composition and field phosphorus balance of cotton fields in Xinjiang,which would be helpful for increasing phosphate fertilizer use efficiency and sustainable phosphate management of cotton field in Xinjiang.The research results are as follows:1.Effect on soil available phosphorus:soil available phosphorus showed an increasing tendency with the increase of phosphorus fertilization rate,soil available phosphorus content in the treatment with organic fertilizer was higher than that in the treatment without organic fertilizer.Content of inorganic phosphorus in various forms of soil in cotton field during the spitting period is roughly increased with the increase of phosphorus application rate.During the flocculation period,both the soil alkaline phosphatase activity and soil microbial biomass phosphorus generally increase with the increase of the amount of phosphate fertilizer.2.The effect on the amount of phosphorus absorbed by plants:Cumulative amount of phosphorus uptake by plants generally shows an increasing trend with the amount of phosphorus applied.Cumulative phosphorus content of plants in the treatment with organic fertilizer was generally higher than that in the treatment without organic fertilizer.During the spitting period,the proportion of total phosphorus uptake in the reproductive organs of plants treated with organic fertilizer was higher than that of treatment without organic fertilizer.3.Effects on cotton yield and phosphorus efficiency:With the increase of phosphorus application,the seed cotton yield showed the trend of first increase and then slight decrease,and the yield of the treatment with organic fertilizer was generally greater than that of the treatment without organic fertilizer.Seed cotton yield was highest 5355.11-5642.24 kg·hm^-2at 100 kg P₂O₅·hm^-2 when organic fertilizers were added.The overall utilization rate of phosphate fertilizer in the treatment with organic fertilizer is higher than that in the treatment without organic fertilizer.Phosphate fertilizer recovery rate was optimal at 100 kg P₂O₅·hm^-2;with the increase of phosphorus fertilization rate,with the increase of phosphorus fertilization rate,field phosphorus surplus showed an increasing trend.This study shows that in the typical calcareous soil of Xinjiang cotton fields.Adding organic fertilizer can improve soil availability,cotton biomass,phosphorus absorption,yield,and phosphorus utilization efficiency.It is recommended to use 100 kg P₂O₅·hm^-2 phosphate fertilizer and add organic fertilizer,it can not only ensure the high utilization efficiency of phosphate fertilizer,but also increase cotton production,which can provide support for the sustainable development of green agriculture.