Effects Of Different Phosphate Fertilizer Treatments On Phosphorus Fractions In Aeolian Sandy Soil And Cotton Nutrient Absorption

Based on the literature data published in CNKI database from 1996 to 2020,soil culture experiment and cotton pot experiment were designed to explore the effects of different phosphate fertilizer treatments on phosphorus fractions and nutrient absorption of cotton in irrigated aeolian sandy soil on the basis that the amount of phosphate fertilizer can fully meet the growth of cotton.It provides theoretical basis for rational application of different phosphate fertilizer in irrigated aeolian sandy soil.（1）Indoor soil culture treatment:In this paper,the indoor soil culture experiment of irrigated aeolian sandy was carried out for120 days,including six treatments were used in the experiment.The treatments were control without P fertilizer（CK）,basal application of triple superphosphate（TSP）,mono-ammonium phosphate（MAP-B）and ammonium polyphosphate（APP-B）,drip application of mono-ammonium phosphate（MAP-D）and ammonium polyphosphate（APP-D）.The changes of soil available P and inorganic P fractions under different treatments were measured,and the correlation between soil available P and inorganic P fractions at 120 days was analyzed.（2）In this paper,there were four treatments in the pot experiment of cotton.The treatments were control without P fertilizer（CK）,basal application of triple superphosphate（TSP）,mono-ammonium phosphate（MAP-B）and ammonium polyphosphate（APP-B）.The contents of available P in soil and total P and inorganic P in flowering and bolling period were measured,and the correlation between the contents of inorganic P in flowering and bolling period and available P in soil and cumulative P uptake by plants was analyzed.The main results are as follows:（1）Through the statistical analysis of literature data,the theoretical basis is provided for the selection of phosphate fertilizer varieties and the setting of phosphate fertilizer dosage.According to the literature review,triple superphosphate and mono-ammonium phosphate are the most widely used phosphate fertilizer varieties in Xinjiang cotton production,and the amount of phosphate fertilizer of 175 kg/hm²can meet the demand of cotton growth and development.（2）In 0-5 cm soil layer,the available P content of drip application of phosphate fertilizer（MAP-D,APP-D）was significantly higher than that of other treatments.However in the 5-10 and 10-20 cm soil layers,the soil available P content of basal application of phosphate fertilizer treatments（TSP,MAP-B and APP-B）was significantly higher than that of other treatments（P<0.05）.Compared with CK and APP-D treatments,TSP,MAP-B and APP-B treatments significantly increased available P content in 0-20 cm soil layer,but there was no significant difference among these three treatments.Compared with CK,each phosphorus application treatment can increase the total inorganic phosphorus of each soil layer to different degrees.The total inorganic phosphorus in 0-5 cm soil layer under MAP-D and APP-D treatments was significantly higher than that in 5-10 and 10-20 cm soil layer,while TSP,MAP-D and APP-D treatments had no significant effect on the total inorganic phosphorus in 0-20 cm soil layer.The ratio of Ca₂-P,Ca₈-P and Al-P decreased with the increase of soil depth under the drip application of phosphate fertilizer,while the ratio of Ca₈-P and Al-P in topsoil was significantly increased under the base application of phosphate fertilizer.In 0-5 cm soil layer,soil available P content was significantly positively correlated with Ca₂-P,Ca₈-P,Al-P and Ca₁₀-P contents（P<0.05）;There was a significant positive correlation between soil available P content and Ca₂-P,Al-P and Fe-P contents in 5-10 and 10-20 cm soil layers（P<0.05）.（3）Pot experiment of cotton showed that three phosphate fertilizer treatments（TSP,MAP-B and APP-B）significantly increased soil available P and total P contents and activation coefficient of P（P<0.05）,the contents of available P,total P and activation coefficient of P in MAP-B treatment were significantly higher than those in TSP and APP-B treatment.There was no significant difference between the total inorganic phosphorus and organic phosphorus of each phosphate fertilizer and CK treatment,and inorganic phosphorus accounted for 69.1%-74.7%of total phosphorus.TSP,MAP-B and APP-B significantly increased Ca₂-P,Ca₈-P and Al-P contents compared with CK treatment,TSP and MAP-B significantly increased Fe-P content compared with CK treatment,and each phosphate fertilizer treatment had no significant effect on O-P and Ca₁₀-P contents.The content of Ca₂-P and Al-P in MAP-B treatment was significantly higher than that in TSP treatment,and the content of Fe-P in MAP-B treatment was significantly higher than that in APP-B treatment.Compared with CK,TSP,MAP-B and APP-B treatments can increase the proportion of Ca₂-P,Ca₈-P and Al-P,and decrease the proportion of O-P and Ca₁₀-P.Correlation analysis showed that Ca₂-P,Ca₈-P,Al-P and Fe-P contents were significantly positively correlated with soil available P content and cumulative P uptake（P<0.05）.It was found in the cotton pot experiment,The cumulative P uptake of cotton increased with the advance of growth stage.The effects of TSP,MAP-B and APP-B treatments on the cumulative P uptake of cotton in each stage were not significant.The biomass per plant of TSP and MAP-B treatment was significantly higher than that of APP-B treatment at flowering and bolling stage.Under the conditions of this experiment,it is recommended to choose the low cost triple superphosphate base application in aeolian sandy soil.Through the analysis of literature data,soil culture experiments and cotton potting experiments,this study provides a theoretical basis for the selection of phosphate fertilizer varieties and fertilizer dosage in cotton planting in aeolian sandy soil in Xinjiang.