Study On Fertilization Effects Of Cotton Field Based On Combined Applications Of Nitrogen,Phosphorus And Potassium Fertilizers In Aksu Prefecture,Xinjiang

Xinjiang is one of the important cotton production bases in China and even the world,and its cotton yield ranks first in the world.Among them,the Aksu Prefecture is the important cotton-producing area in southern Xinjiang of China,due to its unique natural conditions,climatic resources and abundant human resources.At present,due to two irrigation methods-flood irrigation and drip irrigation-still exist in southern Xinjiang,in order to explore the influence mechanism of combined applications of nitrogen,phosphorus and potassium fertilizers on fertilization effects of different irrigation methods and different soil fertility cotton fields,in this study,three typical cotton fields with different irrigation methods are selected as experiment locations in Aksu Prefecture of Xinjiang(the location A-drip-irrigated cotton fields in Shaya County,the location B-drip-irrigated cotton fields in Wensu County,the location C-flood-irrigated cotton fields in Wensu County),and five different combined applications patterns of nitrogen,phosphorus and potassium fertilizers are designed for each experiment location(CK-without any fertilizer,PK-without nitrogen fertilizer,NK-without phosphorus fertilizer,NP-without potassium fertilizer,NPK-with nitrogen,phosphorus and potassium fertilizers),and the study on cotton field fertility,cotton nutrient uptake and fertilization effects of combined applications of nitrogen,phosphorus and potassium fertilizers is carried out.By analyzing the changes of different monitoring indicators in different growth periods of cotton,the nitrogen,phosphorus and potassium combined fertilization mode for cost-saving and efficiency improvement are explored on cotton fields in Xinjiang,which provides the theoretical basis and technical parameters for the high yield on cotton fields and the improvement of fertilizer utilization efficiency in Aksu Prefecture,Xinjiang.The main results of the study are as follows:(1)The study shows that the combined fertilization of nitrogen,phosphorus and potassium has a certain effect on soil nutrient content.Compared with the CK treatment,the nitrogen,phosphorus and potassium combined fertilization mode can significantly increase the contents of soil total nitrogen,alkaline nitrogen,available phosphorus,available potassium and organic matter.This may be related to the basic physical and chemical properties of the experiment locations: the soil p H,total nitrogen,total phosphorus and alkaline nitrogen contents of location A in Shaya County and location B and C in Wensu County are similar,and there is no significant difference;the soil organic matter content of the drip-irrigated cotton fields at location A in Shaya County and location B in Wensu County is similar,but the soil organic matter content in the flood-irrigated cotton fields at location C in Wensu County is higher than the other two locations;the soil total potassium content of cotton fields at location B and C in Wensu County is similar,but the soil total potassium content of cotton fields at location A in Shaya County is lower than the other two points;the soil available phosphorus content of location A in Shaya County is higher than that of location B and C in Wensu County;the content of soil available potassium at location A in Shaya county and location C in Wensu county is similar,and the content of soil available potassium at location B in Wensu county is higher than that in the other two points;(2)The study shows that fertilization is beneficial to promote cotton growth and development and improve nutrient absorption.By monitoring cotton fields with different irrigation methods,under different nitrogen,phosphorus and potassium combined fertilization conditions,cotton plant height,leaf numbers,boll numbers and biomass accumulation all significantly increase.Compared with the CK treatment,the biomass accumulations of other fertilization treatments increase significantly.Among them,NPK treatment has the highest biomass accumulations;(3)The study shows that combined applications of nitrogen,phosphorus and potassium fertilizers significantly improve cotton yields.In drip-irrigated cotton fields,compared with the yield of the CK treatment,the yield increased rate of the combined applications of nitrogen,phosphorus and potassium fertilizers is from 16.72% to 26.31%;while in the flood-irrigated cotton fields,its rate is from 10.83% to20.54%.It can be found that under different nitrogen,phosphorus and potassium combined application conditions,the yield increased rate of drip-irrigated cotton fields is higher than that of flood-irrigated cotton fields,thus drip-irrigation pattern is more suitable for the promotion of farmland planting;(4)The study shows that with different irrigation methods conditions,the fertilizer utilization efficiencies of nitrogen,phosphorus and potassium fertilizers in drip-irrigated cotton fields are 41.59%,14.52% and 69.29% in location A of Shaya County and 47.17%,11.45% and 67.27% in location B of Wensu County,respectively;and those in flood-irrigated cotton fields in location C of Wensu County are30.52%,11.37%,and 59.03%,respectively.As above,potassium fertilizer has the greatest effect on fertilizer utilization efficiency,followed by nitrogen fertilizer,and phosphorus fertilizer has the lowest effect.Moreover,the fertilizer utilization efficiency of flood-irrigated cotton fields is lower than that of drip-irrigated cotton fields.In summary,in cotton fields with different irrigation methods,the effects of different combined applications of nitrogen,phosphorus and potassium fertilizers on fertilization effects of cotton fields are different.In this study,under different nitrogen,phosphorus and potassium combined fertilization conditions,NPK treatment is more conducive to promoting cotton growth,development and nutrient absorption.With different irrigation methods,the yield and the fertilizer utilization efficiency of dripirrigated cotton fields are higher than those of flood-irrigated cotton fields.In actual agricultural production,the drip-irrigation method is more suitable for the cultivation and promotion of farmland,and with a reasonable and scientific combined applications ratio of nitrogen,phosphorus and potassium fertilizers,it can not only improve the soil fertility of cotton fields,but also promote cotton growth,development and nutrient absorption,thereby,the yield and fertilizer utilization efficiency of the cotton fields can be improved,and finally the volume of fertilizer usage can be reduced,while the fertilizer utilization efficiency can be improved.