Effects of Temperature-increasing Water Irrigation on Soil Nutrients and Soil Microbial Biomass in Cotton Rhizosphere

Objective This project aims to explore the effects of drip irrigation temperature on soil nutrients and soil microbial biomass in cotton rhizosphere by the field experiment of temperature-increasing water irrigation(ZW)and well water irrigation(CK).MethodThis experiment set a water warming irrigation and well irrigation of 2 levels and 3 repeats with drip irrigation under plastic film to research the content of cotton rhizosphere soil available N,available P,available K and organic matter during cotton bud stage and boll stage,and collected the rhizosphere fresh soil within the depths of 0-20 cm to detect soil bacteria,fungi,actinomycetes number in complete irrigation cycle during the bud stage.ResultThe result showed that in the bud stage,soil available N content by ZW treatment was reduced by 13.51;(P<0.05)than the CK,in the boll stage,soil available P was reduced by 26.7;(P<0.05),the content of available K and organic matter were decreased slightly in both stages(P>0.05).The number of soil microorganisms by ZW treatment was increased during the single irrigation period.Three days after irrigation,bacteria,fungi and actinomycetes were increased by 41.5;(P< 0.05),45;(P< 0.01),19;(P < 0.05).Five days after irrigation,the number of actinomycetes was increased by 93.2;(P < 0.01).Total increase order was bacteria > actinomycetes > fungi.ConclusionWater warming irrigation can not only promote the absorption of soil nutrients in cotton,thus reducing the nutrient content in soil,but also enrich the amount of microorganism in soil and accelerate soil nutrient cycling.