Effects Of Tillage And Straw Returning Methods On Maize Rhizosphere Soil Properties And Yield

In this study,the semi-arid area in the west of Heilongjiang Province is characterized by low rainfall,frequent wind erosion,poor soil moisture retention ability and low maize yield due to the single soil tillage system,so discusses the effects of different tillage and straw returning methods on soil characteristics and yield of maize.This experiment was carried out in Xingcheng Demonstration Zone,Zhaozhou County,Heilongjiang Province.The maize variety“Dongxu 20” was tested.7 kinds of tillage and straw returning methods were set up,respectively,Conventional rotary ridge tillage(Con),No-tillage straw removed(T1),No-tillage + whole straw crushing mulch returning to the field(T2),Deep loosening of ridge tillage in spring + whole straw plowed in depth and returned to the field(T3),Deep loosening of flatten tillage in spring +whole straw plowed in depth and returned to the field(T4),Ridge tillage + whole straw broken mixture returning to the field(T5),Flatten tillage + whole straw broken mixture returning to the field(T6).It aims to explore tillage and straw returning methods which is suitable for soil conservation,water conservation,drought resistance and yield increase,so as to perfect the maize cultivation and tillage technology system in the semi-arid area of Heilongjiang Province.The main findings are as follows:Deep loosening of flatten tillage in spring + whole straw plowed in depth and returned to the field increased the soil urease,sucrase and catalase in the rhizosphere of maize by1.43%?25.29%,59.93%?112.78% and 3.84%?17.23%,respectively,compared with Flatten tillage + whole straw broken mixture returning to the field in different growth stages under the condition of flatten tillage.Compared with Deep loosening of ridge tillage in spring + whole straw plowed in depth and returned to the field,Deep loosening of flatten tillage in spring +whole straw plowed in depth and returned to the field increased the activities of urease,sucrase,catalase and alkaline phosphatase in rhizosphere soil of maize by 8.16%?38.73%,18.01%?32.45%,5.14%?23.17% and 4.95%?99.53%,respectively,at jointing stage,tasseling stage and maturity stage under the condition of straw total deep tilting and returning to field.Compared with Flatten tillage + whole straw broken mixture returning to the field treatment,Deep loosening of flatten tillage in spring + whole straw plowed in depth and returned to the field treatment significantly increased the contents of organic matter,total nitrogen,alkali-hydrolyzable nitrogen,available phosphorus and available potassium in the rhizosphere soil of maize by 8.53%?19.24%,34.19%?78.32%,20.02%?23.56%,65.79%?107.04% and6.15%?11.46%,respectively,at different growth stages under the condition of flatten tillage.Compared with Deep loosening of ridge tillage in spring + whole straw plowed in depth and returned to the field treatment,Deep loosening of flatten tillage in spring + whole straw plowed in depth and returned to the field treatment increased the leaf area and chlorophyll content of maize by 4.10%?16.36% and 1.71%?4.25%,respectively,at jointing and tasseling stages,and increased the dry matter accumulation of maize by 0.80%?26.90% at jointing,filling and maturity stages under the condition of full straw mulching.Compared with Flatten tillage +whole straw broken mixture returning to the field treatment,Ridge tillage + whole straw broken mixture returning to the field treatment increased the plant height and chlorophyll content of maize by 5.31%?7.54% and 0.72%?4.77%,respectively,at jointing and tasseling stages,and increased the dry matter accumulation of maize by 11.20%?30.09% at each growth stage.The average yield of maize was Deep loosening of flatten tillage in spring + whole straw plowed in depth and returned to the field > Deep loosening of ridge tillage in spring + whole straw plowed in depth and returned to the field > No-tillage + whole straw crushing mulch returning to the field > Ridge tillage + whole straw broken mixture returning to the field >Conventional rotary tillage > Flatten tillage + whole straw broken mixture returning to the field > No-tillage straw removed.The best economic benefit was Deep loosening of flatten tillage in spring + whole straw plowed in depth and returned to the field.In summary,Deep loosening of flatten tillage in spring + whole straw plowed in depth and returned to the field is a better tillage method in this experiment.