| The soil tillage technology of dryland agriculture strives to absorb autumn water and resist spring drought,but the long-term and single tillage method worsens the soil condition,and the traditional fertilizer can not meet the requirement of nutrient during the full growth period of maize.In order to solve the problems of spring drought,low ground temperature and poor seedling emergence quality in dryland maize region,the relationship between different tillage measures and nutrient management on soil moisture and heat dynamics,and the emergence and growth of maize was discussed,which had guiding significance for achieving high yield and high efficiency of maize crop in dryland region.Therefore,four tillage methods were set up in dryland areas of Inner Mongolia:conventional ridge tillage(CP),no-tillage in field(NT),no-tillage in mulch(RNT),and mulch strip tillage(RST).On the basis of RST,four nutrient management modes were set up: no nitrogen application(RST+0N),conventional fertilization(RST+Sd),combined application of 30% controlled release fertilizer(RST+30%Cr),combined application of 50%controlled release fertilizer(RST+50%Cr).The effects of different tillage methods and nutrient management on soil hydrothermal characteristics,maize population construction,yield formation and utilization of hydrothermal resources were systematically analyzed.The main results were as follows:(1)Tillage methods affect soil bulk density and total porosity in 0-40 cm soil.Compared with RNT,RST and CP treatments reduced soil bulk density by 7.2%-8.0% and5.7%-8.9%,and increased total soil porosity by 6.9%-10.0% and 6.8%-8.7%,respectively.(2)RST has outstanding moisture retention and heat preservation ability,which is an appropriate tillage method for cracking moisture retention and catching seedlings in cold and cool dry farming areas.Compared with CP,soil water content of RST increased by2.9%,and water storage before sowing increased by 3.2mm.At the same time,the mean soil temperature in RST seedling stage had no difference with CP and was significantly higher than that in RNT.Compared with CP,the seedling emergence rate increased by15.9%,HUE increased by 4.5% and WUE by 5.2%.(3)RST promoted the growth and development of maize,and the SPAD value of maize leaves increased by 2.1-6.9% and 6.1-9.3% compared with CP and RNT,respectively.Compared with CP and RNT,dry matter accumulation increased by 2.8%-9.9%and 5.2%-12.3%,respectively.In addition,RST could improve lodging resistance,stem breaking resistance,root dry weight and total number of roots were significantly higher than CP,and lodging rate was 9.8% lower than CP.The average yield was 12.3 t/hm2,7.6%higher than CP and 7.6% higher than CP and RNT.(4)RST+50%Cr can meet the demand for fertilizer in the whole growth period of maize.Compared with RST+Sd,SPAD value of maize leaves was increased by 4.1-8.2%.Dry matter accumulation was 7.1%-26.8% higher than RST+Sd.In addition,RST+50%Cr significantly increased stem puncture strength,stem breaking resistance,root dry weight and total number of roots,and lodging rate decreased by 13.4%.The average yield was13.2 t/hm2,7.3% higher than that of RST+Sd,2.4% higher than that of 1000-grain weight,5.4% higher than that of RST+Sd.(5)RST+50%Cr can effectively solve the problems of low seedling emergence rate and weak seedling quality of maize in Inner Mongolia dry farming area,which is one of the rational tillage and fertilization modes more suitable for the cold and cool dry farming area of Inner Mongolia. |
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