| The Hetao irrigation area is one of the main grain producing areas in our district.The non matching farming methods have restricted the development of local maize production.It is of great significance to explore the theory and technology of the rational cultivation of the plough layer in the region.In 2015,the field investigation was conducted in the Inner Mongolia Hetao irrigation area.Each survey point was taken to test low fertility level(LY,corn yield below 7500 kg/ha),medium fertility level(MY,maize yield 7500~12000 kg / ha)and high fertility level(HY,corn yield is higher than12000 kg/ha)in 3 Fertility Levels The indexes of soil physical and chemical properties and yield of three tillage methods such as subsoiling(S),tillage(P)and shallow rotation(RT)were studied.In 2016 and 2017,6 experimental treatments were set up in Hetao irrigation area,including RT,P,S,ploughing + straw returning(PR),ploughing +deep pine(SP),subsoiling + ploughing and straw returning(SPR),and analyzed the cultivation methods and canopy structure,soil characteristics and maize yield.Relationship.The results show that:(1)Soil water content increased by 7.25%-29.67%,5.52%-20.59%,the soil bulk density decreased by 5.23% to 8.61%,0.69% to 4.91%,soil R value decreased by12.29%~89.99%,7.30%~57.77%,and the total nitrogen content of soil was raised and the soil speed was higher than that in the soil under the low,medium and high fertility conditions.The content of effective phosphorus increased from 21.23%-41.26%,10.84%-22.04%,and the content of available potassium in soil increased by 36.85%-71.99%,6.01%-50.99%,and the content of soil organic matter increased by28.85%-54.14%,14.63% to 36.38%.The soil structure of 0-50 cm soil layer was significantly optimized by SPR treatment.The soil water content was increased by4.12%-41.92%,soil water storage was increased by 8.80%-25.65%,soil bulk density was reduced by 1.35% to 12.37%,soil three phase R was reduced by 5.67% to54.26%,soil alkaline nitrogen was increased by 4.10%-54.63%,and soil available phosphorus was increased 4.98%.To 62.23%,soil available potassium increased by5.56%-53.58%,and soil organic matter increased by 6.81% to 62.84%.SP,PR,S and P increased significantly in 20-35 cm soil layer than RT,and SP and PR had little difference,and S had better effect than P.(2)The growth rate of subsoiling in low,medium and high fertility conditions reached 47.97%,40.74% and 16.27% respectively,and the deep ploughing reached32.79%,23.46% and 8.03% respectively.The yield potential of Maize under tillage and subsoiling was 22.75%,16.96%,16.55% and 29.56%,25.37% and 16.13% respectively under different fertility(low,medium and high).(3)Under the treatment of SPR,SP,PR,S and P,the accumulation of dry matter in the front of the flower and the accumulation of dry matter in the mature period were the best,and increased by 4.57% to 33.94% compared with the other treatments.SP,PR,S and P were all significantly higher than RT,and the overall trend was SPR>SP>PR>S>P>RT.The dry matter accumulation after anthesis reached the maximum 243.78 g by SPR treatment.The leaf area duration of different tillage methods reached the maximum value at R1-R3,and the net assimilation rate reached the maximum in V6-V12;the effect of different tillage methods on leaf area effect SPR was the best,compared with other treatments by 4.01% to 55.80%,SP,PR,S and P were significantly higher than those of RT.(4)SPR significantly increased WUE,WPE,NRE,NUE and NHI.There was no significant difference in SPR,SP,PR,S and P among all the indexes,but all were significantly higher than RT.(5)Under different tillage patterns,the response of Maize Yield and its components to farming methods was 2.74% to 26.27% higher than that of other treatments,and the economic benefit of 3 thousand and 600 yuan/ha was increased by SPR>SP>PR>S>P>RT and SPR. |
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