| Farming is an important factor affecting the increase of crop yield.Due to the continuous and high-intensity development and unreasonable use of cultivated land,the soil topsoil is obviously shallow,the soil structure is compact,and the amount of effective topsoil is significantly reduced,which has seriously hindered the increase of corn yield.Therefore,the field experiment was carried out in this study,and two factors(tillage depth and ploughing ratio)and three levels were set [tillage depth: 20 cm(D20),25 cm(D25),30cm(d30);Ploughing ratio: 0% pt(Plow Tillag),100%PT,50%PT],a total of 9 treatments.The effects of tillage depth and ploughing ratio on soil bulk density change,soil water transport and distribution,corn growth,water consumption intensity and yield were studied,which provided theoretical basis for determining reasonable tillage depth and ploughing ratio and improving corn yield.The main conclusions of this study are as follows:(1)After straw is returned to the field,the soil water content with the same soil water suction increases with the increase of straw application amount.The application amount of straw increased the soil water constant,increased the excess water and difficult effective water,but decreased the effective water.The application of straw did not change the variation of specific water capacity with soil water suction,but with the increase of straw application amount,the specific water capacity of soil decreased.(2)The water consumption of maize can be effectively increased by 25 cm depth and 50% ploughing ratio.The effect of tillage depth on crop water consumption is D25>D30>D20,and the water consumption intensity of D25 treatment is 5.1% and2.9% higher than that of D20 and D30 treatment.The effect of tillage ratio on crop water consumption intensity is as follows: 50%PT>100%PT>0%PT,and the water consumption intensity of 50%PT treatment is 4.4% and 8.7% higher than that of 0%PT and 100%PT treatment.The effect of tillage ratio on the water consumption of crops in the whole growth period is as follows: 50%PT>100%PT>0%PT,and the water consumption intensity of 50%PT treatment is 5.2% and 9.1% higher than that of 0%PT and 100%PT treatment.(3)Soil bulk density of 20 cm depth is higher than other treatments: at 20-30 cm before sowing in corn season,the soil bulk density of D20 treatment is significantly higher than that of D25 treatment by 16.5% and that of D30 treatment by 7.6%,but there is no significant difference in soil bulk density among different tillage depth treatments in late corn season.The soil bulk density of 0%PT was significantly higher than that of the other two treatments in every soil layer,with 0-10 cm significantly increased by 16.6% and 17.5%,10-20 cm significantly increased by 8.7% and 7.4%,20-30 cm significantly increased by 10.6% and 9.5%,and 30-60 cm significantly increased by 4.4%.(4)D25-50%PT treatment can effectively improve the biological indexes of maize,and the plant height,stem diameter and leaf area index of maize under this treatment are significantly higher than those of other 8 treatments.(5)D25-50%PT treatment can effectively increase water consumption,yield and water use efficiency of maize.The yield indexes of maize,such as ear length,ear weight,100-grain weight and ear grain weight,were significantly higher than those of other 8treatments.At the same time,the water use efficiency of D25-50%PT treatment was better than other treatments.This study found that the tillage depth of 25 cm combined with 50% tillage(D25-50%PT)could significantly improve the yield and water use efficiency of corn.On this basis,agricultural production has certain guiding significance. |
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