大豆玉米持续轮作免耕对土壤养分及作物产量的影响

Effects of Continuous Rotation and No-till of Soybean-corn on Soil Nutrients and Crop Yield

为了解决免耕减产、秸秆焚烧污染环境、种植结构不合理等问题,试验通过设置免耕和传统垄作田间对比试验,研究了2013—2016年连续4年大豆玉米轮作免耕对土壤养分及作物产量的影响,研究结果可为免耕技术推广及黑龙江省农业持续发展提供理论参考和技术保障。试验结果表明:大豆玉米持续轮作免耕条件下0～7.5、7.5～15、15～22.5、22.5～30 cm土壤养分指标全氮、全磷、全钾、碱解氮、速效磷、速效钾、有机质含量均高于垄作处理,且耕作对全氮、全磷、碱解氮、速效磷、速效钾、有机质含量影响显著;耕作对土壤容重影响显著,免耕处理各层土壤容重高于垄作处理,免耕处理15～22.5 cm与22.5～30 cm土层之间容重差异不显著,而垄作处理各层土壤容重差异显著;与垄作相比,2013年和2015年免耕大豆增产率分别为16.37%和25.33%,2014年和2016年免耕玉米产量增产率分别为0.88%和9.50%。大豆玉米轮作免耕较垄作平均节约成本640元/hm^2,平均增收2220元/hm^2。

The objective of this study is to solve the problems such as yield loss of no-till,environmental pollution of straw burning and unreasonable plantation structure.A field experiment with two types of tillage[conventional tillage(CT)and no-till(NT)]from 2013 to 2016 was conducted to evaluate the effects of continuous rotation and no-till of corn-soybean on soil nutrients and crop yield.The results indicated that soil total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus,available potassium,organic matter at 0-7.5,7.5-15,15-22.5,and 22.5-30 cm depth of NT were higher than that of CT.Tillage had significant effect on soil nutrient except total potassium.Tillage had significant impacts on soil bulk density.Soil bulk density was higher at each soil layer under no-till than that of conventional tillage.The difference of soil bulk density between 15-22.5 cm and 22.5-30 cm under no-till was not significant,while the difference among different layers under conventional tillage was significant.Soybean yield under no-till increased by 16.37%and 25.33%compared with that of conventional tillage in 2013 and 2015,respectively.Corn yield under no-till increased by 0.88%and 9.50%compared with that of conventional tillage in 2014 and 2016,respectively.Soybean-corn rotation and no-till saved the cost of 640 yuan/hm2,and increased the income of 2220 yuan/hm2 compared with conventional tillage.