旱塬地玉米农田免耕覆盖的土壤环境效应

The Effects of No tillage with Mulch on Soil Environment for Maize Dryland

免耕覆盖 45 0 0 kg/ hm2 以上的处理比传统耕作增产 2 2 .15 %～ 2 5 .6 5 %。土壤水分利用率提高 2 .96 2 5kg/ (mm· hm2 )。春播前 0～ 2 0 0 cm土层速动易效水含量比传统耕作增加 17.0 2～ 47.9mm。距地表 5 ,10 ,15 cm处的地积温与覆盖量呈极显著直线负相关。 0～ 10 cm土壤容重随覆盖量增加而减小。土壤有机质、全 N、速效 P与覆盖量呈极显著直线回归关系。脲酶比传统耕作增加幅度为 0 .0 4～ 0 .48m g/ g,碱性磷酸酶增幅为 0 .0 5～ 1.0 8mg/ g,转化酶增幅为 1.7～ 12 .8mg/ g;脲酶、碱性磷酸酶。

Under the condition of no tillage with mulch which amount was above 4 500 kg/hm 2, increase of corn yields was 22.15%~25.65%; the water utilized coefficient of soil can increase 2.962 5 kg/ (mm·hm 2); compared the treatments of no tillage with mulch to the traditional tillage, the contents of quick moving available water in 0~200 cm soil layers can increase 17.02~47.9 mm before spring sowing. There was a significant negative correlation between earth cumulative temperature in 5, 10,15 cm soil layers and the amounts of stalk mulch;the more the mulch amounts were, the less the volume weight in 0~10 cm soil layers was; the significant relations of linear regression were formed between organic substance, total N, available P and mulch amounts. Compared the treatments of no tillage with mulch to the traditional tillage, amounts increased of urease, basic phosphatase, invertase were 0.04~0.48 mg/g, 0.05~1.08 mg/g and 1.7~12.8 mg/g; there was a significant linear correlation between the three kinds of enzyme and the amounts of mulch.