水旱轮作制下连续秸秆覆盖对土壤理化性质和作物产量的影响

采用田间定位试验研究方法，于2008～2010连续3年研究了水旱轮作制下连续秸秆覆盖对土壤理化性质和作物产量的影响。结果表明，连续秸秆覆盖显著降低了土壤表层（05cm）容重，提高了05cm和515cm土层土壤含水量。同时连续秸秆覆盖还田还可以显著提高025cm土层土壤有机质、碱解氮、速效磷和速效钾含量。秸秆覆盖对表层（05cm）土壤养分状况的效应更明显。秸秆连续覆盖5季后，05cm土层土壤速效钾含量的增幅（7.64%～15.33%）速效磷（7.52%～10.03%）碱解氮（7.30%～8.74%）有机质（6.08%～7.53%）。秸秆覆盖还田后，可以提高作物产量。其中旱季作物（小麦、油菜）的增产效应要高于水季作物（水稻），并且随着秸秆还田年限和用量的增加，作物的增产幅度也随之提高。起主要作用的产量构成因素是小麦、水稻的有效穗数以及油菜单株角果数和每角粒数。

Effects of continuous straw mulching on soil physical and chemical properties and crop yields in paddy-upland rotation system

A long-term(2008-2010) experiment was conducted to study the effects of straw mulching on soil physical and chemical properties and crop yields in paddy-upland rotation system.The results show that compared with no straw mulching treatment,the soil bulk density is reduced in 0-5 cm soil layer,and soil water contents are increased in 0-5 cm and 5-15 cm soil layers with the straw mulching treatment.The contents of soil organic matter,alkaki-hydrolyzable N,available P and available K in 0-25 cm soil layer are increased under the straw mulching.Influences of the straw mulching on soil nutrient conditions in 0-5 cm soil layer are higher than those of 5-15 cm and 15-25 cm soil layer.The nutrient contents increase sequence in 0-5 cm soil layer after 5 seasons of the straw mulching are: available K(7.64%-15.33%) >available P(7.52%-10.03%) >alkaki-hydrolyzable N(7.30%-8.74%) > organic matter(6.08%-7.53%).The results also indicate the straw mulching increases the crop yields,and the effects of the straw mulching on wheat and rapeseed are higher than that of rice,and the increases of mulching times and the amount of straw have significantly positive effects on the crop yields.The key components of the yields are effective panicles of wheat and rice,and pod number and seed per pod of rapeseed.