稻草及稻草循环利用后的废弃物还田效益研究

Effect of rice straw and the residues of rice straw recycling on soil fertility and crop yield

本文针对中南丘陵水稻产区农田稻草经过稻草直接还田(鲜稻草)、稻草过腹还田(新鲜牛粪)、稻草栽培食用菌后还田(新鲜菌渣)、稻草产沼气后还田(新鲜沼渣)等几种主要的循环利用方式后的废弃物还田,结合化肥配施对水稻产量及土壤基本理化性状影响的研究,以期寻找一种既能达到有机废弃物的循环再利用,改善生态环境,又能够改良土壤理化性状并达到水稻丰产的目的。试验结果显示:相对于常规的化肥施用,几种有机废弃物还田加化肥配施均有利于土壤有机质(1.71%～6.98%),碱解氮(4.30%～15.05%),有效磷(11.22%～21.43%)等养分的提高;增加了土壤团聚体R0.25(干筛6.60%～8.74%,湿筛2.64%～45.06%)、平均质量直径(干筛26.91%～52.69%,湿筛4.55%～32.73%)及几何平均直径(干筛17.88%～35.56%,湿筛3.08%～6.15%);在产量方面,虽较常规施肥有所下降,但经济效益却是增加的,较常规施肥增收75.6元·hm-2到1057.0元·hm-2,其中沼渣还田的增益率最高达8.59%。

Rice straw is an important organic resource to be used for animal food, mushroom culture medium and methane generating material. In this study, we investigated the effects of the residues from above rice straw recycling activities and fresh rice straw on soil physical and chemical properties, nutrient status and crop yield. The results showed that, in comparison with chemical fertilization, application of rice straw and the residues of recycling rice straw increased the content SOM, soil available nitrogen, soil available phosphorus and macro-aggregate （R0.25）. It also caused the increase of the mean weight diameter （MWD） and geometric mean diameter （GMD） of soil aggregates. Although crop yield slightly decreased under such conditions, the economic benefit was obvious which was between 75.6 and 1057.0 yuan·hm^-2 among the treatments while the highest benefit rate was 8.59% which occurred in the treatment of the residue from biogas producing pool.