农业有机废弃物还田的生态经济效益研究

通过大田试验,将稻草及其利用后的有机废弃物(菌渣、牛粪、沼渣)替代部分无机化肥应用于水稻生产,研究了其对土壤养分、微生物数量、酶活性、水稻产量及经济效益的影响。结果表明,与不施肥处理(CK)和纯施用化肥处理(NPK)相比,4种有机废弃物还田均能一定程度地增加土壤有机质、速效养分的含量,增加细菌、放线菌和真菌的数量,增加微生物总活性及脲酶、磷酸酶及脱氢酶的活性;与常规纯化肥处理相比,早稻增加实际收入15.0~2690.0元/hm2(0.2%~29.7%),晚稻增加实际收入180.0~1737.5元/hm2(1.3%~12.2%),其中沼渣还田效果最佳,同时能减少10%~20%的无机化肥用量和处理农业有机废弃物6250~22500 kg/hm2,获得了生态、经济效益的双赢。但是,稻草焚烧处理在上述方面均未取得理想效果,且焚烧污染大气环境,是不可取的还田方式。

Ecological and economical effects of agricultural organic wastes returning on rice fields

A field experiment was carried out to study the effects of straw and organic wastes of straw recycling (fungus dregs, cow dung and biogas dregs) returning on soil fertility, ecologic benefit and economic benefit. In this paper, two control treatments with no fertilizers and sole chemical fertilizers and four organic matter treatments and a straw burning treatment were set to determine the effects of above four organic residues on soil nutrients, soil microbial CFUs, soil enzyme activities, rice yield and economic benefit. The results showed that the contents of soil organic matter and available nutrients, the CFUs of bacteria and actinomycetes and fungus, and the activities of microorganism and urease, phosphatase and dehydrogenase were increased with the application of the above four organic waste residues. Compared with NPK treatment, the economic benefit in treatments with the incorporation of organic waste residues increased 15.0 - 2 690.0 yuan/hm2 (0.2% - 29.7%) in early rice and 180.0 - 1737.5 yuan/hm2 (1.3% - 12.2%) in late rice, and the economic benefit increased most in NPK+BD treatment. With the incorporation of organic residue (6 250 - 2 2500 kg/hm2), the chemical fertilizer dose was reduced by 10% - 20%. Such practice could bring double win of ecologic benefit and economic benefit. But, the increase of ecologic benefit and economic benefit of straw burning treatment was not significant, and may pollute atmospheric seriously, thus should be give up in the future.