户用沼气工程发展对农田养分流动的影响

该文采用养分流的分析方法，对比分析2007年中国13个沼气发展省份沼气农户和非沼气农户农田养分管理行为的差异。结果显示：两类农户单位面积化肥用量和秸秆还田率方面没有明显差异，部分地区沼气农户生活燃料比例明显减少，但地头秸秆燃烧情况加剧；粪尿养分还田率有较大不同，非沼气农户粪尿直接还田率达到96%，沼气农户只有39%，沼气农户大量粪尿进入沼气池，但只有33%的养分被利用，沼肥养分仅占沼气农户养分输入总量的9%。综合比较，沼气农户家庭有机养分比重仅有24%，而非沼气农户达到了43%；这导致了沼气农户单位面积养分输入总量为 781.62 kg/hm2，显著低于非沼气农户的850.82 kg/hm2。沼气农户的废弃物养分循环利用率只有45%，而非沼气农户达到70%。研究结果表明中国沼气农户并没有因为沼气发展而提高养分再利用，沼肥对化肥的替代效果没有表现出来，导致有机资源浪费。因此，必须加强沼气农户的技术培训，加强沼肥的还田力度，提高养分循环利用率，充分发挥沼气对家庭养分资源再利用的优势。

Effect of household biogas project development on farmland nutrient flow

The method of nutrient flow was adopted to compare farmers' nutrient management behaviors in 2007 between biogas and non-biogas farmer's household in 13 investigated sites which included Sichuan,Guangxi,Heibei,et al.provinces.The results showed the total amount of nutrient for putting was only 781.62 kg/hm2 in biogas household,which was significantly lower than 850.82 kg/hm2 that put into no-biogas farmers' household.The two groups' farmers had no significant difference in fertilizer and straw nutrient for ...