我国果菜茶中畜禽粪便有机肥替代化肥潜力

为探究我国畜禽有机肥对果菜茶理论养分需求量的满足水平,评估果菜茶三大作物有机替代与化肥减量潜力,本研究借助统计资料,定量分析我国畜禽粪便养分资源供应量和果菜茶理论养分需求量,在此基础上进行全国性及区域性替代可行性分析。统计分析表明:2015年,我国果菜茶化肥氮磷(纯养分)施用总量为1.84×107t·a-1,是理论需求量的两倍左右,化肥过量施用十分严重;2015年,我国畜禽粪便产生的氮、磷(以P2O5计,下同)分别为7.98×106、6.42×106t·a-1,若全部用于果菜茶,可替代78%的化肥,减少2.88×106～5.18×106t氮、磷肥损失;90%的省(市、自治区)产生的畜禽粪便可满足区域内化肥减量20%的目标,71%的省(市、自治区)畜禽粪便可满足区域内替代50%化肥;各地区畜禽有机肥替代化肥量空间差异较大,除长三角、珠三角经济发达地区(上海、江苏、浙江、福建、山东、广东、陕西)以外,其余省份(市、自治区)畜禽有机肥可100%替代区域内果菜茶化肥,并且,东北、西北地区的畜禽粪便在满足区域内果菜茶养分需求的基础上仍有较多盈余,可施用于粮食或者经济作物,或者转化为优质商品有机肥补给长三角、珠三角地区。我国果菜茶三大作物通过畜禽有机肥替代化肥,70%省份可实现化肥减量目标,减少氮磷化肥面源污染。研究结果可为我国果菜茶中畜禽粪便有机肥替代化肥施用提供一定理论指导,为实现果菜茶化肥减量的目标提供决策支持。

Potential of animal manure in replacing chemical fertilizers for fruit, vegetable, and tea production in China

In order to estimate the replacement potential of chemical fertilizers with animal manure for fruit, vegetable, and tea production in China, we calculated the nutrient level of animal manure and the theoretical nutrient demands of plants. Thereafter, we analyzed the supply and demand balance on a national and regional scale. According to statistical data from 2015, the quantity of chemical nitrogen (N) and phosphorus (in the form of P₂O₅) applied on fruits, vegetables and tea was 1.84×10⁷ t (N=1.12×10⁷ t; P₂O₅=7.18×10⁶ t), twice the theoretical demands. Meanwhile, animal manure contained 7.98×10⁶ t of N and 6.42×10⁶ t of P₂O₅, an amount which could replace 78% of chemical fertilizers and reduce nutrient losses by 2.88×10⁶~5.18×10⁶ t. We calculated that 71% of the Chinese provinces could replace 50% of presently used chemical fertilizers with animal manure; the percentage of provinces increases up to 90% considering a chemical fertilizer replacement of 20%. Excluding the Shanghai, Jiangsu, Zhejiang, Fujian, Guangdong, Shandong, and Shaanxi provinces, all other Chinese provinces could replace 100% of the chemical fertilizers presently used for their fruit, vegetable and tea production, with animal manure. Furthermore, animal manure exceeded the demands in the northeastern and northwestern regions; hence, these areas could answer the nutrient demands of local plantations, as well as those of other regions. This study provides new scientific bases for policy decisions, encouraging a sensible reduction in the use of chemical fertilizers in China.