武穴市秸秆和畜禽粪污还田化肥减量潜力及土地承载力分析

Analysis of chemical fertilizer reduction potential of straw and livestock manure returning to field and soil carrying capacity in Wuxue city

武穴市是湖北省种植和养殖大市,估算其农作物秸秆、畜禽粪污资源,评估其土地承载力,探讨绿色种养的节约化肥潜力对实现武穴市农业绿色发展具有重要意义。基于统计数据,估算了武穴市主要农作物秸秆、畜禽粪污养分资源量及其化肥替减的潜力,并评估了当前土地承载力及土地承载力指数。结果表明,2020年武穴市产生主要农作物秸秆资源53.19万t,畜禽养殖95.33万头猪当量。秸秆和畜禽粪污养分资源理论可还田量(折纯)分别为1.19万、0.82万t,分别可替代武穴市当年化肥消费量的27.4%和18.9%,理论可实现化肥节约成本分别为6192.76万和4077.36万元,共计10270.12万元。2020年武穴市畜禽粪污氮、磷土地承载力指数分别为0.80、0.48,目前畜禽养殖量没有超过武穴市土地承载力,但已接近氮承载力的上限。

Wuxue is a large planting and breeding city in Hubei province.For fulfilling the green development of agriculture in Wuxue city,it is of great significance to estimate the crop straw and livestock manure resources,evaluate the land carrying capacity and discuss the potential of saving fertilizer by green planting and breeding.Based on the statistical data,this paper estimated the nutrient resources of crop straw and livestock manure,and its potential of fertilizer replacement in Wuxue city.Current land carrying capacity and land carrying capacity index were also evaluated.The results showed that the straw yield of main crops in Wuxue city was 531900 tons in 2020,and the livestock and poultry breeding were 953300 pig equivalents.Theoretical recoverable amount of straw and livestock manure nutrient resources were 11900 and 8200 t in Wuxue city,respectively,which could reduce 27.4%and 18.9%of chemical fertilizer consumption,respectively.The theoretical cost savings of chemical fertilizer were 61.93 million yuan and 40.77 million yuan,with a total of 102.70 million yuan.In 2020,the soil carrying capacity indexes of nitrogen and phosphorus from livestock manure in Wuxue were 0.80 and 0.48,respectively.At present,the livestock and poultry production have not exceeded the land carrying capacity of Wuxue.However,the livestock and poultry production were close to the upper limit of nitrogen carrying capacity.