甘肃省天水市畜禽粪肥资源现状及替代化肥潜力研究

综合考虑农作物种植结构、种植面积及畜禽粪污处理方式等因素,估算了天水市各县区粪污养分资源现状及其替代化肥的潜力。结果表明,天水市畜禽粪污中氮、磷养分分别为22 565.01t和3 384.75t,且各县区畜禽粪污氮和磷供给量均未超过作物需求量;当前天水市大部分养殖场固体粪污储藏堆放还田,液体粪污直接还田,在这种粪污处理方式下,氮、磷的有效供给量分别占作物氮、磷需求量的10.49%和6.72%,表明天水市有足够的耕地消纳畜禽粪污;研究还发现:在固体粪污加工为商品有机肥,液体粪污沼气处理的方式下,粪肥养分损失率最低;各县区氮养分的替代率高于磷养分替代率;我市粪肥替代化肥潜力较大,应提高粪污资源化利用水平。研究结果可为天水市畜禽粪污资源化利用和确定养殖业发展规模提供理论依据。

Nutrient resources in livestock manure and its potential of substituting fertilizers in Tianshui

Based on comprehensive consideration of factors like planting structure, planting area and technology of livestock manure disposal, we assessed the status of nutrient resources in livestock manure and their potential of substituting chemical fertilizer in Tianshui. Results show that the manure excreted by the livestock in the city contained a total of 22565.01 t of N and 3384.75 t of P, which did not meet the demand of the crops in each county and district for N and P. Presently, solid manure are stored and returned to field, liquid manure are discharged directly in many livestock farm in Tianshui, so under such method for livestock manure disposal, available N and P meet the demand of the crop by 10.49 and 6.72%, respectively. The findings indicate that Tianshui has enough agricultural land to digest the livestock manure; And the research found: the method for livestock manure disposal that solid manure are produced into commercial organic fertilizer and liquid manure are utilized to produce biogas can reduce the loss of nutrients in manure maximally; nitrogen rate of substitution is higher than phosphorus rate of substitution in each county and district; the potential of livestock manure substituting chemical fertilizer is higher in Tianshui, so the level of Resource Utilization should be improved. The results may provide a theoretical basis for utilizing livestock manure and make plans for developing scale of livestock raising in Tianshui.