京郊畜禽粪肥资源现状及其替代化肥潜力分析

    Analysis of nutrient resources in livestock manure excretion and its potential of fertilizers substitution in Beijing suburbs

    • 摘要: 随着都市型规模化养殖业快速发展,畜禽粪尿废物大量排放因缺乏足够面积土地消纳所带来的环境压力很大,而粪尿中的氮磷钾养分与化肥一样对作物同等重要,如何合理利用这些废物资源决定了都市化农业的可持续发展。该文针对京郊养殖业和农用地面积现状,结合调研、收集畜禽养分排泄系数和农田养分需求等参数,估算京郊固液粪便养分资源现状及其替代化肥的潜力。结果表明:京郊畜禽固液粪便中N、P、K养分量分别为58.7×103、21.3×103、29.8×103 t,其中固体粪便N、P、K养分分别为43.1×103、20.3×103和19.7×103 t,京郊畜禽固液粪便可分别满足农田N、P、K养分需求量的99.3%、185.2%、62.7%。大部分区县粪肥中P养分产生量超过作物P需求量,粮田秸秆还田可带入的N、P、K养分分别为11.0×103、1.6×103和15.0×103 t,情景分析表明在秸秆还田条件下,按照磷素平衡原则估算本地区所能消纳的粪肥所带入N、P和K养分数量分别为18.3×103、9.9×103和10.3×103 t,同时需要补充N、K化肥分别为29.8×103和22.2×103 t,其余粪肥则需经过堆肥化处理并输往外地。经过堆肥处理,固体粪肥可提供的N、P、K养分分别下降了23%、11%和12%,外输固体粪肥堆肥可进一步减少农田氮磷负荷以及可能的环境风险。

       

      Abstract: Abstract: With the rapid development of urban intensive livestock farms, large amounts of organic waste (feces and urine) discharge obviously led to high environmental pressure in the peri-urban regions with inadequate arable land. However, the N, P, K nutrients in feces and urine could equally contribute to increase crop production as chemical fertilizer. Therefore, sustainable development of urban agriculture is closely dependent on how to recycle these organic wastes as nutrient resources. In this study, considering the current status of livestock farming and arable land area in Beijing suburbs, the current situation of organic waste resources in livestock farming and its substituting potential for chemical fertilizer in Beijing were estimated through livestock farm surveys, the collection of livestock excretion coefficients and crop nutrients demand through literature and related Beijing statistical data. The results indicated that the total amount of N, P, K contained in solid manure and liquid manure production was 58.7×103 t N, 21.3×103 t P, 29.8×103 t K, which included 43.1×103 t N, 20.3×103 t P and 19.7×103 t K in solid manure, respectively. The total amount of N, P, K contained in solid manure and liquid manure could be satisfied with 99.3%, 185.2% and 62.7% of the total crop requirement of N, P, K in Beijing in 2011, especially since the amount of generated manure P has exceeded total crop P requirement in most districts of Beijing. Moreover, cereal crop residue returned to soil could bring equivalent to 11.0×103 t N, 1.6×103 t P, and 15.0×103 t K to arable land. In the scenario analysis, the allowable amount of N, P, K nutrients in livestock manure to be applied to arable land were only 18.3×103 t N, 9.9×103 t P, and 10.3×103 t K, respectively, based on the P balance method, if considering cereal crop residue incorporation. Additional 29.8×103 t N and 22.2×103 t K were needed to be supplied with chemical fertilizers to meet crop nutrient demand. P surplus sourced from organic waste obligated the solid manure to be composted and transported to the neighbor regions with inadequate P supply. Total N, P, K nutrients contained in composted solid manure decreased by 23%, 11% and 12% after aerobic composting, and the transportation of commercial composted solid manure exported out of Beijing will further reduce N and P loads in arable land and consequently reduce the risk of environmental pollution.

       

    /

    返回文章
    返回