基于耕地消纳的畜禽粪便环境承载力分析——以安康市为例

ANALYSIS ON THE ENVIRONMENTAL BEARING CAPACITY OF LIVESTOCK AND POULTRY BREEDING BASED ON LAND CONSUMPTIVE——A CASE OF ANKANG CITY

关键词:  耕地消纳 畜禽粪便 安康市 环境承载力 预警分析

Key words:  land consumption  livestock manure  Ankang city  environmental carrying capacity  early warning analysis

摘要:

［目的］选取陕西省安康市作为实例进行研究。［方法］通过文献调研与相关数据资料收集，理论上量化、分析该区域的畜禽粪便环境承载力，现实中可为优化畜禽养殖结构，推动养殖业绿色发展提供参考。依据我国有关畜禽粪污排泄的标准，运用排污系数法对安康市2014年10个区县的畜禽粪便产生量、主要污染物的产生量与流失量进行核算。科学假设区域内产生的畜禽粪便都通过当年有效耕地方式消纳，并将不同畜种产生的畜禽粪便量统一换算为猪粪当量，计算出单位耕地面积猪粪当量负荷及警报值，在此基础上，参照相关标准得到安康市各区县所对应的预警级别。［结果］ 2014年安康市畜禽粪便总产生量为647.79万t，其中牛粪产生量最大，产生量最少的是家禽粪； 主要污染物中，COD的产生量与流失量都最大且成正比关系； 所有区县中，畜禽粪便污染物产生量最多的县为旬阳县。同时，安康市2014年畜禽粪便单位耕地面积猪粪当量负荷均值是30.4957，单位耕地面积猪粪当量负荷警报均值为0.76，总体警报值级别为Ⅲ级，表明在该区现阶段产生的畜禽粪便已对安康市整体环境有了一定影响。不同区县之间的单位面积耕地畜禽粪便猪粪当量负荷有所差异，全市警报值已经达到Ⅱ级的区县有5个，分别是汉滨区、紫阳县、岚皋县、平利县和白河县，对环境稍有影响； 汉阴县、宁陕县和镇坪县警报值达到了Ⅲ级，对环境已有定影响； 石泉县和旬阳县警报值最大，为Ⅳ级，对环境造成较严重威胁。［结论］针对安康市畜禽粪便对环境所产生的不同级别的威胁与压力，笔者最后提出可行地提高畜禽养殖环境承载力的建议，可能为畜禽养殖区域发展战略提供科学依据。

Abstract:

Taking Ankang city of Shaanxi province as an example, this paper used the method of the excretion coefficient of livestock and poultry to calculate the production and loss of main pollutants in 10 districts and counties of Ankang city in 2014, and then established the corresponding warning levels for different counties based on the per unit cultivated area of pig manure equivalent load and warning value. The results showed that the total production of livestock and poultry manure at Ankang city in 2014 was 6 477 thousand t, of which the cow dung was the largest and the poultry manure was the least. The largest production and loss of pollutants was COD. The largest pollutants production was in Xunyang county. In the year 2014, the livestock manure per cultivated area of pig manure equivalent load was 30.495 7 with the warning level 0.76, the overall alarm value was grade III, which showed that the livestock and poultry dung had a certain effect on the overall environment of health in the region. The livestock and poultry manure equivalent loads in different districts were different.The alarm value had reached level II in 5 counties, i.e., Hanbin, Ziyang, Langao, Pingli and Baihe, which had a little effect on the environment; The warning value in Hanyin, Ningshan and Zhenping had reached III and had influence on the environment, which in Shiquan and Xunyang reached a maximum of IV, causing a serious threat to the environment. Finally, according to the different levels of the health threat and pressure of livestock produced on the environment, it put forward some feasible suggestions to improve livestock carrying capacity, so as to provide scientific basis for the regional development strategy of livestock and poultry breeding.