稻区农牧沼复合生态模式能流特征分析

ANALYSIS ON THE CHARACTERISTICS OF ENERGY-FLOW OF FARMING-STOCKBREEDING-BIOGAS COMPLEX ECOLOGICAL PATTERN IN RICE AREAS

对“紫云英－猪－沼肥－水稻”复合生态模式能流特征进行了分析。试验结果证明：作物种植是该系统主导产业，水稻光能利用率为２．７０％。紫云英较大幅度提高了系统的光合效率。家畜养殖亚系统饲料转化率高，转化为肉能比例较大。紫云英青贮用作饲料在饲料能投中占有重要地位。沼气生产亚系统能量产投比为０．９１，产出能中以沼肥含能为主。紫云英、沼肥和稻草归还农田可大大节约化肥能投，有机能投为主要人工辅助能投，有机肥料为肥料主要能投。整个系统有机能输入输出比为３．１８。说明农牧沼复合生态系统是一个良性循环系统，具有能投少，能量转换率高，养分利用率高，高功能。

The characteristics of energy-flow of Milk Vetch ( Astragalus sinticus L.) pig biogas fertilizer rice complex ecological pattern were analyzed. The results showed that growing crops was the leading industry in the pattern, the photo-utilization efficiency of rice was 2.7%, and the Milk Vetch raised the photo-synthetic efficiency of the system by a big margin. The feed efficiency in the subsystem of livestock breeding and the ratio of coverting the feed to pork energy were high. The ensilaged Milk Vetch used as feed played an important role in feed energy input. The ratio of energy output to input in the subsystem of biogas generation was 0.91, and the energy of biogas fertilizer was the main energy output. Returning Milk Vetch-biogas fertilizer-the straw to field could greatly save the energy input of chemical fertilizers, because the organic energy input was the main input of auxiliary energy and the organic fertilizer was the main energy input of fertilizers. The ratio of organic energy input to output in the whole system was 3.18. Therefore, the farming stockbreeding biogas complex ecosystem was a beneficent cycle system with characteristics of low energy input, high energy conversion ratio and nutrient utilization ratio, high funtion and high efficiency.