草基-鱼塘生态系统的能量转化与养分循环研究

应用模拟试验的方法,研究了“草基-鱼塘”系统中的能量转化与养分循环.结果表明,该系统中饲草对太阳能的利用率为0.83%,鱼对饲料能的转化率为7.3%.与以粮食作为鱼饲料比较,单位面积草地的产鱼当量是粮食作物的1.6倍.鱼对饲料N、P、K的转化率分别为16.8%、32.3%和2.0%.塘泥沉积的N、P分别占饲料的23.4%和56.1%;猪对饲料N、P、K的转化率分别为20.5%、33.7%和4.6%,猪粪尿回收饲料N为36.4%、P为63.8%、K为39.4%.猪-草-鱼结合的基塘系统其能量和养分转化效率均高于单一的养鱼系统.

Energy conversion and nutrient cycling in grassdyke-fish pond ecosystem

The simulation study on the energy conversion and nutrient cycling in the grndyke-fish pond ecosystem shows that for this ecosystem, the photo-utilization rate of forage is 0.83%, and the conversion efficiency of feed energy into fish is 7.3%. Comparing with grain for fish farming, the efficiency of forage is 1.6 times greater. The conversion efficiency of feed nutrients (CEFN) to fish is 16.8, 32.3 and 2.0% respectively for N, Pand K. The recovery of nutrients in fishpond sediment is 23.4% for Nand 56. 1% for P, and the CEFNto hog carcass is 20.5, 33.6 and 4.6%, respectively for N, P and K. The recovery of nutrients in the feces is 36.4% for N, 63.8% for P and 39.4% for K. The conversion efficiency of fed energy and nutrients to fish is higher in compound system than in single one.