贵州岩溶山区绵羊宿营法改良天然草地综合效果的研究Ⅲ改良草地的技术、生态、经济效果研究

Studies of Integrated Effects on Native Pasture Improvement by Sheep Night penning in Guizhou karst Region Ⅲ The Technical Ecological and Economical Benefits of the Improved Pasture

绵羊宿营法(A_2B_1C_8处理)改良后的草地,在不施维持肥的情况下,其第三年牧草干物质产量达11415kg/(hm^2·年),而作为对照区的用常规法建植的人工草地,在施用维持肥的条件下,其第三年牧草干物质产量仅为8628kg/(hm^2·年),P<0.01。前者草地植物组分中豆科牧草所占比例达7%～20%左右,优良牧草所占比例约达100%,后者分别达到7%～20%和88%～98%左右。研究结果表明,绵羊宿营法改良后的草地,在控制水土流失方面,其效果相当于或好于高产人工草地和保护完好的天然草地。在日降雨量为5～10mm和30～40mm水平下,坡度为15°±1°时,其地面迳流量损失仅相当于农田的45%左右,土壤冲刷损失量仅相当于农田的1%左右。经济分析表明,当地条件下,绵羊宿营法改良草地的建植成本相当于常规法的31%,由于前三年可全部免去常规法所需投入的草地维持费用,所以其总成本(包括放牧地化肥补偿费)相当于常规法的20%。

The production, the percentage of legume and the good herbage in the pasture improved by A_2B_1C_8treatments respectively reached about 11415kg DM/hm^2/Yr, 7%～20% and 100% in the third year under the condition of without maintenance fertilizer. But for the pasture improved by conventional method, those were respectively about 8628kg DM/hm^2/Yr, 7%～20% and 88%～98% in the same time under the condition of using maintenance fertilizer. The pasture improved by SNP almost had the same effects as sown pasture of high productivity and good native pasture in controlling rearer losses and soil erosion. Under the condition of 5～10 or 30～40mm rainfall/day and the slope of about 15 degree, the water losses and soil erosion of ground surface for pasture improved by SNP were just 45% and 1% of those of crop field. The results also indicated that the costs of pasture improvement by SNP were just about 31% of that of conventional pasture establishment, and because of not using maintenance fertilizer in the first three years, the actual total costs for the former were only 20% of later.