京郊山地旱作区农田生产力可持续性分析与对策——以延庆县为例

Evaluation of sustainability of farmland productivity in mountainous arid area in the suburb of Beijing

选择延庆县作为研究对象,从生产力、稳定性、资源利用和经济可行性等方面对京郊山地旱作区农田生产力持续性进行了综合分析。结果表明:随着生产要素投入增加和生产条件改善,该地区粮食、油料作物单产持续增长,生产稳定性得到了提高;从资源利用角度来看,农田土壤中有机质和N含量增加,但P、K含量出现下降,春作物生育期降水基本满足作物生长需要,局部地区地下水资源出现超采,水资源供需矛盾加剧;从经济可行性角度来看,各作物单位面积净产值以蔬菜为最高,其次是饲料作物,春玉米最低。总体认为该区域农田生产力持续性呈良好态势。最后,针对区域农田生产力持续性的限制因素提出了具体对策,包括加强土地沙化和水土流失治理,合理保护农田生态环境;调整种植结构,大力发展特色种植业;推广农业污染减控技术,降低农田生态环境负荷;发展现代节水农业,合理利用和保护地下水资源。

Based on a systematic analysis of productivity, stability, resource utilization and economic viability, the sustainability of farmland productivity in mountainous arid area was evaluated through a case study in Yanqing County, Beijing. The result showed that farmland productivity and stability in this region was increasing. Organic matter and N content in the soil increased, heavy metal pollution was not above restriction value, but the content of P and K decreased. Rainfall could almost meet the water requirement of crop, groundwater was overexploited in some extent, but will not exhaust in the near future. In the aspect of economical viability, though the crop economic efficiency was relatively low, present growing model will continue in this region. It was concluded that sustainability of farmland productivity in this region is in a good state. Lastly, strategies on the sustainability of farmland productivity were raised against the problems. These strategies include land desertification and soil erosion control, crop structure adjustment, application of controlling non - point pollution technology, developing modem water- saving agriculture and controlling groundwater overuse.