基于三阶段SBM-Malmquist指数的粮食生产用水绿色效率研究——以宁夏为例

STUDY ON GREEN EFFICIENCY OF WATER USE FOR GRAIN PRODUCTION BASED ON THREE-STAGE SBM-MAIMQUIST INDEX——A CASE STUDY OF NINGXIA

关键词:  三阶段SBM-Malmquist  非期望产出  水足迹  灰水足迹  绿色效率

Key words:  three-stage SBM Malmquist  unexpected output  water footprint  grey water footprint  green efficiency

摘要:

目的 农业可持续发展离不开粮食生产用水效率，探明宁夏区域内粮食生产用水特征有助于提高该地区农水利用效率，实现农业绿色发展。方法 文章以粮食水足迹作为投入指标，粮食灰水足迹作为非期望产出指标，采用三阶段超效率SBM-Malmquist模型，对2006—2020年宁夏18个县区粮食生产用水绿色效率进行了测算。结果 （1）受粮食产量、播种面积以及种植结构的影响，宁夏粮食生产水足迹、灰水足迹地域分异明显，由北向南依次减少；（2）不同粮食品种灰水足迹不同，玉米的灰水足迹最多，造成的污染最严重，主要原因在于玉米播种面积较广，单位面积施氮量大于小麦和水稻；（3）剔除环境因素后发现，环境变量会夸大综合技术效率，导致不同地区粮食生产用水绿色效率不同。结论 研究发现：宁夏粮食生产用水绿色效率高于平均值的地区，如银川、永宁县、贺兰县等，主要受技术效率的影响；而低于平均值的地区，如平罗县、同心县、泾源县，受技术效率影响的同时也受到技术进步的影响。为此，宁夏农业生产用水管理要因地制宜，分区施策，在加大技术创新投入的同时，重点关注单位面积氮肥施用量；继续推进节水型农业，实现粮食生产用水绿色效率的稳步提升。

Abstract:

The sustainable development of agriculture is inseparable from the water use efficiency of grain production. Proving the characteristics of water use in grain production in Ningxia will help to improve the efficiency of agricultural water use in the region and realize the green development of agriculture. Taking water footprint of grain as input index and grey water footprint of grain as undesirable output index, the green efficiency of water for grain production in 18 counties of Ningxia from 2006 to 2020 was calculated by using three-stage super-efficiency SBM-Malmquist model. The results were indicated as follows. (1) Affected by grain yield, sown area and planting structure, the regional differentiation of water footprint and grey water footprint of grain production in Ningxia was obvious, decreasing from north to south ; (2) The gray water footprint of different grain varieties was different, the gray water footprint of maize was the most, and the pollution was the most serious, the main reason was that the sown area of maize was wide, and the nitrogen application per unit area was more than that of wheat and rice. (3) After removing environmental factors, it was found that environmental variables would exaggerate the comprehensive technical efficiency, resulting in different green efficiency of water for grain production in different regions. In summary, Ningxia grain production water green efficiency was higher than the average area, such as Yinchuan, Yongning county, Helan county, mainly affected by technical efficiency ; the areas below the average, such as Pingluo county, Tongxin county, Jingyuan county, were affected by technical efficiency and technological progress. Therefore, the management of agricultural production water in Ningxia should be adapted to local conditions and implemented in different regions. While increasing the investment in technological innovation, the application amount of nitrogen fertilizer per unit area should be focused on, and promoting water-saving agriculture should be continued, so as to achieve a steady improvement in the green efficiency of water for grain production.