保护性耕作技术对粮食生产效率和环境效率的提升效应

Effects of conservation tillage technology on improving grain production and environmental efficiency

保护性耕作是实现耕地可持续利用的重要途径,也是加快落实“藏粮于地、藏粮于技”战略的关键举措,其产生的经济效应日益受到社会各界的广泛关注。该研究基于覆盖粮食主产区的2127份粮食种植户的微观调查数据,借助随机前沿分析方法测度粮食生产效率和环境效率,并采用Tobit模型和倾向得分匹配法实证检验采纳保护性耕作技术的效率提升效应。研究结果显示:①对于粮食生产而言,采纳保护性耕作技术具有“既增效,又减排”的经济效应,该结论在排除潜在的内生性问题及经过一系列稳健性检验后依然成立。②分规模来看,小规模农户采纳保护性耕作技术“只增效,不减排”;中规模农户采纳保护性耕作技术“只减排,不增效”,而大规模农户采纳保护性耕作技术“既增效,又减排”。③分生产效率来看,高生产效率农户采纳保护性耕作技术“既增效,又减排”;中等及以下生产效率农户采纳保护性耕作技术的“增效”与“减排”效应均未得到验证。④分技术组合来看,保护性耕作技术组合采纳侧重于“增效”。相较于未采纳保护性耕作技术而言,采纳秸秆还田+深耕松土、秸秆还田+免耕直播、深耕松土+免耕直播+秸秆还田等技术组合显著地提升了粮食生产效率,未对环境效率发挥出应有的积极效果。基于实证研究认为,一方面应高度重视保护性耕作技术的大众化应用,引导和扶持农户主动自觉地采纳保护性耕作技术,有效发挥采纳保护性耕作技术的经济效应;另一方面要结合不同类型农户的资源禀赋与生产实际需求,选择性地制定保护性耕作技术推广方案。

Conservation tillage is an important way to ensure the sustainable utilization of cultivated land and a key measure to speed up the implementation of a food crop production strategy based on farmland management and technological application.Its economic effects have attracted more and more attention from all walks of life.Based on the micro-survey data from 2127 grain growers in the main grain-producing areas,this paper applied the stochastic frontier production model to estimate the grain production efficiency of adopters and non-adopters.The Tobit model and propensity score matching method were implemented to examine the impact of the adoption of conservation tillage technology on grain production and environmental efficiency.The main results showed that:①The adoption of conservation tillage technology had the effect of‘increasing efficiency and reducing emissions’in grain production,and the conclusion was still valid after alleviating possible endogenous problems and a series of robustness tests.②In terms of scale,small-scale farmers adopted conservation tillage technology‘only to increase efficiency,not to reduce emissions,’medium-scale farmers adopted the technology‘only to reduce emissions,not to increase efficiency,’and large-scale farmers adopted the technology‘to increase efficiency and reduce emissions.’③In terms of production efficiency,the adoption of conservation tillage technology by farmers with high production efficiency‘not only increased efficiency but also reduced emissions.’The effects of‘increasing efficiency’and‘reducing emissions’adopted by farmers with medium or lower production efficiency were not verified.④In terms of technology combination,adopting conservation tillage technology in combination focused on improving efficiency.The adoption of the combination of‘straw returning to field+subsoiling,’‘straw returning to field+no-tillage direct seeding,’and‘subsoiling+no-tillage direct seeding+straw returning to field’significantly improved grain production efficiency but did not play its due positive role in environmental efficiency compared to non-adopters.Based on the conclusion of the empirical research,we should attach great importance to the popular application of conservation tillage technology and guide and support farmers to actively and consciously adopt this technology.On the other hand,it is necessary to combine the resource endowment and actual production demand of different types of farmers and selectively formulate the popularization scheme of conservation tillage technology.