中国小麦绿色全要素生产率时空特征及影响因素

Spatiotemporal characteristics and influencing factors of the green total factor productivity of wheat in China

小麦生产向绿色化转型是保障中国粮食安全以及小麦产业可持续高质量发展的必然要求,该研究以面源污染和碳排放量作为非期望产出,使用超效率SBM-ML模型测算了2004—2019年15个省份的小麦绿色全要素生产率,并使用Tobit模型在经济水平、财政投资、资源禀赋、生产条件等4个方面,对小麦绿色全要素生产率的影响因素进行了实证分析。结果表明,在时间变化上,小麦绿色全要素生产率在2004—2019年间整体处于下降态势,说明小麦产量提高的同时确实付出了环境破坏的代价,技术“退步”是导致这一现象的主要原因。在综合考虑现有播种面积和面积变化趋势的情况下,将样本省份分为三类产区,其中第二产区(山西、内蒙、湖北等省份)绿色生产效率最高、第三产区(黑龙江、云南、宁夏等省份)次之、第一产区(河北、江苏、安徽等省份)最低,考虑到第一产区依旧是未来小麦供给的主要区域,应该尽可能在保障产量的同时,加快推进第一产区小麦绿色生产转型。在影响因素方面,小麦总播种面积和人均小麦播种面积对绿色全要素生产率的影响最为显著,说明可以继续推进小麦播种面积向第一产区集中,但是对于规模种植户要加大绿色技术培训,农村固定投资和小麦最低收购价对于小麦绿色全要素生产率均有负面影响,原因在于这二者的目的在于经济产出和产量提升,对于环境保护缺乏关注。另外,技术进步对各项影响因素的响应积极性要明显高于技术效率,这说明相较于技术研发,中国小麦产业体系在新技术推广等方面存在更大短板。应当完善中国小麦产业支持保护政策,在产量充足的情况下,尽可能考虑环境保护的现实需求。适当扩大休耕补贴覆盖范围,缓解第一产区生态压力。在进行新技术研发的同时,要更加侧重于对绿色生产技术的推广宣传作用,提升农户对绿色生产的认知和技术熟练度。研究结果为准确把握当下小麦绿色生产现状以及未来小麦绿色化转型的政策制定提供一定参考。

Green transformation can be an inevitable requirement to ensure food security in China, particularly for the sustainable development and high quality of wheat production in recent years. Green Total Factor Productivity(GTFP) has been one of the most important indicators to measure economic and environmental efficiency. It is necessary to accurately evaluate the wheat production for the decision-making on the green transformation. Taking the 15 Provinces in China as the research objects, this study aims to investigate the spatiotemporal characteristics and influencing factors of wheat GTFP from 2004 to 2019 using the Slack-Based Measure(SBM) model with the Malmquist-Luenberger(ML) index. Among them, the non-desired outputs were set as the carbon emissions and the surface source pollution by chemical fertilizers and pesticides. A Panel Tobit model was also selected to empirically analyze the influencing factors of wheat GTFP in four aspects, including economic level, financial investment, resource endowment, and production conditions. The robustness of the model was then tested to add the control variables. The results show that there was an overall declining trend in the wheat GTFP from 2004 to 2019, indicating that the wheat production increased at the expense of environmental damage, due mainly to the technological regression. The 15 Provinces were classified into three categories in the spatial dimension, according to the wheat sown area and trends. The inter-regional comparisons demonstrated that the second production region(Shanxi, Inner Mongolia, Hubei and other provinces) was the most efficient level, the third region(Heilongjiang, Yunnan, Ningxia and other provinces) was the second, and the first region(Hebei, Jiangsu, Anhui and other provinces) was the least. The reason was that the third region was better served as the smallest sown area in wheat production, whereas, and the first region as the main wheat production area presented a higher yield with less consideration for ecological protection. Therefore, it was necessary to accelerate the wheat green production transition in the first region, which still remained the main production region of future wheat supply. In terms of influencing factors, the total wheat sown area and wheat sown area per capita posed the most significant impact on the GTFP, indicating that the wheat sown area was still concentrated in the first production area. However, green technology training increased for large-scale growers in recent years. The rural fixed investment and the minimum purchase price of wheat presented a negative impact on the GTFP, due to the improved yield and economic output with less concern for environmental protection. In addition, the technological progress was significantly more positive than the technological efficiency in response to all influencing factors, indicating a greater lacking of the new technologies promotion in the wheat industry system,compared with new technological research. Therefore, it was a high demand for the decision-making on the wheat industry support and protection in the practical needs of environmental protection under the sufficient yield. The coverage of fallow subsidies should be appropriately expanded to relieve the ecological pressure area in the first production. The promotion of new technologies can greatly contribute to enhancing technical proficiency in green production. The finding can provide a strong reference for the green transformation of wheat production.