Hilly and mountainous areas are weak places for the development of agricultural mechanization in China. The way to improve the utilization rate of small agricultural machinery widely used in hilly and mountainous areas is of positive significance for optimizing resource allocation efficiency of agricultural production and ensuring food security supply. Taking microtillers as a representative tool, this study systematically analyzed the main factors affecting the utilization rate of small agricultural machines and its influencing mechanism. Then, based on the survey data of 4905 farmers in 100 counties in 10 hilly and mountainous provinces of China, empirical analysis was carried out by some econometric models, such as censored regression and the mediating effect model. Results show the following.: (1) Among farmers in hilly and mountainous areas, the average use time of each microtiller is 218.41 h per year. (2) Age, social identity, terrain conditions, crop types, land area, the number of microtillers, the number of large tractors, and the machinery purchase subsidy policy are the significant factors affecting the utilization rate of microtillers. (3) The increase of cultivated land area not only directly improves the utilization rate of microtillers, but also indirectly improves the utilization rate of microtillers due to the increase in quantity.

Cotton, as an important cash crop and strategic material, is widely planted in Xinjiang, China. In the traditional way, the management of the cotton field is extensive and the cost is huge. This paper analyzed the economic benefits and the related influence factors of cotton field management digitalization by collecting costs from 2020 of four major tasks in field management in Xinjiang, China. These four main tasks included field scouting, plant protection, topping and irrigation. By analyzing the intersection of the average cost curves of each major task in field management, we obtained the critical size of digital agriculture replacing traditional agriculture. Then, we used sensitivity analysis to find the main factors affecting the promotion and application of digital agricultural equipment. The results show: (1) at a certain critical size, the use of digital agricultural equipment can reduce the cost of production compared to traditional agriculture. However, the critical size varies for different management segments. (2) Fixed equipment costs, labor costs, water costs and energy costs have a large impact on the critical size. On large-scale cotton farms, digital agriculture tends to be more economical than traditional agriculture. In the future, as the cost of fixed equipment decreases, and labor costs and water costs rise, the critical size of digital agriculture replacing traditional agriculture will get smaller, and the scope of the economic benefits of digital cotton field management will increase further.

Agricultural machinery maintenance skill training is conducive to improving the fault diagnosis and maintenance levels of agricultural machinery for agricultural socialized service providers and plays an important role in providing stable and reliable agricultural machinery operation services. This paper aims to study whether maintenance skill training gives agricultural socialized service providers more advantages than untrained providers, exploring the relationship between maintenance skill training and agricultural machinery service area. Based on a survey of 4905 farmers from 10 provinces in China, an empirical analysis was carried out using a fixed effect model and a propensity score matching method. The results showed the following: First, maintenance skill training had a significant positive impact on agricultural machinery operation service area, including 10.426 ha of machinery tilling service area and 8.524 ha of machinery harvesting service area. Second, since maintenance skill training gave agricultural socialized service providers more advantages in agricultural machinery operation services and enabled them to obtain more orders, it had an indirect positive impact on the quantity of demand for large- and middle-sized agricultural machinery.

The CLP Publishing collects CLP journals and partnered optics and photonics journals, and provides readers an optical publishing platform with global influence. SPIE, OSA, CUP. Chinese Laser Press (CLP), established by Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS) and Chinese Optical Society (COS) in 2009, nowadays publishes eight journals and manages three online platforms.

【目的】在中国丘陵山区非粮化趋势加剧的背景下，探究耕地宜机化对中国丘陵山区非粮化缓解的影响机制并实证测度其具体影响程度，这对于保障国内粮食安全具有重要的现实意义。【方法】本文构建基于利润最大化约束的农户生产决策模型并进行机理推导，同时采用双栏模型等实证方法，运用2020年5—7月农业农村部农业机械化管理司组织的全国丘陵山区农业机械化调查数据，从地块规模、耕地平整度以及机耕道通达度3个具体指标来度量耕地宜机化程度，实证测度耕地宜机化对中国丘陵山区非粮化的缓解效应。【结果】①在劳动力成本快速上升、粮食作物机械化技术成熟而非粮作物机械化技术发展滞后的背景下，耕地宜机化程度的提升可以有效降低农户的非粮化程度。②耕地宜机化程度的提升降低非粮化程度的传导路径是：耕地宜机化程度提升降低了农机要素价格，农户选择提升农业综合机械化水平，用价格更低的农机要素来替代劳动力，在非粮作物机械化技术尚不成熟的现实背景下，农户更倾向于选择种植粮食作物，进而降低了非粮化程度。③耕地宜机化对非粮化的影响存在规模异质性，即相比小农户，耕地宜机化程度对种植大户的非粮化程度影响更为显著。【结论】整体看，耕地宜机化有效降低了粮食生产的农机使用成本，促进了粮食生产的劳动力替代和降本，有助于缓解中国丘陵山区非粮化问题，进而保障粮食安全。