زمین مناسب برای کاشت ذرت: یک مطالعه تجربی در زمینه بهره وری استفاده از زمین در چین Does land perform well for corn planting? An empirical study on land use efficiency in China

1. Introduction China’s future agricultural development will pay increasing attention to food nutrition, food safety, efficiency, and effectiveness, according to the 13th Five Year Plan (Long et al., 2016; Long, 2014a; Brødsgaard, 2016; Jin et al., 2016). This period is critical for transformation and reconstruction of China’s agricultural development, and sustainable use of the land resource and ensuring food safety will be keys to development. Corn planting has played an important role in China’s food system because the area planted and output of corn increased dramatically since 1940s, which makes corn surpassed rice to become the largest single crop produced in China (Gale et al., 2014). Estimating the productivity and technical efficiency (TE) of agricultural corn planting by regarding land performance as a primary input will consequently play an essential role in China’s agricultural transformation and development. Area of cultivated land is indisputably a necessary input for assessing agricultural production efficiency. Although it is frequently reported that there is inverse relationship between farm size and yield per unit (Feder, 1985), agricultural productivity and efficiency analysis regarding farm size continues (Carter, 1984; Feder, 1985; Jayne et al., 2016; Mellor and Malik, 2016; Sheng et al., 2016). Almost all the literature to date focuses on the effect of farm size on general grain production or agricultural production, while there is a lack of research examining the relationship between corn planting efficiency and farm size for China’s corn farmers from an economic perspective. In this paper, we analyze the TE and productivity of different farm sizes: small (individual households), medium-sized (family farms), and large (major cooperatives). Apart from farm size, land quality should be considered when planning to increase agricultural technical efficiency and agricultural productivity. Many studies have used the area of cultivated land (i.e., farm size) available to a household as one of the primary inputs (Battese, 1992; Lansink et al., 2002; Pascual, 2005; Brümmer et al., 2006; Chen et al., 2009; Zhang and Brümmer, 2011; Asante et al., 2014). However, it is important (although difficult) to incorporate the heterogeneity of land quality as influenced by soil nutrients, soil type, or soil conservation when evaluating land performance in corn planting (Latruffe et al., 2005; Hoang and Alauddin, 2012; Marchand and Guo, 2012; Rao et al., 2012). Without taking into account land quality for each individual agricultural production unit, the TE for corn planting cannot be properly compared across regions because the variation in land quality is significant. Besides farm size and land quality, some other elements also affect the technical efficiency of agricultural production. For example, Bayacag and Rola (2016) examined whether slope affected soil quality and thus had an influence on agricultural production, while Watkins et al. (2014) investigated whether an area with flat terrain needed less inputs for agricultural production and thus had higher production efficiency. Tang et al. (2015) studied whether improving farmers’ income would promote agricultural production. Deininger et al. (2012) considered whether rental land would increase farmers’ income and thus increase agricultural production efficiency, and Huang et al. (2017) found renting-in grassland improved the technical efficiency significantly.