The impact of cultivated land spatial shift on food crop production in China, 1990–2010

Abstract

Cultivated land has been undergoing significant spatial shift during the last 2 decades in China, according to land‐use data derived from the Landsat Thematic Mapper. Based on soil organic matter data and yield data at county level, we developed a constant crop yield dataset at pixel level with a resolution of 1 km. Using this dataset, this paper quantitatively evaluates average crop yield change due to cultivated land spatial shift at national and regional levels. The results show that (a) at national level, the average crop yield per unit area decreased by 1.99% during the period 1990–2010. The main reason for this is that built‐up areas occupied a significant amount of high‐yield cultivated land whereas low‐yield land converted in ecologically vulnerable areas. (b) In spite of 77.2 thousand km2 cultivated land was converted to built‐up areas, especially in areas with high economic value, such as Huang–Huai–Hai Plain, 329.4 thousand km2 land was converted to cultivated land, especially in Northeastern and Northwestern China. (c) The quality gap between cultivated land converted to built‐up areas nationally and new cultivated land regionally suggests that the loss of 1 km2 of cultivated land converted to built‐up area would, to achieve equivalency, need to be compensated by 1.54 km2 of new land in Xinjiang, or more in Northeastern China. However, cultivated land expansion in these areas may cause land degradation and a series of ecological environment problems.

Effect of dimethoate in controlling Monolepta hieroglyphica (Motschulsky) and its distribution in maize by drip irrigation

“…[1][2][3] In Xinjiang Province, a typical arid and semi-arid region in China, maize planting covers ∼ 1000 ha and maize seed production in the region accounts for 20% of the total in China. [4][5][6] In recent years, pest infestation in maize has become increasingly serious in arid and semi-arid regions, similar to the case of Xinjiang Province. 7 The coleopteran Monolepta hieroglyphica (Motschulsky), or leaf beetle, is an omnivorous insect 8 that eats maize ear spike silk, thereby preventing pollination.…”

“…Maize is one of the main crops cultivated in arid and semi‐arid areas, and serious pest infestation is a key factor limiting its production . In Xinjiang Province, a typical arid and semi‐arid region in China, maize planting covers ∼ 1000 ha and maize seed production in the region accounts for 20% of the total in China . In recent years, pest infestation in maize has become increasingly serious in arid and semi‐arid regions, similar to the case of Xinjiang Province .…”

Spatiotemporal Changes and the Driving Forces of Sloping Farmland Areas in the Sichuan Region

“…S=arctan f x 2 +f y 2 (1) where refers to the elevation change rate in the south-north direction, and refers to the elevation change rate in the east-west direction.…”

“…Cultivated land is a fundamental resource for human survival in developing countries [1][2][3], including China, which has 22% of the world's population and 7% of the world's cultivated land [4,5]. Sloping farmland refers to cultivated land with a slope >2 • [6], which is a key component of relatively scare cultivated land resources, accounting for 28.35% of the total domestic cultivated land in China [7,8].…”

Expansion of Rural Settlements on High-Quality Arable Land in Tongzhou District in Beijing, China

“…The causes of this phenomenon can be summarized as the institutional problems and the personal reasons such as the farmers' willingness to improve housing conditions. For China, given its large population and limited land resource per capita, arable land is a valuable resource [32][33][34][35][36][37]. However, in the last 30 years, this resource has been drastically reducing as a consequence of the rapid economic development [38][39][40][41][42].…”