Layout and mode partition of high-standard basic farmland construction at county level based on four-quadrant method

Abstract: In order to improve the scientificity and rationality of the construction of high-standard basic farmland, this paper explored the layout pattern of high-standard basic farmland construction at county level using four- quadrant method, taking Wuhua County, Guangdong province as an example. By improving the comprehensive productivity of cultivated land and agricultural production conditions, the high-standard basic farmland construction has been playing a key role for the food security of China. The high-standard basic farmland construction is an important part of the local land consolidation plan, therefore, both of the basic condition of cultivated land and the social and economic suitability must be taken into account simultaneously in the high-standard basic farmland construction. This paper evaluated the cultivated land quality from site conditions, physical properties, chemical properties and utilization condition of cultivated land, and evaluated the construction suitability of high-standard basic farmland from infrastructure conditions, regional economic conditions and the desire of the farmers. In the process of evaluation, the selected evaluation factors were first given different weights and then were quantified, and finally comprehensive evaluation on each evaluation unit was made. The results shows that both of the cultivated land quality and the suitability of high-standard basic farmland are higher value along the Wuhua river and Qinjiang region in Wuhua County, and decrease gradually with the increase of the distance to this region. The quality of cultivated land along the river is relatively higher because of the better irrigation condition, more fertilizer application and longer cultivating history along with land improvement. At the same time, the economic conditions and infrastructure conditions in this region are better than other regions. The regions along the river are also the important area of basic farmland, so the cultivated land in this region is relatively suitable for high-standard basic farmland construction. In our study, the cultivated land quality is divided into high quality and low quality, and the suitability of high-standard basic farmland is divided into high suitability and low suitability. Based on four-quadrant method, four zones of high-standard basic farmland are divided, namely high quality and high suitability (HQHS) zone, high quality and low suitability (HQLS) zone, low quality and high suitability (LQHS) zone and low quality and low suitability (LQLS) zone. The area of HQHS zone is 15 460.51 hm2, accounting for 37.65% of the total area of cultivated land; the area of HQLS zone is 8771.85 hm2, accounting for 21.36%, and the area of LQHS zone is 7 508.73 hm2, accounting for 22.71%. In the end, the limiting factors and the distribution of farmland of each area are analyzed. Based on these, the spatial adjustment method of farmland and the layout pattern of high-standard basic farmland construction are proposed, and the corresponding building mode is advised. This research provides a scientific basis for the consolidation plan and construction programs of high-standard basic farmland. It's also a reference for the potential analysis of high-standard basic farmland construction at county level.