Spatial analysis and coordinated layout optimization of farmland-orchard mismatch using spatial decision modeling

Agricultural production has a very serious "spatial dislocation and functional disorganization" in China at present. It is of great significance to optimize the spatial layout of farmland and orchards. This study aims to optimize the spatial layout of farmland for the farmland downhill fruit trees uphill, in order to improve the quality of arable land. The study area was taken as Xunwu County, Ganzhou City, Jiangxi Province, China. The forestry and fruit industries were also dominated by the agricultural industry. 13 indicators were selected to evaluate the farmland quality under the contradiction of spatial mismatch between farming and fruiting. The topography, slope and elevation were used to classify the "on the mountain" and "under the mountain". Land quality, geographic location and landscape pattern were first utilized to evaluate the farmland quality. The topographic space was then coupled with the geographic definition of "on the mountain" and "under the mountain", in order to identify the dislocation space between farmland and orchards. Finally, a spatial decision-making model was constructed using GIS technology. The contradiction zones of farmland and orchards were identified to coordinate the spatial layout. The efficiency of land use was promoted with agricultural activities. The results showed that: 1) The overall quality of finely divided farmland was achieved at the medium level. Among them, the area of farmland with grade Ⅰ was 2 227.02 hm² after quality evaluation, accounting for 24.17% of the total farmland area; The area of farmland with the quality of grade V was 671.70 hm², accounting for 7.29%. The topographic space was divided into "under the mountain" of 24.06% and "on the mountain" of 48.19%. 2) The "on the mountain" and "under the mountain" were taken as the zoning criteria. The farmland space was initially delineated into the protected areas and the areas to be transferred. The forest and fruit space was divided into the suitable for the cultivation and fruits, as well as the reserved areas. The transfer and arable areas belonged to the dislocation space of agricultural production. Specifically, the dislocation spaces of farmland and orchards were 1 221.77 and 5 169.39 hm², respectively. 3) The dislocation space of farmland and orchards was optimized under the spatial decision-making model, according to the contradiction coordination. The 1 247.25 hm² orchards "under the mountain" was adjusted to the farmland, whereas, the 1 221.77 hm² farmland "on the mountain" was to the orchards. The optimal layout of farmland and orchards had improved the quality of farmland, as well as the degree of concentration and contiguity. The finding can also provide a strong reference and theoretical basis to optimize the layout of farmland from "on the mountain" to "under the mountain".