Impact of Cultivated Land Endowment on Crop Planting Structure in Hunan Province

This study aimed to reveal the spatio-temporal differentiation characteristics of cultivated land endowment and crop planting structure in Hunan Province, and analyze the influencing factors of planting structure based on cultivated endowment, so as to provide a scientific basis for optimizing agricultural layout and coordinating resource utilization and crop production.

Based on the remote sensing images and statistical yearbook data at county level of Hunan Province from 2017 to 2021, an evaluation index system of cultivated land endowment was constructed from three dimensions: geographical conditions, cultivated land quality and cultivated land quantity, and the type of planting structure was determined by using the proportion of crop planting area. The Dagum Gini coefficient, spatial autocorrelation model and optimal parameter geodetector were used to analyze the impact of cultivated land endowment on planting structure in 121 counties of the four major geographical regions in the province.

(1) From 2017 to 2021, the endowment of cultivated land in Hunan Province generally presented the characteristics of "east-west differentiation, plain advantage", and showed a gradient strengthening trend over time, with obvious regional gap. (2) The crop planting structure was showing a trend of diversified transformation. The number of counties with single-crop dominant planting structures has decreased by 21.0%, but its proportion in 2021 was 52.9%, and its absolute advantages remained obvious. The number of counties with dual-crop dominant planting structure was relatively small and changed stably. The types of multi-crop dominant planting structures have gradually become more diverse, and their scales have continued to expand. The proportion has increased from 30.6% in 2017 to 44.6% in 2021. (3) Surface roughness and cultivated land slope were important influencing factors affecting crop cultivation in Hunan Province; average slope of the county area, the proportion of cultivated land area, surface undulation, heat conditions and soil fertility were the secondary driving factors affecting crop cultivation in Hunan Province. (4) The cultivated land endowment in the Dongting Lake area was relatively favorable, and the specialization degree of double-cropping rice cultivation was high. However, in the face of the downward trend of soil fertility, the proportion of oil crop cultivation could be reasonably increased in the future. The Changsha-Zhuzhou-Xiangtan region was limited by the amount of cultivated land and was currently facing the adjustment of the planting structure from "double to single", which would to some extent intensify the contradiction of cultivated land utilization. Further adjustments are needed in the future. The crop types in the southern part of Hunan Province were rich. However, limited by the terrain, the advantages of water and heat resources have not been fully utilized. In the future, the adjustment direction should be the cultivation of cash crops. The Greater Western Hunan region was shifting from a single single rice type to a planting structure of single rice-vegetables-other crops, making full use of the vertical climate differences in the mountains to form three-dimensional agriculture. However, the road network in this area was sparse, and the planting areas were far from the consumer market, which was not conducive to the market transactions of agricultural products.

The adjustment of the planting structure in Hunan Province should take into account the resource endowment characteristics of each region. Different strategies such as stabilizing grain production and expanding oil production, responding to the "double to single", developing economic crops, and implementing multi-layered agriculture should be adopted respectively for the areas of Dongting Lake, Changsha-Zhuzhou-Xiangtan, Southern Hunan, and the Greater Western Hunan region.