Construction of the suitability evaluation model for the cultivated function recovery of non-grain cultivated land

Non-grain cultivated land refers to other agricultural land, such as garden land, forest land, pasture and pond, which are transformed from the original cultivated land, due to the non-grain behavior. The cultivated function of non-grain cultivated land can be expected to restore, and then return to the cultivated land category. As such, the non-grain behavior can be used to implement the policy of dynamic "import and export balance" of cultivated land. The suitability evaluation model of non-grain cultivated land for the cultivated function recovery can be used to reasonably and accurately classify the cultivated function recovery suitability levels of non-grain cultivated land. The foundation can be offered for the scientific guidance of actual recovery work in the future. In this study, literature reference was selected to determine the level of model construction and the corresponding indicators. The entropy weight was used to determine the weights. Referred to the relevant regulations to determine the quantitative standards of indicators. The factor evaluation and weighted index sum were restricted to realize the evaluation using ArcGIS software. The suitability evaluation model was constructed in the non-grain cultivated land for the cultivated function recovery from three dimensions of production, ecology and economy, including 12 evaluation indicators. Taking Kangping County of Shenyang City as a case study, the results showed that there were outstanding spatial differences in the suitability of productive, ecological and economic conditions. There were some gaps under the suitability of productive conditions in the different parts of the county, indicating the generally excellent suitability of ecological and economic conditions. The comprehensive evaluation scores of suitable areas were calculated for the cultivated function recovery of non-grain cultivated land, with a range of [1.951, 3.201]. Among them, the evaluation scores of unsuitable areas were recorded as 0 points. The suitability grades of cultivated function recovery of non-grain cultivated land in Kangping County were divided into highly suitable, moderately suitable, low suitable, reluctantly suitable, and unsuitable. The average suitability level of non-grain cultivated land for the cultivated function recovery in each region reached the low suitability level and above. The low suitable and above grades of non-grain cultivated land area, accounted for 67.68%, most of which was arbor forest land. Few constraints were found in the suitability grade of cultivated function recovery. It was easier to implement the restoration projects. The proportion of reluctantly suitable non-grain cultivated land area was the largest among all grades, accounting for 32.30%. Most of them were other forest land, arbor forest land, and orchard. There were more constraints on the suitability of cultivated function recovery, indicating the more difficult implementation of restoration projects. The area of non-grain cultivated land unsuitable for recovery was the least, accounting for only 0.02% of the total area. All of them belonged to other forests with a slope greater than 25°. It was not suitable for the restoration of cultivated land, due to the steep slope. The improved model can be expected to make the classification of suitability grades for the cultivated function recovery of non-grain cultivated land more scientific. The work arrangement of time sequence and the project can be deployed for the cultivated function recovery of non-grain cultivated land in Kangping County of Shenyang City in the future. © 2023 Chinese Society of Agricultural Engineering. All rights reserved.