Evolution of concepts of cultivated land quality and recognition

Abstract: Cultivated land quality has important implications for agricultural benefit, food security, and sustainable utilization ability of cultivated land resources. To understand concept, composition, characteristics and influencing factors of cultivated land quality is important for strengthening basic research in cultivated land quality, promoting land remediation and high-standard basic farmland construction, and launching cultivated land quality management practice work. This paper discusses 3 current main concepts of cultivated land quality, analyzes connotations of quality and land quality, then expounds a new concept of cultivated land quality, and obtains the following main conclusions. 1) The current main 3 concepts of cultivated land quality based on natural attributes, natural-economic attributes and multiple attributes have evolutionary relationships, while they are coexistent and distinct. 2) Quality is the extent about a set of inherent characteristics of the product to meet the requirements; land quality is the ability and level of the specific land use type to meet some specific requirements. 3) Cultivated land is farming land, including not only land used to grow crops, but also roads, ditches, shelterbelts, ridges, electromechanical wells and other infrastructure land attached to these land and the drying field, seedling shed, agricultural stations and other ancillary facilities land. 4) Cultivated land quality is the level of the performances of cultivated land itself to meet the requirements of agricultural production and obtaining economic profits and human well-being. The cultivated land quality includes land fertility quality, engineering quality, space quality, ecology-environment quality and aesthetics-culture quality. Farmland productivity is cultivated production potential determined by soil fertility, geomorphology, climate, hydrology and other natural factors. Fertility quality is the core of cultivated land quality, the background quality or inherent quality of cultivated land. Cultivated engineering quality is embodied as the supporting extent and quality of water conservancy, transportation, electricity, ridge and other infrastructures, and seedling shed, drying field, drying ponds and other ancillary facilities for satisfying agricultural production. Cultivated engineering quality not only affects the degree of realization of production potential, but also has an important influence on convenience and economy of agricultural production. Engineering quality is an additional quality of cultivated land, but it is an important part of China's current high-standard farmland construction. Space quality mainly refers to the characteristics of spatial form and spatial distribution. Spatial form includes field's surface slope, shape and size. Spatial distribution includes degree of transportation convenience, labor radius and concentration ratio of cultivated land. Space quality affects the mechanization level, convenience level, scale level and efficiency of agricultural production, and then affects the economic profitability of cultivated land. Ecology-environment quality includes ecological quality and environmental quality. The former refers to soil and water conservation, air purification, climate regulation and other ecological service functions while cultivated land is regarded as an ecological subsystem. The latter mainly refers to soil environment capacity, and quality of soil environment, irrigation water environment and surrounding air of cultivated land. Aesthetics-culture quality is the aesthetic and cultural characteristics embodied by cultivated land. 5) The characteristics of cultivated land quality include productivity, internality, comprehensiveness, extensity and timeliness. Cultivated land quality is affected by natural factors, engineering factors, social factors and their combination conditions. No matter in the theory study or the management practice of cultivated land quality, it is necessary to treat cultivated land quality comprehensively and without bias, and to unify the objectivity of cultivated land quality and the subjectivity of cultivated land quality demand. We should select cultivated land quality indicators based on cultivated land evaluation purpose, build the evaluation index system scientifically, and monitor spatial scale and temporal frequency to evaluate the quality of cultivated land accurately.