Farmland consolidation zoning based on coupling of improved limiting factors and farmland quality potential

Sustainable utilization of regional land resources requires to scientifically delimit the key areas of farmland consolidation. In this study, taking the Hetao-Tumechuan plain of Inner Mongolia as the research area, the zoning type of farmland consolidation was determined via coupling the limiting factors on the improvement degree of classification, particularly from the improvable limiting factors of farmland. The promotion potential index model of quality grades, and the local spatial auto correlation model were adopted to divide the improvement potential area of farmland quality. The results showed that: 1) the improvement of farmland quality was mainly limited by the content of soil organic matter and the degree of salinization. The farmland in the grade one of improvement degree for the limiting factors was mainly concentrated in the middle region of study area, while, that of grade two and three was in the eastern and western area. The difficulty of farmland consolidation behaved a trend of “high on both sides but low in the middle”. 2) The distribution of promotion potential index in the physical quality grade was high in the West but low in the East. There were obvious spatial differences in the improvement potential of farmland quality. In the eastern Tumechuan plain, the improvement potential of farmland quality mainly presented the “low-low” aggregation distribution, indicating the positive correlation type and concentrated contiguous distribution. In the Western Hetao Plain, the improvement potential of farmland quality with “high-high” aggregation type was mainly distributed in the central region, and the farmland area with the “low-low” aggregation type was less and sporadic, as well as the rest of farmland behaved the non-aggregation type. 3) The farmland in the study area was divided into four types. The farmland of key-consolidation type was 0.84×104 hm2. The promotion potential of farmland quality in this type was higher, while, the difficulty of its consolidation was low, indicating the preferred area of farmland consolidation. The farmland of select-consolidation type was 22.22×104 hm2. The promotion potential of farmland quality in this type was general overall, but the difficulty of its consolidation was relatively low, where the land with the relatively high potential for the quality improvement and concentrated contiguous can be chosen to implement the land consolidation. The farmland of protected-consolidation type was 54.98×104 hm2. The promotion potential of farmland quality in this type was general overall, and the difficulty of its consolidation was high, which can be included in the protective zone of prime farmland. The farmland of unsuitable-consolidation type was 24.46×104 hm2. The promotion potential of farmland quality in this type was higher overall, but the difficulty of its consolidation was high, which can be selectively returned to forest and grassland. The proposed method can provide a sound reference for the application of some limiting factors in farmland consolidation zoning in semi-arid areas.