Evaluation of farmland productivity after rural homestead reclamation in the Three Gorges Reservoir Area - A case study of Fuling District, Chongqing City

Supplementation of farmlands after rural homestead reclamation should take into account land quantity and quality. The evaluation of farmland productivity can provide the basis for comprehensively grasping farmland productivity after reclamation and subsequent fertilization, utilization and management. Using Fuling District of Chongqing City in the Three Gorges Reservoir Area as a case study, 665 soil samples from reclaimed homestead pieces of land were randomly collected. Then 16 participatory indexes were selected using AHP and fuzzy method combined with GIS geostatistical spatial analysis functions to evaluate farmland productivity grades and spatial distribution. The results showed that the average grade of farmlands was 3.03, at the middle level. Grade 3 sample number was most, accounting for 52.18% of the total number of samples. This was followed by grade 4 and grade 2, and then grade 1 and grade 5 were the least. From the spatial distribution, differences were noted among the regions due to topography, natural conditions and soil type. All the grades were distributed within sampled townships. The average grades of riversides, level ground and mountain regions were respectively 2.82, 3.15 and 3.19. Farmland productivity of riversides, level ground, mountain regions (basically along topography), increase in altitude declined in trend. As riverside areas improved farmland productivity, focus should be put on improving farmland irrigation, drainage ditches and road conditions. Aerodrome areas should focus on adjusting soil pH and increasing soil phosphorus content. Then mountain regions needed to increase topsoil thickness, improve the utilization of homestead demolitions by reducing soil gravel content.