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The paddy fields and water storage facilities are seriously damaged by the coal mine subsiding in the hilly post-mining and subsidence-stable areas in China, which make the farmers there being suffered greatly from the lack of water for traditional rice cultivation and daily life. The purpose of this paper is to find a method to restore the damaged paddy fields, thereby promoting sustainable development of land resources, and alleviating the contradiction between people and land, as well as creating a more inhabitable environment. The research methodology included field experiments, cultivated observation, and field investigation. This paper selected the Songzao Mining Area as the research area, and focused on the restoration technologies of damaged paddy fields, through the following four different measures at three experimental fields: (1) Traditional repeated cattle plowing (CK); (2) Water retention agent with repeated cattle plowing (W&C); (3) Film without holes under tilth depth (FO); and (4) Film with holes under tilth depth (FW). At last, a contrastive analysis of the four measures was made according to the results of the experiments. The results show that the use of water retaining agent with repeated cattle plowing (W&C) can be the most appropriate method to restore the damaged paddy field in the hilly post-mining and subsidence-stable area in southwest China. Compared with the other three measures, its water productivity is the maximum (0.81 kg/m3), and the net income is the highest (1 403 $/hm2). What's more, it is simple, short time-consuming, and low cost, which is benefit to generalize the use of this restoration technology [ABSTRACT FROM AUTHOR]

Farming plot reconstruction engineering is important in mitigating cultivated land fragmentation and promoting intensified production in hilly mountainous regions. As an anthropogenic disturbance, farming plot reconstruction and subsequent agricultural intensification have considerable effects on cultivated land, ecological environments, and pedogenesis. Although researchers have given considerable attention to changes in the physical and nutrient properties of soil in reconstructed farming plots, the connection between soil engineering and anthropogenic pedogenesis is often neglected. In this paper, we compared samples obtained during farming plot reconstruction engineering and agricultural intensification in terms of different soil properties. The results indicated that reconstruction changed the soil profile patterns from A–C to A–B–C, thereby significantly increasing the soil thickness, bulk density, clay content, pH, soil organic carbon, total nitrogen, C/N ratio, and cation exchange capacity. The geochemical composition notably varied in topsoil; the chemical index of alteration (CIA) and the chemical index of weathering (CIW) decreased markedly, and the Na 2 O/K 2 O ratio (Na/K) increased slightly. After a period of agricultural intensification, the physical and chemical properties of soil improved gradually with a high coefficient of variation. However, the soil exhibited Mg and Ca leaching and K and Na accumulation, and the intensity of chemical weathering was not significantly stronger with higher CIA values, higher CIW values, and lower Na/K ratios. These changes indicated that the anthropogenic disturbances from soil engineering accelerated the physical weathering and uniformity of purple soil but depressed soil chemical weathering to some extent. The anthropogenic disturbances of agricultural intensification disrupted the homogeneity of soils but did not significantly promoted the physical and chemical weathering of purple soil. This study provides guidelines for rational soil usage in reconstructed farming plots and may aid in soil classification. • Soil engineering accelerates physical weathering but destroys chemical weathering. • Agricultural intensification has positive impacts on soil quality. • Anthropogenic disturbances create a problem for soil classification. [ABSTRACT FROM AUTHOR]