Search

[Objective]The aim of this paper was to explore the distribution characteristics of soil nutrients in different recovery modes of rocky desertification control, and to provide scientific basis for further optimizing the vegetation allocation of rocky desertification control. [Method] Taking soil from five sampling sites as the study object, including Zanthoxylum bungeanum, Lonicera japonica, mixed forests, cardamom and abandoned farmland in Huajiang Rocky Desertification Control Demonstration Area in Guizhou. Soil layers of 0 - 10, 10 -20 and 20 -30 cm were sampled and monitored for 3 years before, during and after rainy season, and the distribution characteristics of soil nutrients under different recovery modes were analyzed. [Result] With the restoration of vegetation, compared with abandoned farmland, average values of soil bulk density, soil retention ability and capillary porosity in the four plots decreased respectively by 0.61 %, 7.97 % and 1.12 % , soil organic carbon, total nitrogen, total phosphorus and total potassium increased by 53.45 %, 45.72 %, 80.81 % and 1.44 % respectively, hydrolyzed nitrogen and available phosphorus increased by 53.36 % and 25.80 % , respectively. In the same plot, the contents of soil organic matter and soil nutrient contents were all shown as during rainy season > after rainy season > before rainy season. With the increase of depth of the soil layer, content of soil nutrients of different recovery models decreased, nutrients mainly concentrated in the surface layer. [Conclusion] There were differences in nutrient contents between different restoration models, and vegetation restoration in karst rocky desertification area had an ameliorative effect on ecological environment. [ABSTRACT FROM AUTHOR]

[Objective]This paper aims to rationally manage paddy soil nutrients, provide the scientific basis for rational fertilization in rice production and realize high production and high efficiency of rice production in Guizhou. [Method]The paddy soil nutrient management sub-area is divided by taking accumulated temperature, elevation, topography, soil type and soil nutrient as subarea indexes and using the second-grade subarea method based on GIS technology. [Result] The paddy soil is divided into six first-grade subareas according to the subarea indexes of topography, paddy soil type, effective accumulated temperature and elevation and nine soil nutrient management subareas are divided according to soil nutrient indexes based on the first-grade subarea results in Guizhou. [Conclusion] The complex effective accumulated temperature, topography, soil type and soil nutrient are orderly classified by planning management subarea of paddy soil nutrients in Guizhou. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aims to provide a reference for rational utilization and scientific fertilization of paddy soil in Guizhou. 【Method】 The temporal and spatial evolution characteristics of paddy soil nutrients was analyzed by ArcGIS geostatistics method and Kriging theoretical model based on the determination data of 177 944 representative topsoil samples from rice-growing areas of nine regions ,Guizhou. 【Result】 The organic matter, total nitrogen and rapidly available potassium content and pH of paddy soil present the declining trends and available phosphorus content shows a rising trend compared with the data from the second national soil survey (1991) from angle of time series. There are quite differences in available phosphorus and rapidly available potassium content and pH of paddy soil but less difference in organic matter and total nitrogen content from angle of spatial distribution. The acidic paddy soil of most regions in Southeastern Guizhou has a higher total nitrogen and organic matter content and lower rapidly available potassium content. The organic matter, total nitrogen and available phosphorus content of paddy soil in Sinan and Shiqian county is low. The water-logging paddy soil has higher nutrient content but the gleyed paddy soil has higher organic matter and total nitrogen content and the lowest available phosphorus and rapidly available potassium content. 【Conclusion 】The nutrient content and pH of paddy soil show a declining trend compared with in 1991. There is a certain difference in soil nutrients among different regions. The nutrients ' content of water-logging paddy soil is the highest among four different paddy soil types. [ABSTRACT FROM AUTHOR]