Analysis on soil nutrient characteristics for sustainable land use in Danangou catchment of the Loess Plateau, China

Abstract

Understanding of the characteristics of soil organic matter (SOM) and soil nutrients at the field and catchment scale is important for refining agricultural management practices and for improving sustainable land use. In order to analyze on SOM and nutrient differences among different land use types and their relationships between land use, landscape position and slope aspect, 94 sampling sites including 7 land uses were selected along 6 transects in the Danangou catchment with an area of 3.5 km 2 on the Loess Plateau of China. Significant differences in SOM, total N (TN), available N (AN) and available P (AP) among these land uses were found. Higher values in SOM, TN and AN were measured in soils from woodland and grassland, but lower values in the soils from fallow land and cropland. Compare SOM and TN with cropland, intercropping land had high contents. The adjusted R 2 values of regression models for SOM and nutrients with land use, landscape position and slope aspect ranged from 0.501 (SOM) to 0.134 (AP). A comparison between average predicted and measured values for SOM and each soil nutrient revealed that the predicted values in TP and AN for each land use, in SOM and TN except for fallow land and in AP except for intercropping land, shrub land and woodland, fell with in a 95% confidence interval about the measured values. The simplified predicted models of soil nutrients combined with the key value of SOM for soil quality can serve to improve agricultural practices and to provide useful information on sustainable land use. Improvement in SOM and nutrients would be expected from more C inputs including manure and crop residues and alternative cultivation practices such as developing intercropping system, building terrace for soil and water conservation, return the cropland with SOM content less than a key value of 0.44% to the grassland and woodland on the hilly areas similar to the Loess Plateau of China. the same time, it is recommended that nitrogen fertilization addition could be decreased in the foot slope and increased on the upper slope. D

The effects of land use on soil moisture variation in the Danangou catchment of the Loess Plateau, China

“…The most common soil is loess with silt ranging from 64% to 73% and clay varying from 17% to 20% (Table 1). The soil is weakly resistant to erosion and its erosion rate was large at about 10-12 kg/m 2 /year (Song et al, 1989;Wang et al, 2003).…”

Land use evaluation and scenario analysis towards sustainable planning on the Loess Plateau in China—case study in a small catchment

“…A simplified soil map was used for this land evaluation considering the small differences between sub-loessial soil units. It was divided into the following groups: yellow loess soil (typical loess), reddish loess soil (loess with more clay), alluvial soil (soils behind check-dams), weathered bedrock and bedrock (Messing et al, 2003a;Wang et al, 2003). The slope gradient and slope aspect maps were derived from a Digital Elevation Model.…”

Spatiotemporal prediction of soil moisture content using multiple-linear regression in a small catchment of the Loess Plateau, China

“…The most common soil in the catchment is loessial soil, and the other two soil types including alluvial soil and calcium skeleton soil are distributed along the first-order channel of the catchment. The detailed description on soil properties is discussed elsewhere in this issue Messing et al, 2003;Stolte et al, 2003;Wang et al, 2003). The soil characteristic for each soil type is shown in Table 1.…”