Edaphic regulation of soil organic carbon fractions in the mattic layer across the Qinghai-Tibetan Plateau.

The mattic layer is a main ecological function bearer of alpine meadow soils in the Qinghai-Tibet Plateau. It has high soil organic carbon (SOC) content with a variety of SOC fractions, which are thought to have different sensitivities to climate change. The effects of soil properties and climate on the SOC fractions in the mattic layer are not well understood.

Nitrate leaching characteristics of red soils from different parent materials in subtropical China.

Globally, nitrate (NO) leaching from agroecosystems has been of major concern. There is evidence that NO leaching exhibits intense seasonal variation in subtropical regions. However, influencing factors to the seasonal dynamics remain unclear.

Soil acidification and loss of base cations in a subtropical agricultural watershed.

Soil acidification along with base cations loss degrades soil quality and is a major environmental problem, especially in agroecosystems with extensive nitrogen (N) fertilization. So far, the rates of proton (H) production and real soil acidification (loss of base cations) remain unclear in subtropical agricultural watersheds. To assess the current status and future risk of soil acidification in subtropical red soil region of China, a two-year monitoring was conducted in a typical agricultural watershed with upland, paddy fields, and orchards where high N fertilizers are applied (320 kg N ha yr).

Seasonal dynamics of soil pH and N transformation as affected by N fertilization in subtropical China: An in situ N labeling study.

Nitrogen (N)-induced soil acidification has received much attention worldwide. Nitrification and soil N mineralization are two key N cycle processes that affect soil acidification. However, the seasonal dynamics of soil pH under their combined influence is unclear.

Nitrate runoff loss and source apportionment in a typical subtropical agricultural watershed.

Nitrate (NO) loss and enrichment in water bodies caused by fertilization are a major environmental problem in agricultural areas. However, the quantitative contribution of different NO sources, especially chemical fertilizers (CF) and soil organic nitrogen (SON), to NO runoff loss remains unclear. In this study, a systematic investigation of NO runoff and its sources was conducted in a subtropical agricultural watershed located in Yujiang County, Jiangxi Province, China.

Intra-horizon differentiation of the bacterial community and its co-occurrence network in a typical Plinthic horizon.

Subsurface soil bacterial community composition and the controlling factors remain largely unknown, especially the micro-zone differentiation of community composition within a horizon. We studied a plinthic horizon to determine how different micro-zones in a horizon affect the bacterial community. The plinthic horizon is a net-like horizon characterized by the segregation of iron forms as shown by contrasting red matrix and white veins, which share common macro-environmental conditions such as climate and land use but differ only in physical and chemical compositions.

[Spatial interpolation of soil organic matter using regression Kriging and geographically weighted regression Kriging].

Relative elevation and stream power index were selected as auxiliary variables based on correlation analysis for mapping soil organic matter. Geographically weighted regression Kriging (GWRK) and regression Kriging (RK) were used for spatial interpolation of soil organic matter and compared with ordinary Kriging (OK), which acts as a control. The results indicated that soil or- ganic matter was significantly positively correlated with relative elevation whilst it had a significantly negative correlation with stream power index.