Transport and distribution of residual nitrogen in ion-adsorption rare earth tailings.

A large amount of nitrogen remains in ion-absorption rare earth tailings with in-situ leaching technology, and it continually ends up in groundwater sources. However, the distribution and transport of ammonium nitrogen (NH-N) and nitrate nitrogen (NO-N) across tailings with both depth and hill slopes is still unknown. In this study, the amount of NH-N and nitrate nitrogen (NO-N) was determined in tailings, and a soil column leaching experiment, served to assess the transport and distribution following mine closure.

Characteristics of Soil Erodibility in the Yinna Mountainous Area, Eastern Guangdong Province, China.

Soil erodibility research is of theoretical and practical significance to the prediction and prevention of regional soil erosion. At present, the study on soil erodibility in the lateritic red soil area of eastern Guangdong province is relatively lacking. Taking the forest land soil of the Yinna mountainous area as the research object, the physical and chemical properties (organic matter mass fraction, texture, moisture, bulk density, pH, aggregate content) of soil samples at different altitudes were measured with field survey sampling and indoor analysis.

Spatial Statistics and Influencing Factors of the COVID-19 Epidemic at Both Prefecture and County Levels in Hubei Province, China.

The coronavirus disease 2019 (COVID-19) epidemic has had a crucial influence on people's lives and socio-economic development throughout China and across the globe since December 2019. An understanding of the spatiotemporal patterns and influencing factors of the COVID-19 epidemic on multiple scales could benefit the control of the outbreak. Therefore, we used spatial autocorrelation and Spearman's rank correlation methods to investigate these two topics, respectively.

Nutrient allocation might affect the cadmium accumulation of Bermuda grass (Cynodon dactylon).

Hydroponic experiments with different cadmium (Cd) concentrations were conducted to explore the impacts of nutrient allocation on the Cd enrichment of Bermuda grass. The results demonstrated with the Cd concentration increase, the accumulation of nitrogen (N), phosphorus (P) and potassium (K) in roots, stems and leaves increased first and then decreased, while the accumulation of Cd had no significant difference. The biomass and N, P and K accumulation of CD1 and CD2 were significantly different from those of CD3 and CD4, but there was no significant difference in Cd accumulation.

Spatial and temporal characteristics of soil conservation service in the area of the upper and middle of the Yellow River, China.

Soil erosion is an important environmental problem in the area of the upper and middle of the Yellow River (AUMYR), China, one of the most severe soil erosion areas in the world. It is significantly influences on the ecological security and sustainable development of the region. Soil conservation (SC) service, as one of the most important regulating services provided by ecosystems, can alter soil and water processes and improve ecosystem services that ensure human welfare.

The decomposition and ecological risk of DDTs and HCHs in the soil-water system of the Meijiang River.

This research project was designed to study the residues of OCPs (organochlorine pesticides) in the sediments of the Meijiang River Basin. Samples from the Meijiang River Basin were analyzed by gas chromatography-mass spectrometry after being pretreated by Soxhlet extraction, and their compositions, distributions and sources were evaluated. The current study presents the distribution of OCPs in the soils and sediments of the Meijiang River Basin.

Calcium Nodules as a Proxy for Quaternary Paleoclimate Change on China's Loess Plateau.

Different proxies have been used to investigate Quaternary paleoclimate change. Here, we used weathering of calcium nodules in paleosols on China's Loess Plateau as a proxy for Quaternary paleoclimate changes to provide an alternative indicator of these changes. Paleosol and carbonate nodules were collected from Luochuan and Lantian counties in Shaanxi Province, China.

The negative effects of cadmium on Bermuda grass growth might be offset by submergence.

Revegetation in the water-level-fluctuation zone (WLFZ) could stabilize riverbanks, maintain local biodiversity, and improve reservoir water quality in the Three Gorges Reservoir Region (TGRR). However, submergence and cadmium (Cd) may seriously affect the survival of transplantations. Bermuda grass (Cynodon dactylon) is a stoloniferous and rhizomatous prostrate weed displaying high growth rate.

Rare earth elements tracing the soil erosion processes on slope surface under natural rainfall.

A field experiment using rare earth elements (REEs) as tracers was conducted to investigate soil erosion processes on slope surfaces during rainfall events. A plot of 10m×2m×0.16m with a gradient of 20° (36.