Discrepant soil microbial community and C cycling function responses to conventional and biodegradable microplastics.

Biodegradable microplastics (MPs) are promising alternatives to conventional MPs and are of high global concern. However, their discrepant effects on soil microorganisms and functions are poorly understood. In this study, polyethylene (PE) and polylactic acid (PLA) MPs were selected to investigate the different effects on soil microbiome and C-cycling genes using high-throughput sequencing and real-time quantitative PCR, as well as the morphology and functional group changes of MPs, using scanning electron microscopy and Fourier transform infrared spectroscopy, and the driving factors were identified.

Effects of macromolecular organic acids on reducing inorganic phosphorus fixation in soil.

To improve the availability of inorganic phosphorus (P) in soil, we investigated the role of three macromolecular organic acids (MOAs), including fulvic acid (FA), polyaspartic acid (PA), and tannic acid (TA), in reducing the fixation of inorganic P fertilizer in the soil. AlPO, FePO, and CaH(PO)·5HO crystals were chosen as insoluble phosphate representatives in the soil to simulate the solubilization process of inorganic P by MOAs. The microstructural and physicochemical properties of AlPO, FePO, and CaH(PO)·5HO were determined by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) before and after treatment of MOAs.

Variation of soil organic carbon and physical properties in relation to land uses in the Yellow River Delta, China.

Soil physical properties and soil organic carbon (SOC) are considered as important factors of soil quality. Arable land, grassland, and forest land coexist in the saline-alkali reclamation area of the Yellow River Delta (YRD), China. Such different land uses strongly influence the services of ecosystem to induce soil degradation and carbon loss.

Humic acid-modified bentonite composite material enhances urea-nitrogen use efficiency.

Bentonite was modified by introducing humic acid (HA) into interlayer space of bentonite. The structural and physicochemical properties of modified bentonite were determined by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray powder diffraction (XRD) and thermogravimetric analysis (TGA). The results showed that HA could enter the bentonite interlayer and increase the interlayer distance.

Soil C, N, and P distribution as affected by plant communities in the Yellow River Delta, China.

Soil carbon (C), nitrogen (N) and phosphorus (P) are important soil properties linked to nutrient limitation and plant productivity in terrestrial ecosystems. Up to 90% of the Yellow River Delta (YRD), China has been affected by soil salination due to groundwater overdraft, improper irrigation, land use and land cover change. The objective of this study is to evaluate the impact of different plant communities on soil quality in a saline-alkaline system of the YRD.

Effects of stocking rate on the variability of peak standing crop in a desert steppe of Eurasia grassland.

Proper grazing management practices can generate corresponding compensatory effects on plant community production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how grazing influences plant community attributes and the variability of standing crop. We examined the effects of sheep grazing at four stocking rate treatments [control, 0 sheep ha(-1) month(-1); light (LG), 0.