quantification-polybutylene-adipate-terephthalate-based-micro-nano

Quantification of Polybutylene Adipate Terephthalate-based Micro- and Nano-plastics from Soil Using Proton Nuclear Magnetic Resonance Spectroscopy

A method to recover and quantify micro- and nano-plastics (MPs and NPs) formed in the soil during biodegradation is needed to accurately assess the ...

University of Tennessee-Knoxville

The effect of modified biochar on the greenhouse gas emission in soil is not clear until now. In this study, biochar (BC) was modified by phosphoric acid (P) and further combined with nano-zero-valent iron (nZVI) to form nZVI-P-BC composite. The P modified biochar could significantly increase the available phosphorus in soil. The release of CO and NO in soil was inhibited during the initial stage of the experiment, with inhibition becoming more obvious over time. On the contrary, CH and NO emission in soil was enhanced by nZVI-P-BC composite. The proportion of Sphingomonas and Gemmatimonas were the most abundant bacterial species, which were related to the metabolism and transformation of nitrogen. The community structure of the fungus was also affected by nZVI-P-BC composite with Fusarium as the main species. PCoA analysis result suggested that bacterial community was more affected by the incubation time while fungal community was more related to the addition of different biochar and modified biochars.

Effects of phosphorus modified nZVI-biochar composite on emission of greenhouse gases and changes of microbial community in soil.

Understanding how conservation agricultural management improves soil nitrogen (N) stability in the face of climate change can help increase agroecosystem productivity and mitigate runoff, leaching and downstream water quality issues. We conducted a 2-year field study in a 36-year-old rain-fed cotton production system to evaluate the impacts of changing climatic factors (temperature and precipitation) on soil N under conservation management, including moderate inorganic N fertilizer application (0 and 67 kg N ha), winter cover crops (fallow; winter wheat, Triticum aestivum L.; hairy vetch, Vicia villosa Roth), and reduced tillage (no-till; disk tillage). Structural equation modeling (SEM) was used to quantify and compare the effects of conservation management and climatic factors on soil N concentrations. Fertilizer and vetch cover crops increased soil total N concentration by 16% and 18%, respectively, and also increased microbial N transformation rate by 41% and 168%. In addition, vetch cover crops also increased soil labile N concentrations by 57%, 21%, and 79%, i.e., extractable organic N, ammonium, and nitrate, respectively. The highest soil δN value (6.4 ± 0.3‰) was observed under the 67 kg N ha fertilizer-wheat-disk tillage treatment, and the lowest value (4.8 ± 0.3‰) under the zero-fertilizer-wheat-no-till treatment, indicating fertilizer and tillage might accelerate microbial N transformation. The SEM showed positive effects of temperature and precipitation on labile N concentrations, suggesting destabilization of soil N and the potential for soil N loss under increased temperature and intensified precipitation. Fertilizer and vetch use might mitigate some of the effects of temperature by accelerating microbial N transformations, with vetch having a larger effect than fertilizer (0.35 vs. 0.15, Table 1). No-till can reduce some of the effects of precipitation on soil labile N by maintaining soil structure. Our study suggests that fertilizer, vetch cover crop, and no-till might help improve function and resilience of agroecosystems in relation to soil N cycling. Soil N stabilization in cropping systems can be enhanced by adjusting agricultural management.

Conservation management improves agroecosystem function and resilience of soil nitrogen cycling in response to seasonal changes in climate.

Microplastics are emerging persistent pollutants which have attracted increasing attention worldwide. Although microplastics have been widely detected in aquatic environments, their presence in soil ecosystems remains largely unexplored. Plastic debris accumulates in farmland, causing serious environmental problems, which may directly affect food substances or indirectly affect the members in each trophic level of the food chain. This review summarizes the origins, migration, and fate of microplastics in agricultural soils and discusses the interaction between microplastics and the components in farmland from the perspectives of toxicology and accumulation and deduces impacts on ecosystems by linking the organismal response to an ecological role. The effects on farmland ecosystem function are also discussed, emphasizing the supply of agricultural products, food chain pathways, carbon deposition, and nitrogen cycling and soil and water conservation, as microplastic pollution will affect agricultural ecosystems for a long period, posing an ecological risk. Finally, several directions for future research are proposed, which is important for reducing the effect of microplastics in agricultural systems.

Article	Year
Effects of phosphorus modified nZVI-biochar composite on emission of greenhouse gases and changes of microbial community in soil. Environmental pollution (Barking, Essex : 1987)\| PubMed ID: 33508717	2021
Conservation management improves agroecosystem function and resilience of soil nitrogen cycling in response to seasonal changes in climate. The Science of the total environment\| PubMed ID: 34030284	2021
Activities of Microplastics (MPs) in Agricultural Soil: A Review of MPs Pollution from the Perspective of Agricultural Ecosystems. Journal of agricultural and food chemistry\| PubMed ID: 35380817	2022

Sean M. Schaeffer

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