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Application of crop residues and chemical nitrogen (N) fertilizer is a conventional practice for achieving high yield in a rice system. However, the fallacious combination of N fertilizers with crop straw not only significantly reduces the N use efficiencies (NUEs) but also leads to serious environmental problems. The present study employed five treatments including no N fertilization and no straw incorporation (ck), N fertilization incorporation only (S0), N fertilization with 40% straw (S40), N fertilization with 60% straw (S60), and N fertilization with 100% straw (S100) to improve N use efficiency as well as reduced Cd distribution in rice. The crop yields were largely enhanced by fertilization ranging from 13 to 52% over the straw addition treatments. Compared with ck, N fertilizer input significantly decreased soil pH, while DOC contents were raised in response to straw amendment, reaching the highest in S60 and S100 treatments, respectively. Moreover, straw addition substantially impacted the Cd accumulation and altered the bacterial community structure. The soil NH4+-N concentration under S0 performed the maximum in yellow soil, while the minimum in black soil compared to straw-incorporated pots. In addition, the soil NO3−-N concentration in straw-incorporated plots tended to be higher than that in straw-removed plots in both soils, indicating that crop straw triggering the N mineralization was associated with native soil N condition. Furthermore, the NUE increased with 15 N uptake in the plant, and the residual 15 N in soil was increased by 26.8% with straw addition across four straw application rates. Overall, our study highlights the trade-offs between straw incorporation with N fertilizer in eliminating potential Cd toxicity, increasing fertilizer-N use efficiencies and help to provide a feasible agricultural management. [ABSTRACT FROM AUTHOR]

With the rapid development of industry, chromium (Cr) pollutants accumulate constantly in the soil, causing severe soil Cr pollution problems. Farmland Cr pollution hurts the safety of agricultural production and indirectly affects human health and safety. However, the current situation of Cr pollution in farmland soil and crops has not been detailed enough. In this study, the evaluation of Cr potential risk in soil-crop systems was conducted in a rural area that was affected by industry and historic sewage irrigation. Ten different crops and rhizosphere soils were sampled from four fields. The results showed that Cr contents in farmland soil exceeded the national standard threshold in China (>21.85%), and the Cr content in edible parts of some agricultural products exceeded that too. According to the PCA and relation analysis, the Cr accumulation in edible parts showed a significant correlation with soil Cr contents and available potassium contents. Except for water spinach, the target hazard quotient (THQ) of the other crops was lower than 1.0 but the carcinogenic health risks all exceeded the limits. The carcinogenic risks (CR) of different types of crops are food crops > legume crops > leafy vegetable crops and root-tuber crops. A comprehensive assessment revealed that planting water spinach in this area had the highest potential risk of Cr pollution. This study provided a scientific and reliable approach by integrating soil environmental quality and agricultural product security, which helps evaluate the potential risk of Cr in arable land more efficiently and lays technical guidelines for local agricultural production safety. [ABSTRACT FROM AUTHOR]

It is easy to adsorb the pollutants from water owning to the hydrophobicity of the poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membrane. To improve the hydrophilicity of the PVDF UF membrane, a novel amphiphilic copolymer PVDF‐g‐poly‐N‐(3‐dimethylaminopropyl)methacrylamide] (PDMAPMA) was developed. The amphiphilic PVDF‐g‐PDMAPMA was synthesized with PVDF and N‐(3‐dimethylaminopropyl)methacrylamide (DMAPMA) via free‐radical polymerization, and characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance. The scanning electron microscopy and energy dispersive X‐ray spectroscopy were used to characterize the structure morphologies and elementals of the blend PVDF membranes, respectively. The pure water flux (PWF), molecular weight cutoff, and bovine serum albumin (BSA) solution filtration experiments were tested to evaluate the permeation performance and antifouling properties of the membranes. The experimental results showed that the PWF was 263.1 L m−2 h−1, BSA rejection rate was 98.1% and flux recovery rate was 95.1% of the prepared blend membrane which had obvious improvement compared with the pristine PVDF membrane (17.3 L m−2 h−1, 91.0, and 83.8%, respectively). The antibacterial activity test showed the prepared blend membrane had good potency against microorganisms. A novel hydrophilic PVDF membrane with good antibacterial properties was developed and would be promising for wastewater treatment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48049. [ABSTRACT FROM AUTHOR]

Application of microbial agents is a novel strategy to improve the quality and health of plant, which can be used to increase zinc (Zn) uptake and alleviate Zn toxicity. Here, endophytic bacteria with Zn solubilizing and growth-promoting properties were isolated from hyperaccumulating ecotype (HE) of Sedum alfredii Hance and their effects on Zn absorption and accumulation of non-hyperaccumulating ecotype (NHE) were studied. The results showed that most endophytic bacteria of HE have good Zn solubilizing or growth-promoting properties. Under the condition of 20 μM ZnSO 4 , the biomass of NHE inoculated with SaPS1, SaEN2, SaPR2, SaBA2, SaBA3 was 2.8-3.2 times higher than that of non-inoculation control, and the Zn concentration of shoots was increased by 45.9, 89.0, 53.7, 77.5, and 42.6% after inoculation with SaPA1, SaP1, SaEN2, SaBA1, and SaBA2. Under the condition of 100 μM ZnSO 4 , inoculation with SaVA1, SaPS3, SaB1, SaPR1, and SaEN3 alleviated Zn stress and significantly reduced Zn concentration of shoots. Therefore, endophytic bacteria can be an effective means of improving plant Zn nutrition quality in the normal condition and benefit plant health in the stress environment.