Soil mineral depletion is a major issue due mainly to soil erosion and nutrient leaching. The addition of biochar is a solution because biochar has been shown to improve soil fertility, to promote plant growth, to increase crop yield, and to reduce contaminations. We review here biochar potential to improve soil fertility. The main properties of biochar are the following: high surface area with many functional groups, high nutrient content, and slow-release fertilizer. We discuss the influence of feedstock, pyrolysis temperature, pH, application rates, and soil types. We review the mechanisms ruling the adsorption of nutrients by biochar.

Real-time video deblurring still remains a challenging task due to the complexity of spatially and temporally varying blur itself and the requirement of low computational cost. To improve the network efficiency, we adopt residual dense blocks into RNN cells, so as to efficiently extract the spatial features of the current frame. Furthermore, a global spatio-temporal attention module is proposed to fuse the effective hierarchical features from past and future frames to help better deblur the current frame. Another issue needs to be addressed urgently is the lack of a real-world benchmark dataset. Thus, we contribute a novel dataset (BSD) to the community, by collecting paired blurry/sharp video clips using a co-axis beam splitter acquisition system. Experimental results show that the proposed method (ESTRNN) can achieve better deblurring performance both quantitatively and qualitatively with less computational cost against state-of-the-art video deblurring methods. In addition, cross-validation experiments between datasets illustrate the high generality of BSD over the synthetic datasets. The code and dataset are released at https://github.com/zzh-tech/ESTRNN.

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Hydroponic experiments were performed to investigate the ameliorating effects and mitigation mechanisms of selenium and silicon on Cd toxicity in Boehmeria nivea (L.) Gaud. Metal accumulation, chlorophyll content, activities of antioxidant enzymes, and antioxidant contents in ramie were evaluated. The results revealed that cadmium was mainly accumulated in the roots of plants rather than in the aerial parts. Additionally, under 5 mg L(-1) Cd stress, both Se (1 μmol L(-1)) and Si (1 mmol L(-1)) treatments decreased the Cd concentrations in plants. Besides, the treatments also inhibited the translocation ability of Cd from roots to the aboveground parts, which might be related to the decline of generation of reactive oxygen species (ROS). The application of Se and/or Si ameliorated Cd toxicity via stimulating the activities of antioxidant enzymes such as superoxide dismutase (SOD), guaiacol peroxidase (POD), and ascorbate peroxidase (APX), which resulted in the significant decrease of the contents of malondialdialdehyde (MDA) and hydrogen peroxide (H2O2) in ramie leaves. In addition, the content of nonenzymatic antioxidant such as glutathione (GSH) was increased significantly through the addition of selenite and silicate. Also, ascorbate (AsA) and vitamin E played a crucial role in scavenging excess ROS within plants. On the whole, appropriate doses of Se and Si were found to benefit plant growth and enhance the ability of ramie to alleviate Cd-induced stress. Moerover, the effects of combination of Se and Si appeared to be more superior compared to addition separately in response to Cd stress.

13A new synthesis method was developed to produce Zinc-biochar nanocomposites 14 from sugarcane bagasse. The modified biochar maintained 1.2 to 2.0 times higher 15 removal efficiency than that of pristine biochar. FTIR, XPS, BET and SEM were used 16 to analysis the physical and chemical properties of the composite adsorbent. Batch 17 sorption experiments were carried out to investigate the adsorption behavior of Cr(VI) 18 by Zinc-biochar. Experimental data were better fitted by pseudo-second-order kinetics 19 equation and Freundlich isotherms model. Thermodynamic analysis indicated that the 20 adsorption process was spontaneous and endothermic. The maximum adsorption of 21 the modified biochar was observed at pH 2.0 with the sorption capacity of 102.66 mg 22 g -1 . The adsorbed Zinc-biochar could be effectively regenerated by 0.5 mol L -1 NaOH 23 solutions and the adsorption ability decreased from 84.16 to 59.75 mg g -1 in the sixth 24 cycles. In conclusion, the porous Zinc-biochar showed great potential advantages in 25 the removal of Cr(VI) from wastewater.26

In this research, chitosan modification of magnetic biochar (CMB) was successfully prepared for effective removal of Cr(VI). Moreover, this study highlighted that the conversion of Eichhornia crassipes into biochar was a promising method for improved management of this highly problematic invasive species. The sorption kinetics, isotherms, thermodynamics, the effects of pH, and background electrolyte on the sorption process were investigated. The results indicated that CMB adsorbed more Cr(VI) (120 mg g À1 ) than that of pristine biochar (30 mg g À1 ). The sorption data could be well illustrated by pseudo-secondorder and Langmuir models. Furthermore, thermodynamic parameters revealed that the sorption reaction was an endothermic and spontaneous process. The adsorption of Cr(VI) was influenced by solution pH and the maximum sorption capacity was achieved at pH 2. The background electrolyte PO 4 3À and SO 4 2À restricted the Cr(VI) sorption. These results are significant for exploring and optimizing the removal of metal ions by the CMB composite.

Three biochars converted from water hyacinth biomass at 300, 450, and 600 °C were used to investigate the adsorption properties of Cd2+ and Pb2+.

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