Search

[Objective] Saline water irrigation is one of the important ways to alleviate the shortage of agricultural water and ensure food production. However, soluble salt in irrigation water leads to soil salt accumulation, which affects the growth of crops. Seeking a suitable salt concentration in irrigation water is a favorable guarantee for the safe utilization of saline water resources. [Methods] In this study, a rain-shielding pot experiment was conducted to plant winter wheat. The deionized water was used as a control (CK), and chloride salts were added to form saline water with different salt concentrations. The electrical conductivity of irrigation water (ECw) was 0.26 (CK), 3.00 (S1), 5.26 (S2), 7.07 (S3), and 9.24 (S4) dS/m respectively. The soil water and salt distribution, growth, photosynthetic physiology, and yield formation of winter wheat were studied. [Results] Soil water content and electrical conductivity increased with the increase of saline water salt concentration under saline water irrigation. When the conductivity of irrigation water was 9.24 dS/m, the soil moisture content was 5.43% (0—10 cm), 4.21% (10—20 cm), and 4.98% (20—40 cm) higher than CK, respectively. The electrical conductivity of soil extract (ECe) in 0-40 cm soil layer was 0.66, 4.89, 7.88, 9.34, and 10.16 dS/m under CK and S1-S4 treatments after winter wheat harvest, respectively. Compared with CK, there was no significant difference in the growth, photosynthetic physiological indexes, and yield of winter wheat when the conductivity of irrigation water was 3.00 and 5.26 dS/m, but it was significantly reduced when the conductivity of irrigation water was 7.07 and 9.24 dS/m. The net photosynthetic rate, maximum plant height, maximum leaf area, shoot dry matter mass at maturity stage, root dry matter mass and yield of winter wheat under 9.24 dS/m were decreased by 71.00%, 2.81%, 15.33%, 15.55%, 47.25%, and 27.53% compared with CK, respectively. The threshold of saline water conductivity for irrigation of winter wheat was calculated as 5.82 dS/m using the fitting sum of FAO piecewise function, if the value exceeded, the relative yield of winter wheat decreased by 8.80% with each increase of 1 dS/m. [Conclusion] In summary, the higher the salt concentration of irrigation water, the greater the impact on soil water and salt distribution and winter wheat growth, 5.82 dS/m is the threshold of saline water conductivity of winter wheat irrigation. Considering the growth, photosynthetic physiological indexes of winter wheat and soil physical and chemical properties, it is suggested that ECw should not exceed 5.82 dS/m when saline water is used to irrigate winter wheat. This study can provide theoretical support for the safe utilization of saline water.

We report an evaluation of a semi-empirical quantum chemical method PM7 from the perspective of uncertainty quantification. Specifically, we apply Bound-to-Bound Data Collaboration, an uncertainty quantification framework, to characterize (a) variability of PM7 model parameter values consistent with the uncertainty in the training data and (b) uncertainty propagation from the training data to the model predictions. Experimental heats of formation of a homologous series of linear alkanes are used as the property of interest. The training data are chemically accurate, i.e., they have very low uncertainty by the standards of computational chemistry. The analysis does not find evidence of PM7 consistency with the entire data set considered as no single set of parameter values is found that captures the experimental uncertainties of all training data. A set of parameter values for PM7 was able to capture the training data within ±1 kcal/mol, but not to the smaller level of uncertainty in the reported data. Nevertheless, PM7 was found to be consistent for subsets of the training data. In such cases, uncertainty propagation from the chemically accurate training data to the predicted values preserves error within bounds of chemical accuracy if predictions are made for the molecules of comparable size. Otherwise, the error grows linearly with the relative size of the molecules.

Cereal + legume rotation is an integrated system that facilitates soil fertility and sustainable agricultural production. However, research on the management compatibility affecting soil physico-chemical properties yields overall agro-ecosystem sustainability, but profitability is lacking, especially under straw retention and potential reductions in fertilizer application. An 11-year field experiment investigated three treatments: no straw retention + traditional mineral fertilization (TNS), straw retention + traditional mineral fertilization (TS), and straw retention + reduced mineral fertilization (DS). Compared with TNS, TS significantly improved soil physico-chemical properties, including macro-aggregates (R > 0.25 mm), porosity, field water capacity (FWC), soil organic carbon (SOC) storage, total nitrogen storage, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) by 17.3%, 3.2%, 13.0%, 5.5%, 3.2%, 15.5%, and 13.8%, respectively. TS also significantly increased total (wheat + soybean) yields (TYs), economic profits, and emergy sustainability index (ESI) by 15.8%, 25.0%, 3.7 times that of TNS, respectively. Surprisingly, compared with TS, DS further significantly improved R > 0.25 mm, porosity, FWC, SOC storage, MBC, MBN, TY, economic profits, and ESI by 11.4%, 1.5%, 6.1%, 3.0%, 10.6%, 7.2%, 5.7%, 11.1%, and 36.5%, respectively. Overall, retaining straw with reduced fertilization enhances soil properties, yields, and emergy sustainability in wheat–soybean rotation systems. [ABSTRACT FROM AUTHOR]

The Co-based heterojunction is regarded as an efficient material for the oxygen evolution reaction (OER), but the synthesis is still time- and labor-consuming, and environmentally unfriendly. Herein, we propose a green and facile L -lysine-induced strategy for the successful synthesis of porous CoS/Co3O4 nanoframes (NFs). L -Lysine played a pivotal role in facilitating the formation of the stable Co(OH)2 nanosheet precursor, which was subsequently in situ converted into CoS/Co3O4 NFs through the sulfuration treatment. The resulting CoS/Co3O4 NFs showed a low overpotential of 304 mV at 10 mA cm−2 and remarkable long-range durability in 1.0 M KOH for the OER. The rechargeable Zn–air battery exhibited high charge–discharge cycling stability (>120 h) with CoS/Co3O4 NFs + Pt/C as an air cathode. Density functional theory calculations demonstrated that the charge density of the CoS/Co3O4 heterostructure can be redistributed by rebalancing the Fermi level after the contact between CoS and Co3O4, potentially modulating the pristine catalytic properties of single components. This work provides a facile and green synthesis strategy for developing efficient Co-based catalysts in sustainable energy conversion devices. [ABSTRACT FROM AUTHOR]

The development of cost-efficient electrocatalysts for oxygen evolution reaction (OER) with high efficiency is crucial to widespread applications of water splitting for hydrogen production. In this work, porous three-dimensional (3D) amorphous NiFe nanoaggregates composed of interconnected nanograins were synthesized by a cyanogel-based wet chemical reduction method using the NiCl2/Na4Fe(CN)6 cyanogel as the precursor and NaBH4 as the reducing agent. The influence of the incorporated Fe amount was carefully studied by slightly changing the feeding molar ratios of the Ni/Fe atoms in the precursors. The intrinsic 3D backbone structure of the cyanogel resulted in crystal nuclei tending to generate along with the backbones, which is key to the formation of NiFe nanoaggregates with a porous 3D interconnected structure. The synthesized NiFe nanoaggregates with a 3D interconnected structure and high porosity, as well as the incorporation of Fe, are in favor of high surface area, more active sites, and abundant oxygen vacancies, leading to superior activity and stability of OER in alkaline electrolytes with a low overpotential of 0.35 V at 10 mA cm−2, a high current density of 24.8 mA cm−2 at 1.65 V, a small Tafel slope of 76.9 mV dec−1, and attractive durability in 1 M KOH solution. [ABSTRACT FROM AUTHOR]