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Soil health assessment is fundamental to guiding sustainable soil management practices, ensuring healthy soil, crop productivity, and provision of other ecosystem services. Interpretation of soil health in intensive agriculture in the North China Plain (NCP) is still lacking due to an over emphasis on soil chemical management and large variations among smallholders’ farmlands. The objectives of this study were to (i) compare soil health assessment approaches in response to fertilization regimes, (ii) quantify relationships between soil health and agronomic outcomes, (iii) develop a minimum data set to simplify soil health assessment, and (iv) validate soil health assessment frameworks in smallholders’ fields on the NCP. We collected soil samples from eight wheat-maize rotation long-term experiments which were divided into three fertilization regimes: (1) NPK, application of chemical fertilizers only; (2) M, application of organic materials only; and (3) MNPK, combined application of organic materials with chemical fertilizer application. Three soil health indexing (SHI) approaches, Comprehensive Assessment of Soil Health (SHI-CASH), linear (SHI-L) and sigmoidal (SHI-Sig) were evaluated. SHIs in the M and MNPK treatments were significantly higher than those in the NPK treatment across assessment approaches and were positively correlated with maize yield. A minimum data set including subsurface hardness, wet aggregate stability, available K, available Fe, soil organic carbon and soil protein was established using best subset regression. The soil health indices of smallholders’ farmlands using CASH and MDS were 0.58 (0.42–0.73) and 0.63 (0.40–0.87), respectively. More than 60% smallholders’ fields was at middle or low level. The relationship between SHI-CASH and SHI-MDS (Sig) was better than those for the CASH and linear methods. Our results demonstrate that an MDS based on best subset regression is applicable for evaluating soil health in wheat-maize rotation systems in the NCP. Soil health assessment in smallholders’ farmland indicates that soil health constraints are related to soil and biomass management, which provides insights on pathways towards addressing soil health gaps.

Soil salinization is a widespread environmental problem adversely impacting global food production. Increasing soil organic matter (SOM) could alleviate salt stress, but soil salinity and SOM have differing effects on microbial diversity and activities. We explored how the relationships between soil biodiversity and multifunctionality were altered by soil salinity and SOM. We collected soils from the wheat-maize cropping system in the North China Plain and categorized soils according to salinity and SOM. Soil functions related to carbon, nitrogen, phosphorus, and micronutrient processing were measured as metrics of soil multifunctionality (SMF) characterization. We found significant positive relationships between SMF and bacterial diversity but not fungal diversity in soils with high SOM (>15 mg/kg) and low EC (

In China, agroforestry is a traditional practice that diversifies agricultural production and enhances natural resource utilization; however, it create competition for light between trees and understory crops due to heterogeneous spatio-temporal light patterns, and can lead to systemic reductions in grain yield as shade increases. The present study simulated reductions in light intensity caused by walnut trees (Juglans regia L.) before budburst, between budburst to tree foliage expansion, and after foliage expansion, to examine the effects on wheat (Triticum aestivum L.) yield and quality in an agroforestry system. We designed artificial shading systems using black polyethylene screen of varying density (21 %, 44 and 74%reductions in light intensity) at the jointing (approximately 70 d of shading), booting (approximately 55 d of shading), and anthesis (approximately 40 d of shading) stages, with full solar radiation (S0) as a control. Reduced light intensity significantly decreased the number of fertile florets per spike, resulting in a marked decline in grains per spike. Decreased light intensity also significantly decreased photosynthetic rates, grain yield and associated components (spike number, grains per spike, and thousand-grain weight), Furthermore, when applied at the anthesis stage, shading had the strongest negative impact on wheat productivity via decreases in thousand-grain weight. Decreased light intensity substantially enhanced grain and stalk nitrogen concentrations, as well as protein and wet gluten contents. However, the increase in grain quality did not compensate for the decreased final grain yield. Our evaluation of the effect of heterogeneous spatio-temporal light patterns on wheat yield and quality via an artificial shade system may help plantation managers to optimize agroforestry practices in Southern Xinjiang, Northwest China.

High temperature oxidation of Al86Ce10Fe4 amorphous alloy at 630°C in static air for 15, 60, 300, 600, 1,200, 3,000, 6,000 and 12,000 minutes was studied. The morphology, composition and microstructure of the oxide films were investigated using SEM, EDS and XRD. The hardness and corrosion resistance of the oxide films were determined by micro-indentation and polarization technique. The results indicate oxidation at 630 °C instigates nucleation, growth and coarsening of fcc-Al, Al11Ce3 and Al13Fe5 crystalline phases inside the Al86Ce10Fe4 matrix, reducing the hardness of the alloy, and oxidation of the alloy surface, forming crystallized Al2O3 and AlFeO3 chemical compounds. Active anodic dissolution behavior and diffusion-controlled cathodic polarization of the oxidized alloy were observed. The corrosion resistance of the oxide films rates in the level of 10-7 ~10-5 [A/cm2]. The results demonstrate Al86Ce10Fe4 amorphous alloy, as a new-developed high temperature high strength glass, exhibits potential application for aerospace and national defense in terms of its high mechanical strength, high temperature endurance, and satisfactory oxidation and corrosion resistance.

Aims: The positive soil biodiversity and multifunctionality relationship has been widely recognized, however in agricultural ecosystems, this relationship is context dependent and could be altered by land use intensity (LUI). Understanding how LUI affects soil microbial community and multifunctionality (SMF) is instructive for optimizing external inputs and managements. Methods: We sampled soils from three cropping systems (cotton, wheat-maize and vegetable) with different LUI, sequenced both bacterial and fungal communities, and quantified the multifunctionality by averaging carbon, nitrogen and phosphorus cycling functions. The relationship between soil microbial diversity and SMF was further explored. Results: The results showed that the positive effects of soil microbial diversity on SMF was significantly affected by LUI. In general, LUI decreased SMF and both bacterial and fungal diversity. Cotton and wheat-maize rotation systems with relatively lower LUI showed higher microbial diversity and SMF compared with the vegetable system, which had the highest LUI and the lowest SMF. Moreover, bacterial but not fungal diversity drove this positive relationship between microbial diversity and SMF in both cotton and wheat-maize systems but not in the vegetable system, indicating a larger bacterial effect in lower LUI system. Random forest and structural equation modeling further confirmed bacterial diversity and composition contributed to SMF mainly via promoting carbon and phosphorus cycling. Conclusions: Our findings highlight the importance of LUI in influencing the relationships of biodiversity-SMF and further demonstrate that soil microbial diversity conservation with less anthropogenic disturbances is important for supporting soil functioning in agroecosystems.

Al86Ce10TM4 amorphous alloys (TM = Ti, Cr, Mn, Fe, Co, Ni and Cu; where the alloys are denoted by A1~A7, respectively) were fabricated using melt-spin fast-quenching method. The glass-forming ability (GFA), thermal stability (TS), and mechanical and corrosion behavior of the as-spun alloys were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS), differential scanning calorimetry (DSC), micro-indentation and electrochemical techniques. It was found Al and Ce microalloyed with Ti, Cr, Mn, Fe, Co, Ni and Cu, respectively enhance glass formation, thus the as-spun Al86Ce10TM4 alloys form an amorphous matrix embedded with short range ordered (SRO) Al-TM, Al-Ce and Al-Ce-TM quasi-crystalline clusters due to a strong heteroatomic interaction related to a covalent character of atomic bonds (for A1~A7) or/and inlaid with face-centered-cubic aluminum (FCC-Al) nano-crystallites which were precipitated during the melt-spin quenching (for A1~A3). The GFA of the alloys ranks in the sequence of A4 > A5 > A6 > A7 > A2 > A3 > A1 which can be assessed by the supercooled liquid region ΔTm (=Tm-Tx), the reduced glass transition temperature Trg (=Tg/Tm), and other criteria such as γ′ = Tx/(Tg + Tm), δ′ = Tx/(Tm − Tg), β′ = TxTg/(Tm + Tx)2, and ω′ = Tm(Tm + Tx)/(Tx(Tm − Tx)); while the TS of the alloys lists in the series of A5 > A6 ~ A4 > A7 > A3 > A2 > A1 that can be evaluated by the first crystallization activation energy Ec, first crystallization activation enthalpy ΔH⁎, frequency factor Ko, fragility parameter m, and theoretical glass transition temperature Tg⁎. The hardness of the alloys A1~A7 accounts to 707, 809, 940, 863, 762, 809, and 715 MPa, respectively, attributing to a composite structure consisting of an amorphous matrix tessellated with SRO quasi-crystalline clusters or/and FCC-Al nano-crystallites. In addition, the alloys exhibit high corrosion resistance in the rate of 10−7–10−8 A/cm2 with a large passivation scope except that the alloy A7 presents a corrosion rate of 10−6 A/cm2 with an active anodic dissolution behavior. The results manifest the Al86Ce10TM4 alloys can be fabricated into a unique composite consisting of an amorphous matrix embedded with SRO quasi-crystalline or/and nano-crystalline phases which confers high mechanical hardness and corrosion resistance for potential engineering applications. Keywords: Amorphous alloys, Glass-forming ability, Thermal behavior, Al-Ce-TM, Electrochemistry