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Addition of microsilica improves the mechanical properties of mixtures containing Ca(OH)2 due to the chemical reaction between SiO2 in microsilica and Ca(OH)2 in the composition of prepared mixtures. This study aims to compare the efficiency of different microsilica-based mulches in sand stabilization. Several mixtures were prepared through combining microsilica with clay, lime, gypsum, and cement. Data were analyzed as a factorial experiment based on completely randomized design with treatments including: 1) mulch type: microsilica-clay-lime, microsilica-clay, microsilica-cement, microsilica-lime, microsilica-clay-gypsum, and microsilica-gypsum; 2) thickness: one- and two-layers, and 3) time (7 and 60 days) in 3 replications. Penetration resistance (PR), shear strength (SS), threshold friction velocity (V), and soil loss (SL) were measured. Results revealed that microsilica-clay-lime and microsilica-cement showed the highest PR (6.02 kgcm−2), SS (7.08 and 6.71 Ncm−2, respectively), and V (18.25 and 18.11 ms−1, respectively), and the lowest SL which makes them the most suitable mulches for sand stabilization. [ABSTRACT FROM AUTHOR]

Biobased residues are local and cost-effective sources of soil amendments that can efficiently provide nutrients to crops, enhance soil health and serve as alternatives to mineral fertilizers. The objective of our study was to comprehensively evaluate the soil health and crop productivity of temperate agroecosystems amended with different types of organic residues (biobased residues), including composted food waste (compost), biosolid slurry (biosolids) and liquid anaerobic digestate (digestate), compared with nitrogen fertilizer. The experiment was conducted on a silt loam soil under maize-soybean rotation in Canada, where a wide range of physical, chemical and biological indicators were measured and integrated into a soil health score. Biobased residues resulted in about 50%-60% increase in soil-exchangeable potassium and 10% soil-exchangeable sodium over levels found in nitrogen fertilizer. Soil microbial biomass and the capacity of soil microbes to utilize carbon substrates differed among growing seasons but not among amendment types (p > .05). Crop productivity was similar among amendment types (p > .05). We found that the soil health score of biosolids was positively correlated with shoot and root biomass and negatively correlated with shoot nitrogen (p < .05), while that of nitrogen fertilizer was positively correlated with shoot carbon (p < .05). This was likely because of a variation in the availability of labile carbon and nitrogen among amendment types. Our research also suggests that temperate silt loam soil amended with biobased residues, especially biosolids, supplied sufficient nitrogen without the need for additional nitrogen fertilizer. [ABSTRACT FROM AUTHOR]

Climate change is associated with more intense phases of heat, drought or precipitation that can have a negative impact on soil properties. Our goal was to understand if elevated CO2 (eCO2) and temperature (eT), and a multicomponent (eCO2eT) climate effect will influence soil properties from cereal‐legume intercrops differently compared to sole crops. We hypothesized that cereal‐legume intercrops can regulate climate effects, causing soil properties and greenhouse gas fluxes to be similar to ambient climate conditions. eT and eCO2eT decreased soil organic carbon (C) (p =.001) and nitrogen (N) (p =.003) but increased (p =.011) soil nitrate in all crop systems, compared to ambient conditions. For crop systems, soil ammonium was lower (p =.001) with all climate effects, but nitrate was greater (p =.011) with eCO2 and eCO2eT compared to ambient conditions. The microbial community had a preferential (p =.024) consumption of C3 sources in the sole crops. Climate effects also influenced how C and N were accessed by microbes in all crop systems, shifting (p =.001) species richness and microbial community structure. CO2 fluxes were greater (p =.001) with eT and eCO2, whereas N2O fluxes were greater (p =.005) with eCO2 and eCO2eT. However, greenhouse gas fluxes from the intercrop were similar between eT or eCO2eT and ambient conditions. For soil properties, we rejected our hypothesis since cereal‐legume intercrops did not have an advantage over sole crops to cope with single‐ and multicomponent climate effects, but we partially accepted our hypothesis since greenhouse gas fluxes were similar between AMB and eT or eCO2eT. [ABSTRACT FROM AUTHOR]

Reviewed by Maren Oelbermann In 1989 the World Wildlife Fund (WWF) launched a ten-year campaign to protect a network of Canada's natural regions. Protecting Canada's Endangered Spaces is a report [...]