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Abstract
Animal manure or organic waste are used frequently by growers to maintain productivity of agricultural soils. Composting is increasingly being used in agriculture due to its contribution to the disposal of waste materials. Nitrogen (N) and phosphorus (P) content in these wastes are in organic forms and must undergo mineralization or hydrolysis reactions to become available to crops as a nutrient source upon application to the soil. Microbial communities are crucial in waste decomposition, regulating nutrient cycling in soil and crop productivity. Use of bio-inoculum agriculture is becoming of more interest to organic and conventional producers. We adapted a locally sourced bio-inoculate for the temperate region, local effective microorganisms (LEM), a fermented mixture of actively decomposing leaf litter and a nutrient rich solution (carbohydrates). We identified the microbial communities in LEM and field studies were carried out to evaluate the efficiency of LEM in reducing N losses as ammonia volatilization during composting, its role in enhancing soil N mineralization and P solubilization in soil where edamame (Glycine max), wheat (Triticum aestivum) and pumpkin (Cucurbita maxima Duchesne) were being grown. We also investigated the effect of LEM in improving macronutrient [e.g., calcium (Ca), magnesium (Mg) and potassium (K)] and micronutrient [e.g., zinc (Zn)] density in edamame bean, wheat grain, and pumpkin (pulp and seed). Our results indicate that LEM contains a wide range of microbial functional groups that includes photosynthetic bacteria, nitrogen cycling microorganisms, phosphorus-solubilizing bacteria (PSBs), and actinomycetes. Significantly greater plant available N was found in the second (2016) and third (2017) years of the study in soils that received LEM, grown with edamame, compared to control (non-chlorinated, well water). Greater plant available P was found in soil during wheat and pumpkin growing seasons compared to the control. Nutrient density of wheat grain, edamame bean and pumpkin pulp and seed showed promising results in response to applications of LEM, especially Ca and Zn.