Assessing the Co-composting of Wheat Straw: A Study on Compost Quality and Phosphorus Levels for Improved Soil Biochemical Responses and Maize Growth

The objective of this study was to investigate the influence of composting method on changes in compost structure and to evaluate the effects compost, phosphorous levels and Streptomyces inoculation on soil biochemical properties and the growth of forage maize in a loess soil. The effect of simultaneous application of urea and Streptomyces inoculation in the decomposition of wheat straw and the formation of mature compost was investigated. A 90-day pot experiment was conducted to assess the alterations in soil microbial activity, enzymatic activity, nutrient concentrations in both soil and plants, and the growth characteristics of maize plants The soil was thoroughly mixed with 2% compost (simple (C1) and enriched (C2)) and four levels of phosphorus (0, 10, 40, and 100 mg kg⁻¹); Additionally, two levels of Streptomyces were inoculated on maize seeds. Field emission scanning electron microscopy and Fourier transform infrared spectroscopy revealed compositional and morphological changes during composting. Pot experiment demonstrated enhanced maize growth with enriched compost, Streptomyces inoculation and phosphorus fertilization. These treatments significantly increased plant biomass and nutrient content. Soil biochemical analysis showed increased microbial activity, enzyme levels, and organic carbon content with compost and Streptomyces. Phosphorus application improved soil fertility and enzymatic activity. Simultaneous application of compost, triple superphosphate and inoculation with Streptomyces led to a significant increase in soil-available phosphorus and plant phosphorus content. The findings of this study highlight the importance of combining compost, phosphorus, and Streptomyces for optimal maize growth and enhancing crucial soil microbial and biochemical functions.