Microbial Consortium Inoculum with Rock Minerals Increased Wheat Grain Yield, Nitrogen-Use Efficiency, and Protein Yield Due to Larger Root Growth and Architecture

Abstract

Polymer-coated rock mineral fertiliser (RMF) has the potential to increase wheat growth and yield; however, its effect on grain protein concentration (GPC) and nitrogen-use efficiency (NUE) remains unclear. Therefore, we examined the efficacy of slow-release RMF combined with microbial consortium inoculant (MI) compared with inorganic fertiliser (IF) with or without the MI to explore their effects on wheat growth, NUE, GPC, grain protein yield and grain yield. The glasshouse experiment was conducted with three factors (fertiliser type (control, RMF and IF), fertiliser rate (0, 23 and 46 mg N kg−1 soil), and MI (with or without)) replicated four times and harvested twice (anthesis and maturity). The treatments were arranged in a randomised complete block design. NUE was higher in plants treated with RMF plus MI compared to IF (with or without MI), likely due to extensive root system, higher shoot N content (at anthesis and maturity) and grain N content in plants treated with RMF plus MI than IF. The application of RMF enhanced grain yield and GPC compared with IF. The grain yield increased due to more grains in RMF-treated than IF-treated plants. The RMF application increased N content in shoots at anthesis and maturity and grain N content, which increased GPC compared to IF-treated plants. RMF in combination with MI can be viewed as a practical approach to assist RMF in supplying nutrients to improve NUE, grain yield and GPC in wheat.