Cow manure compost‐based products as alternative rhizobial carrier materials

Cow manure compost (CMC) has been used widely as soil amendment to improve fertility and health, minimize environmental impacts. However, direct use of commercial CMC-based products alternative rhizobial carrier materials is rare, it could promote inoculant commercialization. This research aimed explore the potential four (CMC powder, CMC granular, + 50% gypsum, 30% biochar) a carrier. Peat was standard (control) material. All carriers were directly mixed with Bradyrhizobium japonicum CB 1809 strain prepare inoculants. Shelf life inoculants evaluated up 120 days storage survival rate in determined after 30 under both optimum moisture (55% WHC—water-holding capacity) drought stress (15% WHC) conditions. Results revealed that overall, gypsum product showed better physicochemical characteristics such WHC (126.9 ± 6.87%), Ca (134.15 5.78 mg kg−1), S (104.9 6.52 kg−1) best shelf during at 28°C 35°C temperatures. The difference between other became more apparent higher temperature (35°C) longer-term (120 days). Additionally, when introduced into soil, outperformed peat (control), showing 95% (under moisture) 87% drought) storage. population biochar lowest values 8.66 Log 10 CFU g−1 7.52 shelf-life test temperatures 35°C, respectively, likely due its alkaline pH. Multivariate analysis carriers' WHC, (involved nodule formation stability), (essential for metabolism nitrogenase activity) contents had strong positive correlation long-term confirming importance materials' retention availability specific elements (Ca, S). Hence, highest S, pH, reflecting density compared carriers. work demonstrated great materials, opening an avenue rapid development