In tropical environments, most soybean growth studies have utilized rice husk biochar (RHB) in soil, even though it is low in nitrogen, potassium, and phosphorous. This may not give short-term agronomic performance relative to enriched biochar. Moreover, the impact of inoculating soybean seeds with atmospheric nitrogen-fixing bacterium Bradyrhizobium japonicum on nodulation and grain yield has produced inconclusive findings in the literature. This research therefore aims to assess the effect of poultry manure (PM), poultry manure biochar (PMB) and RHB alone and in combinations on grain yield, dry shoot and root biomass of soybeans in the semi-deciduous agro-ecological zone. In addition, the effect of B. japonicum inoculated and non-inoculated soybean seeds on nodulation and grain yield was also investigated. The treatments followed a split plot design studying inoculation and non-inoculation, soil amendments (eight), and control subplot factors, respectively. The results show that the amendment of a ferric acrisol with 4 Mg∙ha−1 PM, 10 Mg∙ha−1 RHB + 2 Mg∙ha−1 PM, and 5 Mg∙ha−1 RHB + 4 Mg∙ha−1 PMB with B. japonicum inoculated seed produced significantly greater grain yield (p = 0.05). PM treatment had a significant (p B. japonicum-inoculated soybean seeds significantly (p = 0.014) increased soybean nodulation. This study suggests that RHB combined with PM or PMB provides a beneficial source of N, P, and K, resulting in improved soybean yield and nodulation in a tropical ferric acrisol.
Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds immense significance for agriculture and ecology alike.Zhongdou 63,a newly developed early-maturing summer soybean cultivar in 2021,exhibits remarkable traits such as high yield,superior quality,multi-resistance,and wide adaptability.In this study,eight distinct rhizobia strains from diverse regions were meticulously screened to identify highly effective strains specifically suited for Zhongdou 63.The aboveground biomass,plant height,chlorophyll content,root length,nodule number,and nodule dry weight of Zhongdou 63 were measured and the data were subjected to statistical analysis.The results demonstrated that Y63-1 is a predominant strain of Zhongdou 63.Subsequently,we conducted further investigations on the broad-spectrum nodulation characteristics of Y63-1.Ten representative soybean cultivars were individually inoculated with Y63-1 and subsequently analyzed for nodule numbers and nodule dry weight in their symbiotic systems with rhizobia.The findings revealed that Y63-1 effectively formed nodules with all ten soybean varieties tested.In summary,our current study identified highly efficient broad-spectrum Bradyrhizobium elkanii strain Y63-1 as the predominant strain in Zhongdou 63 and provided a theoretical foundation for enhancing yield potential not only in Zhongdou 63 but also in other varieties through inoculation with highly efficient rhizobia in production.
Soil microbes play a vital role in improving plant growth,crop productivity,and soil health through solubilization of essential nutrients.Present investigation was conducted to access the efficacy of Bradyrhizobium sp.LSBR-3 and the indigenous phosphate-solubilizing Pseudomonas oryzihabitans LSE-3 in improving the symbiosis,nutrient accumulation,and yield of soybean.The isolate LSE-3,selected on the basis of phosphate solubilization,was screened for beneficial traits,antagonistic activities,and pathogenicity.The levels of indole acetic acid production(50.34±2.35μg mL^(-1)),phosphate solubilization(184.4±7.4 mg L^(-1)),biofilm formation(optical density at 560 mm,1.3896±0.04),siderophore production(121.46±1.61μg mL^(-1)),and 1-aminocyclopropane-1-carboxylate deaminase activity(0.51±0.07 mmolα-ketobutyrateμg^(-1) protein h^(-1))were significantly higher with the dual inoculants(LSBR-3 and LSE-3)than with the single inoculant LSBR-3.The plant growth-promoting traits of single and dual inoculants were evaluated for the synergistic effects on soybean under field conditions.Soybean plots treated with LSBR-3+LSE-3 exhibited improvement in seed germination,plant height,plant biomass,and chlorophyll content compared with the uninoculated control.Dual inoculant treatments resulted in significantly higher symbiotic efficacy evidenced by increased nodulation(40.0±0.75 plant^(-1)),nodule biomass(188.52±6.29 mg plant^(-1)),and leghemoglobin content(11.02±0.83 mg g^(-1) fresh nodule),and significantly increased activities of phosphatase(75.16±3.17 and 58.77±6.08μg p-nitrophenol g^(-1) h^(-1) for alkaline and acid phosphatase,respectively)and dehydrogenase(32.66±1.92μg triphenylformazan g^(-1) h^(-1))compared with the control.Dual inoculation with LSBR-3 and LSE-3 enhanced the uptake of macro-and micronutrients,reduced Na content in shoots,and resulted in 10.85%higher grain yield and ca.US$96.80 ha^(-1) higher profit compared with the control.This is the first report on the effectiveness of combined inoculation o
