Yield and economic response of soybean (Glycine max L.) to organic manures and biofertilizer inoculation

Introduction

Soybean (Glycine max L.) is an important oilseed and leguminous crop valued for its high seed protein and oil content. The crop has a direct role in edible-oil supply, livestock feed, nutritional security and agro-industrial development. In India, soybean is mainly grown during the kharif season, and Madhya Pradesh occupies a prominent position in the national soybean economy. However, productivity in the rainfed soybean belt is often limited by poor soil fertility, imbalanced nutrient use, low organic carbon and inadequate biological activity in the rhizosphere. Balanced nutrient management is essential for realizing the genetic yield potential of soybean. Although soybean fixes atmospheric nitrogen through symbiotic association with Rhizobium or Bradyrhizobium, adequate phosphorus availability and favourable soil conditions are required for effective nodulation and nitrogen fixation. Phosphate-solubilizing bacteria improve phosphorus availability, whereas Azotobacter can support rhizospheric activity through nonsymbiotic nitrogen fixation and growth-prom substances. Organic sources such as vermicompost improve soil structure, microbial activity and gradual nutrient release, thereby strengthening the effect of microbial inoculants. Exclusive dependence on inorganic fertilizers may increase crop response in the short term but does not ensure sustained improvement in soil health. Conversely, sole organic sources may not release nutrients rapidly enough to meet crop demand during critical stages. Integrated nutrient management combining organic manure, mineral nutrients and biofertilizers is therefore considered a practical approach for improving yield and profitability. Earlier studies have reported favourable effects of Rhizobium, PSB, vermicompost and their integrated use on soybean growth, nodulation, yield and economics (Singh et al., 2007; Sharma et al., 2018; Ulzen et al., 2020) [17,15,18] . The present paper focuses on the yield attributes, yield and economic outcomes of the investigation entitled "Influence of Organic Manures and Biofertilizers on Growth and Yield of Soybean (Glycine max L.)".

Materials and Methods

The field experiment was conducted during kharif 2025 at the Agriculture Research and Development Centre, Sakatpura, Vikrant University, Gwalior, Madhya Pradesh. The experiment was laid out in a Randomized Block Design with eight treatments and three replications. Soybean variety JS-2172 was used. The crop was sown at a spacing of 45 cm × 15 cm with a seed rate of 80 kg ha⁻¹. The recommended dose of fertilizer was 20:40:20 kg N:P₂O₅:K₂O ha⁻¹, applied as per treatment requirement.

Observations on yield attributes, namely pods plant⁻¹, seeds pod⁻¹, seeds plant⁻¹ and 100-seed weight, were recorded at harvest. Seed yield, stover yield, biological yield and harvest index were computed on plot and hectare basis. Economic analysis was carried out by calculating cost of cultivation, gross monetary return, net monetary return and benefit-cost ratio for each treatment. The recorded data were statistically analysed as per the Randomized Block Design procedure, and treatment differences were interpreted using SEm±, CD at 5% probability and CV. [5] , Sharma et al.

(2018) [15] and Ulzen et al. (2020) [18] .

Seed, stover and biological yield

Seed yield, stover yield, biological yield and harvest index followed a similar treatment response. T₈ recorded the highest seed yield (24.80 q ha⁻¹), stover yield (35.40 q ha⁻¹), biological yield (60.20 q ha⁻¹) and harvest index (41.20%). The yield advantage of T₈ over the absolute control was 87.88% for seed yield. T₇ also performed well and remained statistically at par with T₈ for major yield parameters, recording 23.60 q ha⁻¹ seed yield, 34.20 q ha⁻¹ stover yield and 57.80 q ha⁻¹ biological yield. Among single-inoculant treatments, RDF + Rhizobium (T₄) produced better values than RDF + PSB (T₅) and RDF + Azotobacter (T₆).

The response indicates that soybean productivity was improved most when organic manure and microbial inoculants were combined rather than applied individually. The favourable response may be linked with improved nutrient synchrony, effective nodulation, better phosphorus availability and greater assimilate translocation during pod formation and seed filling. These findings are in agreement with the yield response reported by Singh et al. (2007) [17] , Singh et al. (2010) [16] , Sharma et al.

(2018) [15] , Amanullah et al. (2025) [1] and Malviya et al. (2025) [11] .

Economics

Economic analysis clearly showed that the most productive treatment also generated the highest monetary return. The cost of cultivation was highest under T₈ (₹52,000 ha⁻¹), followed by T₃ (₹51,800 ha⁻¹) and T₇ (₹50,500 ha⁻¹), while the lowest cost was recorded under T₁ (₹38,200 ha⁻¹). Despite the higher input cost, T₈ recorded the maximum gross monetary return (₹1,42,562 ha⁻¹), net monetary return (₹90,562 ha⁻¹) and benefit-cost ratio (2.74).

The net monetary return under T₈ was 133.08% higher than the absolute control. T₇ was the next best treatment with ₹1,35,971 ha⁻¹ gross return, ₹85,471 ha⁻¹ net return and 2.69 benefit-cost ratio. RDF + Rhizobium (T₄) also gave favourable profitability, recording ₹1,26,086 ha⁻¹ gross return, ₹79,086 ha⁻¹ net return and 2.68 benefit-cost ratio. The results demonstrate that added expenditure on vermicompost and compatible biofertilizers was compensated by higher seed and stover yield. Comparable economic advantages of integrated nutrient management in soybean were reported by Gangadhar Eswar Rao et al. (2024) [7] and Malviya et al. (2025) [11] .

Conclusion

On the basis of yield and economics, T₈ (50% vermicompost + Rhizobium + PSB + Azotobacter) was identified as the most effective treatment for soybean under the experimental conditions. It recorded the highest seed yield, stover yield, biological yield, harvest index, gross monetary return, net monetary return and benefit-cost ratio. T₇ (50% vermicompost + Rhizobium + PSB) also gave statistically comparable yield performance and may be considered a practical alternative where Azotobacter culture is not easily available. The study confirms that integration of vermicompost with compatible biofertilizers is a profitable nutrient-management approach for improving soybean productivity and farm income under the agro-climatic conditions of Gwalior, Madhya Pradesh.

Acknowledgement

AcknowledgementThe authors acknowledge the School of Agriculture Science, Vikrant University, Gwalior, Madhya Pradesh, for providing academic and field facilities for conducting the experiment.

References

1. Amanullah, Khan A, Shah Z. Effect of phosphatesolubilizing bacteria under integrated nutrient management on soybean productivity and quality. Journal of Plant Nutrition. 2025;48(2):245-258.
2. Aritonang SP, Sidauruk L. Effect of vermicompost on the growth of soybean (Glycine max L.). International Journal of Ecophysiology. 2020;2(1):18-23.
3. Bhattacharyya PN, Jha DK. Plant growth-promoting rhizobacteria: emergence in agriculture. World Journal of Microbiology and Biotechnology. 2012;28:1327-1350.
4. Chaudhari LS, Mane SS, Giri SN. Effect of integrated nutrient management on growth, yield and quality of soybean. International Journal of Pure and Applied Bioscience. 2019;7(2):209-212.
5. Desai CK, Patel GJ, Rana KN. Effect of organic manures, biofertilizers and levels of nitrogen and phosphorus on growth and yield of soybean. Journal of Pharmacognosy and Phytochemistry. 2019;8(2):966-969.
6. Diacono M, Montemurro F. Long-term effects of organic amendments on soil fertility: a review. Agronomy for Sustainable Development. 2010;30:401-422.
7. Gangadhar Eswar Rao G, et al. Effect of organic phosphorus sources and PSB on growth, yield and economics of soybean. Indian Journal of Agricultural Sciences. 2024;94(3):321-326.
8. Jain R, Trivedi SK. Effect of phosphorus and biofertilizers on soybean productivity. Indian Journal of Agronomy. 2005;50(3):200-203.
9. Mäder P, Fließbach A, Dubois D, Gunst L, Fried P, Niggli U. Soil fertility and biodiversity in organic farming. Science. 2002;296:1694-1697.
10. Mahanta D, Rai RK. Effect of phosphorus and biofertilizers on soybean yield. Indian Journal of Agronomy. 2008;53(4):300-304.
11. Malviya R, Sharma R, Patel S. Economic response of soybean to bio-inoculants. Indian Journal of Agricultural Economics. 2025;80(1):112-118.
12. Medic J, Atkinson C, Hurburgh CR. Current knowledge in soybean composition. Journal of the American Oil Chemists' Society. 2014;91:363-384.
13. Richardson AE, Barea JM, McNeill AM, Prigent-Combaret C. Acquisition of phosphorus and nitrogen in the rhizosphere and plant growth promotion by microorganisms. Plant and Soil. 2009;321:305-339.
14. Salvagiotti F, Cassman KG, Specht JE, Walters DT, Weiss A, Dobermann A. Nitrogen uptake, fixation and response to fertilizer N in soybeans: a review. Field Crops Research. 2008;108:1-13.
15. Sharma RK, Gupta VK, Singh R. Effect of integrated nutrient management on nodulation and yield of soybean. Journal of Soil Science and Plant Nutrition. 2018;18(2):345-352.
16. Singh R, Kumar S, Singh P. Effect of PSB on soybean growth and yield. Indian Journal of Agronomy. 2010;55(1):62-65.
17. Singh Y, Sharma PK, Sharma SK. Effect of Rhizobium and FYM on soybean. Journal of Farming Systems Research. 2007;13(1):45-49.
18. Ulzen J, Abaidoo RC, Mensah NE, Masso C. Combined application of organic manure, Rhizobium and phosphorus on soybean. Agronomy Journal. 2020;112(3):1965-1975.
19. Vessey JK. Plant growth promoting rhizobacteria as biofertilizers. Plant and Soil. 2003;255:571-586.