Managing soil potassium through green manuring with gliricidia for improving cotton yield and quality of shrink-swell soils of Central India

• Published in: Journal of plant nutrition Vol. 46; no. 14; pp. 3499 - 3518
• Main Authors: Gabhane, V. V., Satpute, Usha, Jadhao, S. D., Patode, R. S., Ramteke, Pratik
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 27-08-2023; Taylor & Francis Ltd
• Subjects: Biological properties; Carbon; Cotton; Crop yield; Fertilizers; Gliricidia sepium; Micronutrients; Microorganisms; Nutrient availability; nutrient management; Organic carbon; Organic soils; Physical properties; Potassium; rainfed cotton productivity; Soil improvement; Soil management; Soil physical properties; Soil properties; Soil quality; Soil shrinkage; Soil swelling; Soils; Substitutes; India
• ISSN: 0190-4167; 1532-4087
• DOI: 10.1080/01904167.2023.2206432

Soil potassium (K) content in the swell-shrink soils of Central India has been decreasing in recent decades due to higher inputs of N and P fertilizers concomitant with lower or no inputs of K fertilizers. Therefore, nutrient management to mitigate the negative K budget is urgently required. Therefore, we aimed to exploit the abundance of K in gliricidia (Gliricidia sepium) to substitute the fertilizer K requirement to improve soil quality and sustain cotton productivity. Results indicated a significant (p < 0.05) improvement in soil physical properties and organic carbon under treatment 100% NP + 10 kg K (inorganic) + 20 kg K (gliricidia) (T
4
). The same treatment had 18.2 and 11.4, 36.22 and 4.7, and 17.8 and 9% higher content of available N, P, and K compared to the control and 100% RDF, respectively. Available micronutrients and biological properties were significantly higher under treatment T
4
and 100% NP + 15 kg K (inorganic) + 15 kg K (gliricidia) (T
3
). Hydraulic conductivity, organic carbon, and microbial biomass carbon were identified as key SQ indicators for the experimental soil. The treatments T
3
and T
4
had about 105 and 122% more seed cotton yield compared to the control and 17 and 27% more than 100% RDF treatment (T
2
). We conclude that gliricidia can be efficiently utilized in the nutrient management packages to partially substitute the fertilizer K requirement of rainfed cotton. This will further address the K depletion and nutrient imbalances and help to restore the soil K in shrink-swell soils of Central India.