Potassium Fractions, Soil Chemical properties and Water Use Efficiency as influenced by Polyhalite Multi-nutrient Fertilizer and Irrigation Regimes of Bt. Cotton under Inseptisols

Author: Utkarsha V. Amolic, Ritu S. Thakare, V.S. Patil, B.M. Kamble and B.D. Bhakare

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Abstract

Polyhalite is a hydrated sulphate evaporate mineral containing potassium, calcium, magnesium and sulphur with chemical formula K2Ca2Mg (SO4)4.2H2O. Field experiments were implemented to explore the coupling effects of various drip irrigation and fertilizer levels on the soil properties, potassium fractions and water use efficiency of cotton during the years 2020 and 2021 at AICRP on Irrigation Water Management farm, Mahatma Phule Krishi Vidyapeeth Rahuri, Dist. Ahmednagar (Maharashtra). The field demonstrations were laid out in split plot design with three replications. Total fifty four treatment combinations comprising three irrigation regimes as main plot treatment viz., I1-0.8 ETc, I2-1.0 ETc and I3-1.2 ETc and six fertilizer doses as sub plot treatments. viz., T1- Absolute control, T2 - 100% GRDF (125:65:65 N: P2O5: K2O kg ha-1), Mg, S as per recommendation, T3- 100 % N:P2O5 + 100% K2O through polyhalite, T4-100 % N: P2O5: 25 % K2O through muriate of potash + 75% K2O through polyhalite , T5- 100 % N: P2O5: 50 % K2O through muriate of potash + 50 % K2O through polyhalite, T6- 100 % N:P2O5: 75 % K2O through muriate of potash + 25% K2O through polyhalite. Results of study revealed that, Significantly highest water soluble K ( 10.0 mg kg-1), exchangeable K (190.46 mg kg-1), non-exchangeable (867.50 mg kg-1) and total K (14014.44 mg kg-1) content in soil was recorded with treatment F4-100%N:P2O5:25%K2O through MOP+75%K2O through Polyhalite. The fractions of soil potassium were found to be increased along with increasing level of potassium. Soil chemical properties viz., including pH, EC, organic carbon content, available macronutrients and exchangeable cations showed increased significantly with application of 100% N:P2O5:25%K2O through MOP + 75% K2O through polyhalite. Whereas the deficit irrigation at 0.8 ETc recorded maximum water use efficiency and percentage of water saving. Study concluded that polyhalite shows potential as a commercial fertilizer to supply K, Ca, Mg, and S nutrients. due to low release properties of polyhalite, if integrated in to the fertilization program, a more balance and stable flow of nutrients can be achieve

Keywords

Fractions of soil potassium, chemical properties, Bt. cotton, water use efficiency

Conclusion

From present investigation it can be concluded that the fractions of potassium @100% N:P2O5:25%K2O through MOP + 75% K2O through polyhalite showed increase in soil potassium fractions and improvement in soil fertility. The cultivation of cotton without K application resulted into mining of K reflected in reduction of water soluble, exchangeable and non-exchangeable K due to inability to buffer the various pools of K which ultimately could not fulfill the need of cotton adequately. Irrigation regimes with scheduling of deficit irrigation at 0.8 ETc is significant among other irrigation levels with 20 percentage of saving cost showed highest water use efficiency. Whereas Soil chemical properties viz., including pH, EC, organic carbon content, available macronutrients and exchangeable cations showed increased significantly with application of 100% N:P2O5:25%K2O through MOP + 75% K2O through polyhalite.

References

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How to cite this article

Utkarsha V. Amolic, Ritu S. Thakare, V.S. Patil, B.M. Kamble and B.D. Bhakare (2024). Potassium Fractions, Soil Chemical properties and Water Use Efficiency as influenced by Polyhalite Multi-nutrient Fertilizer and Irrigation Regimes of Bt. Cotton under Inseptisols. Biological Forum – An International Journal, 16(4): 170-177.