Increasing crop productivity in coastal areas by proper management of potassium fertilizers

Abstract

The field experiment was conducted to investigate the alleviation of the adverse effects of soil salinity in rice by efficient management of potassium fertilizers in coastal saline areas.The salt-sensitive (BRRI dhan28) and salt-tolerant (Binadhan-10) rice cultivars were used as test crops. The experiment was laid out in a randomized complete block design with three replications. There were thirteen treatment combinations viz. T₀ (no K from MoP or SoP), T₁ (K₁₀₀ from MoP at final land preparation), T₂ (K₁₅₀ from MoP at final land preparation), T₃ (K₂₀₀ from MoP at final land preparation), T₄ (K₁₀₀ from MoP in two splits), T₅ (K₁₅₀ from MoP in two splits), T₆ (K₂₀₀ from MoP in two splits), T₇ (K₁₀₀ from SoP at final land preparation), T₈ (K₁₅₀ from SoP at final land preparation), T₉ (K₂₀₀ from SoP at final land preparation), T₁₀ (K₁₀₀ from SoP in two splits), T₁₁ (K₁₅₀ from SoP in two splits) and T₁₂ (K₂₀₀ from SoP in two splits). Muriate of potash (MoP) and sulphate of potash (SoP) were applied in two splits and during land preparation as per treatments. Binadhan-10 (salt-tolerant) rice producedhigher grain and straw yields than salt-sensitive (BRRI dhan28) one under saline conditions. Furthermore, application of potassium fertilizers resulted in significant increases growth, and grain and straw yields of both salt-sensitive and salt-tolerant rice cultivars under saline conditions. The nutrient (NPS) uptake and K⁺/Na⁺ ratio increased in both rice cultivars by application of potassium fertilizers under saline conditions. The higher amount of yield as well as nutrient uptake of both rice cultivars was observed when SoP was applied either in land preparation or two split doses. The K⁺/Na⁺ ratio was found to be higher in T₉ and T₁₂ treatments in salt-sensitive cultivar whereas T₂ and T₃ treatments showed higher K⁺/Na⁺ ratio in grain and straw of salt-tolerant rice cultivar, respectively. Therefore, the present study suggests that rice productioncould be improved in saline areas through application of higher doses of potassium fertilizers particularly split application of sulphate of potash.

Progressive Agriculture 26 (2): 115-121, 2015