Vol. 12, Issue 7 (2023)

Author(s):
Ebimol NL, Suresh PR and Binitha NK

Abstract:
Kuttanad the rice bowl of Kerala, constitute acid sulphate soils, face different risks like iron and aluminium toxicity, which causes a decline in rice production in the state. A pot culture experiment was carried out to examine suitable amelioration strategies for the management of iron and aluminium toxicity in rice grown in the acid sulphate soils of Kuttanad. Bulk soil samples were collected from the ‘Kari’ lands of Kuttanad, brought to College of Agriculture, Padannakkad, and analysed for various physical and chemical properties. The analytical results revealed the condition of highly acidic pH and toxic levels of Fe and Al in the soil. Experimental treatments were designed based on this analysis according to the recommendations of KAU POP in two different popular rice varieties Uma and Prathyasa. The treatment combinations included lime (T₁); magnesium carbonate + ½ lime (T₂); phosphogypsum + ½ lime (T3); lime + potassium silicate 0.25% + 0.25% boron (T₄); magnesium carbonate + ½ lime + potassium silicate 0.25% + 0.25% Boron (T₅); phosphogypsum + ½ lime + potassium silicate 0.25% + 0.25% boron (T6); and control (T₇). Different parameters like pH, EC, organic carbon available nutrients like N, P, K, Ca, Mg, S, micronutrients B, Zn, Cu, Mn, Fe and Al were analysed at 30, 60 days after transplanting and at the time of crop harvest. The findings of the experiment revealed that application of phosphogypsum + ½ lime with a foliar spray of 0.25% boron and 0.25% potassium silicate significantly improved crop performance. The positive effects of this treatment included increased soil pH and enhanced available soil nutrient content. This further enabled better nutrient uptake by the plant leading to improved yield and other yield attributes of rice. The treatment also reduced Fe, Al, and Mn toxicity in the soil.