Crescimento do trigo e absorção de nutrientes após aplicações de fósforo e potássio em campo salino-sódico do semi-árido

Resumo

Nutrient deficiency is important limiting factor of saline-sodic soils which results in declining crop production in arid climates. The study investigated wheat response to phosphorus and potassium in saline-sodic field of Kohat, Pakistan. The K₂O was applied at 0(K0), 75(K1), 150 (K2) kg ha^-1 as K₂S0₄ and P₂O₅ at (0(P0), 60(P1), 120(P2) kg ha^-1 as (NH₄)₂HPO₄ in three replications under two-factorial randomized complete block (RCB) design. Both treatments significantly enhanced wheat grain (118%) and dry matter yield (60%) at P2K2 compared to control. The P treatments significantly affected leaf P, Mg, SO₄, Ca:P, SO₄:P ratios and soil P, Ca:P, Cl:P and SO₄:P ratios, while K on leaf K, Na, Ca, SO₄concentration, K:Na, K:Ca, SO₄:P,Ca:P ratios and soil pH, Na, K, Ca, SO₄ concentrations, SAR, Na:K, Ca:K and Na:Ca ratios. Leaf Na was decreased to 85.3 mmol (+) kg^-1 at K2 compared to 105.3 mmol (+) kg^-1at P2K0. Negative correlation (R²=0.906) of leaf K:Na was found with Leaf Na concentration. Correlation of dry matter was more positive (R²=0.851) with leaf K:Na than grain yield (R²=0.392). It is concluded that K and P addition might be beneficial for improving crop nutrition and wheat yield in saline-sodic soils.