Abstract

                                Magenisium fertilization studies were conducted for two sonsons in magnselum deficient and potassium high soil of Titukkal (near Ootecamund, in the Nilgirls District with Sixteen treatments (combination cf two levels of/lime, two levels of K, O and four levels of magnesium in a spilt-plot design with lime and potassium in the main plots and with potato (Solanum tuberosum L. Var, Kufri jyothi) as the test crop. The results indicated that applicantion of magnosium at the rate of 50 kg Mg/ha was the optimum in incresing the yield of potato crops under Nilgiris conditions. However the relationship between Manesium application and yield was quadratic. Under high calcium content in the soil. lower avilability of magnesium and phosperous and was observed. Further lower uptake of magnesium, phosphorus and potassium under high calsium content was observed Thesa were some of the rossens depressed Mg uptake in addition to widening of Ca: Mg ratio. In the presouce of magnesium the tuber yield variations due to potassium "application was non-significant indicatint that.magonisium could, to certain extent, alleviate the adverse effects of K fertilization. Since an incrase in yiaid was obtained with magnesium application the soil available magnesium was inferred to be limiting pota o yield.

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