Swaminathan Hemalatha

Effect of Long Term Fertilizer Experiment on P Dynamics in Inceptisol Swaminathan Hemalatha

The investigation was undertaken to evaluate the long-term effects of different fertilizer schedules adopted over the years in the long-term fertilizer experiment on the properties and fertility status of the soil, P dynamics, enzyme activity related to P fertilization, and nutrient balance after 90th crop of finger millet. There are ten treatments replicated four times in Randomized Block Design. The results revealed that the grain, straw and total dry matter production of the finger millet crop was significantly higher in the treatment that received 100 per cent NPK +FYM. Long term application of FYM in combination with inorganic fertilizers had registered the highest activity of soil enzymes such as Dehydrogenase and Phosphatase compared to the application of inorganic nutrients in various combinations. The N, P and K contents in the finger millet grain and straw and the total uptake of these nutrients by the finger millet crop were significantly higher in 100 per cent NPK + FYM treatment. There was a build up in the soil P status over the years through P fertilization and much of the applied P get fixed when it is supplied through super optimal level of fertilization.