Vol. 8, Issue 7 (2019)

Author(s):
M Malarkodi, M Elayarajan, K Arulmozhiselvan and B Gokila

Abstract:
Permanent Manurial Experiment (PME) was started in Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India during 1909 to monitor the impact of continuous fertilization on crop yield sustainability and soil quality in Alfisol. From 2008 onwards the treatments of PME were revised to eighteen and sunflower - maize cropping sequence is being followed under irrigated condition. The study conducted during 2018 revealed that continuous application of 100% NPK + FYM @ 12.5 t ha^-1 increased the seed yield of sunflower by 21.7 % and grain yield of maize by 11.6 % over 100% NPK besides sustained yield to the greater extent compared to other treatments. Optimal (100% NPK) and 100% NP fertilizers gave comparable crop yields, soil fertility status indicating the lower response to applied K fertilizer as the soil is rich in available K status. The sustainable yield index (SYI) values indicated that sunflower yields were more sustainable than maize. Continuous addition of 100% NPK + FYM at 12.5 t ha^–1 improved soil organic carbon and available nutrient status whereas imbalanced fertilization and unfertilized control decreased the most, results unsustainable yields and soil fertility. Carbon stock during 2018 was highest in integrated addition of 100% NPK + FYM (16.1 Mg ha^-1) and lowest in unfertilized control (8.65 Mg ha^-1). The study emphasis the importance of balanced and integrated application of fertilizers and manures for enhancing soil quality and sustaining crop productivity.