Abstract

                                The Permanent Manurial Experiment (PME) of Tamil Nadu Agricultural University Coimbatore was started in the year 1909 and continuously being maintained in order to investigate the effect of continuous NPK fertilization either singly or in combination of two or more with or without organic manures on yield and nutrient uptake by crops. Since 2008 maize- sunflower cropping sequence is being followed under irrigated conditions. The treatment consists of 18 treatments as non replicated plots with plot size of 100 m2. The results obtained in experimental crops of 2011 and 2012 revealed that continuous application of 100 % recommended dose of N,P2O5 and K2 O along with farm yard manure @ 12.5 t ha-1 (INM practice) recorded the highest grain yield of 9179 kg ha-1 in maize and seed yield of 1461 kg ha-1 in sunflower. The highest stover yield in maize was recorded in application of FYM on nitrogen equivalent basis followed by application of poultry manure on nitrogen equivalent basis and INM practice whereas INM practice recorded the highest stalk yield in sunflower. However total uptake of NPK by both the crops was found to be high in INM practice. When compared to balanced NPK fertilization, skipping of any one or two of fertilizer nutrients reduced the yield and nutrient uptake remarkably. Continuous application of organic manure alone also not produced marked increase in yield and uptake as well as imbalanced fertilization. Organic carbon, available nitrogen and potassium status was also recorded high in INM practice for both the crops. In case of available phosphorus, higher P recorded in INM practice and the highest P recorded in the treatment that receiving application of poultry manure on nitrogen equivalent basis irrespective of the crops.

Key words : Fertilization, manuring, maize, sunflower, yield, uptake, soil properties.