Abstract:
An experiment entitled “yield maximisation of direct sown rice under puddled condition” was conducted at Rice Research Station, Moncompu, Kerala Agricultural University, during the additional crop season (Kharif) of 1995 to study the effect of combined use of organic manures and inorganic fertilizers under different plant population for enhancing rice yield in the lowlands of Kuttanad using the variety Pavizham. Factorial combinations of two levels each of organic manure and seed rate and three levels of chemical fertilizers were tried in Randomised Block Design with three replications. Organic manure addition @ 10 t ha -1 was found to have pronounced effect on various growth and yield attributing characters of rice when applied alone and/or in combination with chemical fertilizers at recommended dose of 90: 45: 45 kg NPK ha-1 and at increased seed rate of 133 kg ha -1. At normal seed rate also, organic manuring resulted in higher yields in combination with chemical fertilizers at the higher level of 120: 60: 60 kg NPK ha-1. The available soil N content after harvest was significantly reduced from the content prior to experimentation in all the treatments. The available P status was maintained at the initial level in all the treatments. The efficiency of applied N in terms of grain production/ kg of N applied was greater when organic manures were applied along with inorganic fertilisers. In the absence of organic manure, the apparent recovery of N at normal rates of application was greater than that at higher levels.
