Effects of a Combination of Nitrogen Fertilizer and Composted Manure on Production and Nitrogen Use Efficiency of Paddy Rice

Abstract

The experiment was conducted to examine the effects of a combination of nitrogenous (N) fertilizer (FN) and composted manure (CM) on production and nitrogen use efficiency (NUE) of paddy rice grown under greenhouse condition during May – December 2011. A completely randomized design with 6 replications was used. Seven treatments consisted of various combination levels of CM and FN. They were 1) on CM and FN (control). 2) CM 500 kg/rai ©. 3) FN 12 kg N/rai (F12), 4) CM 500 kg/rai+FN6 kg N/rai (CF), 5) CM 500 kg/rai + FN 12 kg N/rai (CF12), 6) CM 500 kg/rai + FN 24 kg N/rai (CF24), and 7) CM 500 kg/rai + FN 36 kg N/rai (CF36). The results showed  that the average plant height in the CF6 was significantly the highest at 48, 62 and 76 days after transplanting. Tillers per plant of the CF12 were maximum. The CF36 had infertile-grain percentage and grains per spike similar to the CF24, but higher than other treatments. Moreover, spikes per plant (15.33) and grain yield (1}006 kg/rai) of the CF36 were the highest. The NUE of the CF36 (37.33%) did not deffer from the CF24 (33.33%), but greater than the CF6 and the CF12, In conclusion,based on grain yield and  NUE, it is recommended using a combination of chemical fertilizer at the rate of 24 kg N/rai and composed manure at the rate of 500 kg/rai.