Effects of Nitrogen Fertilization Management Practice on the Yield and Straw Nutritional Quality of Commercial Rice Varieties

An experiment with treatments comprising of five nitrogen rates (0, 120, 160, 200 and 240 kg n/ha) was carried out to assess the effects of nitrogen fertilization management practice on the grain yield and straw nutritive quality in two commercial rice varieties; mr 211 and mr 219. increases in nitrogen application was found to increase (p<0.01) the grain yield, total spikelets per square meter, number of spikelets per panicle and straw crude protein from 4.56% to a maximum level of 8.45%. it also decreased (p<0.05) the in vitro true dry matter organic digestibility (ivtomd) from 59.1% to 55.14%, neutral detergent fiber (ndf) and acid detergent fiber (adf). there were varietal differences in the straw nutritional properties, where mr 219 had higher ndf, hemicellulose and cellulose (p<0.05) concentration where as mr 211 had higher amount of acid detergent lignin (adl) (p<0.01) and silica (p<0.05) in the straw. between the two varieties, mr 219 is superior to mr 211 in view of the higher grain production and grain: straw ratio. the result from correlation between agronomic characteristics and straw nutritive quality implies that rice varieties with good agronomic characteristics have potential in yielding straws with better nutritive quality