Uptake and utilization of 15N-urea in grain-straw of a dual-purpose rice strain-202

The uptake and utilization of 15N-urea in a dual-purpose rice strain 202 with grain-straw were studied. The result showed that under equal fertilizing condition the grain characters of strain 202 were the same as that of the control strain 308. The N content in the straw of strain 202 was 37.57% higher than that of CK strain. Strain 308 followed the distribution pattern, in which the N was mostly distributed in panicle when top dressing was done at early stage. N was concentrated in stalks and leaves when the fertilizer was applied at late stage. The utilization of rice straw by animals was investigated by 15N-traced rice straw. The digesting rates of powdered straw of strain 202 by grass carp and mice were 13.6% and 16.5% higher than that of CK respectively. 15N-recovery rates in the both animal bodies when fed with 202 powered-straw were 9.6% and 6.0% higher than that of CK respectively. 15N-recovery rate was 19.1% higher than CK when using 202 rice straw to grow Pleurotus ostreatus. The results indicate that the straw of dual-purpose rice strain 202 is a good material for the comprehensive utilization