Effect Of Manure-N And Inorganic Fertilizer-N Incorporation On Yield Of Rice And Wheat And Soil Nitrogen Supply

A field experiment was conducted in jintan, Jiangsu province from 2006 to 2007 to investigate whether manure nitrogen can be used to partly replace inorganic fertilizer N in rice/wheat rotation system. The treatments were control (unfertilized), inorganic fertilizer, manure/inorganic nitrogen incorporation at the rate of 25%/75%, 50%/50%, and 100%/0%, respectively. The results obtained are listed as follows.1. Experiments of rice/wheat in 2006-2007 showed that the treatment of only inorganic-N is the highest in the soil mineral N after fertilizing in the period of tillering, and is 23.8%-39.2% higher than the two treatments of manure-N and inorganic fertilizer-N, but there aren't any difference among other treatments in soil mineral until maturaing stage ; but in rice season in 2007, theatments of manure-N and inorganic fertilizer-N have the highest content of NH₄⁺-N, 17.9-17.6 mg/kg, and are 18.5%-16.6% higher than the treatment of only inorganic-N in tillering stage. The result showed that there was a significantly positive effect of manure and inorganic nitrogen application on soil mineral nitrogen.2. In the two experiments of rice, the biology yield of the treatments of manure-N substituted inorganic-N is 3.6%-32% higher than the treatment of inorganic-N only; in wheat season of 2007, biomass accumulation of the treatment of inorganic-N is the tiptop ,50.1%, 20.1 % and 2.1% higher than the other fertilized treatments. According to the experments, compared with inorganic nitrogen fertilizer only, manure/inorganic nitrogen incorportation is propitious to conlony structure of rice and wheat in the bearing prophase, and make good basic for havst.3. The nitrogen accumulation of wheat in the treatment of inorganic-N only and manure/inorganic nitrogen incorportation(50%N/50%N) are 11.5% and 6.1% lower than the treatment manure/inorganic nitrogen incorportation (25%N/75%N) in 2007 In rice season of 2007, the treatment of manure/inorganic nitrogen incorportation (50%N/50%N) got the highest accumulation of nitrogen. The result showed that inorganic-N substituted by manure-N can urge more nitrogen transporting from stem and leaves to grain and the corpcanabsorg more nitrogen.4. The rice-wheat-rice field experment from 2006 to 2007 showed that the gain yield of the 25% manure-N substituted inorganic-N treatment is similar with the inorganic-N only. The result demonstrates that manure-N only can't increase gain yield, it should make use with inorganic-N all together. Aslo, appropriate ratio of the manure nitrogen with the inorganic fertilizer nitrogen can improve rice production.5. In rice season of 2006 and wheat season of 2007, nitrogen use efficiency of the 25% manure-N substituted inorganic-N treatment is 4.7% and 7.4% higher than the treatment of inorganic-N only, respectively, in rice season of 2007, nitrogen use efficiency of the treatment of 50% manure-N substituted inorganic-N is the tiptop, 25.2% and 19.3% higher than the treatment of 25% manure-N substituted inorganic-N and the treatment of inorganic-N only. It demonstrates that employing manure-N can increase nitrogen accumulation of rice and wheat, and enhance nitrogen use effency.To conclude, the application of organic-inorganic mixed fertilizers could improve the soil nitrogen supplying characteristics and synchronize the soil nitrogen supplying process with the requirement by crops. And better crop yield and quality could be obtained in the application of the manure-N and inorganic fertilizer-N. Summarily, appropriate ratio of the manure nitrogen with the inorganic fertilizer nitrogen can improve soil nitrogen supply and rice production. Therefore, the manure-N and inorganic fertilizer-N will have a brilliant future in the development of sustainable agriculture.