Effects Of Different Soil Fertility Levels And N Application Rate On Super Rice Xu Dao 3 Yield, Quality, Nitrogen Absorption And Utilization After Wheat In Huaibei Region

The test was carried on in the ping ming town of dong hai of Huai bei reigion of Jang Su in 2007-2009,taking the rice as an object which is in the south of Huang huai region after wheat. In this district, choose representative seed—Up Dao 3 as materials, six nitrogen levels was set up after rice in three kinds of high, middle and low different fertility levels field. This test had systematically studied nitrogen application rate on rice yield and its composition, physical production index, the quality and the effect of nitrogen uptake and utilization etc, for the rice high-yield, high-quality and high-efficiency production provides theory basis. The main result of study was following:1. There were prominent conic section relation among the nitrogen application rate and output at very fertility level. By equation can calculate the maximum yield of Xu Dao 3 in high, middle and low fertility soil, respectively were 716.5㎏·667m-2,652.5㎏·667m-2,584.8㎏·667m-2.The appropriate nitrogen application rate which the high-yield rice needed in the high ,middle and low fertility,respectively were 17.4㎏·667m-2,19.4㎏·667m-2,22.8㎏·667m-2. In the three best nitrogen fertility conditions, have corresponding safety capacity storage, there is enough grain output and coordinate corresponding higher panicle. The group also has the reasonable formation dynamic, leaf area index, photosynthetic potential, the net assimilation rate and high growth rate. So in supper rice Xu Dao 3 production process,different target yield and corresponding nitrogen should be made with the level of fertility.2.The brown rice rate,head rice rate,perfect head rice rate of super rice Xu Dao 3 showed the linear trend according with the increasing quantity of N at three different fertility level. The chalkiness ratio exhibited significant and very significant differences at the different nitrogen and fertility level, chalkiness ratio which showed the linear downtrend following the increasing of nitrogen ,high fertility was significantly higher than medium and low fertility; there was little difference of the chalkiness degree among the three different kinds of soil, the chalkiness degree dropped slightly according with the fertility levels, but the change was slight ,there was no obvious rule at the different nitrogen and fertility levels. The cooking and eating ,the amylase exhibited the linear downtrend at the different nitrogen and fertility levels, the high fertility was higher than medium and low fertility level; the gel consistency showed the opposite trend as the amylase; the eight eigenvalue of the up Xu Dao 3 at different nitrogen and fertility level, which the peakviscosity, hotpaste viscosity,breakdown value, final viscosity, recovery showed downtrend, elimination showed the uptrend,peak viscosity and temperature variation law were not obvious. After analysis of screening,when the nitrogen respectively was 14.9㎏·667m-2,19.8 kg·667m-2,24.8 kg·667m-2,the rice quality was best.3. The nitrogen uptake of Up Dao 3 showed significant linear positive correlation with the nitrogen at the early and middle growing stage, which showed the first increased and then decreased trend at the late growing stage; the stage accumulation of nitrogen showed the same trend as the nitrogen uptake; the nitrogen uptake intensity showed the trend that, the high fertility>medium fertility>low fertility; when nitrogen application rate was 9.9㎏·667m-2,absorption efficiency of nitrogen and agricultural utilization ratio of the nitrogen were both the highest under every fertility condition. Because of the comprehensive functions of rice nitrogen of factor in many aspects of absorbing and shifting etc, each treatment of nitrogen application rate at different fertility levels appeared relative supreme nitrogen use efficiency. But this kind of nitrogen use efficiency rose notably with the improvement of the fertility level, on the contrary, the corresponding nitrogen application rate what could achieve the supreme nitrogen use efficiency was relatively small on high fertility, the supreme nitrogen use efficiency of rice under the high medium and low fertility condition appeared in the treatments which nitrogen application rates were 17.1㎏·667m-2,18.9㎏·667m-2,22.9㎏·667m-2separately.Therefore, to obtain the high-efficient of nitrogen utilization in rice production, different accurate nitrogen application rates should bee made with the level of the fertility.By studying the rice yield, quality and nitrogen uptake and utilization of corresponding analysis, namely rice high-yield, high-quality and high-efficiency nitrogen, take the same part of the N, could get the appropriate nitrogen application at the three different soil fertility, this can be as the reference scope of nitrogen, respectively was the high fertility 15～17 kg·667m-2,the middle 18～20 kg·667 m-2,the low21～23 kg·667m-2.