Effect Of Cultivation Models On Rice Yield Formation And Nitrogen Fertilizer Use Efficiency In Soda-alkali Land

In order to explore the difference of rice yield formation mechanism and nitrogen fertilizer utilization efficiency in the western soda saline-alkali rice region of Songnen Plain,and to improve the yield and fertilizer utilization efficiency of local farmers,different cultivation models were used to improve the yield and fertilizer use efficiency of local farmers.Taking Jijing 88 as the test material,and the field experiment was carried out in the rice test base of Baicheng Agricultural Science Research Institute of Jilin Province from 2017 to 2018.Four cultivation modes were established,including no nitrogen treatment(0N),local farmers cultivation(control),high-yield and high-efficiency cultivation and super-high-yielding cultivation.The differences in photosynthetic production,yield formation,nitrogen use efficiency of rice under different cultivation models were compared and analyzed.The following results were drawn as follows:1.Two-year average yields in high-yield and high-efficiency cultivation and super-high-yielding cultivation reached 10.34 t/hm~2 and 12.16 t/hm~2,which were respectively improved by 8.44%and 27.45%by comparing with the cultivation of peasant households(control).By high-yield and high-efficiency cultivation and super-high-yielding cultivation,the number of productive ear was respectively improved by 3.03%and 34.10%.The number of grain per ear was respectively improved by 4.06%and 9.37%.2.From rice heading to physiological maturity stage,leaf area index(LAI)in the high-yield and high-efficiency cultivation and super-high-yielding cultivation was increased by 9.51%~137.04%and 58.45%~211.11%.Photosynthetic potential was respectively improved by 15.89%and 48.10%.Leaf color value(SPAD value)was respectively increased by 27.61%~62.36%and 19.54%~132.35%.Net photosynthetic rate of leaves was respectively increased by 3.99%~17.35%.Dry matter accumulation from rice jointing to mature stage was significantly improved.3.Compared with the control,nitrogen accumulation in high-yield and high-efficiency cultivation and super-high-yielding cultivation was respectively increased by 9.19 kg/hm~2 and 40.07 kg/hm~2;Nitrogenous fertilizer's rate of absorption and utilization was respectively improved by 4.51%and 13.27%;Agricultural utilization rate of nitrogenous fertilizer was respectively increased by7.97%and 21.50%.Nitrogen partial factor productivity of high-yield and high-efficiency cultivation model was 59.09 kg/kg N,which was significantly higher than cultivation of peasant households(control)and super-high-yielding cultivation.The nitrogen harvest index of super-high-yielding cultivation was significantly lower than other 3 cultivation modes.In summary,the integration and optimization of cultivation techniques in the soda saline-alkaline rice region in the western Songnen Plain can improve the fertilizer utilization rate,promote the accumulation and transport of photosynthetic materials from rice heading to physiological maturity stage,and increase the effective panicle per unit area,increases the number of grains per panicle,increases the yield,the yield can be increased by 8.44%to 27.45%.