Study On Water, Nitrogen And Potassium Coupling Effects On Rice In Meadow Soil And Lessive

Based on the measured data pot experiment, applying methods as comparative analysis, regression analysis and statistical analysis in this thesis to analyze character indices of different growth stages of rice such as plant height and number of tillers of rice in different types of soil, influence laws of water demand, water use efficiency(WUE), yield and its components were also analyzed in different levels of water and fertilizer coupling on Rice, the conclusions were as the following :Statistical analysis the plant heigh and tiller number of rice in meadow soil and albic soil in each growth stages, the results showed that it’s difference on the influence of water and fertilizer in different growth stages of rice on plant height and tiller number, plant height of rice in meadow soil could increase by improving the nitrogen application and irrigation low limit after jointing and booting stage.The jointing and booting pumping and opening stage of rice in meadow soils are the most sensitive to water,so it’s needed to supply adequate water, only do this it will not affect the height of the late growth.Significant difference existed on tillering of rice in different growth stages, water is the main influenced factors. Tiller number of rice in both soil could increase by improving the irrigation low limit and amount of N, for meadow soil, the key period is late tillering stage, for albic soil, the the key period is mid-tillering stage.Soil sype made little difference on water demand of rice, while it had big difference on daily water requirement. Changing trend of water demand in meadow soil in different stages is stable and only one peak. While trends of water demand in albic soil changed a lot.Lessive’s daily water demand changed at a large range.Coupling effect of water and fertilizer on WUE of rice in meadow soil and albic soil was significant, its order was X1(irrigation low limit)>X2(N)>X3(K). irrigation low limit had a negative effect on WUE, N and K had inhibitory effect on each other on improving WUE, cooperation between other factors on WUE is of mutual promotion.Water and fertilizer coupling effect on rice yield significantly, its order in both soil was X1(W)>X2(N)>X3(K). all of them showed positive effect. In the meadow soil there existed mutual negative effect between N and K, effects between other factors showed positive. In albic soil,there existed mutual negative effect between N and K, so it did between W and K, while effect between W and N is negative.Considering about both WUE and yield of rice, optimal range of water and fertilizer in this experiment were as follows, for meadow soil: N(309.5~321)kg/hm2, K(107~112.75) kg/hm2, irrigation low limit 67.9%~75%;for albic soil: N(317~322.5)kg/hm2, K(97.75~101.25)kg/hm2, irrigation low limit 66.3%~77.1%.