The Study On Fertilization Effect Of Late Rice And Flue-cured Tobacco Under The Rotation System Of Tobacco And Rice

The N, P and K fertilization effect of late rice and tobacco was been studied on White eel clayey paddy soil, paddy lime soil, yellow paddy soil in Guiyang County, Hunan Province by field plot experiment of "3414" design to explore the fertilization effect of rice and tobacco and provide a scientific basis for rational fertilization guiding the local farmers. The fertilization efficiency model of late rice and tobacco production in the tested soil of Guiyang County was established by use of computer technique based on the experiment result. The main results were as follows:1. The effect can be significantly increased by applying of nitrogen, phosphorus and potash under the conditions of the rice and tobacco rotation, the production effect of nitrogen fertilizer is greatest. Respectively the yield of rice was increased by6.6kg and tobacco was8.4kg using1kg of pure N, paddy yield was increased by5.53kg and tobacco was2.90kg by using1kg of K, The interaction is more positive by using the nitrogen, potassium and phosphorus. So, the yield and synergism in the production of rice and tobacco can be significantly increased while increasing the phosphorus and potassium on the basis of a reasonable amount of nitrogen2. According to the result of "3415" field experiment, the composite fertilization efficiency models of tobacco and late rice were also established. The composite fertilization efficiency models were:The composite fertilization efficiency models of tobacco: y=1226.98+7.4951N+1.8962P+2.9566K-0.0407N2-0.0299P2-0.0071K2+0.0291NP+0.0066NK+0.0092PK;The composite fertilization efficiency models of late rice: y=6457.16+1.8644N+12.5637P+8.9701K-0.0555N2-0.1122P2-0.0548K2+0.098NP+0.0702NK-0.0884PK.3. According to the fertilization efficiency models, the optimum economic fertilization and its optimal economic output were obtained for tobacco and late rice.The best economic fertilization of late rice:N=104.90kg/hm2, P2O5=50.65kg/hm2, K2O=101.84kg/hm2, the best available economic yield was7505kg/hm2;The best economic fertilization of tobacco:N=195.35kg/hm2, P2O5=192.0kg/ hm2,K2O=425.5kg/hm2,the best available economic yield was2770kg／hm2.