Effect Of Nitrogen And Silicon On Growth And Yield Of Chinese Cabbage

The silicon element is only inferior to the oxygen element in the earth's crust and is an important mineral matrix for most plant. The silicon can promote the vegetables to grow, raise the vegetable's output, improve cultivated soil character, alleviate and reduce the poisoning of heavy metal, protect the vegetables to avoid the germ to invade, enhance resistance and so on.The cabbage (Brassica campestris L.ssp.Pekinensis) which is in the mustard family is an biennial herb and native to the north part of our country. Chinese cabbage is a widely grown vegetable in our country. The studying of effect of N fertilizer and Si fertilizer on the growth and yield of Chinese cabbage plays an important part in safe produce of Chinese cabbage.The experimental material was Weibai No.6. The organic matter of experimental plot soil was 1.27%, the Alkaline hydrolysis nitrogen, Available phosphorus, Available potassium content respectively were 70.0, 37.6, 111.0,617.1mg/kg. The experiment used the D- saturated most superior design and had three repeats. Before sowing seeds, calcium superphosphate (100kg/ 667m2) and K2SO4 (80 kg/ 667m2) were used for base fertilizer in each treatment. The nitrogenous fertilizer and silicon fertilizer were divided to three: urea occupied 40% and silicon occupied 100% in the base fertilizer; the urea occupied 40% before Rosette stage; the urea used 20% before growing into a ball. The main test result was as follows.1. The silicon fertilizer had a significant effect on the yield a of Chinese cabbage. The experiment showed that So did nitrogenous fertilizer. But the effect of Si was bigger than N and there was remarkable interaction between them. The yield was more than 3000 kg/666.7m2 only when the application rates of N was 20.65～35.85 kg/666.7m2 and the application rates of Si was 17.78～39.06 kg/666.7m2 in this experiment.2. The silicon fertilizer had an obvious effect on the Chinese cabbage's growth. Among the treatments, T5 (high N and low Si)'s change was the most remarkable in the aspect of fresh weight and dry weight of root, stem and leaf. T3's Si was most in all treatments, but its growth is obviously slower than others in addition to T1 because excluding nitrogenous fertilizer.3. The use of high nitrogenous fertilizer and low silicon (T5) could increase chlorophyll content, heighten photosynthetic rate, enhance photosynthetic power and augment photosynthetic matter accumulated of the greatest degree.4. The silicon fertilizer had an obvious effect on the Chinese cabbage's resistance. The treatments of T3 (high Si without N) and T4 (low Si and low N) had a low incidence of downy mildew and putrescence. But it hadn't obvious effects on Chinese cabbage's TMV in this experiment.