Effects Of Fertilization On Rice Growth And Resistance To Pests And Diseases

The Dianshan Lake is located in the western suburbs of Shanghai,at the upstream Huangpu River which belongs to the drinking water sources areas of Shanghai. In order to protect the water environment in Shanghai, any industries around the Dianshan lake were forbidden in the history.However,the surroundings of the Dianshan Lake have about 20000 acres of paddy fields around it. The inputs of large amounts of chemical fertilizers and pesticides pose great threat to the surrouding water-source areas of the Dianshan Lake. Therefore,under ensurance of the premise with the rice yield, the development of the fertilizer reduction farming around the Dianshan Lake is of significant importance to protect the water source areas in Shanghai. This work mainly studied the effects of different fertilizer applications including the treatments of no fertilizers(CK),low cake manure(CML), high cake manure(CMH) and chemical fertilizers(CF), and on rice growth and the incidences of rice pests and diseases, under the conditions of no using any pesticides in the year2013.And study the occurrence of rice pests and diseases, and monitor the soil and water environment changes in the paddy field.Explore an optimum fertilization model which conducive to crop growth and control the incidence of pest and disease,to improve the theory and methods for implementing the the chemicals reduction organic farming around the Dianshan Lake.1、CF treatment rice seedlings height, ammonium, nitrate, chlorophyll, soluble protein and soluble sugar content and other indicators were significantly higher than other fertilization treatments and the control check.The tillers of CMH treatment in rice grain filling period(September 15) was significantly higher than CF treatment.CMH and CML treatments rice plants physiological and chemical indicators were significantly higher than CK treatment.It suggested that fertilizer make since quickly,the plants accumulate nutrients faster, and promote the rapid growth and photosynthesis of rice plants.And the cake manure fertilizer make since slow,nutrient accumulation is less than fertilizer,conducive provide lasting nutrient supplyto the plants.2 、 It had significant effects for fertilization on the nutrient of rice soil and water.One day after fertilization, CF treatment surface water ammonium, nitrate, total nitrogen, soluble phosphorus, phosphorus content rising rapidly, significantly higher than other treatments, but one to two weeks later,it rapidly dropped significantly.Each nutrition indicators of CMH treatment in surface water kept at a low and stable level,but the chroma had been significantly higher than other treatments.Similarly,CF treatment was applied to make paddy soil ammonium nitrogen, total nitrogen, total phosphorus increased rapidly, and it was significantly higher than other treatments.Therefore, excessive use of fertilizers conventional farming surface water and soil nutrients instantly rise, could easily lead to agricultural nonpoint source pollution which pose a threat to surface and groundwater.The use of cake manure as an organic fertilizer, make low effective nutrients of field surface water,and can effectively reduce agricultural nonpoint source pollution.3、Fertilization can increase the amount of soil microbe,the effect of cake manure is more significant.The quantity of soil bacteria, fungi and actinomycetes of CMH treatment was the highest.CF treatment was slightly lower than the number of bacteria CML treatment, but CF treatment actinomycetes and fungi were slightly higher than CML treatment.This is because the bacteria are prokaryotes, may be more susceptible to toxic fertilizerCake fertilizer could significantly increase soil dehydrogenase activity, CF treatment inhibiting dehydrogenase activity.But because of the increase in the content of urease substrate,CF treatment can significantly improve the urease activity.To improve soil phosphate enzyme activity cake manure was stronger than the chemical fertilizer.The effect of application of fertilizer and cake manure fertilizer on soil catalase enzyme activity had no significant differences.In the whole process of rice grown,only during the period of growing out the ear and filling in rice, CMH and CF treatments can significantly improve the soil invertase activity, and other period period of time had no significant effect on invertase activity.4、In the late rice growth for the CF treatment,the incidence of medinalis, borer and planthoppers are significantly higher than other treatments.In particular, CF treatment borer incidence is about 10 times of other treatment and CK treatment,planthoppers quantity was 1.73,1.42,3.04 times of CMH,CML, CK treatment,respectively.The application of chemical fertilizer makes excessive accumulation of nitrogen nutrients in plants, leads to lower resistance to pests and diseases, and the rice plants can easily be attacked by pests and diseases.Cake manure fertilizer use can effectively enhance pests and disease resistance in rice.The incitence of pests and diseases was also effected by the annual weather..For the rice growing season in 2012,it had a higher rainfall, and strong tropical storms occur many times. And the year 2013 sustained high temperatures, no big wind weather.The weather with temperature and humidity and strong winds is conducive to pests and diseases.Rice sheath blight, rice stem borers incidence and the number of planthoppers in 2012 was much higher than in 2013.5 、 The actual yield of CK, CMH, CML and CF treatment is 7.45×103kg hm-2,8.85×103kg hm-2,7.41×103kg hm-2 and 3.70×103kg hm-2, respectively. It suggested that the CF treatment can enhance the growth of rice plants, but the occourrence of pests and diseases is very serious, and the yield is the lower when compared with CMH and CML treatment. Therefore, applying fertilizer needs with the use of pesticides in order to ensure a high yield, but the dual role of chemical fertilizers and pesticides pose a great threat to the environment.