| To explore the effect of different components of urea formaldehyde which are synthesized under different conditions and provide a theoretical basis for one time fertilization of summer maize。This article carries out a series of experiments, including synthetic conditions experiment of urea formaldehyde, property analysis experiment, field fertilizer efficiency experiment, ratio effect experiment and nitrogen application amount experiment. The "zhengdan958" was used in field as the tested varieties. In 2014 and 2015 years, this research based on field condition mainly focuses on the influence of the different components of urea formaldehyde on yield, nitrogen use efficiency, above-ground portion nitrogen accumulation rate, soil inorganic nitrogen content. Finally, screen and select the urea formaldehyde fertilizer that accords with growth pattern of summer maize. Main conclusions are as follows:1、Main influence factors of urea formaldehyde synthesis include seven conditions——U/F, temperature, pH and time in two-step reaction. The most critical factor for activity index( AI), cold water insoluble nitrogen(CWIN) and hot water insoluble nitrogen(HWIN) is U/F. Main effect on CWIN occurs during the process of methylene reaction, and the key factors to HWIN are temperatures and pH2 in the first and second steps reaction.2、Urea formaldehyde fertilizer has worked out very well in production increase of summer maize as a one time fertilization. Compared with blank treatment, the average yield of UFI, UFⅡ, UFⅢ fertilization treatments has increased respectively by 25.96%, 27.26% and 24.13%; compared with conventional fertilization(CF), the average yield has increased by 6.53%, 7.63% and 4.98% in two years. Three kinds of urea formaldehyde are all effective in yield increase, and UFⅡ has the highest yield and the best effect.3、The suitable ratio of urea and urea formaldehyde is 40%: 60%. Under the test setting conditions, as to the yield and other indicators, the ratio of 60%:40% is better than the ratio of 50%:50%. Compared with PUFⅠ, UFⅠhad no significant elevation and yield was stable; UFⅡrose by 8.5% as compared with PUFⅡ, and it had the most signif icant effect; Compared with UF III, the above-ground portion nitrogen accumulation amount and yield of PUF III decreased.4 、 In nitrogen application amount experiment, the yield and nitrogen use efficiency of recommended fertilization amount treatments(UF) are better than reduction of nitrogen treatments(RUF). The yield of RUFI was 10038.9 kg/hm2, which UFI is 7.2% higher than that. But when Ⅱ and Ⅲ urea formaldehyde fertilizers reduce 20% nitrogen, their yield had no significant reduction. Especially fertilizer Ⅲ——its yield and above-ground portion nitrogen accumulation amount w ere stable and no signif icant difference. For the same kind of urea formaldehyde fertilizer, nitrogen use efficiency decreases after nitrogen is reduced. But nitrogen partial productivity increases significantly because of reduction in amount of nitrogen fertilizer.5、UFⅡ fertilizer which produced by urea formaldehyde(synthesized under T3 conditions) and urea. When it is used as one time fertilizer of summer maize, its nutrient release can meet the demand of maize for nutrient during the whole growth period. Under the condition that nitrogen is reduced by 20%, UFⅡ still has a good performance. It is the best choice for one time fertilizer of summer maize. Effect of UFⅠ fertilizer is second only to UFⅡ. UFⅠcan basically ensure stable production when proportion of urea formaldehyde is reduced. So it is another good choice for one time fertilizer of summer maize. UFⅢ fertilizer effect is less than UFⅠand UFⅡ,But it has stable yield when nitrogen is reduced by 20%. So it also has some research value. |
PDF Full Text Request