mmonia volatilization characteristics of different kinds of high-nitrogen compound fertilizers and their effects on nitrogen balance

【Objective】 With development of single fertilization as a main fertilization practice of maize(Zea mays L.) in northeast China, proportion of high nitrogen compound fertilizers such as controlled release fertilizer, urea formaldehyde fertilizer, and stability fertilizer in the single fertilization increases. In order to clear effects of the yield increase and ammonia volatilization status of different types of high nitrogen compound fertilizers on maize(Zea mays L.) in the same nutrient condition, a field experiment was conductedin a chernozem with maize(Zea mays L.) cropping in the center of Jilin Province, China. 【Methods】 The experiment was conducted from May to October 2013 in chernozem soil in the Huangjiawobao village in Lishu County of Jilin Province with 7 treatments, which were the treatment without nitrogen application(N0), conventional fertilizer(Con), the high-tower fertilizer compound fertilizer processed in high tower(HT), bulk blanding fertilizer(BB), controlled release fertilizer(CRF), urea formaldehyde fertilizer(UF) and stability fertilizer(ST). Each treatment was replicated 3 times. The conventional fertilizer was basal and top-dressed in proportion of 1:2,the other fertilizaters were all basal applicated completely with rate of N, P2O5 and K2O in 224, 88, and 88 kg/hm2. The ammonia volatilization was tested by a ventilation method in situ after the fertilization. Soil samples in the 0-100 cm soil layer were collected by drilling before sowing and after harvest. The yield of each treatment wasweighted, three plants were selected in each plot and divided into straw and grain, the nitrogen uptake was calculated.【Results】 The nitrogen fertilizer application increases the yields significantly. Compared with N0, the yield increase ranges from 18.9% to 24.1%, there are not significant differences among the different types of fertilizers, and the yield are from 12197 to 12899 kg/hm2. The utilization rates of the controlled release fertilizer(CRF), urea formaldehyde fertilizer(UF), and stability fertilizer(ST) are 27.9%, 37.7% and 28.8%, respectively, and the plant nitrogen uptake amounts are 277.5, 299.3 and 279.3 kg/hm2, respectively, which are higher than those in the other treatments. The ammonia volatilization rates at different periods after the fertilizer application show that the overall rate of ammonia volatilization is firstly increased and then decreased, the differences of ammonia volatilization rates of the treatments mainly concentrate in the 3-13 days after the fertilization, the peak of the ammonia volatilization rate is in oreder: conventional fertilization(Con) high-tower fertilizer(HT) mixing fertilizer(BB) controlled release fertilizer(CRF) stability fertilizer(ST) urea formaldehyde fertilizer(UF). The ammonia volatilization amounts of the controlled release fertilizer, urea formaldehyde and stability fertilizer are 10.6, 8.1 and 10.3 kg/km2, respectively, which are equivalent to the amounts of the nitrogen fertilizer in 4.7%, 3.6% and 4.6% and significantly lower than the mixing fertilizer(14.8 kg/hm2) and the high-tower Fertilizer(23.0 kg/hm2). From the nitrogen balance in soil-crop system, it can be seen that the apparent loss amounts of the controlled release fertilizer, urea formaldehyde fertilizer and the stability fertilizer are 103, 79 and 73 kg/hm2, and significantly lower than those of the mixing fertilizer(136 kg/hm2) and high-tower fertilizer(123 kg/hm2). The mixing fertilizer, controlled release fertilizer, urea formaldehyde fertilizer and stability fertilizer improve the nitrogen utilization rate of 7.7%-17.5%, and reduce the nitrogen loss effectively. 【Conclusions】 In chernozem soil and single fertilization mode, the yields of different types of high nitrogen compound fertilizer have no significant differences, which are ranged from 12197 to 12899 kg/hm2. Compared with the mixing fertilizer(BB), the controlled release fertilizer(CRF), urea formaldehyde fertilizer(UF) and stability fertilizer(ST) promote the plant nitrogen uptake, and the utilization rates are improved by 38.1%-86.6%, the ammonia volatilization rates are reduced by 40%-96.5% and the amounts of ammonia volatilization loss are reduced by 39.2%-81.3%. The controlled release fertilizer, urea formaldehyde fertilizer and stability fertilizer effectively keep soil inorganic nitrogen content in corn growth period within an acceptable range and guarantee soil nitrogen supply