Studying On The Manufacture And Effect Of Nitrogen Inhibitor PBP From Banana Pseudostem

Nitrogen is on a chief position of the tri-element of plant nutriton. The applied amount of fertilizer of N is larger than P and K in modern agriculture, but the utilization ratio of N is very low, so some environmental and ecological problems were brought, which threatening the health and existence of humanity. According this, people have been still paying close attentions to increase the utilization ratio of N.In this study, 9 kinds of 'PBP' were taken, which were extracted by different ways from the banana pseudostem discarded in farmland. 12 treatments were designed with 3 replicates, one was blank test as CK, another two (10 and 11) used as contrasts with different DCD(dicyandiamide) contents. In both the urea and ammonium sulfate N-sources, the effects of PBP to soil nitrifying potential and nitrifying capacity was studied by incubation experiment. On the basis of above, the better kind of PBP was chosen to carry out the pot trial in greenhouse at last.The chief results are showed as follows1. The results of simple incubation with the juice of banana pseudostem:The simple incubation verified that the juice contained nitrification inhibitor. The results showed, the nitrifying potential difference reached 5% significant level, among all treatments, and the nitrifying capacity was especially reduced by the treatments of 4, 5, 6 , 7.2. The results of nitrifying potential incubation experimen:The treatments of 3, 4, 5, 6, 7 and 8, were able to reduce the soil nitrifying potential significantly in urea N-source, and retard the hydrolysis of amide nitrogen in a degree. In ammonium sulfate N-source, all treatments were able to reduce the soil nitrifying potential significantly. So the treatments of 3, 4, 5, 6, 7, 8 and 9, had inhibiting effects on the transformations of amide-N and ammonium-N also. The treatments of 1, 2, 10 and 11, only reduced the soilnitrifying potential in ammonium N-source. From above all, we could draw a conclusion: in amide N-source, 3, 6 and 9 showed more inhibition efficiency than others; in ammonium N-source, 6, 7, 8 and 9 showed better.In the respect of ammonium retaining capacity, the treatments of 6, 9, 3, 11, 10 and 7, successively showed better effects with amide-N, and all treatments had a significant capacity of with ammonium-N.With each of the two N-source, those treatments, 3, 4, 6, 7, 8, 9, 10 and 11, were able to reduce nitrogen loss and keep a high level of total amount of N-available (NH₄⁺-N + NO₃-N). 3. The results of nitrifying capacity incubation experimentIn amide N-source, during the first period from beginning to the 28th day, all treatments were able to significantly and gradually reduce the nitrifying capacity; then rapidly increased and got the peak among the 33rd to 49th day.In ammonium N-source, every treatment was able to reduce the soil nitrifying capacity, but the change was not steady in different time. From beginning to the 13th day, the nitrifying capacity of these treatments, 5, 6, 7, 9, 10 and 11,rapidly declined, but the others' capacities changed steadily. After the 23rd day, some treatments' capacities increased rapidly and the others still varied smoothly.The treatments of 3, 5, 6, 8 and 9, could availably retard the hydrolysis amide-N, and retain the level of soil N-amide in a certain degree until the 4th day, then began to lower.In the respect of ammonium retaining capacity, every treatment was able to keep highly the level of ammonium-N in soil before the 18th or 23rd day, then declined rapidly or smoothly. Among the treatments, 4,5,6,7,8,9,10 and 11 had better effects over 49 days.In the respect of retaining N-available (NH₄⁺-N + NO₃-N) and decreasing the loss of nitrogen, 4,5,6,7,8,9,10 and 11 were better. 4. The results of pot trials in greenhouseCompared with blank test (CK) and the treatments of DCD. The treatments, A,B,C and D of PBP, were able to improve the average biomass productions ofpotted plant significantly, Chinese cabbage, A,B,C and E could keep a high...