尿酶抑制剂对猪粪氮素水平和挥发性脂肪酸产生量影响的研究

Effect of Adding Urease Inhibitors to Swine Manure on Nitrogen Conservation and Volatile Fatty Acids Emissions

采用室内培养方法,研究评估了苯磷酸二酰胺(PPDA)、环己基磷酸三胺(CHPT)和N-n-丁基硫代磷酸三酰胺(NBPT)3种尿酶抑制剂对猪粪氨的挥发、恶臭化合物的排放、猪粪的化学成分及猪粪中主要菌群的影响。结果表明,3种尿酶抑制剂都能不同程度地抑制氨的挥发,累积更多的尿素。不添加尿酶抑制剂组尿素在2d内基本被水解完;而PPDA组2d内尿素浓度达到4.9g·kg-1粪,然后逐渐水解,至第10d水解完全;CHPT组4d内尿素浓度达到5.2g·kg-1粪,至第14d仍可检测到少量的尿素;NBPT组8d内尿素浓度达到5.9g·kg-1粪,至14d仍可检测到0.8g·kg-1粪。3种尿酶抑制剂抑制尿素水解减少氨的挥发时,可以使更多的氮素以NH4-N的形式得以保留。PPDA、CHPT和NBPT组的NH4-N分别比对照组增加了4.4%(P<0.01)、21.6%(P<0.01)和26%(P<0.01)。NBPT的使用还能降低猪粪pH值,减少戊酸(37.4%,P<0.01)和异戊酸(50.3%,P<0.01)的含量。就猪粪的主要菌群而言,NBPT能减少梭菌(33.7%,P<0.01)和增加乳酸菌(29.4%,P<0.01)的数量,但对大肠杆菌和优杆菌的数量却无显著影响。

60% to 80% of the nitrogen excreted is lost through ammonia volatilization in swine wastes, which is mainly generated from urea. The volatilization of ammonia pollutes environment and leads to an unbalance ratio of nitrogen to phosphorous （N： P） for crop. In this study, three urease inhibitors, phenyl phosphorodiamidate （PPDA）, cyclohexylphosphoric triamide （CHPT） and N-（n-butyl） thiosphosphoric triamide （NBPT） were used to evaluate their ability to reduce urea hydrolysis, ammonia volatilization and odorous compounds emissions. The chemical components and indigenous genera in swine manure were also monitored. The results showed three urease inhibitors at 20mg·kg^-1 manure could inhibit ammonia volatilization and reduced the rate of urea hydrolysis and retained more NH4-N. Little urea was found in untreated groups at 2 d. However, with PPDA treatment, 4.9 g of urea· kg^-1 accumulated at 2 d, and all gradually disappeared at 10 d; CHPT retained 5.2 g of urea·kg^-1 at 4 d, then gradually broken down, but was detected 0.14 g of urea· kg^-1 at 14 d; NBPT conserved 5.9 g of urea· kg^-1 at 8 d and was detected 0.8 g of urea· kg^-1 at 14 d. Compared with the untreated groups, the concentrations of NH4-N in PPDA, CHPT and NBPT groups increased by 4.4% （P〈0.05）, 21.6% （P〈0.01） and 26% （P〈0.01） respectively. In addition, under the NBPT treatment, pH values in manure, emissions of valeric acids （37.4%, P〈0.01） and iso-valeric acids （50.3%, P〈0.01）, and the counts of Clostridia （33.7%, P〈0.01） were reduced, However, with CHPT and NBPT treatments, the counts of Lactobacilli increased by 27.5% （P〈0.01） and 29.4% （P〈0.01）. It was concluded that urease inhibitors could be used to prevent temporarily urea hydrolysis and ammonia volatilization from swine manure.