利用堆肥反应器, 以鸡粪和蘑菇渣为原料进行好氧堆肥, 在堆肥中添加不同浓度的脲酶抑制剂NBPT, 研究其对堆肥氮素转化的影响及保氮效果。结果表明: 添加不同浓度的脲酶抑制剂NBPT对堆肥进程中温度无显著影响, 在堆肥的高温阶段可有效控制堆料pH的升高, 在堆肥高温前期的0~10 d可有效降低堆肥的脲酶活性, 在堆肥中后期10~25 d明显提高全氮含量。堆肥25 d后, 添加0.04 mL·kg-1、0.08 mL·kg-1、0.16 mL·kg-1脲酶抑制剂NBPT分别比CK减少氮素损失6.61%、4.89%和13.51%。堆肥过程中, 堆料铵态氮含量呈升-降-升-降的双峰趋势, 且大部分时间CK处理的铵态氮含量高于添加脲酶抑制剂NBPT处理, 且CK处理铵态氮的两次升高速度均高于添加脲酶抑制剂NBPT处理。在堆肥的升温和高温期硝态氮含量不稳定, 但堆肥结束时, 各添加脲酶抑制剂NBPT处理的硝态氮含量显著高于CK处理。本试验结果表明, 在堆肥过程中添加脲酶抑制剂NBPT可延缓鸡粪中的尿素态氮向铵态氮的转化, 增加堆肥成品中的硝态氮含量。在畜禽粪好氧堆肥中加入脲酶抑制NBPT可起到一定的保氮作用。
By using compost bioreactors, we studied nitrogen conservation in compost treated with urease inhibitor NBPT over a 25 day composting process of chicken manure and mushroom residue feed-stocks under controlled aerobic conditions. In this experiment, NBPT was added at the rates of 0.00 mL·kg-1 (non-NBPT, CK), 0.04 mL·kg-1 (T1), 0.08 mL·kg-1 (T2) and 0.16 mL·kg-1 (T3). Results show that adding NBPT does not result in a substantive variation in temperature over 25-day composting. It also maintains a relatively stable pH during the thermophillic period (high temperatures greater than 50 ℃) of composting. Compared with CK, adding NBPT decreases urease activity during the 0~10-day initial composting, but significantly increases total nitrogen content in the late 10~25-day composting. After 25 days of composting, adding NBPT decreases nitrogen loss by 6.61%, 4.89% and 13.51% respectively in treatments T1, T2 and T3. NH4-N content shows two peaks with alternating low-high trend in the duration of the experiment. For most of the time, NH4-N content in NBPT treatments is lower than that of CK. During two increasing periods, CK exhibits higher velocity than the NBPT treatments. NO3-N content is unstable during the increasing temperature and thermophillic periods. It is, however, obviously higher under NBPT treatments than under CK at the end of the experiment. This result indicates that adding NBPT could retard N conversion from urea-N (contained in chicken manure) to the NH4-N, increasing NO3-N content in finished compost products. NBPT plays a role in minimizing N loss via gaseous ammonia (NH3) by potentially conserving N during composting.