添加秸秆和生物炭土壤N_(2)O排放对温度的响应

Responses of soil N_(2)O emission to temperature under straw and biochar addition

为探讨添加秸秆和生物炭土壤N_(2)O排放对温度的响应,利用室内培养试验,研究CK(不施秸秆和生物炭)、LC(1%生物炭)、HC(2%生物炭)和HS(2.75%秸秆)4个处理分别在10℃(T1)、20℃(T2)和30℃(T3)3个培养温度下的N_(2)O排放。随培养温度升高,CK、LC、HC和HS处理的土壤NH_(4)~+-N含量降低,NO_(3)~--N含量升高。相同温度下,添加不同物料的土壤铵态氮浓度表现为CK>LC>HC>HS,硝态氮含量表现为HC>LC>CK>HS。不同温度下,添加不同物料的土壤N_(2)O排放差异较大。随着温度的升高(T1~T3),CK、LC、HC和HS处理土壤N_(2)O累积排放量分别升高了46.49%~412.81%、64.69%~456.55%、7.42%~145.96%和105.91%~1421.66%。T3时,生物炭添加越多对土壤N_(2)O排放的抑制作用越明显,LC和HC处理土壤N_(2)O累积排放量显著低于CK处理,减排分别为64.27%和159.43%;添加秸秆显著促进土壤N_(2)O排放,HS处理N_(2)O累积排放量分别比CK、LC和HC处理高了178.12%、456.87%和721.54%。因此,升温有利于土壤N_(2)O排放,秸秆还田促进土壤N_(2)O排放,秸秆制成生物炭后还田显著降低土壤N_(2)O排放。

To investigate the responses of soil N_(2)O emission to temperature under straw and biochar addition,soil N_(2)O emission of CK(without straw and biochar),LC(1% biochar),HC(2% biochar) and HS(2.75% straw) was examined at three incubation temperatures of 10 ℃(T1),20 ℃(T2) and 30 ℃(T3),respectively.The results showed that the concentration of NH_(4)^(+)-N in all the four treatments decreased and the concentration of NO_(3)^(-)-N increased with increasing incubation temperature.At the same temperature,the concentration of NH_(4)^(+)-N in soil under additions of different materials was in an order of CK>LC>HC>HS,and the concentration of NO_(3)^(-)-N was HC>LC>CK>HS.At different temperatures,soil N_(2)O emission under additions of different materials was significantly different.With rising temperature(T1-T3),the cumulative soil N_(2)O emission under CK,LC,HC and HS treatments increased by 46.49%-412.81%,64.69%-456.55%,7.42%-145.96%,and 105.91%-1421.66%,respectively.At T3,the more biochar added,the more obvious inhibition effect on N_(2)O emission.The cumulative N_(2)O emission of LC and HC treatments was significantly lower than that of CK,with a reduction of 64.27% and 159.43%,respectively.The addition of straw significantly promoted soil N_(2)O emission,with the cumulative N_(2)O emission of HS treatment being 178.12%,456.87% and 721.54% higher than that of CK,LC and HC,respectively.Therefore,rising temperature is beneficial to soil N_(2)O emissions,and returning straw to the field promotes soil N_(2)O emissions.Returning straw-derived biochar to the field significantly reduces soil N_(2)O emissions.