【摘要】 基于2014-2015年华北农田定位试验,设CK（单施氮磷钾肥）、C1(生物炭4.5t?hm^-2?a^-1+氮磷钾肥)、C2(生物炭9.0t?hm^-2?a^-1+氮磷钾肥)和SR（秸秆还田+氮磷钾肥）4个处理,对施用生物炭和秸秆还田对表层土壤矿质氮（NO₃^--N、NH₄⁺-N）含量以及土壤p H值的影响进行研究。结果表明,不同处理土壤矿质氮的动态变化趋势基本一致,施用生物炭和秸秆还田均可显著提高土壤NO₃^--N含量（P<0.05）,但对土壤NH₄⁺-N含量影响不大。与秸秆还田相比,高量施用生物炭有利于增加土壤NO₃^--N含量。各处理土壤中矿质氮主要以NO₃^--N为主,NH₄⁺-N含量均保持在一个较低水平。将冬小麦整个生育期内各处理土壤NO₃^--N、NH₄⁺-N含量与夏玉米的相比,前者显著高于后者。在整个冬小麦-玉米轮作周期内,高量施用生物炭显著提高了土壤p H值,且各处理土壤NO₃^--N与土壤p H值呈显著负相关（P<0.05）,土壤NH₄⁺-N含量与土壤p H值相关性不显著;而各处理土壤NO₃^--N、NH₄⁺-N含量与土壤含水量均呈显著正相关（P<0.05）。可见,添加生物炭对减少氮素的转化和流失具有较大潜力。更多还原

【Abstract】 Based on the location experiment, which consisted of four treatments（CK, C1, C2, SR） with three replications: CK（single NPK fertilizer）, C1(biochar 4.5t·ha^-1·y-1+NPK fertilizer) and C2(biochar 9.0t·ha^-1·y-1 + NPK fertilizer) and SR（straw return + NPK fertilizer）. The effects of biochar and straw return on mineral nitrogen（N） and p H of the surface soil in farmland of the North China Plain in 2014 and 2015 were studied. Results showed that the dynamic trend of soil mineral N content（NO₃^--N, NH₄⁺-N） were similar. Application of biochar and straw return significantly increased soil NO₃^--N（P<0.05）. However, there were no significant effects on soil NH₄⁺-N. Compared with SR treatment, C2 treatment was more helpful to increase soil NO₃^--N. The mineral N in the soil was dominated by NO₃^--N, and NH₄⁺-N was kept at a low level. The contents of soil mineral N in the whole growth period of winter wheat was higher than in that of summer maize. Biochar significantly increased soil p H（P<0.05）, and soil NO₃^--N was negatively correlated with soil p H（P<0.05）, and soil NH₄⁺-N was not correlated with soil p H. But soil NO₃^--N and NH₄⁺-N were positively correlated with soil moisture content in each treatment（P<0.05）. In short, adding biochar had greater potential in slowing N transformation, reducing N mobility and so on. The results can be used a scientific reference on improving soil quality and reducing soil N loss in farmland.更多还原