摘要
秸秆的质量,特别是C/N是影响秸秆分解速率和养分释放的重要因素。在秸秆还田条件下,如何科学合理地施用氮肥是秸秆利用和优化施肥研究的关键问题。本研究以秸秆还田施入碳氮的C/N为切入点,于2012—2013年通过田间试验(设秸秆不还田不施肥、秸秆还田不施氮、秸秆还田施用无机氮肥调节C/N为10∶1、16∶1和25∶1以及秸秆还田施用有机氮肥调节C/N为25∶1处理),研究秸秆还田不同氮输入对小麦-玉米轮作田土壤无机氮、土壤微生物量氮、酶活性以及作物产量的影响。结果表明:1)在C/N为25∶1下,施用有机氮肥和无机氮肥对土壤无机氮含量无显著影响;在施用无机氮肥的情况下,C/N越低土壤无机氮含量越高。2)秸秆还田施氮提高了土壤微生物量氮含量,但是各秸秆还田施氮处理之间差异不显著;秸秆还田不同施氮处理对脲酶活性无显著影响;秸秆还田施氮提高了FDA水解酶活性,并随C/N降低呈升高趋势,施用无机氮肥的效果强于施用有机氮肥的。3)秸秆还田施用无机氮肥显著提高了小麦和玉米地上部生物量,施用无机氮肥调节C/N为10∶1和16∶1相比于C/N为25∶1提高了小麦和玉米的苗期和成熟期地上部生物量;施用有机氮肥调节C/N为25∶1相比秸秆还田不施氮对地上部生物量无显著影响。秸秆还田施用无机氮肥提高了作物产量,施用无机氮肥调节C/N为16∶1产量最高,而施用有机氮肥调节C/N为25∶1有降低作物产量的趋势。综合以上结果来看,施用无机氮肥调节C/N为16∶1较为合理。
The quality of straw affects N release after straw retention. As straw with high C/N ratio could result in N immobilization, additional N is needed to compensate N demand of crop. More and more N fertilizer is applied to soil for high crop yields in China. Therefore, how to scientifically apply N fertilizer is a key problem after straw retention. Based on C/N ratio, we carried out a field experiment to study the effects of different C/N ratios on soil mineral N content, microbial parameters and crop yields during the period of 2012-2013 in a winter wheat-summer maize double cropping system. The field experiment consisted of six treatments： 1） straw removal without fertilizer; 2） straw retention without N fertilizer; 3） straw retention with conventional N fertilizer（C/N ratio 10︰1）; 4）straw retention with mineral N fertilizer（adjusted C/N ratio of 16︰1）; 5） straw retention with mineral N fertilizer（adjusted C/N ratio of 25︰1）; 6） straw retention with an adjusted C/N ratio of 25︰1 using organic N fertilizer（cattle manure）. The results showed that： 1） there was no difference between the addition of mineral N fertilizer and organic N fertilizer on soil mineral N content under the same C/N ratio（25︰1） input. In the case of straw retention amended with mineral N fertilizer, C/N ratio of straw retention had significant influence on soil mineral N content, and C/N ratio was negatively related to soil mineral N content. 2） Straw retention amendment with N fertilizer increased soil microbial biomass N content, while no difference in soil microbial biomass N content among different N fertilizer inputs treatments. Straw retention amended with N fertilizer with sitting in integrated judgment, the urease activity had no remarkably different. Straw retention amended with N fertilizer increased FDA hydrolyase activity, and there was an increasing tendency with the decreasing of C/N ratio. 3） Straw retention amended with miner N fertilizer significantly increased crop above-grou
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2016年第12期1633-1642,共10页
Chinese Journal of Eco-Agriculture
基金
国家高技术研究发展计划(863计划)项目(2013AA102903)资助~~
关键词
秸秆还田
有机氮肥
无机氮肥
C/N
土壤酶
土壤微生物量氮
作物产量
Straw retention
Organic N fertilizer
inorganic N fertilizer
C/N ratio
Soil enzyme
Soil microbial biomass N
Crop yield
