论文部分内容阅读
以保护性耕作13年田间定位试验玉米-大豆轮作黑土为研究对象,探讨了玉米不同生长期(2013年6月至次年4月)0~5、5~10和10~20 cm土层土壤微生物生物量碳(MBC)对耕作方式响应的动态变化.土壤MBC含量采用氯仿熏蒸法测定.结果表明:土壤MBC含量受时间和土层影响显著.免耕和垄作下土壤MBC含量表现为4月最低,各土层最高值多出现在8月,而秋翻各土层土壤MBC含量也表现为4月最低,但最高值出现在6月.同一采样时间下,耕作方式仅显著影响表层0~5 cm的MBC含量,免耕和垄作下土壤MBC含量出现明显的分层现象,表现为在表层0~5 cm富集.各采样时间下免耕和垄作土壤层化率(0~5 cm/10~20 cm)均显著高于秋翻,9月的土壤层化率增幅最大,为67.8%和95.5%.综上,时间和土层显著影响土壤MBC,而耕作方式主要影响表层土壤MBC的积累与分布.免耕和垄作下表层土壤MBC的积累明显.
Taking 13 years of field trials of conservation tillage as test maize - soybean rotation black soil, the effects of 0-5, 5-10 and 10-20 cm soil layers of soil were studied in different growth stages (June 2013 to April) The dynamic changes of microbial biomass carbon (MBC) in response to tillage patterns were analyzed.The MBC content in soil was determined by chloroform fumigation method.The results showed that MBC content in soil was significantly affected by time and soil conditions.The MBC content of soil under no-tillage and ridge cultivation was April The highest in all soil layers appeared in August and the soil MBC content in autumn soil layers also showed the lowest in April but the highest appeared in June.Under the same sampling time, MBC content of 5 cm showed obvious stratification in no-tillage and ridge-mulched soil, which showed that the content of MBC was 0 ~ 5 cm in the surface layer.Under the condition of no-tillage and ridge soil stratification (0 ~ 5 cm / 10-20 cm) were significantly higher than that of autumn turning, and the rates of soil stratification increased by 67.8% and 95.5%, respectively, in September. In conclusion, time and soil affected MBC significantly, while tillage mode mainly affected the MBC of topsoil Accumulation and Distribution The accumulation of MBC in the surface soils under no-till and ridge-planting was obvious.