【作者】 李传宝；

【导师】 王宏燕；

【作者基本信息】 东北农业大学 ， 生态学， 2012， 硕士

【摘要】 土壤中的氮素和碳素是作物生长所必需的营养元素,随着黑土土壤风蚀水蚀的加重和土壤肥力的下降,明确土壤碳氮关系,对提高土壤碳氮水平和推进秸秆还田的利用来提高黑土土壤肥力具有重要意义。本研究采用“三分法”大垄深松耕作玉米的栽培模式,施加有机肥及秸秆还田配施微生物菌剂,探索秸杆还田对黑土土壤主要物理化学性质的影响。实验为七个处理：小垄处理(TR)、大垄处理(BR)、大垄配施有机肥(BO)、大垄秸秆还田(BC)、大垄秸秆还田配施纤维素分解菌(BCC)、大垄秸秆还田配施表面活性剂(BCS)和大垄秸秆还田配施纤维素分解菌和生物表面活性剂处理(BCSC)。测定指标主要包括农田生态系统的土壤容重、孔隙度、比重、有机质、全氮、土壤微生物量碳、无机态氮(NO3--N、NH4+-N)、土壤可溶性有机碳的含量变化,分析了大垄模式下不同处理对土壤主要物理和化学性状的影响,主要结论如下：大垄处理(140公分垄距)土壤容重低于小垄(65公分垄距),与大垄相比,大垄施加有机肥与大垄秸秆还田处理土壤容重降低显著：尤其是大垄秸秆还田的基础上施加表面活性剂处理和纤维素分解菌和表面活性剂混用处理,大垄秸秆还田的耕作方式更能改善土壤的物理性状。在大垄秸秆还田的基础上,施加纤维素分解菌菌剂亦或纤维素分解菌菌剂与表面活性剂混合施用对土壤有机质含量有促进作用,但没有达到显著水平,而秸秆还田单一配施表面活性剂菌剂处理,显著提高了土壤有机质的含量,使土壤有机质含量提高了13.43%。土壤全氮含量在秸秆腐熟过程中相对降低。大垄处理在玉米的拔节期、灌浆期和成熟期,对微生物量氮、微生物量碳含量的影响均达到了显著水平；以大垄处理为对照,大垄施加有机肥在玉米的整个生育期内显著的提高了土壤微生物生物量氮的含量。同时,在秸秆还田的基础上施加纤维素分解菌菌剂和表面活性剂处理对土壤微生物量碳氮含量的影响也达到了显著水平。各处理土壤可溶性碳含量在玉米的拔节期和灌浆期最高,且大垄秸秆还田处理明显优于对照大垄处理。但施加菌剂处理对可溶性碳含量有所影响,差异不显著。各处理土壤无机态氮含量在供试土壤中玉米的苗期和拔节期差异显著,表现为大垄与大垄秸秆还田处理显著高于其对照。在玉米的抽雄期、灌浆期和成熟期各处理土壤无机态氮含量无显著差异。更多还原

【Abstract】 The soil nitrogen and carbon are the nutritive elements of crops grow. The soil carbon and nitrogen not only be related with the productivity of soil, but also have close contacting with the change of the greenhouse gas in atmospheric. To make clear about the relationship between soil carbon and nitrogen, which will help to improve the level of soil carbon and nitrogen.The experiment was carried out on cultivation corn in experimental base of the Northeast Agricultural University. The purpose of the study was to understand how soil fertility maintaining practices, such as’trichotomy" Big Ridge subsoiling with the return of crop straw to the field, the use of organic fertilizers, and the adding of different microbial agents affected the dynamics of soil microbial biomass carbon (MBC) content. Five treatments of fertility maintaining practices in the field were chosen (where the symbol"+" means combination application):①Traditional small ridge (TR);②Big Ridge subsoiling (BR);③Big Ridge subsoiling+organic fertilizers (BO);④Big Ridge subsoiling+corn straw (BC);⑤Big Ridge subsoiling+corn straw+cellulose decomposing bacteria agents (BCC);⑥Big Ridge subsoiling+corn straw+surface active agents (BCS);⑦Big Ridge subsoiling+corn straw+surface active agents+cellulose decomposing bacteria agents (BCSC).The main conclusions are shown as follow:The treatment of BC’s soil bulk density was significantly lower than TR, but its soil porosity was significantly higher than TR. BC’s soil bulk density and porosity can be better ensure the requirements of the crops. BC or BCSC’s soil organic matter content also be increased on the basis of the straw and Big Ridge, but its did not reach significant level,The treatment of BCS significantly increased the soil organic matter content by13.43%in the maturity of the corn.The total soil nitrogen content was relatively reduced in straw decomposition process. Microbial biomass nitrogen and microbial biomass carbon content of big ridge treatment have been promoted and the effects reached a significant level in the jointing stage、 filling stage and maturity stage.The soil microbial biomass nitrogen content of BO treatment has been improved significantly in n whole growth period of corn compared with the BR.At the same time, the effects of cellulose decomposing bacteria agents and surface active agent treatments on soil microbial biomass carbon and nitrogen content influence also reached a significant level on the basis of the corn straw returning. The soil soluble carbon content was highest in the jointing stage and grain filling stage of the corn between different treatments.BC’s soil soluble carbon content was significantly higher than BR treatment. But the impact of BCC on soil soluble carbon content was not significant. The soil inorganic nitrogen content was significant difference between different treatments during the first two stage s of the corn growth. The performance of the BR and BC’s soil inorganic nitrogen content was significantly higher than CK, But the last three periods in each treatments were no significant differences.更多还原