种还分离模式秸秆还田对土壤生物学特征的影响

发布时间：2018-08-21 11:20

【摘要】：秸秆还田已成为耕地培肥土壤的主要途径,但也可能产生土壤跑墒漏风、影响作物出苗、增加病虫害等不利影响,这是传统的栽培耕作模式不能适应所致,因而我们提出玉米种植与秸秆还田分离的栽培耕作方式。种植行与休闲行年际间轮作,在玉米种植前对休闲行适当深翻加深耕层。种还分离下还田区秸秆量是均匀还田的2倍,必然引起土壤生物特性的变化。因此本文在大田环境中,通过田间原位培养模拟种还分离条件,研究不同量秸秆还田,对0-15、15-30、30-45cm土层土壤有机碳、微生物数量、微生物量碳含量,纤维素酶和过氧化氢酶活性的动态影响。另在种还分离模式下,研究全量秸秆对耕层土壤生物特性的动态变化,及对玉米产量的影响。(1)通过在吉林四平梨树泉眼沟中国农业大学试验站的大田采集0-15、15-30、30-45cm土层土壤,分别添加0%、0.44%、0.88%、1.32%比例的秸秆进行田间原位培养试验,在两年的腐解过程中,各土层土壤有机碳含量、微生物量碳含量均随秸秆还田量增加而增加,不同土层间则表现为0-15cm15-30cm30-45cm。高量秸秆还田显著提高了各层土壤中纤维素酶活性,但不同还田量对过氧化氢酶活性的提升效果差异不显著。年际间对比发现,成熟期不同还田量处理土壤总有机碳、微生物量碳、纤维素酶活性均有降低,降低幅度为8.59%~35.36%、6.74%~29.16%、6.18%~31.72%;但过氧化氢酶活性呈增加趋势,以R3增幅最大(随土层加深,提升幅度为14.14%、10.14%、12.11%)。(2)通过研究种还分离模式下的全量秸秆还田对0-15、15-30、30-45cm土层微生物数量的动态影响,及对玉米产量的影响,结果表明,不同土层秸秆还田后,均提高了土壤中细菌、真菌、放线菌数量,且秸秆还田对表层土壤微生物数量的增势明显,深层土壤微生物对秸秆施入的响应较弱。取样时期不同,土壤中微生物数量表现不同。种还分离模式下进行秸秆还田,对玉米产量有所提高,但与对照没有显著性差异,说明种还分离模式下的表层秸秆还田并没有对玉米的生长产生干扰,造成玉米减产。
[Abstract]:Straw returning to the field has become the main way for cultivated land to fertilize the soil, but it may also produce adverse effects such as soil moisture leakage, crop emergence, increasing diseases and pests, etc., which is the result of the traditional cultivation and cultivation mode being unable to adapt to the situation. Therefore, we put forward a separate cultivation method of corn planting and straw returning to the field. Crop rotation between planting and leisure row, before maize planting, appropriate depth of tilling layer of leisure line. The amount of straw returned to the field under seed separation was twice as much as that of uniform return, which would inevitably lead to the change of soil biological characteristics. Therefore, in the field environment, the soil organic carbon, microbial quantity, microbial biomass carbon content in 0-15 ~ 30 ~ 30 ~ 45 cm soil layer were studied. The dynamic effect of cellulase and catalase activity. In addition, under the model of seed separation, the dynamic changes of total straw on the biological characteristics of topsoil and the effect on maize yield were studied. (1) the soil of 0-1515-30 ~ 30 ~ 45 cm soil layer was collected in the field of Quanyan ditch of Lish Shu, Jilin Province, from the experimental station of China Agricultural University. The in situ culture experiment was carried out with 0.44% 0.88% straw and 1.32% straw respectively. During the two years of decomposition, the soil organic carbon content and microbial biomass carbon content in each soil layer increased with the increase of straw returning amount, and the results showed that the soil organic carbon content and microbial biomass carbon content were 0-15 cm 15 ~ 30 cm 30 cm ~ 45 cm between different soil layers. The cellulase activity in each layer of soil was significantly increased by returning high amount of straw, but there was no significant difference in the enhancement effect of different returning amount of straw to catalase activity. The interannual comparison showed that the total organic carbon, microbial biomass carbon and cellulase activity of soil were all decreased by 8.59 ~ 35.36 ~ 35.36 ~ 29.74 ~ 29.16 ~ 6.18 ~ 31.72%, but the activity of catalase showed an increasing trend, with the increase of R _ 3 being the largest (as the soil layer deepened). The dynamic effects of the total straw returning to the soil layer of 0-1515-30 ~ 45cm soil layer and the yield of maize were studied. The results showed that the return of straw from different soil layers increased the bacteria and fungi in the soil. The number of actinomycetes and returning straw to the field had a significant increase on the number of microbes in surface soil, but the response of deep soil microbes to straw application was weak. The number of microbes in soil varies with the sampling period. Under the model of seed separation, the yield of maize was increased, but there was no significant difference between the seed and the control, which indicated that the return of surface straw did not interfere with the growth of maize, resulting in the reduction of maize yield.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154

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