秸秆深还不同年限对土壤水分物理性质及抗剪强度的影响

发布时间：2018-10-09 13:17

【摘要】：我国是秸秆产量大国,2006年中国秸秆总量超过7.6亿t。吉林省是中国粮食的主要产区之一,其2010年玉米秸秆产量约为2400万t,价值在15亿元左右。但是秸秆资源的价值却没有得到充分利用,在东北约有30%的作物秸秆在收获后直接原地焚烧,不仅浪费了宝贵的资源,而且对造成空气污染、危害交通安全、增加火灾隐患等方面产生巨大危害。此外,作为粮食主产区的东北黑土区正面临着严重的土壤退化问题,自开垦以来,黑土区的黑土厚度、土壤理化性状和肥力状况日趋恶化,部分地区已经丧失农业生产能力。秸秆中含有丰富的养分原料,其在矿化过程中能够释放大量有机质及土壤和动植物所需的营养元素,本文针对秸秆资源焚烧和农田黑土退化问题,通过将玉米秸秆施入土壤亚表层(20~40 cm),来解决秸秆资源等问题,同时提升土壤肥力、通透性及蓄水能力。过去主要专注于秸秆覆盖和表层浅施后表层土壤理化性质的研究,因此对秸秆深还及土壤亚表层物理特征的研究很少。研究的主要结论如下:(1)秸秆深还之后玉米的生长状况和玉米产量较对照有显著提升,秸秆配施化肥处理中,NPK+O12处理增产效果最显著。(2)秸秆深还三年内表层和亚表层的土壤总孔隙度、非毛管孔隙度、毛管孔隙度、最大持水量、毛管持水量、田间持水量均得到显著提高,其中秸秆在深还两年后各试验处理数据达到峰值。(3)秸秆深还能够增强土壤渗透能力,秸秆深还的第2年水稳定入渗值显著高于其他各处理,秸秆深还处理水稳定入渗值均高于对照。(4)秸秆深还能够促进了0.25 mm微团聚体向0.25 mm大团聚体进行转换,其中秸秆深还2年后效果最显著。(5)土壤粘聚力随含水量的增加呈现显著的先增加后降低的趋势,而内摩擦角呈线性下降的趋势。试验表明秸秆深能够有效降低土壤粘聚力和内摩擦角,且秸秆深还第2年对土壤粘聚力和内摩擦角降低幅度最大,其次是第1年,第3年土壤的粘聚力和内摩擦角出现回升的趋势,但仍然低于CK。
[Abstract]:China is a big country in straw production, the total amount of straw in China exceeded 760 million t in 2006. Jilin Province is one of the main grain producing areas in China. The yield of corn straw in 2010 is about 24 million tons and the value is about 1.5 billion yuan. However, the value of straw resources has not been fully utilized. In Northeast China, about 30% of crop straw is burned directly after harvest, which not only wastes precious resources, but also causes air pollution and endangers traffic safety. Increase the hidden danger of fire and other aspects of great harm. In addition, the northeast black soil region, as the main grain producing area, is facing the serious problem of soil degradation. Since the reclamation, the black soil thickness, soil physical and chemical properties and fertility in the black soil region have deteriorated day by day, and some areas have lost their agricultural production capacity. Straw contains abundant nutrient raw materials, which can release a large amount of organic matter and nutrients needed by soil, plant and animal in the course of mineralization. In this paper, the problems of straw resource burning and farmland black soil degradation are discussed. Maize straw was applied to the subsurface layer of soil (20 ~ 40 cm),) to solve the problems of straw resources, and to improve soil fertility, permeability and water storage capacity. In the past, the physical and chemical properties of the topsoil were mainly studied after straw mulching and superficial application, so there was little research on the physical characteristics of straw depth and soil subsurface layer. The main conclusions are as follows: (1) the growth status and yield of maize were significantly improved compared with the control. (2) the soil total porosity, non-capillary porosity, maximum water holding capacity and capillary water holding capacity of the surface and subsurface layer of straw were increased in the treatment of NPK O 12. The field water holding capacity was significantly increased, among which the straw treatment data reached the peak value two years later. (3) Straw depth also enhanced the soil osmotic capacity, and the water stable infiltration value in the second year of straw depth was significantly higher than that of other treatments. (4) Straw depth could also promote the transformation from 0.25 mm microaggregate to 0.25 mm large aggregate. Among them, the effect of straw depth was the most significant after 2 years. (5) with the increase of water content, the cohesion of soil increased first and then decreased, while the angle of internal friction decreased linearly. The results showed that straw depth could effectively reduce soil cohesion and internal friction angle, and the second year straw depth had the largest decrease in soil cohesion and internal friction angle, followed by the first year. In the third year, the cohesion and internal friction angle of soil increased, but still lower than CK..
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141.4

【参考文献】