黑土区施用生物炭条件下的土壤水分运动与溶质运移模拟

发布时间：2017-12-28 08:04

  本文关键词：黑土区施用生物炭条件下的土壤水分运动与溶质运移模拟　出处：《东北农业大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 生物炭 水分运动 溶质运移 坡耕地 黑土区

【摘要】：东北黑土是我国重要的土壤资源,同时黑土区也是我国重要的商品粮食生产和出口区域,粮食产能对于保障我国粮食安全具有至关重要的作用。然而该区多年平均降雨量少且分布不均,年降雨量的80%分布在7~9月份,降雨强度较大,再加上长期以来人类不合理的开发和利用,导致黑土区坡耕地水土壤资源流失现象日趋严重,黑土层逐年变薄、土地生产力降低,严重威胁着黑土区农业水土资源的可持续利用和社会经济的可持续发展。因此,黑土区坡耕地水土资源的利用与保护迫在眉睫。本文基于以上背景,选择位于东北典型黑土带上的黑龙江省北安市红星农场为试验区,以土壤改良剂秸秆生物炭为试验材料,生物炭不仅可以提高土壤肥力、改善土壤结构、增加作物产量,还能固定碳素减缓气候变化。黑龙江省不仅粮食产量大而且秸秆资源丰富,但秸秆利用率低,故秸秆生物炭应用于黑土区的改良达到了“一举多得”的效果。从秸秆生物炭对黑土结构及理化性质、土壤水分运动和养分吸附与滞留等方面,研究生物炭施加于黑土区农田土壤中对土壤理化性质、土壤水分运动和溶质运移参数的影响,进而建立适合研究区域的土壤水分运动和溶质运移模型,对特定场次的降雨进行土壤水分分布和溶质运移模拟。得到初步结论如下:(1)生物炭添加到土壤中使耕层土壤的孔隙度增加,容重降低,改善了土壤结构。土壤饱和含水量、田间持水量、凋萎系数和土壤有效水均随着施炭量的增加而增大,不同处理饱和含水量提高范围为16.50%~32.27%;田间持水量提高范围为0.32%~10.48%;凋萎系数提高范围为:0.28%~10.69%;土壤有效水提高范围为0.34%~10.36%。生物炭添加量对水分参数影响的显著程度依次为饱和含水量、田间持水量、土壤有效水含量和凋萎系数。(2)土壤中的有机质、铵态氮、有效磷、速效钾含量和p H值均随施炭量的增加而变大,有机质和铵态氮含量与施炭量相关性显著;有效磷、速效钾以及p H值与施炭量并无显著相关性。100t/hm2处理的土壤铵态氮、有效磷、速效钾和有机质的空间分布较对照组相比,在含量和均匀程度上都优于后者。土壤铵态氮和有效磷都与有机质表现出极显著的正相关关系,铵态氮和有效磷也呈现出显著的正相关关系,而速效钾与有机质几乎表现为负相关关系。(3)在土壤入渗过程中,对照处理的试验用时最长,其次为25t/hm2、50t/hm2和75t/hm2处理,100t/hm2处理用时最短。同等时间内,添加生物炭处理的累积下渗量都高于对照处理。添加生物炭的土壤比对照土壤的饱和导水率增大幅度为14.05%~194.59%。生物炭施加量越大的处理,饱和导水率的增大程度越显著,不同生物炭处理对土壤水分扩散率的影响不尽相同,土壤扩散率的大小关系为25t/hm250t/hm20t/hm275t/hm2100t/hm2。(4)添加生物炭对土壤持水性的影响有促进作用,当吸力在2~1100 k Pa变化时,各处理在最低吸力和最高吸力下的含水率差值分别为:0t/hm2(0.196 g·g~(-1))、25t/hm2(0.261g·g~(-1))、50t/hm2(0.259 g·g~(-1))、75t/hm2(0.258 g·g~(-1))和100t/hm2(0.298 g·g~(-1));有效含水量与生物炭的施加量之间基本呈正相关关系;孔隙度和土壤水分特征曲线均随生物炭施加量的增加而增大;土壤水动力弥撒参数的模拟值基本表现为随施炭量的增加而增大的趋势。(5)通过对2015年7月和8月两个典型月份的两场降雨进行径流小区的土壤全剖面水分和溶质分布情况的模拟表明,各处理土壤水分表现为由地表往下土壤含水率逐渐增大,随着施炭量的增加,土壤垂直剖面范围内含水量逐渐增加;降雨12 h后土壤表层含水量的变化情况不大,基本在一定范围内呈上下波动状态,但生物炭施加量大的处理土壤水分在表层的波动相对较小,且含水量总体水平较高。各生物炭处理土壤表层溶质含量高于底层溶质含量,且溶质浓度随施炭量的增加而增大。
[Abstract]:Black soil in Northeast China is an important soil resource in China. At the same time, black soil area is also an important commodity grain production and export area in China. Grain production capacity plays a crucial role in ensuring food security in China. However, the average rainfall in the area for many years and the uneven distribution, 80% of the annual rainfall distribution in 7~9 months, the rainfall intensity is larger, and the development and utilization of long-term since human irrational, resulting in black soil region of soil water resources loss in slope farmland is becoming more and more serious, black soil layer thinning, land productivity decreased year by year, a serious threat the sustainable development of agricultural water and soil resources in the black soil region of sustainable use and social economy. Therefore, the utilization and protection of soil and water resources in the sloping farmland in black soil area is imminent. Based on the above background, select the typical black soil zone is located in the northeast of the city of Bei'an Hongxing farm of Heilongjiang Province as a test area, the soil conditioner straw biochar as experimental materials, biological carbon can not only improve soil fertility, improve soil structure, increase crop yield, but also the fixed carbon mitigation of climate change. Heilongjiang province not only has large grain production but also has abundant straw resources, but the utilization rate of straw is low. Therefore, straw biochar applied to black soil improvement has achieved the effect of "multiple gains at one stroke". From the straw biochar on physical and chemical properties, soil structure and soil water movement and nutrient absorption and retention of biological effects of carbon, physical and chemical properties, soil water movement and solute transport parameters of soil on the soil in the black soil area, and then establish the soil water movement and solute transport model for the study area. For specific screenings of rainfall distribution of soil water and solute transport simulation. The preliminary conclusions are as follows: (1) the addition of biological carbon to soil increases the porosity of the plough soil, and reduces the bulk density, and improves the soil structure. The soil saturated water content, field capacity, wilting coefficient and soil available water increased with increasing nitrogen carbon amount, different treatment of saturated water content increased in the range of 16.50%~32.27%; field capacity increase range of 0.32%~10.48%; improve the wilting coefficient range: 0.28%~10.69%; soil available water to improve the range of 0.34%~10.36%. A significant degree of biochar addition on water parameters in saturated water content, field capacity, soil water content and wilting coefficient. (2) the contents of organic matter, ammonium nitrogen, available phosphorus and available potassium in soil and P H value increased with the increase of carbon application. There was a significant correlation between organic matter and ammonium nitrogen content and carbon application amount. There was no significant correlation between available phosphorus, available potassium and P H value and carbon application amount. The spatial distribution of ammonium nitrogen, available phosphorus, available potassium and organic matter in soil treated by 100t/hm2 was better than that of the control group, and the content and uniformity of soil were better than those of the latter. Soil ammonium nitrogen and available phosphorus showed a significant positive correlation with organic matter, and ammonium nitrogen and available phosphorus also showed a significant positive correlation, while available potassium and organic matter almost showed a negative correlation. (3) in the process of soil infiltration, the test used for control was the longest, followed by 25t/hm2, 50t/hm2 and 75t/hm2 treatment, and 100t/hm2 treatment was the shortest. In the same time, the cumulative infiltration of biochar treatment was higher than that of the control treatment. The saturated water conductivity of soil added with biological carbon was increased by 14.05%~194.59% than that of the control soil. The greater the applied amount of biochar, the more significant the degree of saturated hydraulic conductivity increased. The effect of different biochar treatments on soil water diffusivity was different. The size of soil diffusivity was 25t/hm250t/hm20t/hm275t/hm2100t/hm2. (4) promote the effects of biochar on soil water holding capacity, when the 2~1100 K Pa changes in suction, the water content in the lowest and the highest suction suction rate under the difference were: 0t/hm2 (0.196 G - g~ (-1), 25t/hm2 (0.261g) - g~ (-1)), 50t/hm2 (0.259 G - g~ (-1)), 75t/hm2 (0.258 G - g~ (-1)) and 100t/hm2 (0.298 G - g~ (-1)); the basic positive correlation between the amount of available water and biological carbon; increase the porosity and the soil water characteristic curve with the increase of the amount of biochar applied; simulation of soil water dynamic mass parameter values the basic performance increases with increasing carbon content for the trend. (5) simulated runoff through the two months of July 2015 and August of two typical rainfall soil moisture profile and solute distribution showed that the soil moisture from the surface down to the soil moisture content increased gradually, with the increase in carbon content, soil water content gradually increased vertical scope changes; little rain after 12 h of surface soil moisture, basically in a certain range fluctuated, but biochar applied soil moisture at the surface of the large amount of volatility is relatively small, and the water level is higher. The surface solute content of soil surface was higher than that of the bottom solute, and the concentration of solute increased with the increase of carbon amount.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S152.7
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本文编号：1345218