EVALUATION OF THE EFFECTS OF SOIL COMPACTION ON HYDROLOGY AND SOIL EROSION

土壤压实对水文和土壤侵蚀影响的评价

• 批准号: RGPIN-2014-05506
• 负责人: Gumiere, Silvio
• 金额: $ 1.89万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681483
• 关键词: EVALUATION; EFFECTS; SOIL; COMPACTION; HYDROLOGY

Soil compaction presents a major issue in modern day farming, and it is suspected that this process is to a large extent responsible for losses in productivity associated with yield reduction in precision agriculture. Commonly defined as the process by which soil grains are rearranged, soil compaction decreases the void between them and brings them into closer contact. The spatial extent of compacted soil is estimated at 68 million hectares worldwide, and in Europe alone soil compaction is responsible for the degradation of 33 million hectares of arable land. Similar problems have been reported in Canada and the USA.*Although compaction is viewed as one of the severest environmental problems in conventional agriculture, it is also the most difficult type of degradation to identify because the symptoms are not always apparent at the surface. Soil compaction reduces infiltration rates, which leads to increased runoff, enhanced erosion and loss of nutrients and pesticides to surface water. It is very well possible that the spatial distribution of compacted areas alters hydrological and sediment connectivity. In addition, reduced infiltration indirectly affects the efficiency of surface and subsurface drainage systems and increases flood risk. Therefore, in order to prevent damage and rehabilitate affected areas, it is essential to develop more advanced modeling tools, create mapping tools, and optimize tillage practices and agricultural machinery.*The long-term objective of the proposed research program is to increase our understanding of how the spatial distribution of soil compaction affects the hydrology and soil erosion at the watershed scale. Outcomes will provide a solid scientific support for improving regulatory government policies related to the application of beneficial management practices (BMPs), and establish methods of identifying contamination sources with better precision.*Short-term objectives of this research program are: (i) to increase our comprehension of the effects of soil compaction on runoff production and erosion at the scale of the soil pedon; (ii) to understand the spatially distributed impact of compacted areas on hydrological and sedimentological connectivity at the watershed scale; and (iii) based on the findings of objectives (i) and (ii), to develop a distributed water erosion model able to account for the effects of soil compaction on watershed hydrological and sedimentological connectivity.*These research program will significantly improve our understanding on how soil compaction contributes to changes in watershed hydrology. Addressing this issue is of paramount importance to ongoing agricultural and earth science research because very few studies to date have attempted to illustrate how soil compaction can influence diffuse and concentrated sediment and nutrient transport during storm events. Research of this topic is essential for developing management strategies in areas where sediment and nutrient losses are significant and present serious risks for the quality of surface waters. However, the manner in which connectivity and associated nutrient and sediment transport are modified by the process of soil compaction remains unclear and may be specific to each watershed. For Canada, Outcomes will provide a solid scientific support for improving regulatory government policies related to the application of (BMPs), and establish new methods for the identification of contamination sources of agricultural watersheds with better precision.

土壤压实提出了现代耕作的一个主要问题，并且怀疑这一过程在很大程度上是导致生产率损失与精确农业产量降低相关的损失。通常定义为土壤颗粒重新排列的过程，土壤压实减少了它们之间的空隙，并将其带入更紧密的接触。全世界估计压实土壤的空间范围估计为6800万公顷，仅在欧洲，土壤压实就会导致3,300万公顷的耕地退化。在加拿大和美国也报道了类似的问题。土壤压实降低了渗透率，从而导致径流增加，侵蚀增强，养分和农药对地表水的损失。 压实区域的空间分布很可能改变水文和沉积物连接。此外，减少的渗透会间接影响地表和地下引流系统的效率，并增加洪水风险。因此，为了防止损害和恢复受影响的地区，必须开发更先进的建模工具，创建映射工具并优化耕作实践和农业机械。结果将为改善与实用管理实践（BMP）相关的监管政府政策提供良好的科学支持，并建立具有更好精度的污染源的方法。 （ii）了解压实区域对流域量表的水文和沉积学连通性的空间分布的影响； （iii）基于目标（i）和（ii）的发现，以开发出分布式水侵蚀模型，能够说明土壤压实对流域水文和沉积学连接性的影响。解决这个问题对于正在进行的农业和地球科学研究至关重要，因为迄今为止，很少有研究试图说明在暴风雨事件中，土壤压实如何影响弥漫性和浓缩沉积物和养分运输。对该主题的研究对于在沉积物和营养损失巨大的领域制定管理策略至关重要，并对地表水质量呈现严重的风险。但是，通过土壤压实的过程修改了连通性和相关的营养和沉积物传输的方式尚不清楚，并且可能针对每个流域具有特异性。对于加拿大，结果将为改善与（BMP）相关的监管政府政策提供良好的科学支持，并建立新的方法来识别以更好的精度来识别农业流域的污染源。