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Soil Compaction (agriculture), Soil Compaction
In geotechnical engineering, soil compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other liquid) being displaced from between the soil grains, then consolidation (soil), consolidation, not compaction, has occurred. Normally, compaction is the result of heavy machinery compressing the soil, but it can also occur due to the passage of, for example, animal feet. In soil science and agronomy, soil compaction is usually a combination of both engineering compaction and consolidation, so may occur due to a lack of water in the soil, the applied stress being internal suction due to water evaporation as well as due to passage of animal feet. Affected soils become less able to absorb rainfall, thus increasing Runoff (water), runoff and erosion. Plants have difficulty in compacted soil because the mineral grains are pressed together, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Compaction (agriculture)
Soil compaction, also known as soil structure degradation, is the increase of bulk density or decrease in porosity of soil due to externally or internally applied loads. Compaction can adversely affect nearly all physical, chemical and biological properties and functions of soil. Together with soil erosion, it is regarded as the "costliest and most serious environmental problem caused by conventional agriculture." In agriculture, soil compaction is a complex problem in which soil, crops, weather and machinery interact. External pressure due to the use of heavy machinery and inappropriate soil management can lead to the compaction of subsoil, creating impermeable layers within the soil that restrict water and nutrient cycles. This process can cause on-site effects such as reduced crop growth, yield and quality as well as off-site effects such as increased surface water run-off, soil erosion, greenhouse gas emissions, eutrophication, reduced groundwater recharge and a loss of bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabees Compactor Roller
United States Naval Construction Battalions, better known as the Navy Seabees, form the U.S. Naval Construction Forces (NCF). The Seabee nickname is a heterograph of the initial letters "CB" from the words "Construction Battalion". Depending upon context, "Seabee" can refer to all enlisted personnel in the USN's occupational field 7 (OF-7), all personnel in the Naval Construction Force (NCF), or Construction Battalion. Seabees serve both in and outside the NCF. During World War II they were plankowner, plank-holders of both the Naval Combat Demolition Units and the Underwater Demolition Teams (UDTs). The men in the NCF considered these units to be "Seabee". In addition, Seabees served as elements of Cubs, Lions, Acorns and the United States Marine Corps. They also provided the manpower for the top secret CWS Chemical Warfare Service: Flame Tank Group Seabees, Flame Tank Group. Today the Seabees have many special task assignments starting with Camp David and the Naval Support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
