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farm depends on the assumption that it will maximize net farm income and/or reduce risk taking. Factors that contribute to the net farm income include yield, cost of inputs used in crop production (labour, fuel, fertilizer, pesticide, seed and machinery), and expected output (commodities) prices. On average crop yields are generally higher in no-till systems, There is a lower cost for labour, there is a significant reduction in fuel consumption with reduced and no-till as compared to conventional tillage No-till and minimum tillage require fewer trips across the field, allow two or more activities to be combined into one, and permit the use of machines with greater capacity and lower draft No-till reduces run-off because increases runoff infiltration by slowing the flow of rainwater or snowmelt from the field. In no-till fields, there is also more infiltration as compared to tilled yields; consequently this results in fewer pollutants entering the streams and open water bodies. Reduced runoff in no-tillage is also associated with decreased flooding and an increase in soil moisture. However, by not tilling the soil, there is a concern that it may increase leaching of water, nutrients and pesticide to the ground water. There are conflicting reports in the literature about the role of no-till in enhancing leaching. Some studies have found little or no difference in leaching of water and nutrients between no-till and tilled fields while others report greater leaching in no-till soils than in tilled soils No-till reduces sediment loss – The most common pollutants in environmentally impaired waterways are sediment, nutrients, and bacteria. No-till practices reduce the amount of sediment by 60 – 90%. No-till reduces phosphorus loss – No-till practices typically reduce soil erosion and sedimentation losses and may result in less phosphorus lost in runoff. Information on the effects of tillage systems on phosphorus loss is contradictory. Some studies have reported significantly lower dissolved phosphorus losses under no-till as compared to conventional tillage, while other studies have demonstrated that no-till reduced the loss of particulate and total phosphorus in surface runoff; however, it does increase the loss of soluble phosphorus to ground water. No-till reduces nitrogen losses – No till may reduce runoff resulting in less nitrogen loss. Several studies have shown that no-till reduces sedimentation up to 97 % (relative to conventional tillage), and this results in a 75 to 90 % reduction in total nitrogen loss for soybeans planted following corn and 50 to 73 %reduction in nitrogen loss for corn following soybeans. No-till crop production also increases the amount of soil macropores and allows for greater water infiltration, increasing potential for nitrate leaching No-till impact on weeds, diseases and insect population – Adoption of no-till has an impact on weeds, diseases, and insect species diversity and numbers No-till sequesters atmospheric CO2 – In Canada, conservation tillage practices on the farmland offer a large opportunity to sequester carbon and consequently enhance the soil carbon sink. Over the years, various models have been developed to estimate the national potential of CO2 sequestration on the cultivated land Notill enhances wildlife habitat Studies in Canada and the United States have shown that no-till
__________________________________________________________________________________ MSc. thesis; Ecopolis international master, Ferrara Roberto Tinella (2010)