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Wednesday, November 4, 2009
Convention Center, Exhibit Hall BC, Second Floor
Abstract:
In 1994 a field experiment started at three locations in Austria to evaluate the effect of different tillage systems on soil erosion, surface runoff, and nutrient and pesticide losses. Following treatments were compared: 1) conventional tillage, 2) conservation tillage and 3) direct seeding. During the whole investigation period crop yields were determined and economic efficiency of the investigated treatments were estimated.
Eight years after initiation of the project main physical, chemical and biological soil properties were determined for all treatments using field and lab measurements. Soil quality was evaluated using a framework including major soil functions. Obtained data from lab analyses were used as model input data. Field measured runoff, soil loss, losses of nutrients and crop yields were used to verify the model results.
Compared to conventional tillage, conservation tillage and no-till reduced soil loss on average by 68 % and 82 %, respectively. The loss of nutrients (N, P, C) was strongly linked to the soil loss. Overall, CS and DS reduced nitrogen loss by 59 % and 71% and phosphorus loss by 71 % and 79%. Reductions in the loss of organic carbon were 68% for CS and 79% for DS. Associated with a decrease in soil erosion a high reduction of losses of pesticides was determined.
Since 2007 the impact of the tillage systems on soil respiration are investigated at one site. Referred to CT plots calculated carbon losses for vegetation period amounted to 65-94% for NT plots while for the different RT plots they ranged between 84 and 128%.
The results show that reduced tillage practices are efficient methods to prevent soil erosion and to improve the functions of agriculturally used soils. Nevertheless site specific conditions like soil and climate have to be considered when choosing the proper erosion control measure.
Eight years after initiation of the project main physical, chemical and biological soil properties were determined for all treatments using field and lab measurements. Soil quality was evaluated using a framework including major soil functions. Obtained data from lab analyses were used as model input data. Field measured runoff, soil loss, losses of nutrients and crop yields were used to verify the model results.
Compared to conventional tillage, conservation tillage and no-till reduced soil loss on average by 68 % and 82 %, respectively. The loss of nutrients (N, P, C) was strongly linked to the soil loss. Overall, CS and DS reduced nitrogen loss by 59 % and 71% and phosphorus loss by 71 % and 79%. Reductions in the loss of organic carbon were 68% for CS and 79% for DS. Associated with a decrease in soil erosion a high reduction of losses of pesticides was determined.
Since 2007 the impact of the tillage systems on soil respiration are investigated at one site. Referred to CT plots calculated carbon losses for vegetation period amounted to 65-94% for NT plots while for the different RT plots they ranged between 84 and 128%.
The results show that reduced tillage practices are efficient methods to prevent soil erosion and to improve the functions of agriculturally used soils. Nevertheless site specific conditions like soil and climate have to be considered when choosing the proper erosion control measure.