New study shows: Conservation tillage depends on the use of herbicides such as glyphosate
A recent paper from the Justus Liebig University Giessen (Germany) has presented data that highlights the advantages of conservation tillage with the help of herbicides and in particular the role of glyphosate in sustainable agriculture.
Ploughing (a form of tillage) encourages the erosion of soil by water and wind. As loss of fertile soil is becoming a real challenge for farmers, other forms of tillage are being considered such as cultivation of catch crops before summer crops which provide cover for the soil surface with organic material throughout the year. Maize grown without tillage (© Monsanto) This practice also leads to an increase in soil organisms, especially earthworms which have a positive effect on topsoil stability. Conservation tillage practices therefore reduce the vulnerability of the soil surface and increase water absorption and water holding capacity of the soil.
According to the study, two million hectares (ha) or 17.3 per cent of total arable area in Germany is classified as land with high soil erosion risks. As a consequence there is potential for soil loss of up to 15 tons/ha annually which corresponds to a topsoil reduction of about 12 mm each year. Therefore conservation tillage is an excellent method to prevent erosion.
Conservation tillage has also a direct and indirect positive impact on CO2 emissions. The study finds that this practice could lead to a reduction of emissions of up to 1.85 tons per ha and year, almost the amount of CO2 produced annually by an average car. Emissions of N2O, another significant greenhouse gas, could also be reduced by up to 10 per cent. In their analysis of two arable farming regions in Germany, the scientists concluded that conservation tillage results in an average reduction of diesel consumption of between 9 to 12 per cent or 8 liters/ha (North-East Germany) and 26 to 33 per cent or 30 liters/ha (Low Mountain region).
In terms of financial benefits, these positive environmental effects are complemented by lower operating costs for farmers. The authors of the study selected two regions with typical crop rotations, one with high production in North-East Germany and the other one with low production intensity in the Low Mountain region. The results of the business-management approach shows that conservation tillage in both regions offers higher profit margins through reduced working costs, with quite significant effects in the Low Mountain region.
The switch to conservation tillage practices makes it necessary to substitute ploughing with another method of weed control. For this, the study recommends herbicides as the best option and concludes that without herbicide use, especially glyphosate, conservation tillage systems are not feasible.
P.M. Schmitz, P. Mal, J.W. Hesse (2014), “The Importance of Conservation Tillage as a Contribution to Sustainable Agriculture: A Special Case of Soil Erosion". Ed. Institute for Agribusiness, Agribusiness-Research no. 32, Giessen.
Food and Agriculture Organization of the United Nations (FAO): Conservation Agriculture
Last update: 21 January 2015