Direct seeding under cover crop is an agricultural technique whereby a crop is sown directly in a vegetation cover without having previously tilled the soil. There are two types: 1) the case where the cover is destroyed (mechanically, naturally, by frost for instance, and as a last resort chemically) before, during or soon after the sowing, and whose biomass is kept on the soil surface, and 2) the case where the cover is kept alive and in this case it is called direct seeding under permanent living plant cover. In both cases, the farmer uses a special “direct” seed drill equipped with disks with or without tines, which are capable of positioning the seed in contact with the soil by cutting or pushing the vegetation aside (then repositioned by a closing device).
Direct seeding under cover crop is a flagship practice of conservation agriculture because it maintains a permanent organic cover, limits tillage to the sowing line and thus reduces soil erosion and enhances biological activity, which contributes to sustainable management of soil organic matter. This technique also allows a reduction of work time compared to ploughing as well as a reduction in the number of phytosanitary treatments of up to 50% (or more in certain circumstances).
However, this technique also has limits: the yields can be lower than in the ploughing system, mainly when resources are limited and the system with permanent living plant cover..
L. García-Torres (Editor), J. Benites (Editor), A. Martínez-Vilela (Editor), A. Holgado-Cabrera (Editor). 2003. Conservation Agriculture: Environment, Farmers Experiences, Innovations, Socio-economy, Policy. Springer, 516 pp. ISBN-13: 978-1402011061
M. Farooq (Editor) and K. Siddique (Editor). 2015. Conservation agriculture. Springer, 665 p. ISBN 978-3-319-11620-4