Since Michael Ehmann took over the farm in 1989, his first priority has been to practice conservation tillage. The first implement he bought was a Horsch Seed-Exactor, which is still used today to plant the winter wheat following the corn.
With regards to the spring crops, the challenge was a more difficult one. It is a real problem and a big challenge in the southwest of France, to find methods to securely plant spring crops without using the plough . Spring storms often severly damage the soil in steep fields.
Starting from 2005, strip-till has been tested on the farm through the planting of cover crops.
Between 2005 and 2011, many tests were carried out by Christophe Morelière who has managed the farm since 2006. These tests involve the use of different cover crops, different types of tines, different packer types and different tillage depths.
The results of these 6 years of testing are mixed and inconclusive. However, what does become clear is that this system doesn’t allow a secure development of neither the cover crop nor the corn.
Efforts are then redirected to another concept, developed by Horsch on their farm in the Czech Republic : planting spring crops on ridges. This concept gives good and secure results in heavy soils. It consists of tilling the future corn row, but also between the rows and making a little ridge. The frost during the winter structures the ridge and allows a good seedbed preparation. The ridge will also warm up and dry more quickly.
Since 2011, Michael Ehmann and Christophe Morelière have been trying to adapt the concept to the soil and climatic conditions of southwest France. In order to achieve this goal, a 2-bar cultivator was designed. This cultivator also allows the planting of the cover-crop between the ridges. To control the drift of the machines in hilly fields, disks linked to a GPS RTK active steering system control the path of the implement.
Between 2011 and 2013, tests were done on the destruction of the cover crop. Results are clearly for a destruction at the same time as planting. A late destruction allows the cover crop to grow more and therefore develops a much higher biomass volume. This also means a higher amount of nitrogen (biomass doubles in the last 3 weeks before planting). Also, having fresh green matter will attract slugs and other harmful insect towards the cover crop instead of the corn.
For planting in 2014, the system was improved with the development of a planter adapted to the green tillage concept. The planter is designed to mechanically destroy the cover crop between the rows with little packers. Like for the cultivator, it’s equipped with a GPS RTK active steering system.
Green Tillage is a concept that allows to precisely handle the planting of a cover crop with the help of modern auto steer equipment. And done in this manner, the cover crop isn’t an obstacle for the secure establishment of the next crop.