Design and Agronomic Assessment of an Implement for Conservation Agriculture Bed Planting in Tunisia.
Worldwide water is becoming a scarse resource particularly in semiarid areas. Prediction scenarios show it will be increasingly so in the coming. This will limit crop production and jeopardize human livelihood. Moreover, volatile energy prices will impose significant changes in farmer practices because of the economic implications on farming net returns. Traditional irrigated cropping systems in Tunisia use intensive soil tillage and flood (flat) irrigation techniques, which generally lead to a water table depletion, soil compaction, poor water use efficiency and low crop productivity. Previous studies in other countries (Mexico, Bangladesh...), indicate significant advantages with conservation agriculture (CA) and raised bed techniques. These were not assessed before in Tunisia. A three year work conducted during 2010-2013 period at Chbika experimental Station in central Tunisia (353713.71N, 95616.23E) showed a potential for net benefits from a combination of CA and irrigation using raised beds techniques. During the first year grain yield of two durum varieties were collected from fresh raised 60 cm width beds and flat irrigated 200 m plots with two replications. During the second year, the same varieties were sown on fresh bed, permanent bed and flat irrigated plots that harbored a faba bean crop during the previous year. In the third year both varieties were sown on same first year (permanent bed, fresh and flat) plots that were sown to faba bean during the second year