Effects of the Speed of Mechanical Tillage on the Structure of Ferralitic Soil

The present work consists in evaluating the impacts of the plowing speed of three-body plows/discs hitched to a 60 HP tractor, on the structure of the ferralitic soil, and determining the optimal speed which guarantees good soil and biomass retention capacities, bearing capacity and soil preservation leading to better yield and with a view to using motorized tools wisely in agricultural practices in the Benin plateau, from 2019-2021. All plowing was carried out on the same day on 21 plots, divided into 3 blocks of 7 elementary plots. The treatments are V0, V1, V2, V3, V4, V5, and V6, i.e. 2, 4, 6, 8, 10, and 12 km/h. V0 is a control. The tests are carried out according to the standards: NF EN ISO 17892-4.2018, for the particle size analysis, NF EN ISO 17892.2018, for the Atterberg limits, NF P 94-050.1995, for the water content by weight, NF XP P 94 -047.1998, for the rate of organic matter, NF EN 1097-3.1998, for the apparent density. Soil conductivity is determined by the Muntz method (double rings). The results show that plowing at an average speed (6 km/h) generates a better content of water and organic matter which are respectively 5.04 ± 0.76% and 0.304 ± 0.004% for the ploughshare than (6. 47±0.35%; 0.324± 0.012%) for the disc plow. The higher content of water and organic matter generated by the average speed of 6 km/h would limit the risks of embrittlement while guaranteeing a conservative tendency of fertility. This work will allow agricultural tractor operators to better perform ferralitic tillage operations taking into account the optimal plowing speed without seriously damaging the soil structure, a guarantee of sustainable development in agriculture.