Effect of no tillage on the physico-chemical properties of soils of the El Koudia region, Rabat (Morocco)

Abstract

In Morocco, agriculture is an important sector of the economy, accounting for 15 to 20% of Gross Domestic Product. However, it has faced several challenges: intensive tillage of land that has accelerated water erosion, seriously threatening water and soil potential, low plant cover density and misuse of traditional agricultural practices, causing a decrease in organic matter levels and destroying aggregate stability. Climate change is making water and soil management in agriculture more and more complicated. The major challenge for Moroccan agriculture is to increase agricultural production while preserving natural resources. The objective of our study is to evaluate the effect of no tillage (NT) on the physico- chemical properties of soil in the El Koudia experimental station, Rabat, Morocco. The crop is durum wheat, Arrehane variety. Soil samples are pre-dried, ground and screened to 0.2mm for organic matter (OM) analysis and 2mm for the remainder of the analyses. Plugs, canned, are then sintered, screened and dried for structural stability tests. The results show that no tillage (NT) favours the accumulation of surface OM, particularly at the 0-5cm horizon unlike conventional tillage (CT). The NT promotes structural stability, with a mean weight diameter (MWD) = 0.94mm for the NT compared to 0.83mm for the CT. These results show that soils ploughed in CT are more exposed to erosion degradation than soils not ploughed (NT). In addition, NT preserves soil moisture and promotes additional water retention of 5 to 10%.