Rachid Moussadek

Tillage System Affects Soil Organic Carbon Storage and Quality in Central Morocco

Stabilizing or improving soil organic carbon content is essential for sustainable crop production under changing climate conditions. Therefore, soil organic carbon research is gaining momentum in the Mediterranean basin. Our objective is to quantify effects of no tillage (NT) and conventional tillage (CT) on soil organic carbon stock (SOCs) in three soil types (Vertisol, Cambisol, and Luvisol) within Central Morocco. Chemical analyses were used to determine how tillage affected various humic substances. Our results showed that, after 5 years, surface horizon (0–30 cm) SOC stocks varied between tillage systems and with soil type. The SOCs was significantly higher in NT compared to CT (10% more in Vertisol and 8% more in Cambisol), but no significant difference was observed in the Luvisol. Average SOCs within the 0–30 cm depth was 29.35 and 27.36 Mg ha−1 under NT and CT, respectively. The highest SOCs (31.89 Mg ha−1) was found in Vertisols under NT. A comparison of humic substances showed that humic acids and humin were significantly higher under NT compared to CT, but fulvic acid concentrations were significantly lower. These studies confirm that NT does have beneficial effects on SOCs and quality in these soils.

Long and Midterm Effect of Conservation Agriculture on Soil Properties in Dry Areas of Morocco

In Morocco, conservation agriculture, particularly no tillage systems, has become an alternative strategy to mitigate land degradation caused by conventional tillage in semiarid to arid regions. This paper is based on behaviour to tillage treatments of two Vertisols in Morocco. After 11 years of testing, soil organic matter content results showed a significant difference () only at soil surface (0–10 cm) in favour of no tillage and a variation of 30% at this depth. The results obtained after 32 years of testing showed a significant soil profile difference (), up to 40 cm under no tillage compared to conventional tillage, and a variation of 54% at 5–10 cm. For total nitrogen, there was no significant effect between no tillage and conventional tillage at the soil surface after 11 years unlike the result obtained after 32 years. There are no significant differences in bulk density between tillage treatments at soil surface for both sites. The measurement of soil structural stability showed a significant effect () for all three tests and for both sites. This means that no tillage helped Vertisols to resist different climatic constraints, preserving environmental soil quality.