Influence of tillage practices on physical properties of a sandy loam in semi-arid region
The contrasts observed in soil tillage research studies documented the need for more research in many regions of the world if the mechanics of tillage effects on soil physical properties is to be well understood. Thus, the effect of three tillage systems: no-tillage (NT), reduce tillage (RT) and
conventional tillage (CT) on the physical properties of a sandy loam soil in Maiduguri, Nigeria was investigated after 9-15 years of management. During the growing season of 2010, triplicate undisturbed core samples (5.5 cm in diameter and 4 cm height) were obtained at two soil depths (0-
15 cm and 15-30 cm), for determination of volumetric (.v) moisture content, bulk density (Bd), and total porosity (TP) of the soil at selected dates, while soil penetration resistance (PR) was determined using hand held digital penetrometer. Tillage systems significantly (p = 0.05) affected
Bd and TP of the soil at two of the four sampling dates. The RT treatment recorded highest Bd and lowest TP at (0-15 cm) depth across most sampling dates, while at (15-30 cm) soil depth, the CT and RT treatments maintained higher Bd. Soil PR was significantly influenced by tillage systems only at the surface (0-15 cm) soil depth. The NT treatment recorded significantly (p = 0.05) higher PR while the RT treatment recorded the least. Further, significant (p = 0.05) tillage treatment effects on the .v content of the soil was observed at both surface (0-15 cm) and sub surface (15-30 cm) soil depths. The NT and RT treatments, on average, recorded higher values of .v relative to the CT treatment. Soil organic carbon (OC) and aggregate stability in water (MAW, ASC, DR and WSI) were found to correlate (p < 0.05) well with .v content of the soil for most sampling dates particularly a surface soil layer. The study revealed that, the NT and RT treatments promotes better physical quality of the soil relative to the CT treatment. It ishowever recommended that, other reduced tillage systems such as animal traction and ridgetillage be tried to assess their efficacy of improving soil physical quality.
Key words: Tillage, Tillage systems, Soil Physical properties, Moisture storage, Physical quality