Spatial variability of soil physical properties as affected by different tillage systems

Abstract

Penetration resistance (PR), soil bulk density (BD), and volumetric water content (VWC) are important determinants of crop production. The objectives of this study were to: (1) evaluate the effect of conventional (S1), conservation (S2), and reduced tillage (S3) systems on BD, PR, and VWC shortly after soil tillage; and (2) characterise the spatial variations of these soil properties before the seedbed preparation for the second crop in Taşliçiftlik clay loam (medium, mixed, mesic Ustic Fluvents) located in north‐central Anatolia, Turkey. Tillage effect was evaluated at two different soil depths (0–10 cm and 10–20 cm). Soil BD and VWC measurements were conducted on undisturbed soil samples and PR was measured with a hand‐pushing penetrometer. All three tillage systems increased the variation in the PR; S1 and S3 decreased and S2 increased the variation in BD; and S2 and S3 increased, and S1 decreased the variation in soil VWC in 0–10 cm depth. Spatial structure of PR in 0–10 cm was not affected by the tillage systems. Slight changes occurred in spatial structure of PR in 10–20 cm after the tillage. Spatial structure of BD in 0–10cm was considerably affected by S1 compared to both S2 and S3. In 10–20 cm depth, chiseling considerably altered the BD as indicated by semivariograms. However, tillage effect on BD was negligible in S1 and S3 in the same depth. Although the spatial structure of VWC in 0–10 cm depth was highly altered in S1, S2 and S3 had smaller effects on VWC in 0–10cm. Both S1 and S3 resulted in more uniform volumetric water content in 10–20 cm depth.