Spatial variability of soil physical properties in a cultivated field

Abstract

Spatial variability of soil physical properties in a cultivated field such as; bulk density (BD), penetration resistance (PNT), saturated hydraulic conductivity (Ks), field capacity (FC) and permanent wilting point (PWP), were determined by geostatistical method. While BD values varied between 1.12 and 1.41 gcm -3 , PNT resistance (0.66 to 1.88 MPa), clay content (31.48 to 43.97%), Ks (1.46 to 3.37 mm h -1 ), FC (30.40 to 39.66%) and PWP (19.22 to 24.42%) values showed variations with soil cultivation. In kriging interpolation for the spatial variability of soil properties, the biggest r 2 and cross validation r 2 values were determined with spherical model for PNT, Ks, FC values, and exponential model for clay, BD and PWP. Spatial dependences of the properties, except BD, were found to be strong in the field. Ks values significantly increased with increasing BD (0.340*), and decreasing clay content (-0.905**) and PNT (-0.288*) values in the field. Spatial variations of soil physical properties in the field are generally controlled by the particle size distribution as a fundamental factor. Heterogeneity and variation of soil physical parameters in a field due to soil plowing should be taken into consideration for a successful agricultural management.