Spatial relationships among cereal yields and selected soil physical and chemical properties

Abstract

Sandy soils occupy large area in Poland (about 50%) and in the world. This study aimed at determining spatial relationships of cereal yields and the selected soil physical and chemical properties in three study years (2001 −2003) on lowproductive sandy Podzol soil (Podlasie, Poland). The yields and soil properties in plough and subsoil layers were determined at 72–150 points. The test crops were:wheat,wheat and barleymixture and oats. To explore the spatial relationship between cereal yields and each soil property spatial statistics was used. The best fitting models were adjusted to empirical semivariance and cross-semivariance, which were used to drawmaps using kriging.Majority of the soil properties and crop yields exhibited lowand mediumvariability (coefficient of variation 5–70%). The effective ranges of the spatial dependence (the distance at which data are autocorrelated) for yields and all soil propertieswere 24.3–58.5mand 10.5–373m, respectively. Nugget to sill ratios showed that crop yields and soil properties were strongly spatially dependent except bulk density. Majority of the pairs in cross-semivariograms exhibited strong spatial interdependence. The ranges of the spatial dependence varied in plough layer between 54.6mfor yield × pH up to 2433mfor yield × silt content. Corresponding ranges in subsoil were 24.8mfor crop yield × clay content in 2003 and 1404mfor yield × bulk density. Krigingmaps allowed separating sub-field areawith the lowest yield and soil cation exchange capacity, organic carbon content and pH. This area had lighter color on the aerial photograph due to high content of the sand and low content of soil organic carbon. The resultswill help farmers at identifying sub-field areas for applying localized management practices to improve these soil properties and further spatial studies in larger scale.