Spatial variability of physical atributes of a Spodosol and sugarcane yield¹

Variabilidade espacial de atributos físicos de um Espodossolo e da produtividade da cana-de-açúcar

HIGHLIGHTS:

Total porosity, microporosity and macroporosity of the soil did not show spatial dependence.

Among the soil granulometric fractions, only the clay present in the 0.20-0.40 m layer showed spatial dependence.

Sugarcane yield was higher in points with lower bulk density and higher total soil porosity.

ABSTRACT

Agricultural practices promote alterations in the physical properties of the soil, causing changes in its bulk density, porosity, distribution of pore diameter and water retention, which influences the availability to the plants. Precision agriculture acts as a tool that assists in soil management, favoring agricultural yield. The objective of this study was to evaluate the influence of the spatial variability of the physical attributes of a Spodosol on sugarcane yield. Soil sampling and crop yield evaluations were performed at 90 randomly chosen points in the experimental area. Disturbed and undisturbed samples were collected in the soil layers of 0.00-0.20 and 0.20-0.40 m to analyze the attributes: particle size, bulk density, field capacity, total porosity, macroporosity and microporosity. The highest sugarcane yields were observed in regions with more aerated soil, with lower bulk density and higher total porosity, and with greater water retention capacity in the 0.00-0.20 m layer. It was not possible to detect spatial dependence for the granulometric fractions of the soil with the sampling scheme used, except for the clay in the 0.20-0.40 m layer. The spherical model was the one that best fitted to the set of data of the studied variables.

Key words:
precision agriculture; spatial dependence; geostatistics; soil physics