Resumen

TIMM, Luís Carlos et al. Field spatial and temporal patterns of soil water content and bulk density changes. Sci. agric. (Piracicaba, Braz.) [online]. 2006, vol.63, n.1, pp. 55-64. ISSN 0103-9016.  http://dx.doi.org/10.1590/S0103-90162006000100009.

Soil water content (q) and bulk density (r_s) greatly influence important soil and plant processes, such as water movement, soil compaction, soil aeration, and plant root system development. Spatial and temporal variability of q and r_s during different periods of the year and different phases of crops are of fundamental interest. This work involves the characterization of spatial and temporal patterns of q and r_s during different climatic periods of year, aiming to verify whether there are significant temporal changes in r_s at the soil surface layer when submitted to wetting and drying cycles. The field experiment was carried out in a coffee plantation, Rhodic Kandiudalf soil, clayey texture. Using a neutron/gamma surface probe, q and r_s were measured meter by meter along a 200 m spatial transect, along an interrow contour line. During the wet period there was no difference of spatial patterns of q while during the dry period differences were observed, and can be associated to precipitation events. It was also observed that there are r_s temporal changes at the soil surface along the studied period as a consequence of the in situ wetting and drying cycles.

Palabras llave : neutron/gamma surface probe; wetting/drying cycles; spatial and temporal variability.