Pesquisa Agropecuária Brasileira
On-line version ISSN 1678-3921
SILVEIRA, PEDRO MARQUES DA; ZIMMERMANN, FRANCISCO JOSÉ PFEILSTICKER; SILVA, SILVANDO CARLOS DA and CUNHA, ADRIANY ALVES DA. Sampling size and spatial variability of chemical properties of a latosol subjected to different soil preparations. Pesq. agropec. bras. [online]. 2000, vol.35, n.10, pp. 2057-2064. ISSN 1678-3921. http://dx.doi.org/10.1590/S0100-204X2000001000018.
The study was conducted at the Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, in Santo Antônio de Goiás, GO, Brazil, on a clayey Oxisol subjected to different soil tillage systems for five consecutive years and cultivated with corn in the summer and bean in the winter under sprinkler irrigation. The objective of this study was to determine the effects of three soil tillage systems, using moldboard plough, harrow disc and no-tillage. Forty nine soil samples were collected from a 7x7 lattice sampling area spaced 4 m x 4 m at 0-5 cm and 5-20 cm soil depth. Soil samples were analyzed for pH, Ca, Mg, P, K and base saturation. Minimum, maximum and average values were calculated along with the coefficient of variation and average values were compared by the t test. Values of pH, Ca, Mg, P, K and base saturation of soil varied for different treatments. All soil chemical properties values were higher at 0-5 cm soil depth in no-tillage treatment as compared to harrow disc and moldboard plough treatments. Among the soil chemical properties evaluated, P and K concentrations showed the highest variability, whereas pH presented the lowest.
Keywords : soil chemicophysical properties; mineral nutrients; soil pH; moldboard plough; disc harrows; direct sowing.