Abstract

FIDALSKI, Jonez  and  AULER, Pedro Antonio Martins. Yield and temporal chemical changes in fertilizer bands and inter-rows of an orange orchard after surface liming. Rev. Bras. Ciênc. Solo [online]. 2008, vol.32, n.2, pp. 689-696. ISSN 0100-0683.  http://dx.doi.org/10.1590/S0100-06832008000200023.

Despite the chemical differences in soils under the fertilizer bands and inter-rows in orange orchards, no criterion to determine the need of liming in the two areas is yet known. The objective of this study was to quantify the temporary chemical alterations in fertilizer bands and inter-rows of a "Pêra" orange orchard as well as nutrition and fruit yield after surface liming, in a Typic Paleudults, in northwestern Paraná, Brazil. The soil surface was limed four times between 1996 and 1999 to reach a base saturation of 70 % since the first fruit harvest. Dolomitic and calcitic limestone were broadcast over six permanent groundcover plant types in the inter-rows and fertilization bands, which were mowed and sprayed with post-emergence herbicide. From 1996 to 2004 leaf samples, and soil samples in the layers 0-20 and 20-40 cm were collected and the orange yield was evaluated. Maximal alterations of soil chemical characteristics and leaf nutrient concentrations (Ca) were observed after the fourth successive annual surface liming. The orange yield was negatively correlated with Al³⁺ and positively correlated with soil pH (CaCl₂), Ca²⁺ and Mg²⁺ in the fertilizer bands and inter-rows. Surface liming increased base saturation in the 0-20 cm layer to 46 % in the fertilizer bands and to 64 % inter-rows.

Keywords : citrus; soil acidity; calcium; base saturation; liming.