Development of castor beans with different levels of lime in a compacted Oxisol

Abstract

The objective of this work was to evaluate the development of castor beans in an Oxisol with different doses of lime. The experiment was carried out in the Campus of Gurupi at Federal University of Tocantins. The experiment consisted of 20 plots of 12 m² (4x3m). The treatments involved five levels of lime (to raise the soil base saturation to levels to 50, 60, 70 and 80%) plus the control (no lime) and three depths in a randomized block design. The area was prepared in advance (dry season) for weed removal and the incorporation of lime was performed manually in early December 2005. The Savanna cultivar  was used and the following parameters were evaluated: stem diameter, weight of one hundred seeds in shell, weight of one hundred seeds without shell, productivity, number of bunches per plant, number of fruits per bunch, and bunch length. Furthermore, soil density and soil resistance to penetration were also measured. The treatments 80% and 70% showed better results than the others, producing a greater number of bunches per plant. It was concluded that castor beans showed good penetration capacity, with higher productivity at the treatment with 80% base saturation. No differences were observed in the bulk density with depth and within treatments.