Growth and mineral composition of Jatropha curcasL.under phosphate fertilization and soil compaction

Abstract

The present work aimed to quantify the growth of young physic nut plants submitted to variations in phosphorus (P) and specific masses of a Red Yellow Latosol soil. Previously, a soil sample was collected in the 20 to 40 cm layer, making sure in the laboratory the low availability of P - 1.4 mg dm-3 - to apply the treatments of interest. Doses of 0, 106 and 318 mg dm-3 of P were applied, using the simple superphosphate source; and the soils were compacted until reaching specific soil masses equal to 1.53; 1.72 and 1.91 kg dm-3, in a complete factorial scheme, totaling nine treatments. The cultivation was carried out in pots and the dry biomass of the aerial part of the physic nut and its parts fractionated in the stem, leaves adhered to the stem and senescent leaves were determined. The contents of P, K, Ca, Mg, Cu, Fe, Mn and Zn were determined, and from the dry mass accumulation data, the contents of these minerals in the plants were quantified. The statistical analysis of the data consisted of analysis of variance, Tukey average test and regression analysis. In general, the mineral composition characteristics of the plants showed a more pronounced response to phosphate fertilization compared to the tested physical compression. The maximum estimated mineral content in physic nut plants was 51.78 mg of P; 463.37 mg of K; 201.84 mg of Ca; 124.18 mg of Mg; 76.17 µg of Cu; 4,254.07 µg of Fe; 18,787.15 µg of Mn and 769,97 µg of Zn.