Nutrients content in lettuce plants and seeds in function of organic compost levels, with and without added phosphorus to the soil

Abstract

This study was conducted in the São Manuel experimental Farm, in São Manuel-SP, which belongs to the Faculdade de Ciências Agronômicas (FCA) of the Universidade Estadual Paulista (UNESP), Botucatu/SP Campus, in order to evaluate the influence of organic compost doses, with and without added phosphorus to the soil, on the levels of macronutrients in plants and seeds of the lettuce cultivar Veronica. The experimental design was randomized blocks with ten treatments (0, 20, 40, 60, 80 Mg ha-1 of organic compost, with and without 400 kg ha-1 P205 added to the soil) and four replicates. The content of macronutrients in plants and seeds was evaluated. The data were submitted to analysis of variance and regression. The decreaning order of macronutrient content in plants was potassium> calcium> nitrogen> magnesium> phosphorus> sulfur and in seeds it was nitrogen > phosphorus> potassium> calcium> magnesium> sulfur. The nitrogen content in seeds, was about three and a half times higher than in plants, the sulfur was one and half times higher, while phosphorus content was approximately five times higher.