Five plants of Phyllanthus niruri L. were cultivated in a greenhouse in 3.4 dm³ pots with Alic Cambisol (medium texture) as substrate. Soil samples were collected in Nazareno - MG and seeds from 'quebra-pedra' were originated from Belém, Brazil. The treatments consisted of five concentrations of N (0,30,60,100 and 150 mg/dm³ of N), two levels of liming (with and without limestone, aiming at raising the pH to 6.0). The experimental design was completely randomized with 6 replications. Plants were harvested eighty days after transplanting. Root, stem and leaves dry matter production were evaluated and chemical and phytochemical analysis of stems and leaves were performed. 'Quebra-pedra' is a plant species responsive to liming and nitrogen fertilization showing, in the presence of liming, the equivalent to 90% of the maximum total dry matter yield (12.25 g/pot) for the nitrogen level of 77.81 mg/dm³ of soil. In the absence of liming the total dry matter decreased linearly (from 2.0 g/pot to 3.9 g/pot) with an increase in doses of N. Higher contents of P, S, Ca, and Mg were observed in plants from treatments with liming, independently of the doses of N used. In the absence of liming the content of macronutrients in the dry matter was small, as a consequence of a smaller production of dry matter. An increase in dry matter and total alkaloids was observed when the dose of nitrogen was increased. The maximum production of total alkaloids was of 0.676 mg of alkaloid per gram of stems and leaves dry matter that corresponds to the dose of N responsible for 90% of the maximum production dry matter.
Phyllanthus niruri; mineral nutrition
