Lowland soils cultivated with flooded rice in the State of Rio Grande do Sul, Brazil, show a lack of response to potassium fertilization in this culture, even in soils with a low level of available potassium. This study was carried out with the objective to verify the contribution of soil mineralogy as a potential potassium source for rice cultivation. Four representative soils from regions of the State of Rio Grande do Sul (Planossolo Hidromórfico, Planossolo Haplico, Gleissolo Haplico and Chernossolo […]

This work was conducted under greenhouse conditions to evaluate how doses and methods of manganese (Mn) application may affect vegetative characteristics as well as the production of upland rice. The treatments consisted of five manganese doses applied either via soil (0, 4, 8, and 16 mg dm-3) or leaf (3 4 g L-1 applications), associated with two rice cultivars (Canastra and Confiança). The experiment was randomly designed, with four replications, in a 2 x 5 factorial scheme. Each plot consisted […]

Nutrient transport towards root surface can be accomplished by mass flow or by mass flow and diffusion, depending on the activity of the nutrient in the soil solution, and on the nutrient demand of the plant. The objective of this greenhouse experiment was to verify the contribution of the mechanisms of mass flow and diffusion for supplying potassium, calcium and magnesium to rice plants. Samples of a clayey Oxysol were treated with Na2CO3, K2CO3, CaCO3 and MgCO3 as amendments. Seventy-five […]

The nutritional limitations of an organic soil supporting a lowland rice crop, cv. Inca, were identified in a greenhouse experiment in Lavras, State of Minas Gerais, from December, 1994, to June, 1995. Soil samples were collected in Northern Fluminense region. Treatments consisted of control (natural soil), complete (N, P, K, limestone, S, B, Co, Cu, Mo, and Zn) and complete lacking one of these nutrients at a time. At the grain maturation time, the treatments lacking N and K showed […]