The use of rock powders as a source of nutrients aim costs reduction and environmental problems associated with soluble sources. Thus, the aim of this study was to evaluate the use potential of different rock powder doses, associated or not with bovine manure, after two applications in approximately one year, as a source of nutrients for wheat and its effect on soil chemical attributes. The sources were applied, without incorporation, in two successive crops, at the rates of 0, 3, 6, 9 and 12 Mg ha -1 of rock powder, isolated or associated to 17 Mg ha -1 and 28 Mg ha -1 of bovine manure, on first and second applications, respectively. The experiment was carried out in completely randomized blocks, in a 2×5 (bovine manure × rock powder doses) factorial arrangement with three replicates. The use of bovine manure resulted in increments in the following variables: plant height, number of spikelets per spike, number of grain per spike, grain yield, mass of one thousand grains and soil phosphorus and calcium (Ca 2+ ) contents. The association of rock powder, at dose of 3 Mg ha -1 , and bovine manure promoted reduction of soil potential acidity (1.54 cmol c dm -3 ) and increase soil Mg 2+ content (0.9 cmol c dm -3 ). The application of rock powder doses does not improve wheat yield and soil chemical attributes after two applications in approximately one year. In contrast, the application of bovine manure, independently of the rock powder dose, results in improvements in these variables.

SUMMARYThe Diagnosis and Recommendation Integrated System (DRIS) can improve interpretations of leaf analysis to determine the nutrient status. Diagnoses by this method require DRIS norms, which are however not known for oil content of soybean seeds. The aims of this study were to establish and test the DRIS method for oil content of soybean seed (maturity group II cultivars). Soybean leaves (207 samples) in the full flowering stage were analyzed for macro and micro-nutrients, and the DRIS was applied to assess the relationship between nutrient ratios and the seed oil content. Samples from experimental and farm field sites of the southernmost Brazilian state Rio Grande do Sul (28° -29° southern latitude; 52° -53° western longitude) were assessed in two growing seasons ( (1) Part of the thesis of the first author presented to the Graduate Program in Agronomy, University of Passo Fundo (UPF

The use of rock powder as a source of nutrients to plants can be an alternative or complement to mineral soluble and organic sources. Thus, the aim of this study was to evaluate the potential of different rock powder doses, associated or not with livestock manure, as a source of nutrients for bean and its effect on soil chemical attributes. The treatments consisted of the application of 0, 3, 6, 9 and 12 Mg ha-1 of rock powder, associated or not with livestock manure (17 Mg ha-1), applied on the soil surface, without incorporation. The experiment was carried out in completely randomized blocks, with three replicates, and in a factorial arrangement (5x2). The grain yield of bean, height plants and number of plants m-2 were not influenced by the treatments. On the other hand, the application of 3 Mg ha-1 of rock powder associated with livestock manure resulted in a higher number of grains per pod, and the increase in the rock powder doses affected the number of pods per plant. In the soil, only the manure application, regardless of the rock powder, resulted in effects: reduced potential acidity and potential cation exchange capacity, and increased phosphorus content and base saturation. Thus, rock powder, associated or not with livestock manure, is not effective in improving bean yield and soil chemical attributes after approximately three months of application, and the use of livestock manure, regardless of the rock powder doses, improves some chemical attributes in the soil.

White Star (Nymphoides humboldtiana), an aquatic-environmental native species of Brazilian flora, was selected in order to be used as ornamental plant in lakes. White Star plants were submitted to two water levels (high water level, up to 30 cm water depth and, low water level until substrate saturation) and two light intensities (full sun and 50% shading) to evaluate vegetative and flowering development. The experimental design was completely randomized, in a subplot scheme, being the water level the main plot and luminosity the subplot. Seven replicates were performed, and the sample unit consisted of one plant. Data related to number of leaves and flowers, length and diameter of petioles and leaf area were submitted to analyze of variance and regression. We observed an increase in number of leaves and flowers in the treatment of high water level in full sun, and an increase of petiole length in high water level with shading. No difference between leaf area of plants grown under full sun and with shading (p<0.05) was observed. At low water level, plants presented lower vegetative development than those grown at high water level, besides the flowering inhibition in shaded condition. These results demonstrated that White Star can be used in ornamental lakes with a water depth of at least 20 cm above the rhizome and exposed to full sun.

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