Search

The soybean is one of the main agricultural crops in Brazil, because the use of its grains is an important source of protein and vegetable oil. One of the main limiting factors for obtaining high yields in soybean in tropical soils is related to the need to correct soil acidity. The objective of this study was to evaluate the growth of (Glycine max (L.) Merrill) and the variation of soil pH values under the application of limestone and agricultural gypsum. The experimental design was completely randomized, distributed in a 4x4 factorial scheme. The treatments consisted of doses of 0, 1.5, 3.0 and 4.5 t ha-1 of only limestone, only gypsum and the combination of limestone and gypsum, repeated four times, totaling 64 experimental units. The soil pH was evaluated at 30, 45, 60, 75 days before sowing. The growth variables were: number of pods, shoot dry mass, root dry mass, root length and shoot/root ratio. The variables pH 75 days, root length and shoot/root ratio were significantly influenced by the treatments, alone or in interaction. For pH 30, pH 45 and pH 60 days, number of pods and shoot dry mass, there were isolated effects of treatments for gypsum and limestone. In root dry mass, the effect of the treatment was verified only with the use of limestone. As a conclusion, the application of limestone and gypsum reduces the soil acidity, obtaining higher pH values from the doses of 3000 kg ha-1, with the combination of limestone and gypsum. The use of gypsum consortium with limestone promotes significant results in the growth of soybean plants. [ABSTRACT FROM AUTHOR]

The high demand for forest products in Brazil estimates a 2 million hectares increase in reforestation areas over the next 10 years, highlighting Eucalyptus species. However, these crops usually occur in acid soils that need correction to achieve high productivity. Besides limestone, lime mud, a residue from the cellulose industry, and gypsum can also be used as correctives, but there are doubts about doses and ways of application with the best results. Thus, were evaluated the soil chemical attributes, foliar nutrient content, and initial growth of a Eucalyptus dunnii Maiden crop in response to the application of limestone, lime mud, and gypsum in different doses and ways of applications, on a Humic Cambisol from Santa Catarina Plateau. The experiment was carried out with nine treatments in four replicates, where the evaluated parameters were determined up to 24 months after planting. In general, both limestone, lime mud, and gypsum, in different doses and ways of application, affected the chemical attributes of the soil but did not affect the foliar nutrient content at 12 months, height, and diameter at breast high (DBH) from trees and timber volume at 24 months. Gypsum do not correct soil acidity but lime mud provides similar results to limestone indicating that can substitute this corrective without damage to nutritional status and initial development of Eucalyptus dunnii. [ABSTRACT FROM AUTHOR]

The bovine production in pastures is characterized in Brazil as a condition of extract exploration, in soils exhausted by other cultures, for the erosion or of low natural fertility, causing low productivities. The work had main objective to evaluate the effects of the acidity corection and nitrogen in Brachiaria brizantha, cv. Xaraés, evaluating the production and the elevation of the tenors of Nitrogen and Calcium in the plant. The experiment was led vegetation home in UNOESTE, in the period of august to november of 2003. 20 seeds were distributed by vase and to the 44 days after the sow the doses of nitrogen and 78 days were applied after the planting took place the cut of the aerial part for determination of the matter it evaporates. The limestone application and nitrogen provided a significant increase in the production of the forage, besides elevating the tenor of Nitrogen and Calcium significantly in the plant. It is like this evident the importance of the manuring in cultures forage for the obtaining of discharges productivities and larger capacity for hectare. [ABSTRACT FROM AUTHOR]