Volume 40, 2016

ABSTRACT Upland rice cultivars manifest different nutritional demands. A field study was conducted to quantify the extraction, distribution, and removal of micronutrients and silicon by the upland rice cultivars. The experiment was arranged in a randomized complete block-split plot design. Plots consisted of three cultivars (Caiapó – traditional, BRS Primavera – intermediate, and Maravilha – modern) of upland rice. Split-plots consisted of plant samplings, which occurred at 39, 46, 55, 67, 75, 83, 92, 102, 111, 118, and 125 days […]

ABSTRACT Improper management of rangelands can cause land degradation and reduce the economic efficiency of livestock activity. The aim of this study was to evaluate soil properties and quantify plant biomass production in four natural rangeland management systems in the Santa Catarina Plateau (Planalto Catarinense) of Brazil. The treatments, which included mowed natural rangeland (NR), burned natural rangeland (BR), natural rangeland improved through the introduction of plant species after harrowing (IH), and natural rangeland improved through the introduction of plant […]

ABSTRACT Soil contamination by heavy metals threatens ecosystems and human health. Environmental monitoring bodies need reference values for these contaminants to assess the impacts of anthropogenic activities on soil contamination. Quality reference values (QRVs) reflect the natural concentrations of heavy metals in soils without anthropic interference and must be regionally established. The aim of this study was to determine the natural concentrations and quality reference values for the metals Ag, Ba, Cd, Co, Cu, Cr, Mo, Ni, Pb, Sb and […]

ABSTRACT Oxidic soils are phosphorus drains in soil; hence, P availability is a limiting factor in tropical, weathered Oxidic soils. It has been shown that some brachiarias grown as cover crops may increase soil available P to subsequent crops. The objective of this study was to evaluate soil P cycling and availability, as well as the response of soybean to soluble and natural reactive phosphates as affected by ruzi grass (Urochloa ruziziensis, R. Germ. and C.M. Evrard, Crin) grown as […]

ABSTRACT Water erosion is the process of disaggregation and transport of sediments, and rainfall erosivity is a numerical value that expresses the erosive capacity of rain. The scarcity of information on rainfall erosivity makes it difficult or impossible to use to estimate losses occasioned by the erosive process. The objective of this study was to develop Artificial Neural Networks (ANNs) for spatial interpolation of the monthly and annual values of rainfall erosivity at any location in the state of Rio […]

ABSTRACT Root growth can be limited by physical and chemical conditions of the soil. Compacted and acidic soils, where there is an occurrence of exchangeable Al, constitute barriers to use of the soil by plant roots. The hypothesis of this study was that physical and chemical properties of the inter-row soil of a peach orchard influence the root distribution of different rootstocks. The aim of this study was to describe and register the soil physical and chemical properties and root […]

ABSTRACT In no-tillage (NT) systems, there is no plowed layer since the soil is not tilled. Thus, the soil layer for fertility evaluation can be defined as the one in which the fertility indices are affected by the surface application of lime and fertilizers and soil properties have the closest relationship with crop yields. The objective of this study was to determine the most appropriate soil layer under long-term NT for sampling for fertility evaluation in the South-Central region of […]

ABSTRACT Soil organic matter (SOM) is important to fertility, since it performs several functions such as cycling, water and nutrient retention and soil aggregation, in addition to being an energy requirement for biological activity. This study proposes new trends to the Embrapa, Walkley-Black, and Mebius methods that allowed the determination of SOM by spectrophotometry, increasing functionality. The mass of 500 mg was reduced to 200 mg, generating a mean of 60 % saving of reagents and a decrease of 91 […]

ABSTRACT The composition of organic waste (OW) and its effect on soil processes may change soil fertility and electrical conductivity (EC). The side effects of waste use in crop fertilization are poorly understood for Brazilian soils. This study examined the effect of the addition of 15 different organic wastes to Oxisols and a Neosol on pH, base saturation, EC, cation exchange capacity (CEC at pH 7), and the availability of Al, macro (P, K, Ca2+, Mg2+ and S) and micronutrients […]

ABSTRACT Organic acids present in organic matter and, or, exudates by microorganisms and plants can increase the liberation of potassium present in minerals. The objective of this study was to characterize the residue from ornamental rocks and evaluate the release of K from these residues after the application of organic acids. The experiment was conducted under laboratory conditions and followed a 2 × 3 × 5 factorial design with three replicates. The studied factors were: two organic acids (citric acid […]