Volume 35, Number 3, 2011

Given the scarcity of information in the literature and the importance of a proper management of organic waste in agriculture, this paper evaluated the effects of applying residues of the guava processing industry to an Ultisol, by evaluating changes in soil chemical properties, in the nutritional status of guava plants and fruit production. The residue rates applied in the orchard were established according to the residue N content and evaluated in a randomized block design with four replications, and the […]

Water soluble phosphates are the most often used phosphorus sources in fertilizers for ease of P release to the soil. However, in tropical soils, much of this P is adsorbed to soil particles and becomes unavailable to plants. Conversely, reactive phosphates may be slow initial releasers of the nutrient, but be released continually to the developing crops, reducing soil P fixation. The aim of this study was to investigate the application of two P sources to triticale and assess the […]

In view of the different managements used in coffee production, this study aimed to quantify the changes of some physical properties of an Oxisol under four-year-old coffee, in southern Minas Gerais. Three management systems were compared to native forest. The following management systems were evaluated: mechanized coffee production (CCM), coffee without mechanization (CSM), dense coffee plantation (CA) and native forest (MN) as reference. Undisturbed samples were collected with an Uhland sampler and aluminum rings (diameter 6.35 cm, height 2.54 cm), […]

A change in the type of land use, if not properly planned and conducted, may result in soils with diminished production capacity and increased erosion susceptibility, which will reduce crop yields and hamper soil and water conservation. This study had the purpose of investigating the soil erosion caused by rainfall in an originally native pasture area, in the second and third year of cultivation of two annual row crops (respectively, cowpea – Vigna unguiculata – and shorgum – Shorgum bicolor), […]

Soil management in perennial crops such as orchards can influence erosion. This study evaluated soil and water losses from an Oxisol under simulated rain, from August 2007 to April 2008, at the experimental station of Embrapa Uva e Vinho, in Vacaria (RS). On the 3.5 m x 11 m plots, rains of one hour were simulated at a constant intensity of 70 to 88 mm h-1. In the apple orchard, the following soil management systems were studied: i) manual weeding […]

Precision agriculture can increase efficiency and sustainability of grain crops in Brazil, especially in support of soil and crop management. In this study the importance of spatially-variable soil and crop attributes on the variability of grain crop yield and the use of this information to improve management decisions was examined. The study used data from the 2005/6 corn growing season of a 18 ha commercial field on a clayey Latossolo Bruno (FAO: Ferralsol). Soil (0-0.10 m layer) and crop properties […]

The Brazilian program of environmental services, called “Water Supplier”, is based on financial incentives relative to the erosion reduction by the implementation of voluntary soil conservation projects by farmers. However, this program has no pre-established restrictions of eligibility of application areas or conservation proposals. With a view to contribute to the methodological development of this program, a new approach was proposed, by analysis of two main changes: introduction of eligibility criteria, and the use of land suitability for recommendation of […]

The negative impacts of the increasing volume of wastewater and of its discharge into the environment have become a worldwide concern. This study assessed the potential impacts of using treated effluent from pig raising for cotton irrigation, to evaluate their effects on soil chemical properties, and compare the results with those under conventional management. The experiment was conducted in an experimental area of the Company for the Development of the San Francisco and Parnaíba valleys “Perímetro Irrigado Formoso”, in Bom […]

Heavy metals are a group of elements with specific features and natural occurrence in the environment, representing an accessory in the formation of rocks. These elements, although associated with toxicity, must be treated different from xenobiotics, since many metals are evidentially essentials (Fe, Mn, Cu, Zn, and Ni) and beneficial (Co) for plants. In this context, the objective was to determine the natural contents of the metals iron (Fe), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu) and cobalt (Co) […]