3312 results

Establishment of DRIS norms for organic and conventional conilon coffee in the State of Espírito Santo (Brazil)

Fabio Luiz Partelli, Henrique Duarte Vieira, Pedro Henrique Monnerat, Alexandre Pio Viana

01/Jun/2006

Conilon coffee (Coffea canephora) is very important for the economy of the state of Espírito Santo and its organic cultivation is increasing. However, there is a lack of information on leaf reference values for this form of management, as well as a nutritional diagnosis. The objective of this study was to establish and compare reference patterns and to propose adequate values of leaf nutrient concentrations obtained on high yielding conilon coffee plantations, cultivated under organic or conventional systems, in the […]

Effect of liming and ammonium sulfate on cotton. I – Cation and anion transport in the soil

José Salvador Simoneti Foloni, Ciro Antonio Rosolem

01/Jun/2006

Applying lime on the soil surface in soils managed under no-tillage has caused an excess of basic cations in the most superficial layers of the soil profile. On the other hand, subsoil acidity is considered a constraint to the development of deep plant roots. The objective of this study was to evaluate Ca2+, Mg2+, NO3– and SO42- leaching in the soil profile as affected by liming and top dressing nitrogen fertilization in cotton, grown with straw cover on the soil […]

Critical phosphorus levels for greenhouse-grown corn, as a function of its placement in the soil

Paulo Batista Leite, Víctor Hugo Alvarez V., Nairam Félix de Barros, Júlio César Lima Neves, André Guarçoni M.

01/Jun/2006

Localized application of P in the soil has great influence on its availability because it reduces de adsorption reactions, precipitation and fixation, due to the lowered soil contact surface area. This study, carried out in a greenhouse, aimed to calibrate P soil concentrations for corn growth as affected by fertilizer placement. Samples of two Oxisols (LVAd and LVAm) were used. The treatment consisted of 14 combinations of 7 P rates, which were placed in holes in the upper mid part of […]

Phosphorus sources and application methods for Maize in Soil of the Cerrado region

Alvaro Vilela de Resende, Antonio Eduardo Furtini Neto, Vera Maria Carvalho Alves, Joel Augusto Muniz, Nilton Curi, Valdemar Faquin, [...]

01/Jun/2006

The efficient use of phosphate fertilizers in soils of the tropical region is still a challenge, mainly regarding long-term soil management. Based on the cumulative response of three successive maize cultivations, alternatives of phosphorus supply combining P sources and application methods were compared in a formerly fertilized Red Argisol. Treatments arranged in a 4 x 3 + 1 factorial scheme represented by four P sources (180 kg ha-1 P2O5) as triple superphosphate – TS, magnesium termophosphate – MT, Arad reactive rock phosphate – RP, and Araxá […]

Relations of soil surface roughness with the rainfall volume and water aggregate stability

Ildegardis Bertol, André Júlio do Amaral, Eva Vidal Vázquez, Antonio Paz González, Fabrício Tondello Barbosa, Leonardo Felipe Brignoni

01/Jun/2006

Soil surface roughness is, among other factors, affected by soil tillage, cumulative rainfall and aggregate stability in relation to destructive water action. The soil surface roughness of a soil classified as a Haplumbrept was evaluated in an area where a water erosion experiment under natural rainfall has been carried out over the course of 15 years in the South of the Planalto Catarinense, Santa Catarina State, Brazil. The soil microrelief was characterized by the indices: roughness (RR), tortuosity (T) and limiting […]

Effects of soil characteristics on hexachlorobenzene degradation

Lia Emi Nakagawa, Mara Mercedes de Andréa

01/Jun/2006

Artificial changes in the properties of a soil contaminated with hexachlorobenzene were promoted in order to study the effects on the microbial community and the degradation of this compound. The soil samples were flooded or enriched with organic material or lime under laboratory conditions. The microbial activity and density as well as the total (mineralization) or partial hexachlorobenzene degradation (transformation into metabolites) were analyzed. The mineralization of 14C-hexachlorobenzene was analyzed by adding a 14C-hexachlorobenzene solution to soil samples, capturing the […]

Symbiotic compatibility of arbuscular mycorrhizal fungi with tropical tree species

Enrique Pouyu-Rojas, José Oswaldo Siqueira, José Geraldo Donizetti Santos

01/Jun/2006

Revegetation with tree species is an appropriate strategy for the rehabilitation of degraded areas. However, the establishment and growth of these species in low nutrient soils depends upon several factors, such as the ability of the species to form and benefit from mycorrhizae. In this study, conducted in pots under greenhouse conditions at the Federal University of Lavras in Minas Gerais, Brazil, aspects of host-fungus relationship in tree species found in Southeastern Brazil were evaluated. The following arbuscular mycorrhiza (AM) […]

Interrill erosion under different conditions of soil cover of sugarcane

Sandro Augusto Bezerra, José Ramon Barros Cantalice

01/Jun/2006

Interrill erosion occurs as a result of detachment of soil surface particles caused by raindrop impact and their transportation by overland flow (drag and suspension), which contain the organic matter and nutrients that are essential for agricultural production. An experiment was carried out to evaluate the effect of different soil cover types on the overland flow in interrill erosion in an area of sugarcane cultivation. The following situations were evaluated: bare soil; sugarcane straw mulch; sugarcane canopy cover; sugarcane canopy […]

Testing ALES (Automated Land Evaluation System) in the microregions Chapecó and Xanxerê, Western Santa Catarina State, for bean crop

César da Silva Chagas, Waldir de Carvalho Junior, Nilson Rendeiro Pereira, Elpidio Inácio Fernandes Filho

01/Jun/2006

Land evaluation is a process that estimates the land use potential based on its properties. A large variety of analytic models can be used in this process. In Brazil, the two most widely used land evaluation systems are the “Sistema de Classificação da Capacidade de Uso da Terra” and “Sistema FAO/Brasileiro de Aptidão Agrícola das Terras”. Although different in several aspects, both require the crossing of countless environmental variables. ALES (Automated Land Evaluation System) is a computer program that allows […]

Liming criteria for soybean in established no-tillage system

Antonio Nolla, Ibanor Anghinoni

01/Jun/2006

Lime recommendations developed for conventional systems are being used in no-tillage systems with different dynamics of the acidity attributes, due to organic matter and nutrient accumulation on the superficial layer and lower aluminum toxicity. This study associated different acidity indicators of a Rhodic Hapludox after eight years under no-tillage system with soybean plant characteristics in order to establish liming criteria. Two field experiments were compared, both under no-tillage for eight years; one had previously been under conventional tillage and the […]

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