Two systems of sugar cane harvesting were compared: 1-previous burning (burned cane) and 2-straw spreading over the soil surface (green cane), over an area of Linhares Agropecuária S.A. plantation, in Linhares, Espírito Santo, Brazil. The soil was classified as Yellow Podzolic sandy over medium texture, developed from Barreiras Formation sediments. After six years of sugar cane cultivation (1989-1994), nutrient distribution, humified fractions, and soil microbial biomass dynamics were determined. The green cane system showed an increasing of soil carbon content […]

A micropedological characterization of eight selected soils from Zona da Mata, MG, Brazil was carried out encompassing an iron-rich Red-Yellow Latosol (“Una” Latosol), two Dark-Red Podzolic, two Reddish Brunizens, one “Terra Roxa”, one Vertisol and one Cambic Red-Yellow Podzolic. Thin sections were analyzed by Optical Microscopy (OM) to identify micropedological features such as: microstructure, porosity, skeleton-grain composition and illuviation cutans. In addition, surface features of undisturbed aggregates were studied at submicroscopic level, using a JEOL 840 Scanning Electron Microscope, in […]

Undisturbed samples of representative horizons of soils from Jaíba Project, northern Minas Gerais, Brazil, and compacted and non-compacted layers of soils under intensive use were collected and micromorphologically analyzed to obtain more information on their evolution degree and also to evaluate the soil alterations caused by agricultural use. Four soils derived from limestone (P1 to P4) and one originated from detritic sediments (P5) were studied, as well as layers with and without indication of compaction. The micromorphological study revelead that […]

The effect of nitrogen levels on the growth and yield of garlic plants grown from tissue culture and conventional propagation. The trial was conducted at an experimental field of the Plant Science Department/UFLA, Lavras, MG, Brazil. A complete randomized block design in a factorial scheme with four replications was used. Plants originated from two propagation methods-tissue culture and conventional and five levels of nitrogen fertilizer – 0, 35, 70, 105 and 140 kg ha-1 were applied during the treatments. Plant […]

The efficiency of surface application of lime under a no-tillage system is doubtful, particularly with regard to subsoil acidity and to methods of lime requirement determination. A field experiment was carried out on a dystrophic Dark Red Latosol (Haplortox) from Ponta Grossa, Paraná, Brazil, from 1993 to 1998, to evaluate the extent of downward movement of lime applied on the surface under a no-tillage system, and the effect on crop rotation grain yields. A randomized complete block design was used, […]

Redox processes affect the reactivity of iron oxides and this can affect the P availability in soils. To evaluate how this processes can affect phosphorus availability, this study was carried out with six Uruguayan soils, which differed in their parent material, and subjected to alternation of the flooded-drained conditions. Soil samples (0-15 cm) of the A horizon, were flooded during 0, 5, 15 and 45 days, drained and sampled after 21 days of air-drying. Fe extracted by ammonium oxalate at […]

The aim of this study was to evaluate the effects of vinasse (100 and 200 m3 ha-1) on the degradation and sorption of diuron in Rhodudalf and Haplorthox soiIs. For the degradation study an experiment was carried out in a completely randomized design with a factorial experiment of 2 (soils) x 3 (vinasse: 0, 100 and 200 m3 ha-1), for 120 days. The mineralization was evaluated by radiorespirometry. At the end of the incubation, the original compounds and their metabolites […]

With the objective to evaluate the desorption of phosphorus by silicon in surface layers of a Dark-Red Latosol (Oxisol) under cerrado vegetation and Cambisol (Inceptisol), under open cerrado vegetation at Campos das Vertentes physiographical region State Minas Gerais, experiments were carried out under greenhouse conditions at the Soil Science Department of the Federal University of Lavras, Minas Gerais state, Brazil, from August 1997 to May 1998. Each soil was submitted to three sequential incubations: (a) CaCO3 + MgCO3 to maintain […]

A soybean crop experiment using samples from a sandy Dark Red Latosol was conducted in a greenhouse at the Universidade Federal de Uberlândia, Minas Gerais, Brazil from July/1996 to February/1997, to evaluate the effects of inoculation and subsoil compaction on the shoot dry matter production (ADMP), root dry matter production in the superior ring of the column, and nitrogen absorption and concentration in soybean shoots.. The treatments were set in a 2 x 3 x 4 factorial design and corresponded […]

The objective of this work was to evaluate the effects of molybdenum (Mo) leaf application in beans on leaf and grain concentration of Mo, total N, organic N and nitrate as well as the grain nutrient accumulation. Beans cv. “Ouro Negro” was cultivated at the Universidade Federal de Viçosa. Treatments consisted of increasing levels of Mo (0, 40, 80 and 120 g ha-1), using ammonium molybdate applied to the leaves 25 days after emergence. The experimental design was a randomized […]