Inadequate soil management systems can lead to water erosion, nutrient losses and superficial water pollution, accelerating environmental degradation. The P and K losses caused by water erosion were evaluated from November 1999 to October 2001 in an Inceptisol with 0.102 m m-1 slope, in Lages, Santa Catarina State, Brazil, under natural rainfall conditions. The evaluated soil management systems were: no-tillage for six years (NT6), no-tillage for nine years (NT9), chiseling plus one disking for nine years (C + D9), and […]

Late season potassium (K) deficiency has been observed quite frequently for cotton crops in the Brazilian cerrado region. One possible reason for such a problem could be the low water availability at this period of the season. Thus, an experiment was conducted in order to quantify the relative contribution of mass flow and diffusion in supplying K to cotton roots, as affected by soil water and K availability. The arable layer of a typic Red Latosol (Haplortox), with 630 mg […]

A field trial was carried out to evaluate the effects of nitrogen and potassium top dressing on upland rice. The treatments consisted of a 5 x 3 factorial design (five nitrogen doses – 0, 25, 50, 75, and 100 kg ha– and three potassium doses – 0, 25 and 50 kg ha-1), arranged in a complete randomized design, with three replicates. The results showed that several yield characteristics were positively influenced by nitrogen and potassium fertilization. The best combination of […]

Iron deficiency in coffee plants cultivated in ferric Latosols may be induced by conditions that affect the transport of this nutrient in soils, such as P concentration, high pH values and low soil moisture content. The iron diffusive flux (FeF) in soils was evaluated as a function of P rates and levels of acidity and moisture. Surface soil samples of a clayey dystroferric Red Latosol and a loamy-sand dystroferric Yellow Red Latosol were supplied with 20 mg dm-3 Fe as […]

The objective of this study was to evaluate alterations in the physical soil quality of a Dystroferric Red Latosol (Typic Haplorthox) caused by chiseling, after thirteen years of no-tillage. The experiment consisted of two management systems: soil chiseling down to a 0.30 m depth (NTC) and no-tillage (NT). Undisturbed soil samples were collected at depths of 0-0.15 m and 0.15-0.30 m, and the soil water retention curve, the soil resistance to penetration curve, the soil bulk density, and the “Least […]

The efficacy of no-tillage systems in reducing water erosion depends largely on the soil cover by crop residues. The study was carried out in Santa Catarina State, Southern Brazil, from August 2001 to July 2002, aiming to evaluate the decay of corn residue on the surface of an Inseptisol and its influence on soil properties. The treatments, with three replicates, were: bare soil (BS), 8.77 Mg ha-1 of air dried corn residue (CR) and 8.77 Mg ha-1 of air dried corn residue plus 100 kg ha-1 […]

The understanding and quantification of the impact caused by soil use and management on the physical soil quality are fundamental for the development of sustainable agricultural systems. The objective of this research was to quantify some physical soil properties to evaluate the physical quality of a dystrophic Red Latosol (Rhodic Ferralsol) in the northwest of the State of Paraná, Brazil. Undisturbed soil samples were collected from two contiguous areas on an Experimental Farm of the State University of Maringá. One […]

Sewage sludge from wastewater treatments contains organic matter and plant nutrients that may play an important role in agricultural production and maintenance of soil fertility. The present study aimed to evaluate the effect of increasing sewage sludge rates on soil chemical properties, heavy metal concentration in soils and plants, and the growth of maize and bean plants cultivated in pots under greenhouse conditions. Two soil types with different clay contents were used for application of six sewage sludge rates (equivalent […]

The vegetation cover plays a key role in protection and conservation of natural resources, particularly concerning soils. This study had as objective to analyze space and time dimensions of anthropic influence on the vegetation cover in part of the semi-arid region of the Ceará State, Brazil. LANDSAT TM-5 satellite images of 1985 and 1994 combined with geoprocessing techniques were used to verify the hypothesis of intensification of environmental degradation. Maps of the vegetation cover, land use, soils, and hydrography were […]

The present study evaluated the influence of halomorphic, hydromorphic, and sulfate reduction conditions on sand fraction mineralogy and on the geochemistry of three mangrove soils from the Iriri River estuary. Three representative soil profiles selected from a transect had their geochemical conditions characterized and their effects on the mineralogy of the soils were described. The mineralogical analyses (XRD and EDS) and the physicochemical (Eh and pH) conditions found indicate the occurrence of pyritization in the investigated area. The mineralogical soil […]