Volume 22, Number 4, 1998

The determination of land degradation risk in a watershed is an important factor in environmental and agricultural land-use planning. The current trend is to analyze the necessary information for land evaluation in a less subjective way and compatible with geoprocessing techniques. However, criteria and parameters used to quantitatively evaluate the land degradation risk at the watershed scale and based on Geographic Information Systems (GIS) still need to be better defined. The objective of this study, conducted in the second semester […]

Micro-macromorphological, physical, chemical and mineralogical investigations were conducted on irrigated and non-irrigated Podzolic soils from Petrolina, Pernambuco, Brazil. The aim of this study was to characterize and evaluate differentiation among soils, as a function of their position in the landscape, due to the combined effects of surface and subsurface relief as well as five years of sprinkle irrigation on mango trees. Data from four profiles were used, two from the irrigated area and two from a contiguous area of natural […]

Handling a large volume of data from nutritional surveys of forest plantation is a hard task in studies of tree nutrition. A mathematical process named “Method of Mathematical Chance” was developed, based on probability calculation, to interpret such data by levels of nutrient sufficiency. By this method it is possible to identify optimum, sub-optimum and supra-optimum ranges, for each growth factor, as well as permit the classification of tree stands according to their distribution in each sufficiency level. In this […]