Indicadores de fertilidade do solo em pastagem com diferentes idades no estado de Rondônia

Abstract

The intensification of cattle farming in Rondônia, predominantly based on extensive systems using pastures, has led to continuous soil use without proper nutrient replenishment, resulting in decreased fertility and productivity. This study aimed to evaluate soil fertility indicators in pasture areas with different usage durations and cultivation histories, located in the municipality of Machadinho D’Oeste – RO, focusing on chemical attributes and macro- and micronutrient levels. The research was conducted in four experimental areas, including a native forest and three pasture areas with varying years of deforestation and agricultural occupation. Soil samples were collected at a 0–0.20 m depth, and data were analyzed using ANOVA and Tukey’s test at a 5% significance level. The following parameters were assessed: pH, organic matter, phosphorus, potassium, calcium, magnesium, sulfur, aluminum, H+Al, sum of bases, cation exchange capacity, base saturation, and aluminum saturation, as well as boron and iron content. The results revealed low levels of magnesium in all areas, low levels of sulfur and calcium in older pasture areas, and high acidity and aluminum saturation in the forest area. The pasture areas exhibited variable fertility levels, with better performance in sites with more recent pasture renewal. It was concluded that the duration of land use and previous management practices significantly affect soil quality. The absence of corrective practices such as liming and fertilization impairs soil fertility attributes, emphasizing the need for sustainable soil management strategies to ensure productivity and the conservation of natural resources in the Amazon region.