The objective of this study, which employed a randomized complete block design, with four replicates, was to evaluate, after eight years (1995 to 2003), the soil fertility of a typical dystrophic red latosol (typic hapludox) located in Coxilha, Rio Grande do Sul State, Brazil, in six crop-livestock production systems (ILP): I) wheat/soybean, black oats + common vetch pasture/corn; II) wheat/soybean, black oat + common vetch + ryegrass pasture/corn; III) wheat/soybean, black oat + common vetch pasture/pearl millet pasture; IV) wheat/soybean, black oat + common vetch + ryegrass pasture/pearl millet pasture; V) wheat/soybean, oats/soybean, and black oat + common vetch pasture/pearl millet pasture; and VI) wheat/soybean, oats/soybean, and black oat + common vetch + ryegrass pasture/pearl millet pasture). Soil core samples were also collected in a fragment of subtropical forest adjacent to the experiment. After eight years, acidification in the top soil layer was observed. The exchangeable Mg and K and extractable P were affected by mixed-crop production models. The soil layers of 0-5 and 5-10 cm presented higher values of soil organic matter, P, and K. The reverse occurred with values of pH and exchangeable Al. The levels of soil organic matter, P, K and Ca + Mg decreased with soil depth. The crop systems studied presented higher values of C in the soil than the subtropical forest.
organic matter; phosphorus; potassium; lay farming; mixed systems
