ACUMULAÇÃO DE NUTRIENTES NO LIMBO FOLIAR DE GUANDU E ESTILOSANTES

Pigeon pea ( Cajanus cajan ) and stylo plants ( Stylosanthes guianensis var. vulgaris cv. Mineirao) are two legumes cultivated in cerrado soils of central-west Brazil and cultivates for green manure, seed production, and pasture. The objective of this study was to evaluate accumulation of N, P, K, Ca, Mg, Zn, Cu, Mn, and Fe in leaf blades as a function of days after emergence. The experiment was developed in a dystrophic Oxisol at Embrapa Rice and Bean Research Center, in Santo Antonio de Goias, Goias State, Brazil. The treatments were arranged in a completely randomized block design with four replications. Plot size was 6.0 m wide and 20.0 m long. Planting fertilization was 400 kg ha-1 of a 5-30-15 formula. Sowing was done in December 2001. During crop growth, nine random leaf blades samples were collected on the different days after sowing for chemical analysis. Nutrient accumulation (Y) was determined and data were adjusted as a function of days after emergence (X) using a quadratic exponential regression model Y = a exp(bx + cx2). Pigeon pea showed higher dry matter and, generally, higher nutrient accumulation than stylo plants until 98 days. Among macronutrients, N had the highest accumulation and P the lowest. Among micronutrients, Fe had the highest accumulation and Cu the lowest in the leaf laminas of the two legumes. KEY-WORDS: Legumes, nutrient content, mineral nutrition, Cajanus cajan , Stylosanthes guyanensis .