In the humid tropics the buildup and maintenance of soil fertility are major challenges in terms of sustainability of agroecosystems. The objective of this study was to evaluate an alley cropping system with pigeon pea (Cajanus cajan) on an Alfisol, with annual application of lime and potassium, with special concern regarding the viability of this system as an alternative to slash and burn practiced in tropical agriculture. Pigeon pea and maize (Zea mays) were planted in the experiment with the following treatments: T = control, with bare soil; G2, G2.5 and G3 = treatments with pigeon pea, spacing between lines of 2, 2.5 and 3 m, respectively; G2K, G2.5K and G3K = pigeon pea, same spacing, plus potassium; G2C, G2.5C and G3C = pigeon pea, same spacing, plus liming; G2KC, G2.5KC and G3KC = pigeon pea, same spacing, plus potassium and liming. Mulch and nutrient balance affected maize yield most in the alley cropping system and must therefore be considered fundamental for the sustainable management of sandy-loamy Alfisols in the humid tropics.
Cajanus cajan; maize; yield; potassium fertilization; liming
