Spontaneous plants in the soil covering and accumulate of nutrients in areas cultivated with cashew

Abstract

The potential of weeds as soil cover in fields planted with cashew was evaluated in a field experiment conducted in Pacajus, Ceara, Brazil from 1999 to 2001. Weed persistence during drought and dry matter yield were determined, and nutrient accumulation was quantified. The weeds provided soil cover throughout the year, and accumulated K, Ca, Mg and C mainly during the initial growth stage of cashew. Wedelia padulosa [Sphagneticola trilobata], Slephontopur hirtoflorus [Elephantopus hirtiflorus?], Setaria geniculata [Setaria parviflora], Leptochloa filiformis, Hyptis suaveolens, Alternanthera brasiliana and Porophyllum ruderale exhibited the greatest potential for use as green manures.