Produção e composição química da folhada em soutos submetidos a diferentes técnicas de mobilização do solo

The objectives of this study were to determine the influence of different soil tillage systems on chestnut tree (Castanea sativa) productivity. The plots, established in Macedo de Cavaleiros, were given to three treatments: chisel ploughing, three times per year (traditional system) (T1), minimum tillage with disc plough, twice a year (T2) and zero tillage (T3). Vegetation was controlled either by sheep or by cutting. Litter was collected from April 1996 to March 1999. The largest litterfall production was obtained in T3, which may be related to the fact of roots not being damaged. In all treatments, leaves made the highest contribution to total litter, followed by burs and nuts. In relation to the chestnut fruit, the highest production was obtained in T3, followed by T2 and T1. The largest nut production in T2 than in T1 may be related to the more damaging effect that chisel ploughing has on the root system when compared to disc ploughing. In general, the lowest nutrient concentration occurred in T1, which is related not only with the lower litter production but also with the nutrient concentration in the different litterfall components. In general, it was the lowest in T1, mainly in leaves.