Propriedades físicas do solo e sistema radicular do cacaueiro, da pupunheira e do açaizeiro na Amazônia oriental

Physical properties of soil and root system of cocoa, peach palm and acai in the eastern Amazon The knowledge on the relationship between roots of crop plants and soil physical properties is very important. This article evaluates the distribution of the root systems of cocoa, palm peach and acai and their relationships with the soil physical properties. The research was carried out in an alic Yellow Latosol and root and soil samples were obtained from 10 cm to 40 cm depth. The experiment was arranged in a randomized block in the factorial design (four depth soils and three root class), with four replications. The acai root amount is twice of the palm peach and ten times more that of cacao. No difference was verified in the amount of roots of peach between the distances of the plants. The roots were collected in two distances of the plant stem in monolith samples and separated in three diameter class: 3.0 mm. The roots amount of the three plants was directly correlated with the coarse sand content and inversely correlated with clay content and bulk density. The large pores size was also directly correlated with the amount of cacao and acai roots in the three classes of diameter . The acai showed the most abundant root system and it the greatest number of correlations between the amount of roots and the physical properties of soil involving the three diameter root classes.