Development of ryegrass roots as affected by humic compounds addition to a complete nutritive solution under greenhouse conditions

This work was carried out under greenhouse conditions, in 1997, at Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul (UFRGS). A split plot randomized complete block experimental design was used, with six replications, to evaluate root lengths, average radius, roots surface and dry matter of roots with the objective to evaluate the effect of humic compounds addition in the development of ryegrass roots. Ryegrass forage was grown in pots with irrigated sand with four I eve Is of humic compounds added to a complete nutritive solution with four-doses of humic compounds (0, 10, 20 and 30-mg/liter). The humic compounds were extracted from the charcoals of the Capane (Palermo CE-4,200 and Palermo CE-4,700). Leao (Leao CE-5,200) and Candiota (Candiota superior layer, Candiota inferior layer, CE-3,300 and Candiota CE-4.700) mines, For all variables, the statistical analyses showed significance for the interaction dose x raw material effects. Results demonstrated that humic compounds promoted roots development. increasing: a) roots length at 100.87%: b) roots weight at 49.23% and c) 68% of the roots surface. The humic compounds influence ryegrass roots development and that these substances from different raw materials distinctly act on the parameters of the four variables analyzed.