ABSTRACT
The potential of vegetation cover of soil by cover crops is an important parameter for the selection of forage species adapted to a given region. However, one of the restrictions the use this variable is associated the adoption of the estimation technique, since there are different forms of calculation. Thus, the objective was to compare the cover fractional of soil cultivated with Urochloa ruziziensis and Urochloa spp., using three measurement techniques: visual evaluation, evaluation by intercept or transect and evaluation by photographic image. For this, six experiments were conducted in the field, in randomized block design. The experiment 1, 2 and 3 was formed by the species of Urochloa ruziziensis and composed of three treatments, represented by the three measuring techniques (visual evaluation, evaluation by transect and evaluation by photographic image), with eight replications. The experiment 4, 5 and 6 had factorial arrangement 2 x 3, the factor A was formed of two species of Urochloa (Urochloa ruziziensis and Urochloa spp. cv. Mulato II) and the factor B by the three measuring techniques (visual evaluation, evaluation by transect and evaluation by photographic image), with four replications. The measures of fractional of cover soil were made at 30, 60 and 90 days after sowing. Was found that the greater the uniformity of soil cover by forage plants, closest are the values of fractional of vegetation cover obtained by the three estimation techniques. The measurement techniques of visual and to transect of the fraction of soil cover were considered similar, and the efficiency of the evaluation by photographic image depend on the individual calibration of each image.
Brachiaria spp; brachiaria-grass; forage; visual evaluation; evaluation by transect; evaluation by image
