Studies on the interaction among weeds, crops and planting systems can provide new systems of pasture introduction, recovering, and renovation. This research aimed to study weed phytosociology in pasture implanted in the fallow cropping. Considering the need of liming application, the treatments followed the combination of two planting systems (no-tillage and plowing followed by harrowing) and four soil pH adjustment levels (0, 1/3, 1/2 and 1 time of the recommendation). It was observed that Sida species showed higher importance value indexes in all treatments. Sida urens and Sida rhombifolia were the most representative. Importance value indexes of plants from the Genus Sida were increased with corrective rates, showing maximum values with half of recommended lime rate, with posterior decrease. Besides grasses and forage legumes which can benefit the system, other species toxic to animals occurred. Perennial grasses showed higher importance value index under conventional planting than in no-tillage system, making possible the use of specific herbicides in conventional system. Comparing no-tillage and conventional systems, the similarity index was 81.1%, which is considered high. In general, conventional planting system showed even higher weed density than no-tillage in the implementation of the integration system .
Brachiaria brizantha; soil acidity correction; phytosociologic assessment; no-tillage; fallow cropping; Zea mays
