Evaluation of weed changes according to different fertilization management systems, through phytosociological analyzes in lettuce and carrot

Abstract

The population dynamics of weeds due to different fertilization management systems is essential in the agricultural areas for the understanding of their interference and possible damages. The objective of this study was to evaluate the influence of different fertilization management systems on the weed community through phytosociological analyzes in lettuce and carrot crops grown in succession. The experimental design was a randomized block design, with eight treatments and four replications in each plant, following the same experimental layout. The treatments, referring to different management of fertilization were: Conventional; With Weeds; No Weeds; Compound; Crotalaria; Crotalaria more Compound; Lab-Lab and Lab-Lab + Compound. During cultivataion of lettuce and carrot, we collected more than 3,000 weed specimens, representing 25 species distributed in 11 families, 88% dicotyledonous and 22% monocotyledonous. The weed families with the highest value of importance in all stages of collection were Asteraceae, Brassicaceae and Poaceae. The most representative species in the area were Eleusine indica, Cyperus rotundus L., Galinsoga parviflora, Richardia brasiliensis, Oxalis latifolia, Cynodon dactylon and Conyza canadensis. The different forms of fertilization and use of cover crops were able to promote changes in the weed community and decrease in the population density during the experimental period. The treatments contributed to reduce the daily amplitudes of thermal and water changes and the incidence of sunlight on the surface layer of the soil, delaying the emergence of these weeds and contributing to other soil benefits inherent to the use of each type of fertilization.