Persistence of Desmodium incanum DC. in croplands established on natural grassland

• Autor(a) principal: Medeiros, Renato Borges de
• Data de Publicação: 2006
• Outros Autores: Favreto, Rodrigo, Ferreira, Otoniel Ceter Lauz, Siewerdt, Lotar
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Gaúcha (Online)
• Texto Completo: http://revistapag.agricultura.rs.gov.br/ojs/index.php/revistapag/article/view/311
• topic: soil seed bank, natural grassland, Desmodium incanum, crop-grazing intcgration, tillagc systems, spontaneous vegetation; banco de sementes do solo, campo natural, Desmodium incanum, integração lavoura-pecuária, sistemas dc preparo de solo, planta espontânea

This work was carricd out at Depressão Central/RS (alt.46m, lat.30°05"S, long.51°40'0), to determine the effect ofsoil tillagc systems on the persistente of Desmodium incanum DC. in field crops established on natural grassland. In arandomized complete block design three tillage methods were used as plots: direct drill (DD), minimum tillage (MT) andconventional tillagc (CT). Surveying of cover-abundance, frequency and soil secd bank (soil core samples and germination) of D.incanum were carricd in: autumn and spring of 2002 and 2003, and autumn of 2004. A very low amount of seeds was registered.D. incanum frequency and cover-abundance were higher in the DD than MT and CT, of which the latter shówed ver> , Iow valucs.In DD and MT, the relationship between frequency and cover-abundance with vegetation sampling dates were described bynegative linear regressions. Positive linear regressions were recorded between frcquency and cover-abundance with pH andorganic mattcr of soil surface. In solte of the gradual reduction in persistente, D. incanum showed ability to persist for unti I fouryears, in soil tillagc systems under Iow disturbancc such as direct drill.