Abstract

MONQUERO, P.A; MILAN, B.; SILVA, P.V.  and  HIRATA, A.C.S.. Desiccation timings of soil cover crop before soybean sowing. Planta daninha [online]. 2010, vol.28, n.3, pp. 561-573. ISSN 0100-8358.  http://dx.doi.org/10.1590/S0100-83582010000300013.

The objective of this work was to evaluate the effect of desiccation timings (2, 7, 14, 21 and 28  days) before soybean sowing - DBS) of the following cover crops (Brachiaria ruziziensis, Pennisetum americanum and Brachiaria brizantha) on initial crop development, nutritional soybean content and weed management. The experiment was arranged in a complete randomized block design with four replicates. At soybean sowing, the desiccated species were controlled above 90% at 21 and 28 DBS while desiccation at 2, 7 and 14 2 DBS presented lower control, differing between the species. In desiccation at 2 and 7 DBS, soybean emergence occurred under a large amount of green biomass, showing a lower stand. However, in desiccation at 2  DAS, straw remained for a longer time on the soil, reducing new weed emergence flows. Increased intervals between P. americanum desiccation and soybean sowing led to a pronounced increase in soybean phosphorus content. The highest potassium contents in soybean were observed in B. ruziziensis and B. brizantha straw. The highest Nitrogen content was observed when B. brizantha and P. americanum were desiccated at 21 DBS.

Keywords : brachiaria; pearl millet; glyphosate; no-till.