INVESTIGADORES
BUSCHIAZZO Daniel Eduardo
artículos
Título:
Competition between wheat and weeds in two tillage and fertilization systems in a semiarid environment
Autor/es:
ABASCAL SERGIO; BUSCHIAZZO, DANIEL E.
Revista:
AGROCHIMICA (PISA)
Editorial:
IST CHIMICA AGRARIA
Referencias:
Lugar: Pisa; Año: 2005 vol. XVLV p. 1 - 9
ISSN:
0002-1857
Resumen:
Weeds can affect crop productivity because of competition for light, water and nutrients. The objective of this study was to evaluate the ability of wheat to compete for nitrogen in the presence of weeds in the semiarid Pampas of Argentina. With this purpose a field experiment was carried out between June 2001 and December 2001 a period characterized by high rains, which discarded weed competition for water. Treatments consisted of two tillage systems: no-till (NT) and conventional tillage (CT), with application of two nitrogen sources (urea and diammonium phosphate, DAP) at two stages of wheat growth (seeding and tillering). Results showed that under the conditions of this study 42 to 61 % of total dry biomass was represented by weeds, 24 to 37 % by wheat straw, and 15 to 23 % by wheat grain. Weeds dry matter was not affected by tillage system nor by the stage at which fertilizers were applied, but by fertilizer type (urea > DAP). Wheat grain and wheat straw were not different between fertilization sources nor between fertilization moments. Wheat grain yields were negatively affected by weeds dry matter in treatments with fertilizers applied at wheat tillering (urea > DAP) but not in treatments with fertilizers applied at wheat seeding. Nitrogen concentration was higher in wheat grain (0.54 to 1.97%) than in weeds (0.85 to 1.82%) or wheat straw (0.39 to 0.97%), but total extracted nitrogen was higher in weeds (56%) than in wheat grain (30%) or wheat straw (14%). Wheat grain nitrogen correlated weakly and negatively with weeds dry matter production (R2 = -0.14, n = 30, p < 0.05), indicating a low competitive effect. It can be concluded that under no water stress conditions weeds competition will affect more the wheat grain productivity than wheat grain nitrogen contents in the semiarid Pampas of Argentina.
