Abstract

DELGADO, Rodolfo et al. Evaluation of some characteristics of the root system of maize (hybrid inia 68) sowed under minimum and conventional tillagein a fluventic haplustoll soil of maracay, venezuela ¹. Agronomía Trop. [online]. 2008, vol.58, n.4, pp.427-438. ISSN 0002-192X.

The characterization of the root growth of maize, Zea mays L., and characteristics related to water and nutrient uptake, could be used to development management practices to promote efficient use of them, and better yields. In this work we evaluated the accumulation of root dry matter (RDM), and root length density (RLD) of maize (Hybrid INIA 68), sowed under minimum (MT) and conventional tillage (CT) in a Fluventic Haplustoll soil of Maracay, Aragua State. There were significant differences in RLD and RDM among soil layers of the same tillage type, but not between MT and CT. The RLD and RDM there were higher in the 0-10 cm layers, that in the others soil layers: 93% of the RDM was found in the 0-20 layer, and between 50 to 80% there was found under the plant. We also found that between 50.7 and 62.3% of the total RDM was accumulated during the reproductive period (60-75 days). Under MT there was significantly more DMR in the 0-5 cm layer than in the 5-10 cm layer, while under CT there were not differences. During the firsts 15 days of the crop cycle, there was horizontal root growth until 37.5 cm in NT, while for CT that position was reached at 30 days, although under CT there was faster vertical growth than under NT. At the 45-60 and 60-75 days period there was an important root length growth for CT and MT respectively, which was probably associated to higher soil water content under MT than under CT.

Keywords : Root length density; root mass; maize; tillage; roots.