Efeitos da calagem em semedura direta de milho

Abstract

Palavras-chave: Zea mays L., acidez do solo, calcário dolomítico, sistema radicular, nutrição mineral. ABSTRACT EFFECT OF LIME APPLICATION ON NO-TILLAGE CORNThe effects of superficial lime application on chemical soil attributes under no-tillage systems and its influence on root growth and mineral nutrition in maize crops have not been thoroughly investigated yet. To evaluate these effects on maize and its reflexes on grain yield performance, a field trial was carried out on a dystrophic clayey Rhodic Hapludox, previously managed under no-tillage for six years, at Tibagi, State of Paraná, Brazil. The experimental design was a randomized complete block with four replications, using 44.8 m 2 plots. The treatments consisted of four liming rates (0, 1, 2 and 3 t.ha -1 , pure CaCO 3 equivalents) which represented 1/3, 2/3 and the total amount calculated for the soil to reach a base saturation of 70%, in the 0-20 cm layer. Dolomitic limestone (27% of CaO, 20% of MgO and 85% of ECCE) was broadcast-applied to the soil surface without incorporation. After 22 months, lime application increased soil pH in CaCl 2 0.01 mol.L -1 , exchangeable Ca and Mg, and base saturation, and reduced H + Al and exchangeable Al at the superficial layer (0-10 cm). It also increased exchangeable Ca and decreased exchangeable Al at the subsoil (20-40 cm). Liming did not significantly affect length and relative distribution of corn root at the 40 cm depth, reduced average root radius and increased plant uptake of P, Ca, Mg, and S, with no significant effects on grain yields. Surface lime application did not affect Cu, Fe, Mn and Zn concentrations in the soil and leaves or plant uptake of these micronutrients.

Surface application of lime ameliorates subsoil acidity and improves root growth and yield of wheat in an acid soil under no-till system

“…The aluminum in toxic concentrations causes reduction in root growth rate, but the reaction of genotypes to the aluminum in acid soils is variable (Muzilli et al, 1978;Costa et al, 2003;Tang et al, 2002;. These results differ substantially from those obtained for soybean (Caires et al, 2001) and corn (Caires et al, 2002b;Tissi et al, 2004), in similar conditions of soil acidity under NT. In these studies, concentrations of exchangeable Al 3+ in the soil from 8 to 11 mmol c dm -3…”

“…The higher content of organic matter (Bayer et al, 2000;Rhoton, 2000) and the greater nutrient concentration on the soil surface (Rhoton, 2000) under NT may reduce aluminum toxicity through the formation of Al-organic complexes and the greater ionic strength of the soil solution (Salet et al, 1999). However, this low toxicity of aluminum for root growth of plants under NT (Caires et al, 2001;2002b;Tissi et al, 2004) should only occur in the absence of water deficit. In this study, although the rain episodes occurred in adequate intensity soon after sowing and at the beginning of wheat flowering, rainfall was irregular during the crop cycle -long periods with water limitation were observed during the vegetative development stage (Figure 1).…”

“…Several experiments have attested no limitation to root growth (Caires et al, 2001;2002a;2002b;Tissi et al, 2004) and high crop yield (Pöttker & Ben, 1998;Caires et al, 1999;Rheinheimer et al, 2000;Caires et al 2002a;2002b) in adverse acid soil conditions under NT.…”

Efecto de la aplicación de enmiendas líquidas en el suelo y en el crecimiento de maíz bajo condiciones de invernadero

“…Esta forma de obtención de nutrimentos está bien documentado por diversos autores (Clarkson y Hanson 1980, Lynch y Van Beem 1993, Villalobos 2001) al evidenciar la relación área.volumen -1 de la raíz. Los resultados coinciden con Tissi et al (2004) y Azevedo et al (2011) donde encontraron respuesta en la captación de nutrimentos con la aplicación de encalado en maíz, lo cual mejoró la captación de P, Ca, Mg, S y no alteraron la concentración de Cu, Fe, Mn y Zn en el suelo ni el tejido vegetal.…”

Propriedades químicas e fauna do solo influenciadas pela calagem em sistema semeadura direta

“…Neste caso, a baixa solubilidade do calcário dificulta a mobilidade de Ca 2+ e Mg 2+ ao longo do perfil (TISSI et al, 2004). Outra característica relevante deste sistema consiste na permanência de restos culturais sobre o solo, o que pode influenciar no incremento do estoque de carbono orgânico.…”