Corn Yield as Affected by Liming and Tillage System on an Acid Brazilian Oxisol

Abstract

and P (Rhoton, 2000) accumulate in the upper few centimeters under NT compared with CT soil, which may Tillage system affects many soil parameters that may influence reduce Al toxicity. Other nutrients also accumulate near plant growth. This study evaluated the effect of liming on corn (Zea mays L.) yield and chemical characteristics of a Humic Hapludox the surface in NT soils (Rhoton, 2000), causing increases (clayey, kaolinitic, goethitic, termic) under both conventional tillage in the concentration of electrolytes, reductions of soil (CT) and no-tillage (NT) systems. Rates of dolomitic lime, from 0 to pH, and increases in both Al activity (Ernani and Bar-18 t ha Ϫ1 , were plowed into the soil in 1992 in southern Brazil; our ber, 1991) and P sorption. These effects may offset the study was conducted from 1996 through 1999. Lime rate was allocated benefits of soil organic matter (SOM) and P accumulato subplots, and tillage systems to main plots, in a split-plot design.tion on Al toxicity in NT soils. Corn yield increased with liming in all years and was higher with CTVariations in soil pH also affect availability of most than with NT in 2 of 3 yr. Averaged across years and systems, liming soil nutrients (Helyar and Anderson, 1974, Ernani et increased yield by 66%, which ranged from 4.4 to 7.8 t ha Ϫ1 . The al., 1998), organic matter decay (Azevedo et al., 1996), highest average yield (7.8 t ha Ϫ1 ) was obtained at pH 6.5; yields at N mineralization, and some physical and chemical prop-pH 6.0 or 5.5 were 97 and 89% of the maximum, respectively. Liming reduced soil organic matter (SOM) in both systems, but nutrients (P, erties (Albuquerque et al., 2000), especially on highly K, Ca, Mg, Fe, Cu, Zn, and Mn) remained above sufficiency on all weathered soils. The magnitude of these changes varies treatments. Aluminum, pH, SOM, and other nutritional parameterswith soil, soil pH range, organic matter content, and did not differ between tillage systems, partly because limestone was tillage system (Torbert et al., 1998). Thus, liming has initially incorporated in all plots and partly due to dilution effects in direct and indirect effects on nutrient availability and the plow layer because sampling was not stratified in small depths.

Hard Red Winter Wheat Cultivar Responses to a pH and Aluminum Concentration Gradient

“…Likewise, threshold pH was found to be cultivar-dependent (Table 1). This was in contrast with a pH of 5.5 previously reported as the ideal pH for wheat production Ernani, et al, 2002). At a range of 5.3 to 6.6, threshold pH for grain was more variable among cultivars than for forage,…”

“…Increased soil acidity causes solubilization of Al, which is the primary source of toxicity to plants at pH below 5.5 Ernani, et al, 2002Parker et al 1989. Aluminum chemistry varies with soil pH, but only the soluble ions such as Al 3+ , which exists between pH 4.7 and 6.5, are toxic to plants.…”

Absorção de fósforo em doze genótipos de milho inoculados com fungo micorrízico arbuscular em solo de cerrado

“…As favoráveis são topografia plana e textura dos solos, que facilitam a mecanização, a precipitação suficiente, a temperatura e a luminosidade adequadas e a boa drenagem dos solos. Quanto às desfavoráveis, a maior restrição consiste na associação da alta acidez (pH baixo e elevada saturação por alumínio) com a baixa fertilidade natural dos solos, principalmente em relação à disponibilidade de fósforo (ERNANI et al, 2002).…”

Influence of micronutrients on dry matter yield and interaction with other nutrients in annual crops

“…Most of the cerrado soils are acidic and liming is an essential practice to improve soil pH and decrease toxicity of Al 3+ Ernani et al, 2002). Liming significantly & Klamt, 1999;Galrão, 1999;Oliveira Júnior et al, 2000;Fageria et al, 2002).…”