Soil Chemical and Physical Properties on an Inceptisol after Liming (Surface and Incorporated) Associated with Gypsum Application

Abstract

Inceptsoils have high aluminum contents, and amendments are required to ensure a satisfactory crop development. Liming is efficient in neutralizing Al 3+ , but when applied to the topsoil its action is restricted to the surface layers, and sometimes lime incorporation into the soil is recommendable. However, tillage may negatively alter physical soil properties. Thus, gypsum could be an alternative to increase Ca ) and incorporated into the soil by plowing and light harrowing. Gypsum was applied to the subplot (0 and 6 Mg ha , soil organic matter, water retention, and least limiting water range (LLWR). Lime incorporated into the soil reduced Al 3+ and increased pH and Ca 2+ levels, especially in the deeper soil layers, although pH levels did not exceed 5.1 and base saturation was lower than 60 %, still inadequate for crops. The gypsum rate of 6 Mg ha -1 did not decrease Al saturation, but reduced Mg 2+ levels in top soil layers. Soil water retention and LLWR were not affected by plowing and harrowing within a period of three years. Gypsum rates below 6 Mg ha -1 were not effective in reducing Al saturation and increasing Ca 2+ levels. Incorporated lime is more effective in correcting the acidity of the soil profile and, after three years, soil water retention and LLWR were similar under both liming methods.

Lime movement through highly weathered soil profiles

“…In general, liming effects are limited to the specific areas where the material is applied or incorporated for several reasons, including low solubility (Shainberg et al 1989) and soil texture. Pöttker and Ben (1998), Alleoni et al (2005), and Bortolanza and Klein (2016) demonstrated that after 3, 2.5 and 11 years the main effects of surface-applied lime to weathered soils under NT were limited to depths of 5, 10 and 5 cm, respectively (table 5). The trials described by those authors, as well as our field trial which was conducted under high annual precipitation (1500-mm) and with high lime rates (7.2 Mg/ha), were conducted on soils with high clay content (57%), and therefore increased resistance to lime movement (Conyers et al 2003).…”

“…Since lime moves very slowly into the soil profile, continued surface applications can cause chemical stratification (Bortolanza and Klein 2016, Martínez et al 2016, Barth et al 2018. Surface liming increases soil pH to levels above the optimum for crop growth (Fageria 2009) Excess lime can also affect soil biology (Paradelo et al 2015, Barth et al 2018).…”

“…Surface lime application is suggested as the best practice to alleviate soil acidity under NT, but its effects throughout the soil profile are unclear. Several studies have shown that surface-applied lime can mitigate soil acidity to a depth of 20 cm or more, thereby maximizing crop productivity (Caires et al 2008, Joris et al 2013, Caires et al 2015, but others have shown very slow lime migration and minimal effects below 10 cm (Conyers et al 2003, Godsey et al 2007, Bortolanza and Klein 2016, Barth et al 2018. Factors influencing lime migration through the soil profile include the amount applied, time between application and planting, quantity of precipitation after liming, soil texture, soil mineralogy, lime type and particle size, and degree of soil compaction (Blevins et al 1978, Farina et al 2000, Godsey et al 2007, Caires et al 2015.…”

“…Since lime is relatively insoluble, surface application may not be effective for ameliorating subsoil acidity (Shainberg et al 1989) and neutralizing Al toxicity (Ernani et al 2004, Godsey et al 2007, Kirkegaard et al 2014, Santos et al 2018, Barth et al 2018 in NT fields. If lime does not move downward into the soil profile under NT, continued surface applications can cause significant increases in pH and nutrient concentrations in the nearsurface layer (i.e., 0 to 3 cm) over time (Kirkegaard et al 2014, Bortolanza and Klein 2016, Nunes et al 2017a, Barth et al 2018. Excessive accumulation of lime within the topsoil can promote chemical stratification, increase surface soil pH, and decrease availability of cationic micronutrients such as Cu, Mn, and Zn (Tahervand and Jalali 2017) within the soil profile.…”

Influence of Limestone and Gypsum Application on Chemical Attributes of Dystrophic Yellow Latosol Soil and Corn Yield in Eastern Amazon

“…The action of limestone on soil pH-related improvements is already known due to the increase in OHin soil solution caused by the reaction of calcium carbonate with water, which contributes to the reduction in exchangeable Al activity and increases in Ca 2+ and Mg 2+ contents, promoting the development of the root system and, consequently, improvement in the absorption of the supplied nutrients, which is the most effective action in the most superficial soil layers. Bortolanza;Klein (2016) and Crusciol et al (2016) found an increase in topsoil pH after calcium carbonate application, which is related to the efficiency of the action in the topsoil due to its low mobility rate in the soil. Shamshuddin & Fauziah (2010) found results similar results to those found in this work.…”