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Limestone is the most widely used agricultural input for soil acidity correction and calcium (Ca) and magnesium (Mg) fertilization. However, other materials have the potential to fulfill these purposes, such as steel slags, also known as silicates. Silicates have higher solubility than limestone, serving as agents for increase pH in no‐till, in addition to being a source of Ca, Mg, and silicon (Si). This study aimed to compare the effects of surface application of dolomitic lime and calcium magnesium silicate on soil chemical properties, soybean [Glycine max (L.) Merr.] nutritional status, and grain yield under no‐till. The experiment was installed in the northwest Paraná State, Brazil, on a Rhodic Eutrustox. Lime and silicate rates were applied by broadcasting before the sowing of soybean. Silicate treatment increases soil Ca2+, pH, and base saturation up to a depth of 0.10 m. By contrast, liming effects on soil chemistry were restricted to the 0.05 m top layer after 24 months of application. The acidity correction and Ca2+ supply to greater soil depths and the increased leaf Si as a beneficial element provided by silicate treatment contributed to increasing soybean yield in the 2018/2019 and 2019/2020 seasons. Lime application, regardless of the rate, did not improve soybean yield. Waste from the steel industry can be used as acidity correctives and source of Si, Ca, and Mg, improving the agronomic performance of soybean. Core Ideas: Silicate is more efficient in maintaining soil fertility compared to lime.Changes in soil fertility were observed up to a depth of 0.10 m after 24 months.Silicate increases silicon content in soybean leaf.Surface application of silicate increased soybean yield up to 43%.Soybean yield did not improve with lime. [ABSTRACT FROM AUTHOR]

Crop yield gains and improvements in surface and subsurface soil chemical properties are evident when agricultural lime and gypsum are used in high-acidity soils. However, there is scarce information on the effects of lime and gypsum application on no-till tropical soils previously treated with these additives (low-acidity soils). The duration of the effects of lime applied to the soil surface varies according to lime rate, product characteristics, soil conditions, and water and thermal regimes. Such residual effects influence the timing of lime reapplication. This study aimed to investigate the effects of surface application of agricultural lime and gypsum on soil chemical properties, soybean and second-crop corn yields, and lime residual contents. The experiment was conducted on a Red Latosol with a very clayey texture in Floresta, Paraná, Brazil. Four rates of dolomitic lime (0.0, 2.6, 5.4, and 8.1 Mg ha−1) and agricultural gypsum (0, 4, 8, and 12 Mg ha−1) were used. The experimental design was a randomized complete block with subplots and four replications. The experiment lasted for four soybean seasons and three second-crop corn seasons. At 6, 12, 24, and 36 months after treatment, soil samples were collected from the 0.00–0.05, 0.05–0.10, 0.10–0.20, 0.20–0.30, 0.30–0.40, and 0.40–0.60 m layers for chemical analysis. No significant interaction effects were observed on soil chemical properties. Liming resulted in soil alkalization, with a consequent reduction in Al3+ and an increase in Ca, Mg, base saturation, and pH. Residual lime was not detected in layers deeper than 0.05 m, suggesting a lack of physical movement of particles in the soil pore space. Residual lime was detected on surface soil (0.00–0.05 m) up to 36 months after application, demonstrating the low reactivity of lime on no-till soils. At 6 months after gypsum application, there was an increase in Ca2+ levels up to the 0.6 m layer, whereas Mg2+ levels were reduced throughout the soil profile for up to 36 months. In no-till soybean–second-crop corn rotation systems, use of agricultural gypsum alone did not provide consistent effects on crop yield and reduced foliar Mg contents. Under the studied conditions of low acidity, liming did not produce significant differences in crop yield but improved soil chemical properties for plant growth under no-till. • Residual lime was restricted to the 0.05 m layer. • Lime remained on the soil surface for up to 36 months after application. • Agricultural gypsum increased calcium content up to 0.6 m depth for 6 months. • Lime and gypsum application increased corn yield in some seasons. • Soybean yield did not improve with lime and reduced with gypsum in the first season. [ABSTRACT FROM AUTHOR]