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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. 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.

Purpose: This study aimed to assess the relationship of soil chemical and mineralogical properties with P sorption and develop a maximum phosphorus adsorption capacity (MPAC) prediction model for Brazilian subtropical soils. Methods: The data were analyzed using descriptive statistics and Pearson’s correlation analysis. The following prediction models were tested: multiple linear regression, multiple linear regression with interaction, elastic net regression, and partial least squares regression. Model quality was assessed using mean squared error (MSE), root mean squared error (RMSE), and coefficient of determination. Results: MPAC was positively correlated with clay content and cation-exchange capacity (CEC), which were negatively correlated with remaining P (Prem). Soil samples collected in Rio Grande do Sul State showed stronger correlations between MPAC and Premin the highly and poorly crystalline aluminum fractions than in the respective iron fractions. The low-crystallinity aluminum fraction had a stronger correlation with CEC than the low-crystallinity iron fraction. The multiple linear regression model with interaction, which includes soil properties easily analyzed in routine laboratories, was the most efficient in predicting MPAC, with MSE and RMSE values of 169.20 and 13.01 mg kg− 1, respectively. Conclusions: Clay content and CEC were the soil chemical attributes most strongly associated with MPAC and Prem. The proposed model may be a valuable tool for estimating MPAC in Brazilian subtropical soils.

Context In no-tillage agriculture, maintenance of soil cover combined with liming without incorporation increases nitrogen (N) loss via ammonia (NH3 ) volatilisation, decreasing the efficiency of nitrogen fertilisers. Aims To quantify N losses by NH3 volatilisation from conventional and enhanced efficiency fertilisers applied to a clayey and a sandy loam soil subjected or not to lime (CaCO3 ) application and straw mulching. Methods Two laboratory experiments were carried out; one using a clayey soil, and the other using a sandy loam soil. Both experiments followed a 4×2×2 factorial design with four N sources (urea, urea-NBPT, urea-formaldehyde, and ammonium sulfate), absence and presence of liming, and absence and presence of Brachiaria ruziziensis straw mulching. NH3 volatilisation was measured using closed flasks containing filter paper soaked with sulfuric acid and quantified by titration with sodium hydroxide. Key results NH3 volatilisation was up to 62% of the N applied. Losses due to NH3 volatilisation from both soil types decreased in the following order of treatment: liming+straw mulching>straw mulching only>liming only. Urea-formaldehyde and ammonium sulfate were the most efficient in reducing NH3 emissions. However, when ammonium sulfate was applied to a clayey soil after liming, it resulted in higher NH3 emissions than conventional urea. Conclusions Urea-formaldehyde showed better performance in reducing NH3 losses due to greater stability in the presence of straw or liming. Implications Soils with straw and limestone can lead to large NH3 volatilisation losses if urea conventional is broadcast.