Gypsum and potassium application to acid soils for maize (Zea mays L.) production in La Frailesca, Chiapas, Mexico

Introduction. Maize (Zea mays L.) production in La Frailesca region, Mexico, is limited by sandy soils, low in potassium (K), and with acidic arable layers and subsoils. There is information on the management of lime but not on amendments that could be used for subsoil acidity — such as gypsum — nor on the interactions between amendments for soil acidity and K fertilization. Objective. To evaluate the effects of K and gypsum on maize and on previously limed soils. Materials and methods. The evaluations were conducted in farmers’ fields in La Frailesca region, Chiapas (Mexico) in 2016 and 2017. Four gypsum rates (0, 1.25, 2.5 and 5 t ha-1) and four K rates (0, 60, 90, and 120 kg ha-1 as K2O) were factorially combined in a randomized block design, with three replicates. In both years, before the beginning of the experiments, dolomitic lime was applied to the experimental area following standard practices. Responses of crop yield, soil exchangeable K, Ca, Mg, and Al, and soil pH were obtained. Results. Maize yields increased with gypsum (stabilizing at 1.25-3.0 t ha-1), and K (stabilizing at 70-120 kg ha-1 of K2O) applications. In soils, K application increased exchangeable K content, while gypsum increased exchangeable Ca content and pH, and decreased exchangeable Al content. Liming increased pHCa and exchangeable Ca and Mg contents, and lowered the exchangeable Al content in the top 7.5 cm of soil. Conclusion. Soils with exchangeable K (≤0.3 cmolc kg-1) were responsive to K fertilization. The positive effects on yields from gypsum were probably linked to a greater Ca supply in the top 7.5 cm. These results are encouraging about the benefits of the combined application of dolomitic lime, gypsum, and K, but longer evaluations are needed to properly determine the effects of gypsum on subsoil acidity.

Evaluation of the Effect of Dolomitic Lime Application on Pastures—Case Study in the Montado Mediterranean Ecosystem

The Montado ecosystem, predominant in the Mediterranean region, consists of poor soils, a sparse cover of cork and holm with an understory of natural biodiverse pastures, grazed by animals in extensive regime. The recommended procedure for increasing productivity of these pastures is based on the application of phosphate fertilizer. One of the main productivity-limiting factors is, however, associated with soil acidity. The objective of this work was to evaluate the simultaneous effect of the holm oak canopy and the application of dolomitic lime on the productivity and quality of a permanent biodiverse pasture, grazed by sheep, in an acid soil (pH = 5.4 ± 0.3). Pasture was monitored at the end of autumn 2018 and winter and spring 2019. The results show that amendment of soil acidity is a slow and gradual process that improves soil Mg/Mn ratio and has a positive impact on pasture productivity and quality. Pasture crude protein availability (CP, kg·ha−1), which is based on both pasture dry matter yield (kg·ha−1) and quality (CP, %), proved to be a very practical indicator of the contributions of tree canopy and soil acidity correction to the holistic management of the Montado ecosystem.

Mineralogical investigations on pozzolanic dolomitic lime mortars to assess the phase development at different curing conditions

<p>For a long time, historical mortars were primarily associated with mortars based on calcium carbonate as the main binder phase. Recent publications show that considerable amounts of magnesium are often present in the binder of historical mortars, which is referred to the use of dolomite rock as raw material (Diekamp, ​​2009; Diekamp, ​​2014). A special feature are Roman and medieval dolomitic lime mortars with the addition of brick fragments as a pozzolanic component (Schidlowski, 2019).In order to characterize the phase formation in modern pozzolanic dolomitic lime mortars, mortar prisms based on dolomitic lime were produced with three different pozzolans (antique and modern brick dust and metakaolin). To draw comparisons with other binders, identical prisms based on calcite and magnesite were produced. These specimens were stored under different environmental conditions (60 % and 95 % relative humidity) and examined by X-ray diffraction and simultaneous thermal analysis after periods of 28, 90 and 180 days.</p><p>The results obtained so far show that the binder phases that have evolved in the mortars based on dolomitic lime are calcite, aragonite, portlandite, brucite and AFm phases. Aragonite is only found in traces in the samples with metakaolin. In contrast to the samples stored at 65 % relative humidity, the samples stored at 95 % relative humidity have lower calcite and higher contents of portlandite and AFm phases.</p><p>No significant differences in the amount of calcite and water-containing mineral phases (portlandite, brucite, hydrotalcite) can be found after 28, 90 and 180 days. It can be concluded that a large part of the reactions has already taken place after 28 days.</p><p>The present study is believed to be beneficial for a thorough understanding of the phase formations in dolomitic lime based mortars at different curing conditions.</p>

Effect of Calcium Source and Irrigation on Soil and Plant Cation Concentrations in Peanut (Arachis hypogaea L.)

ABSTRACT Calcium improves seed formation and development of peanut kernels. Two primary sources of Ca fertilization in peanut are gypsum (CaSO4) and dolomitic lime (CaMg[CO3]2+CaCO3). Objectives of this research are to determine whether gypsum, lime, or application of both influences pH, extractable [Ca], [Mg], and [K] in the soil along with nutrient absorption, yield, and total sound mature kernels (TSMK) in peanut pods in irrigated compared to non-irrigated conditions. Experiments conducted in Tifton, GA in 2016 and 2017 evaluated Ca treatments with no supplemental Ca fertilizer, gypsum (330 kg Ca/ha) applied at first bloom, lime (897 kg Ca/ha) applied at planting, and lime (897 kg Ca/ha) applied at planting followed by gypsum (330 kg Ca/ha) applied at first bloom. Irrigating increased soil pH, [Ca] and [Mg] in pods, plus yield and TSMK of peanut. Irrigation also decreased [K] in pods, which was correlated with increased pod [Ca]. Soil pH and soil [Ca], [Mg], and [K] were influenced by fertilizer treatment, along with [Ca] and [Mg] in pods. Applications of lime increased pH and soil [Ca]. Lime also increased soil [Mg] when applied alone, but not when gypsum was also included. Application of gypsum reduced soil [Mg] when applied alone, but not when lime was included. The inclusion of both lime and gypsum reduced soil [K] compared to no application. These results display the competition of cations in soil. In peanut pods, using lime and gypsum increased [Ca] compared to no application, or only lime. However, when only gypsum was used, it reduced [Mg] in pods compared to a lime application or no fertilization. Although Ca fertilization did not affect yield, TSMK was greater when lime followed by gypsum were applied in sequence than where neither were applied in 2016. It is important to realize that applications of Ca can also influence concentrations of other cations important for growth. Peanut growers are encouraged to conduct soil tests to ensure soil [Mg] is not deficient or borderline before choosing to apply gypsum, and may require a supplemental Mg fertilizer if dolomitic lime was not applied.

Nutritional Behavior of Heliconia Grown Under Different Levels of Lime

Production and commercialization of tropical flowers and plants has grown in recent years, mainly due to the increasing value of these products in temperate climate countries, such as heliconia, one of the most cultivated tropical ornamental plants in Brazil. This study was developed to determine the effect of lime applications on the nutrients in heliconia plants (Heliconia psittacorum L. × Heliconia sparthocircinata Arist. [cv. Golden Torch]) cultivated in yellow latosol in a greenhouse. The macronutrient levels in the leaves, pseudostem and roots of the heliconia plants were determined after cultivating the plants in containers with a medium texture, yellow latosol, collected from the 0 to 20 cm layer and submitted to doses of 0, 0.9, 2.6, 4.2 and 5.9 t of lime ha-1. Nitrogen and phosphorous performed better in the absence of the correction and in the 0.9 t ha-1 dose for the vegetative parts of the heliconia plants. The application of dolomitic lime promoted greater absorption of potassium, calcium and magnesium, and sulfur performed better for the doses 2.6 and 5.9 t of lime ha-1, for the pseudostem and roots, respectively.