Doses Of Limestone Research Articles

Effect of liming in plinthic and petroplinthic soils for soybean cultivation in the Brazilian Savanna

Agricultural expansion is advancing on marginal soils (Plinthic soils), but the liming recommendation for this soil, especially for soybean cultivation, remains unknown. This study aimed to evaluate soybean (Glycine max) responses to limestone doses in concretionary soils (plinthic and/or petroplinthic). The experiment was carried out in the greenhouse, in randomized blocks, with four soil types and six limestone doses (4x6 factorial scheme), with four replicates. Soils were: RYO: Red-Yellow Oxisols; CPP-29, CPP-72, CPP-82 corresponds to the Concretionary Petric Plinthosol with 29, 72, and 82% concretions, respectively. Limestone doses varied from 0 to 4 times for each soil, based on the recommendation of regional bulletins. Soil temperature, crop emergence, development, and soybean yield characteristics were evaluated. Results were evaluated by ANOVA, followed by the LSD test or polynomial regression adjustment (p ≤ 0.05). Soybean response to liming varied with soil types. Seedlings showed lower vigor in Plinthic soils with plinthite contents ≥72%. These soils showed higher thermal accumulation (°C), and this increase showed a strong negative correlation with soybean development and reproductive characteristics. Evidence of liming response was observed after crop stage V5. Limestone substantially improved soybean growth and development in Plinthic soils with high plinthite levels, although they had lower yield potential than low plinthite levels and Oxisol. In general, the maximum response of the crop occurred at doses ~2 times higher than that practiced in the Brazilian Savanna region, especially in Plinthic soils

Using of Limestone Cement in Fibre-Cement Corrugated Sheets Production

The paper deals with the production of fibre-cement and the use of limestone cement in its production. The paper describes the basic properties of final products, the basic raw materials and the Hatschek production technology used for the production of corrugated sheets. The attention is paid especially to the wet part of the production when describing the production process. The emphasis was mainly placed on the preparation of fibre-cement slurry and the gradual formation of a layer of fibre-cement on the surface of the cylindrical sieve. The paper describes the possible use of limestone cement in the production of corrugated sheets. Trial recipes were designed with using limestone cement CEM II with and without separately dosed limestone. The fibre-cement corrugated sheets were produced with using Hatschek technology. Mainly was investigated the influence of limestone dosing on the strength characteristics and the volume weight of the final products. The produced sheets were tested according to EN 494+A1: 2016 Fibre-cement profiled sheets and fittings - Product specification and test methods. The tested samples reached comparable results like sheets produced according to standard recipe. No negative effect on the strength characteristics of final products was proven between the standard and the trial recipes.

Growth, nutrition and health of coffee seedlings grown with increasing limestone doses in the substrate

During coffee crop formation, seedlings quality is an essential factor to ensure the plants full development. Applying limestone to the substrate is a common practice to correct acidity, thus increasing nutrient availability. Therefore, we aimed to evaluate the effect of increasing limestone doses in the substrate regarding growth, nutrition, health, and quality of coffee seedlings. The experiment was conducted in the plant nursery at the IFSULDEMINAS – Inconfidentes Campus, with an experimental design in randomized blocks with five replications; the treatments received the following limestone doses per cubic meter of substrate: T1: 0 g; T2: 600 g; T3: 1,200 g; T4: 1,800 g; T5: 3,000 g. After 208 days of sowing, samples were collected for leaf analysis. The growth and quality of the seedlings and their incidence and severity of Cercospora were also evaluated. A statistical difference was found in leaf analysis for nitrogen, potassium, and manganese absorption, with no statistical difference for Cercospora coffeicola leaf spots in all treatments. Therefore, the increasing limestone doses do not influence growth, nutrition, and health of the coffee seedlings of the Mundo Novo 376/4 cultivar.

Iron (oxyhydr)oxides are responsible for the stabilization of Cu and Zn in AMD after treatment with limestone.

The formation and transformation of secondary iron (oxyhydr)oxides and their role in the stabilization of copper (Cu) and zinc (Zn) in acid mine drainage (AMD) after limestone treatment are worth studying to better understand the impacts of limestone AMD treatment. In this study, the wastewater from a copper mine ditch was sampled. Two different doses of limestone (S: 5.33 g L-1 and SS: 8.00 g L-1) were applied to adjust the pH range of the sampled AMD. The concentrations of Fe, Cu and Zn in the supernatant and the levels of iron (oxyhydr)oxides and heavy metals in AMD sediments were dynamically monitored for 300 days to analyze the transformation of the secondary iron mineral phase and the role iron (oxyhydr)oxides play in the removal and stabilization of Cu and Zn. The results showed that the pH rose rapidly to 6.82, decreased to 5.82 on the 150th day, and finally decreased to approximately 4.63 by the 300th day, when the dosage of limestone (S) was 5.33 g L-1. Goethite was the main form of iron oxides in the sediments. As the incubation time increased, so did the content of crystalline Fe (oxyhydr)oxides. In addition, the Cu and Zn content in the fraction of crystalline Fe (oxyhydr)oxides increased as the corresponding iron (oxyhydr)oxide increased. When the high dosage of limestone (8.00 g L-1 or SS) was applied, the pH remained at approximately at 7.46 during the whole period and goethite and lepidocrocite were present in the sediment. Amorphous/ poorly crystalline Fe-oxyhydroxide was the main product after SS limestone dosage, indicating that the risk of Cu and Zn reactivation in the sediment was higher with a higher limestone treatment dosage.

Detecção de estresse nutricional em cana-de-açúcar por espectroscopia de reflectância VIS-NIR-SWIR

ABSTRACT: This study applied spectroradiometry techniques with hyperspectral data to identify the correlations between sugarcane leaf reflectance and the contents of Nitrogen (N), phosphorus (P), Potassium (K), Sulfur (S), Calcium (Ca) and Magnesium (Mg). During the harvests 2019/20 and 2020/21, sugarcane was introduced to nutritional stress by the application of limestone doses. Liming was applied in a fractional way and, at the end of five years, the amounts corresponded to 0, 9, 15 and 21 t ha-1 of dolomitic limestone. The leaf hyperspectral reflectance data and the state of nutrients in the exponential growth phase of the culture were registered. The wavelengths correlated with N, P, K, S, Ca and Mg were identified using the Spearman’s correlation analysis. The test of similarity (ANOSIM) and the Principal Component Analysis (PCA) were applied to evaluate data variability, as well as the Partial Least Squares Regression (PLSR) for the prediction of the nutritional contents. The order of the degree of correlation in the region of visible was: P > K > N > Ca > S > Mg and for the region of the near infrared: P > K > Ca > N > S > Mg. P presented peaks with high correlations in the wavelengths 706-717 nm (-0.78) and 522-543 nm (-0.76). The values of the PLSR registered the best spectral responses in the region of VIS and red-edge, regions that are more sensitive to the deficiency of sulfur, potassium and phosphorus.

Spectral method for macro and micronutrient prediction in soybean leaves using interval partial least squares regression

Studies on the use of hyperspectral remote sensing for nutrient prediction in soybean (Glycine max L.) leaves are limited, especially regarding the selection of wavelengths. Therefore, the objective of this study was to estimate macro and micronutrients in soybean leaves by employing reflectance data modeled by Partial Least Squares Regression (PLSR) from bands selected by the iPLS (Interval PLS), method with a script developed for MATLAB R2018a. The experimental area was treated with different doses of limestone, with and without incorporation, also with phosphogypsum application in additional treatments. The soybean crops of 2018/2019 and 2019/2020 had the nutritional status evaluated by a random collection of the third fully developed trefoil in the R2 (full flowering) and R5.5 (76–100% grain filling) reproductive phenological stages. The leaf samples were submitted to conventional laboratory analyses. The Ca, Mg, K, P, S, Cu, Fe, Mn, and Zn elements in the leaves were quantified through spectrometry. A field spectroradiometer performed spectral data acquisition in the visible-near infrared, short-wave infrared spectral range of soybean leaves. The spectral curves were subjected to iPLS, and PLSR models were fitted. After iPLS selection, the coefficient of determination (R2) values of PLSR models were on average 15.3% and 16.6% higher in calibration and validation, respectively, compared to classical methods. The PLSR model for Mn, which obtained R2 above 0.90 in the calibration and validation phases, stood out. The Root Mean Square Error (RMSE) decreased, on average, more than 15.0%, both in calibration and validation, after applying the iPLS selection. The models for Ca and Mn stood out with over a 30.0% decrease in RMSE, in calibration and validation. The iPLS selection was efficient in improving the performance and accuracy of the PLSR models, increasing the R2 and decreasing the RMSE, opening new possibilities for the analysis and prediction of macro and micronutrients in plants.

Effect of limestone dose on the incidence of Rhizoctonia root rot and soybean yield in four soil types

AbstractRhizoctonia root rot (RRR) is a disease caused by the soilborne pathogen Rhizoctonia solani, which kills soybean plants in patches over croplands. Control is difficult because the pathogen survives in the soil and has a wide host range; therefore, cultural control methods might help to diminish disease pressure. The objective of this study was to evaluate liming as a strategy to reduce the incidence of RRR in soybean grown in four soil types: acrisol (Ac), cambisol Ta (CaTa), cambisol Tb (CaTb) and nitisol (Nit). The treatments were arranged in a factorial design of four doses of limestone (0, 3, 6 and 9 t/ha) at two sites within each field (inside and outside a Rhizoctonia patch). The incidence of RRR inside the patch was on average 40.3% whereas outside it was 1.2%. The reduction in disease incidence was 3.9%, 3.7%, 3.6% and 1.8% per 1000 kg of limestone applied for the Ac, CaTa, CaTb and Nit soils, respectively. The highest soybean yield was of 4713 and 3349 kg/ha for the Ac and Nit soils with application of 6.6 and 6.2 t/ha of limestone, respectively. Soybean yield in the cambisols increased linearly with liming, with an increase in yield of 121 and 172 kg/ha in CaTa and CaTb, respectively, for each 1000 kg of limestone applied. Thus, liming reduced the incidence of RRR in all soils and promoted better soybean nutrition, increasing soybean yield. Therefore, liming is a practice that contributes to both soil fertility and disease control.

Doses of Acidity Corrective in Some Chemical Attributes to Build the Fertility of Concretional Soils

With the increase in agriculture in the state of Tocantins, especially with soybean cultivation, areas with concrete have been increasingly applied to high doses of limestone, although they do not know the dynamics of the reaction of these correctives in the soil conditions of Tocantins. For the study, soil with different soil/gravel ratio and 01:02, 01:05 and 1:10 proportions of fine ground/gravel were used. The incubation assay was installed under a greenhouse in a completely randomized experimental project. The 15 treatments were obtained in a 3x5 factorial scheme, combining three fine ground/gravel (01:02, 01:05 and 01:10) and five limestones (0; 1.0; 2.0; 4, 0 and 6.0 t ha−1). The soils were prepared as TFSA and sent to the soil laboratory for analysis of Ca + Mg, Ca, Al, potential acidity (H + Al) and pH. Al levels and potential acidity (H + Al) were reduced and Ca and Ca + Mg contents were significantly increased with the increase of the limestone dose in gravel ratios. The pH of the 1:5 ratio decreased until reaching its lowest value at the dose of 3.31 t ha−1, increasing the dose rate greater than 3.31 t ha−1. The pHs of ratio 1:2 and 1:10 increased as the limestone dose increased. Ca, Ca + Mg levels and pH value are already at adequate levels in 0t ha-1dose of limestone, and it is not necessary to recommend correctives for gravel relations.

Soil Chemical Attributes, Nutrient Levels, and Yield of Arabica Coffee under Limestone Managements

ABSTRACT Soil pH correction and balanced fertilization are essential for coffee production and drink quality. The objective of this study was to evaluate strategies of soil limestone management to Arabica coffee plant development and yield. Five limestone management strategies were studied [T1: 100% limestone, relative power of total neutralization (RPTN) 100%, applied in September; T2: 50% in September + 50% in January (RPTN 100%); T3: 50% in September + 50% in January (RPTN 140%); T4: 100% (RPTN 100%) in September + 100% (RPTN 140%) in January; T5: 100% (RPTN 140%) in September + 100% (RPTN 100%) in January] in a 25-years-old commercial Arabica coffee area. Soil chemical attributes, plant nutritional status, biometrics, and yield were evaluated 120 days after treatment’s application. Soil Ca and Mg levels and base saturation increased for T5 limestone management strategy. The improvements in soil fertility did not alter the coffee leaf contents of the macronutrients but increased the micronutrient levels after the second limestone application. Split limestone application and mixing limestone with different RPTNs (140 before 100%) improved soil Ca, Mg, base saturation, and coffee cherry production. The sole application of the recommended limestone dose (RPTN 100%) can reduce responses compared to more complex limestone managements.

Soil fertility, growth, nutrition and production of red pitaya subjected to liming

This study aimed to evaluate the effects of liming on soil fertility, growth, nutrition and production of red pitaya (Hylocereus monacanthus) plants cultivated in pot. The experiment was conducted in blocks, with five doses of limestone (0.0; 0.6; 1.2; 1.8; and 2.5 t ha − 1) and four replicates. Corrective doses were established to achieve base saturation of 20 to 70%. Liming increased soil pH (4.5 to 6.7), Ca concentration (5.36 to 20.11 mmolc dm − 3), Mg concentration (4.36 to 16.53 mmolc dm − 3) and base saturation (23.69 to 72.61%) and reduced potential acidity (37.39 to 15.41 mmolc dm − 3). Liming reduces nitrogen concentration and increased phosphorus, calcium and sulfur concentrations in the cladodes. There was an increase in phosphorus concentration and decrease in boron and iron concentrations in fruit peel according to the increase in limestone doses; in the pulp, there was an increase in boron concentration and decrease in iron and zinc concentrations, from the lowest to the highest dose of limestone. Based on the principal component analysis, the limestone dose of 1.8 t ha − 1 increased base saturation to 59%, providing favorable chemical conditions for the growth and productivity of red pitaya.

Liming in soils with plinthic materials of the Brazilian Savanna: potentials and limitations

The expansion of agriculture has been taking place in marginal soils with low productive potential, such as Plinthosols. The liming can increase the economic and environmental sustainability of agriculture. However, there are no studies on the dissolution or recommendation of limestone for Plinthosols. The objective was to evaluate the effect of limestone doses on the chemical attributes of three soils with different gravel contents (ironstone concretions). The soils were collected (0-20 cm layer) in native areas of the central region of the Brazilian Savanna. They were classified as Red-Yellow Latosol (RYO) and two Concretionary Pétric Plinthosol (with 29% [CPP-29] and 72.8% [CPP-72] of soil volume with gravel). A factorial scheme (3x6) with the three soils (RYO, CPP-29, and CPP-72), six limestone doses, and four replications. The evolution of pH was verified at 10, 20, 30, and 40 days after the beginning of incubation (DAI), and determined the chemical attributes (Al, H+Al, Ca, Mg, BS, V%, P, and K) at 40 DAI. The doses to reach pH 6 were 1.4 t ha-1 for RYO, 3.9 t ha-1 for CPP-29, and 2.7 t ha-1 for CPP-72. Al3+ neutralization was 100% with doses above 3.5, 2.5 and 0.5 t ha-1 for CPP-29, CPP-72, RYO. There was a significant increase in Ca and Mg contents in all soils. However, the Soil CPP-72 did not reach a critical level for Ca (>2.41 cmolc dm-3) and Mg (>0.91 cmolc dm-3) for Plinthosols with higher plinthite content. Thus, we recommend using agricultural practices that increase the capacity of the soil to retain and recycle nutrients.

A Study of Dispersed, Thermally Activated Limestone from Ukraine for the Safe Liming of Water Using ANN Models

Liming surface water is a fairly popular method of increasing the pH values and decreasing the concentration of phosphates and heavy metals. According to the Environmental Protection Agency (EPA) recommendations, the increase of water pH should not exceed 1.5. If surface water is the source of water supply, liming is a process that reduces water contamination. This should prevent the creation of an additional load for the water treatment plants in urban settlements. This article is an interdisciplinary research study aiming to (1) determine and compare the doses of new dispersed, thermally activated limestone and natural limestone, (2) find the relation between dose value and initial water parameters (pH, Eh and total mineralization), and (3) create an artificial neural network (ANN) model to predict changes in water pH values according to EPA recommendations. Recommended doses were obtained from experimental studies, and those of dispersed, thermally activated limestone were lower than the doses of natural limestone. Neural networks were used to predict the changes in water pH values when adding different doses of limestone with different initial water parameters using the ANN model. Four ANN models with different activation functions and loss function optimizers were tested. The best results were obtained for the network with the ReLU activation function for hidden layers of neurons and Adam’s loss function optimizer (MAPE = 14.1%; R2 = 0.847). Further comparison of the results of the loss function and the results of calculating the quality metric for the training and validation dataset has shown that the created ANN can be used to solve the set research issue.

Doses of limestone, phosphorus and potassium on the initial development of Anacardium humile seedlings

The objective of this work was to evaluate the effect of different doses of limestone, phosphorus, and potassium on the initial development of Anacardium humile (Cajuzinho-do-cerrado) seedlings. The experiment was conducted in a greenhouse. A randomized block design was adopted in a 3x4x4 factorial scheme (liming x phosphorus x potassium doses). The treatments consisted of three liming doses (0; 40; and 70% of base saturation), four doses of potassium chloride with 60% of K2O (0; 60; 120; and 180 kg ha-1), and four doses of triple superphosphate with 46% of P2O5 (0; 80; 160; and 240 kg ha-1), with six replications. The following characteristics were evaluated: stem diameter (SD), plant height (PH), root length (RL), shoot dry matter (SDM), and root dry matter (RDM). The data were submitted to analysis of variance and the averages were compared by Tukey’s test (p < 0.05). It was concluded that there was no influence of phosphorus doses on the initial development of A. humile seedlings and that there was a response to the association between liming and potassium chloride in vegetative growth.

Agronomic performance of cowpea cultivars (Vigna unguiculata (L.) Walp) under application of limestone doses

Evaluating agricultural management practices, such as liming, is essential in regions with acidic soils to increase the yield of agricultural crops. The aim was to evaluate soil fertility, agronomic performance, and grain quality of cowpea cultivars under application of limestone doses. The experiment was carried out in Argissolo Vermelho Amarelo (Ultisol), with initial base saturation of 26%, during two agricultural years. A randomized block design was used, in split plots, with four replications. The plots were composed of five limestone doses (0, 1, 2, 3 and 4 times the recommended rate to reach 50% base saturation), and the subplots were formed by two cowpea cultivars (BR 17 Gurgueia and BRS Guariba). The applied doses of limestone, with relative total neutralizing power (RTNP) of 91%, were 0, 1.3, 2.6, 3.9 and 5.2 t ha-1. Liming increased soil fertility, increasing pH, calcium, magnesium, and base saturation, and decreasing soil acidity. Maximum grain yields were obtained with limestone doses between 3.1 and 3.2 t ha-1 for the cultivar BR 17 Gurgueia and between 3.3 and 3.4 t ha-1 for the cultivar BRS Guariba, reaching average base saturation values of approximately 48 and 55%, respectively.

Co-products from the limestone mining as sources of calcium, magnesium and sulphur

This paper aims at assessing the use of co-products from the limestone mining of the Irati Formation as sources of calcium, magnesium and sulphur. Therefore, a study was carried out at a greenhouse by applying different inputs in a Paleudalf. The inputs consisted of co-products from mining, which were referred to as layer 1, layer 2 and limestone. Such inputs were incorporated in pots at the doses of 0, 0.489, 0.978, 1.956 and 3.912 g kg−1, which equal 0, 0.5, 1, 2 and 4 times the limestone dose required to reach soil pH 6.0. After incubation, soil samples were taken to determine the macronutrients. Subsequently, NPK fertiliser was applied and corn sowing was carried out. The application of the co-products provided average increases in the contents of Ca2+, Mg2+ and S-SO42− in the soil by up to 147, 193 and 166 %, respectively. In addition, other benefits, such as increased soil pH and contents of exchangeable potassium and available phosphorus were found. There was also an increase in the dry mass production of the corn shoots and an accumulation of macronutrients with the doses applied. The application of co-products has the potential for being used as an alternative source of secondary macronutrients.

Liming and Fertilization on the Growth of Eucalyptus benthamii and Eucalyptus dunnii in Brazil

The use of mineral fertilizers has shown substantial productivity gains for the vast majority of Eucalyptus forests. The objective of the present work is to evaluate the response of Eucalyptus benthamii and Eucalyptus dunnii at 48 months of age, to different doses of limestone, soluble NPK, and natural phosphates. The experiment was conducted in a plantation located in South Brazil. The experimental design was a randomized block with three replications, and the treatments consisted of combinations of doses of natural phosphate (NP) (0, 400, 600, and 800 kg ha−1 of Gafsa reactive NP P2O5), limestone (0, 3, 5, 6, and 10 Mg ha−1 of dolomitic limestone), and mineral fertilizer–NPK (0, 100, 133, and 167 kg ha−1 of mixed mineral fertilizer 6-30-6). Height and diameter measurements were taken after 48 months. There was a positive response with the increase of NPK fertilizer dose, and the dose where the highest averages were obtained was 167 kg ha−1. The doses of NP had significant effects on the increase of the variables up to 600 kg ha−1, also the averages decreased with the increase of the dosage. For liming, positive results were observed from its absence to the maximum dose, justifying its use in minimum dose in order to supply the necessary amounts of Ca and Mg in the soil. The use of NPK, natural phosphate, and limestone is recommended, causing an increase in the growth of both species of Eucalyptus studied.

Limestone dosage response of cadmium phytoavailability minimization in rice: A trade-off relationship between soil pH and amorphous manganese content

Limestone shows great potential to reduce the production of cadmium (Cd)-contaminated rice in acidic paddy soils, but has generated uncertainty effects. We conducted batch sorption and greenhouse experiments to investigate optimal conditions of pH and amorphous manganese content (Mnox) in limestone treated-soil for suppressing the Cd uptake by rice plants. The adsorption/desorption behavior of Cd in a soil/limestone mixture was dominated by the composition and density of sorption sites, followed by sorption conditions, which were mainly influenced by soil pH and exchangeable Ca2+. Interactions among soil factors were influenced both by the limestone effects and plant responses. The Cd uptake of rice plants did not matched to the doses of limestone applied. The increase in pH and decrease in Mnox following higher dosages of limestone treatment might produce contradictory effects on rice Cd uptake. We proposed a trade-off model to demonstrate how did the interactions of soil pH and Mnox affect the rice Cd uptake. To minimize the accumulation of Cd in rice grain harvested from acidic paddy soils, limestone was applied at 0.25 % to achieve an optimal pH of 6.5 and a Mnox of 95 mg kg−1.

Correção do solo e adubação fosfatada no crescimento e produção de biomassa em mudas de mogno africano

Objetivou-se avaliar o crescimento de mudas de Khaya ivorensis A. Chev. (Mogno africano) cultivadas com e sem calagem em amostras de solo submetido à adubação fosfatada. O estudo foi conduzido em casa de vegetação na Universidade Federal Rural da Amazônia (UFRA) – Campus Capitão Poço/PA e o solo utilizado para compor o substrato foi um Latossolo Amarelo proveniente da camada de 0–20 cm de profundidade. Os tratamentos constituíram-se de cinco doses de fósforo, tendo como fonte o fosfato natural reativo de Arad. O experimento foi montado em delineamento inteiramente casualizado (DIC) em esquema fatorial, sendo duas doses de calcário (0 e 5 g vaso-1) e cinco doses de fósforo (0, 10, 20, 40 e 80 g vaso-1 de P2O5) com 6 repetições, totalizando 60 parcelas experimentais. Cada parcela foi formada por uma muda, cultivada em vasos com capacidade de 12 quilos de solo durante 210 dias. Ao final do experimento foram realizadas avaliações de altura da planta (H), diâmetro do coleto (DC), número de folhas (NF), massa seca da parte aérea (MSPA), massa seca da raiz (MSR) e do índice de qualidade de Dickson (IQD). As mudas responderam positivamente às doses de P2O5 em todas as variáveis avaliadas e não há necessidade de correção do solo ao se utilizar como fonte de P2O5 o Arad. Para a obtenção de mudas de qualidade em condições semelhantes a este experimento, deve ser utilizada a dose 40 g vaso-1 de P2O5.

Use of limestone and agricultural gypsum in cauliflower crop management and clubroot control in mountain farming

The effects of the dose and application method of limestone - broadcast or in furrow - and of agricultural gypsum on soil fertility, the control of clubroot, and cauliflower development in mountain farming areas were evaluated. Initially, four doses of broadcast limestone (0.0, 1.0, 2.0, and 4.0 Mg ha-1) and two cauliflower cultivars (Sharon and Piracicaba Precoce) were analyzed. A second experiment evaluated limestone (4.0 Mg ha-1) application treatments: broadcast and in furrow, broadcast limestone + gypsum (3.0 + 1.0 Mg ha-1), and broadcast gypsum (1.0 Mg ha-1). Soil fertility was improved, and significant increases were observed in the total and healthy root volume with increasing doses of limestone. With 4.0 Mg ha-1, a 58 and 85% increase in yield was observed in Sharon and Piracicaba, respectively, compared to the control. Treatments with limestone and limestone + gypsum, regardless of the application method, elevated pH (≥ 10%), base saturation (V%) (≥ 37%), and calcium (Ca) contents (≥ 100%), and reduced the levels of aluminum ions (Al3+) (≥ 60%) and clubroot severity (≥ 64%) and favored biomass accumulation (≥ 27%) and yield (≥ 9.2%). The application of limestone in the furrow yielded results similar to the broadcast application.

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

The objective of this study was to evaluate changes in the chemical attributes of the soil caused by the use of limestone associated or not to with gypsum in no-tillage system. The experiment was conducted on a dystrophic Yellow Latosol in Pará state, Brazil. The experimental design was in randomized blocks in split plots with three replications. The treatments consisted of five doses of limestone (0, 1, 2, 3 and 4 t ha-1), with and without gypsum (0, 0.5 and 1 t ha-1). Soil samples were collected at depths of 0-20 and 20-40 cm. There was a significant effect on the analyzed variables at both depths. The doses of 3.64 and 2.19 t ha-1 of limestone associated with 0.5 t ha-1 of gypsum, were responsible for the largest increase in soil calcium content in the 0-20 and 20-40 cm layers, respectively. The highest increase in Ca + Mg content was found at 3.63 t ha-1 limestone combined with 0.5 t ha-1 gypsum. It was observed that 3.13 t ha-1 of limestone combined with 0.5 t of gypsum increased soil CEC. The 2.89 t ha-1 dose of limestone combined with 0.5 t of gypsum contributed to the increase in base saturation (V%). The use of limestone and gypsum promotes soil chemical conditions, as reflected by increased corn yield when compared with control (no treatment) plots.