Red-Yellow Latosol Research Articles

Performance of infiltration trenches in different soils in native vegetation and urban area of the Federal District of Brazil

The increase in flooding events in major cities has driven the search for new strategies that incorporate Low Impact Development (LID) units into urban drainage. This research analyzes the performance of infiltration trenches to determine flow and infiltration physical parameters in different soil types in the Federal District of Brazil (FDB), comparing urban area and preserved Cerrado biome. The results show that most soils in the Federal District of Brazil have good infiltration conditions, particularly the Red Latosol and Red-Yellow Latosol. Infiltration trenches were effective in storing significant volumes of water, especially during initial runoff events where favorable soil moisture conditions exist. The Regolithic Neosol exhibited low infiltrability, making its use for infiltration trenches not recommended. Keywords: cerrado, infiltration trench, red latosol.

Agronomic Evaluation Study: Use of Caiapônia Shale as Magnesium Supplementation for Soybean (Glycine max) and Maize (Zea mays) Cultivation

The soil of the cerrado is acidic, with high levels of iron and aluminum, and has low fertility due to weathering, which removes elements such as magnesium. To increase the availability of magnesium, essential for various plant processes, an alternative is the use of agrominerals rich in this element. The objective of this work was the agronomic evaluation of the use of Caiapônia shale as magnesium supplementation for soybean and corn crops. It is characterized as Magnesium Silicate containing 18% Magnesium Oxide (MgO) in its composition, in addition to the minerals Montmorillonite, Albite and Ilite. The product was screened to 0.425 mm in sieve no. 40. The study was conducted at the School of Agronomy of the Federal University of Goiás, located in the municipality of Goiânia, Goiás, in a greenhouse in two soils: Red Latosol (LV) and Yellow Latosol (LA). The treatments of Caiapônia Shale (CS) were increasing doses (0, 50, 100, 200 and 400 kg. ha-1 of MgO), in addition to the reference agrominerals, Dianutri (SiMg) and Ibar (MgO) and Wollastonite, source of Ca, with addition of MgO. The experimental design was completely randomized, with eight treatments conducted in quadruplicate. The variables analyzed were magnesium and calcium content and pH in the soil. The Caiapônia Shale (CS) released Mg+2, increasing the availability of magnesium, especially in LV in the first year of soybean and residual in corn in the second year, while in LA it was efficient in the first year.

NPK fertilization for the first years of physic nut cultivated in two regions

The physic nut is an oilseed plant that has stood out as an alternative source for biodiesel. However, using it in this way requires determining the edaphoclimatic conditions and adequate fertilization to guarantee maximum productivity. This study objectived to evaluate and establish adequate rates of Nitrogen (N), Phosphorus (P), Potassium (K) to maximize the growth and productivity of physic nut in two edaphoclimatic conditions. Two experiments were performed over two consecutive years, one under Quartzarenic Neosol in the municipality of Diamantina and the other under Red-Yellow Latosol in the municipality of Governador Valadares. The treatments comprised rates of N: 0, 25, 50, 100 kg ha−1; P: 0, 35, 70, 140 kg ha−1; and K: 0, 40, 80, 160 kg ha−1. Plant growth was evaluated every 30 days until flowering. Seed and oil productivity was also assessed, with one harvest in Diamantina and two harvests in Governador Valadares. The edaphoclimatic condition of Governador Valadares was a determining factor in providing greater growth and productivity of the physic nut when compared to that of Diamantina. The application of N rates was unnecessary for the growth and productivity of the physic nut in Diamantina. Thus, phosphate fertilization was unnecessary in Governador Valadares and potassium fertilization was unnecessary for both regions. In Diamantina, 84 kg ha−1 and 87 kg ha−1 of P is recommended for growth and maximum productivity, respectively. Whereas, in Governador Valadares, 49 kg ha−1 and 55 kg ha−1 of N is recommended for growth and maximum crop productivity, respectively.

Soil erodibility by simulated rainfall in Latosols

Determining a soil's resistance to disaggregation and particle transport is a complex factor that depends on the interaction of multiple attributes. Therefore, this study aimed to determine the indirect and direct erodibility of Latosols in the suborders Red, Yellow and Red-Yellow in the state of Alagoas. The soils were identified through the modal profile of the Agroecological Zoning of the State of Alagoas and through surveys of own classification of companies in the sugar and alcohol sector that have identification of areas of occurrence. They were submitted to chemical and physical analysis, by direct methods (aggregate stability and erodibility determination) and indirect (simulated rain) through mathematical models. The soil erodibility factor in interfurrows presented values that varied from 6.01 x 10-6 Kg s-1 m-4 for Yellow Latosol, to 16.65 x 10-6 Kg s-1 m-4 for Red-Yellow Latosol. This variation was also significant within the suborders, with more homogeneous values observed in the Red Latosols suborder. Thus, it is concluded that for the soil erodibility factor for Latosols, it is recommended to use the simulated rainfall methodology, in field or laboratory conditions through the Water Erosion Prediction Project model.

Influence of Forest-Pasture Conversion on the Erodibility of a Dystrophic Red Yellow Latosol with Different Deforestation Temporalities in the Southwestern Amazon

The objective was to evaluate the erodibility of a Dystrophic Red Yellow Latosol from the Mutum Paraná River sub-basin to understand the influence of forest conversion and different pasture temporalities on its physical structure and the potential for sediment release after surface samples undisturbed were subjected to the Inderbitzen experiment. Tests of Mechanical Resistance to penetration and physical parameters under forest and pasture conditions were carried out. A simulation of surface runoff by water spraying (Inderbitzen) was carried out to analyze the disaggregation and transportability of particles. The erodibility equation (K factor) was applied, and the Limits of Consistency were defined to measure the Plasticity Index of the soil that qualifies its erodibility. The pasture samples submitted to the experiment indicated soils of low susceptibility to erosion, even under conditions of maximum slope of the area (17°) and under intense simulated flow (3 L and 6 L min-1) of sprinkler, not showing large losses of sediments or intense surface degradation. There was a relation between soil physical properties and the response of the sample in the experiment. Samples with higher total porosity (r = 0,89) and lower apparent densities (r = -0,88) showed higher disaggregation. There was a significant correlation between the simulated samples that showed lower sediment losses, with a higher percentage of clay (r = -0,65). Samples with a higher percentage of total sand indicated higher percentages of disaggregation (r = 0,68). Erodibility data obtained by the K-factor equation and Plasticity Index endorsed the low soil erodibility

Analysis of sorption/desorption of cadmium and lead in the legal amazon soils

Sorption and desorption tests were carried out for competitive and non-competitive systems with isotherms to verify the presence of Cd and Pb in soils. The soils investigated were: (i) with natural content of organic matter and (ii) with residual content of organic matter. Hydrated nitrate salts of Cd and Pb diluted in 0.01 M calcium nitrate solution in six concentrations were used for the Cd solutions and, for the solutions of Pb, five concentrations. For multielement solutions, mixtures of the simple Cd and Pb solutions in a 1:1 ratio were used. The results of the first stage tests (i) showed good adjustments of the experimental data to the isotherms of Langmuir, Freundlich and Linear, which did not occur for the tests in stage (ii). According to the tests (i), the organic matter was the soil attribute of dominant influence in the sorting mechanisms. The parameters Qo and Kd were adequate to evaluate the adsorption of the studied metals, especially Cd. In step (ii), there was a significant increase in metal retention, especially for element Pb in the samples of Haplic Cambisol (AM) and Red-Yellow Latosol1 (RO), justified by the combined action of (1) increasing the surface area of the mineral fraction, previously covered by organic matter; and (2) increase in soil pH. The Cd element was more bioavailable in relation to the Pb. This was confirmed by the high desorption values observed for Cd. The samples of Haplic Cambisol and Red-Yellow Latosol demonstrated greater capacity to retain Cd and Pb.

Soil Chemical Attributes under Agrosilvopastoral Systems and Pasture

Agrosilvopastoral systems involve the consortium of trees, agricultural crops, and pasture, in the same area, concomitant or sequential, based on agroecological bases and on the cycling of organic matter and nutrients. This research compares soil fertility under pasture and agrosilvopastoral system. The area of 5 ha, is located on the Campus of the Federal University of Viçosa in Florestal city, central region of Minas Gerais state, formed by Urochloa decumbens for about 30 years, in an argisolic dystrophic Red Yellow Latosol. Two agrosilvopastoral systems - in single lines 2 x 10 m and double lines 2 x 2 + 10 m - were compared with pasture without trees. The soil preparation was conventional, with ploughing and leveling grids, in December 2009. Seedlings of the hybrid Eucalyptpus urophylla and E. grandis, clone GG100, were planted in level and subsoiler lines, which received 500 kg ha-1 of reactive phosphate at a depth of 0.5 m. At planting, each seedling received 120 g of N:P:K 10:28:06 + 0.3% B + 0.5% Zn; and 120 g of N:P:K 20:00:20, at 60 days. The corn was sown in the alleys, receiving 360 kg ha-1 of N:P:K 08:28:16 + 0.5% Zn, at planting, and 240 kg of urea ha-1, at 30 days. After the corn harvest, the pasture was formed naturally from the seed bank. At 135 months post-planting, five composite soil samples were collected in each studied area, obtained from ten simple samples of the 0-5 cm layer. The following attributes were analyzed: pH, P, K, Ca, Mg, Al, H + Al, OM, and Prem. The results were submitted to analysis of variance and F test (p,0.05), and the means of the significant treatments were compared by the Scott Knott test (p<0.05). Both APS provided an increase in the levels of OM, P, Ca, SB, t, and H + Al in the soil, keeping unchanged the other attributes analyzed in relation to conventional pasture. No significant differences in fertility were detected between the two agrosilvopastoral systems studied.

Sigmoid models in the description of CO₂ evolved from legumes in the soil

The decomposition of legumes in the soil over time can be described by nonlinear sigmoid models. Thus, this study aimedto describe and to compare the fit of the nonlinear sigmoid models, Logistic and Gompertz, to the CO2 mineralization of fourlegume species over time in the soil, and indicate the most suitable model. Furthermore, it is also proposed to evaluate the CO2mineralization of legumes from two different edaphoclimatic conditions when added to the soil under controlled temperatureand humidity conditions. The following legume species used in green manure were evaluated: Arachis pintoi (forage peanut),Calopogonium mucunoides (calopo), Stylosanthes guianensis (Caribbean stylo), and Stizolobium aterrimum (mucuna). Arandomized block design with four replications was used. The soils from both areas are classified as Red-Yellow Latosol andhave a clayey texture. The mineralized carbon was measured at 48, 96, 144, 192, 240, 312, 384, and 480 hours fromthe beginning of incubation. Legumes in different locations had the same amount of potentially mineralizable carbon, andmicroorganisms had the same adaptation time to reach the maximum decomposition rate. The maximum decompositionrate occurs at the beginning of mineralization, and therefore the Gompertz model was more suitable than the Logistic modelin describing the decomposition of the four legumes in the soil.

Agronomic performance of green corn at different sowing times and nitrogen doses

The present study aimed to identify the best sowing time and the best nitrogen dose in topdressing of the corn crop for "green ear" consumption. The experiment was conducted between October 2018 and June 2019 in a commercial crop, in Ipameri, Goiás, Brazil. The soil in the experimental area is classified as dystrophic Red-Yellow Latosol with clayey texture. The experimental design used was the randomized blocks, in a 5 x 5 factorial scheme, with five sowing times [1st (10/19/2018); 2nd (11/29/2018); 3rd (01/08/2019); 4th (02/18/2019) and 5th (03/28/2019)], implemented with 40 days intervals, after the first sowing, and five nitrogen doses (0, 50, 100, 150, and 200 kg ha-1), with four replicates. The following factors were evaluated for each sowing time: relative chlorophyll index, leaf dry mass, leaf nitrogen content, plant height, first ear insertion height, ears diameter and length, the total yield of ears with husks, the yield of commercial ears without husks and grain yield. The data were submitted to the analysis of variance (F-test). The sowing times and nitrogen doses in topdressing influenced the leaf nitrogen content, relative chlorophyll index, leaf dry mass, yield, and most of its components. Thus, it can be indicated that the best time for sowing corn for fresh consumption is in October (1st sowing time), and the estimated nitrogen dose in topdressing to obtain the maximum yield is 160 kg ha-1 of nitrogen.

Agronomic and environmental aspects of organo-mineral fertilizers produced with a by-product of the intermediate process of tanning

IntroductionThe by-product of the intermediate process of tanning (BPIPT) can be used in the manufacturing of environmentally-friendly organo-mineral fertilizers (OMF). However, the presence of potentially toxic elements (e.g., chromium, Cr), can hinder the use of BPIPT in agriculture. This study aimed: i) to evaluate soil chemical and biological properties following the application of fertilizers produced with a BPIPT, in contrast to other OMF produced with traditional organic matrices; and ii) to assess the impacts of such products on wheat growth and nutrition.MethodsSamples (0-0.2 m) of two Oxisols [Red-Yellow Latosol (LVAd) and Red Latosol (LVd)] were used in this study, consisting of two experiments (with five treatments and five replicates) using different OMF, in a sequence: 1) incubation of fertilizers in soil samples for 30 days, and 2) wheat cultivation (30 days) after the fertilizer incubation. The treatments consisted of an arrangement of mineral fertilizers based on nitrogen, phosphorus, and potassium (NPK fertilizers), associated with OMF based on BPIPT (OM-IPT and OM-IPT+S) or commercial manure (OM-CM and OM-CM+S), with or without sulfur (S), and a control treatment. Elemental availability in soils and microbial attributes were determined after the incubation of the OMF in the soils. After wheat cultivation, plant biomass, nutritional composition, β-glucosidase activity, and fluorescein diacetate hydrolysis (FDA) were measured.Results and discussionThe application of BPIPT-derived OMF in the present study increased available Cr fraction contents in both soils. However, OM-IPT caused low soil acidification, enhanced wheat growth and nutrition, and stimulated microbial activity in soils (FDA and β-glucosidase), thus evidencing the agronomic and environmental benefits of this OMF and their potential to contribute to a cleaner, more sustainable agriculture.

Multivariate analysis to estimate the erodibility of Latosols in Alagoas, Brazil

Soil erodibility is one of the most important factors in understanding the erosive process. In view of the need to explore methods for determining the values of erodibility by simulated rainfall, the objective was to evaluate, through the tools of multivariate statistics, the erodibility of Latosols from Alagoas influenced by the physical, chemical and stability attributes of aggregates. The research activities were carried out at the Arapiraca Campus, of the Federal University of Alagoas (Universidade Federal de Alagoas), where Latosols were used in the suborders Red, Yellow and Red-Yellow, collected in two of the three geomorphological regions of the state of Alagoas. The prediction of correlation metrics shows that the cluster grouping indicates that the best correlations found were between the variables: clay and clay dispersed in water (r = 0.94), lime and sand (r = 90), and between the Water Erosion Prediction Project and the erodibility factor in midgrooves (r = 1.00). These strong positive correlations are proven through scatterplots, confidence regions, dendrogram, density estimation, and ellipses. The multivariate statistics allow a better understanding of the behavior of the correlations between the physical, chemical and stability attributes of aggregates with the erodibility of Latosols of Alagoas, as well as demonstrating the relationship of the variables studied with any of the three suborders of soils of Alagoas (Yellow, Red and Red-Yellow Latosol).

INITIAL GROWTH OF Citharexyllum myrianthum plants UNDER PLANTING FERTILIZATION

The objective of this work was to evaluate the initial growth of Citharexyllum myrianthum under the influence of three sources of planting fertilizers, in conditions of 18 L pots. The treatments used were, as follows: absolute control; 5 L of biosolid/pot; 300 g of natural rock phosphate (NRP), and 200 grams of NPK 06-29-06. The seedlings were grown in pots in full sun, supplemented with Dystrophic Red Yellow Latosol. At 150 days after transplanting, the plants were measured, obtaining the height of the aerial part and the diameter of the stem. Then, the increment of these two variables was calculated. Subsequently, the leaves were removed to determine the leaf area (LA), separating the aerial part from the root system, and then packed in a paper bag and placed in an oven at 65ºC, for drying until reaching constant weight. After weighing this material to obtain the dry matter of the aerial part (APDM) and root (RDM). The leaves were ground to determine the foliar contents of N, P, K, Ca, and Mg. To evaluate the effect of treatments on the soil, samples were taken from the pots to determine the levels of macronutrients, organic matter, and CEC(t). It was found that the LA and APDM of plants fertilized with NPK showed significantly higher values when compared to plants cultivated in the control treatment. It is recommended to fertilize Citharexyllum myrianthum plants with 200 grams of N-P-K 06-29-06/hole or with 5 L of biosolid.

USE OF PSEUDOMONAS PUTIDA AND PANTOEA AGLLOMERANS AS PHOSPHORUS SOLUBILIZING BACTERIA IN OXISOL

largest biome in total area in South America, this biome has great aptitude for agriculture and stands out every year in the production of agricultural commodities in the national territory, being consolidated as the largest producer of soy, corn, cotton and the largest cattle herd in the world. country. However, it is worth mentioning that there is a limiting factor for production in the cerrado, which is the low natural fertility of its main type of soil, these soils with intense weathering are strongly acidic, have low saturation of bases and predominance of iron and aluminum oxides that adsorb phosphates. The objective of this work was to evaluate the efficiency of the bacteria Pseudomonas putida and Pantoea agglomerans, present in the commercial product Phospho Bavar-2, as potential phosphorus solubilizing bacteria (BSP) in latosols, acting in the conversion of non-labile phosphorus into forms readily available to plants. . The experiment was carried out from 03/11/2019 to 04/03/2020 at the experimental farm of IFMT Campus Sorriso in red yellow latosol. The treatments consisted of different doses of triple superphosphate in seeds treated with the bacteria Pseudomonas putida and Pantoea agglomerans, present in Biofertilizante BARVAR-P-2® from Green Biotech Brasil. The treatments were: T1 (Without inoculant+100% fertilizer dose), T2: (With inoculant+100% fertilizer dose), T3: (With inoculant+50% fertilizer dose), T4 (Comm inoculant+0% fertilizer dose), T5: (Without inoculant+50% fertilizer dose), T6: (Without inoculant+0% fertilizer dose). There was no significant interaction between inoculant use and productivity in Kg/Ha-1. However, when comparing the productivity averages achieved in the experiment with productivity data at regional and national level, it is possible to verify satisfactory averages that may be directly related to the use of the product.

Evaluation of low-cost capacitive moisture sensors in three types of soils in the Cerrado, Brazil

Soil moisture sensors enabled new automation and computerization solutions in agriculture. However, its use still requires prior calibrations to attest its accuracy to estimate soil moisture. Thus, in this study a prototype for soil moisture monitoring was developed using the capacitive sensor SKU:SEN0193 integrated with the Arduino microcontroller. The prototype was calibrated based on the relationship between volumetric moisture and sensor output voltage in deformed samples of Red-yellow Latosol (RYL), Regolitic Neosol (RN), and Red Latosol (RL) of the Cerrado region, Federal District, Brazil. The calibration of sensors resulted in a second-degree polynomial model with R² between 0.93 and 0.96 for RYL, 0.89 and 0.92 for RN, and 0.86 and 0.88 for RL. Root mean square errors (RMSE) of volumetric moisture were 0.08, 0.12, and 0.15 cm3.cm-3 for RYL, RN, and RL, respectively. Sensors at operating voltage of 5.00 V showed less variability of readings, with coefficient of variation (CV) between 0.21 and 1.54%, while sensors at 3.30 V showed CVs between 3.27 and 17.84%. It is recommended to calibrate the SKU:SEN0193 for each soil type in order to obtain reliable estimates of water content for RYL, RN, and RL.

Soil of the parent plant and AMF mix improve Cerrado’s seedlings growth in forest nurseries

The soil microbiota plays an extremely important role in the growth and survival of plants. The presence of some microorganisms can positively and significantly impact the growth of tree species, which can improve the performance of seedlings after planting for commercial purposes and/or for ecosystem restoration. The present study aimed to evaluate the initial growth of seedlings of Hancornia speciosa and Brosimum gaudichaudii associated with microorganisms from the soil of the parent tree and/or inoculated with arbuscular mycorrhizal fungi (AMF). Four substrates were tested: T1 (control) = Autoclaved dystrophic Red-Yellow Latosol (Aut-dRYL) + autoclaved commercial substrate (Aut-CS); T2 = Aut-dRYL + Aut-CS + inoculum of AMF (Mix); T3 = Aut-dRYL + Aut-CS + soil of the parent plant (SPP); and T4 = Aut-dRYL + Aut-CS + SPP + Mix. The AMF inoculum comprised a mix of the species Gigaspora decipiens, Rhizophagus clarus, and Scutellospora heterogama. Seedling growth was determined 270-350 days after transplanting by measuring the following parameters: mycorrhizal colonization rate (MC), abundance of spores (AS), height (H), stem diameter (D), H/D ratio, volume of roots (VR), dry matter of shoot (SDM), roots (RDM), total (TDM), shoot / root dry matter ratio (SDM/RDM), height / shoot dry matter ratio (H/SDM), and Dickson quality index (DQI). The results showed that the addition of SPP improved the growth and DQI of the seedlings, while the AMF mix minimally changed both growth and DQI. The use of symbiotic microorganisms in the nursery in Brazil is scarse due to the difficulty of acquiring these microorganisms and the lack of commercialization of specific isolates for species native to the Cerrado biome. The present study evaluated the use of soil from naturally occurring areas as a source of inoculum. The higher growth and biomass production of inoculated plants support the use of SPP as a form of inoculum and/or inoculation with native AMF to produce seedlings of H. speciosa and B. gaudichaudii.

Dry matter allocation and chemical composition of brachiaria brizantha and decumbens 45 days after emergence / Alocação da matéria seca e composição química das braquiárias brizantha e decumbens, aos 45 dias após emergência

This study evaluated dry matter allocation and chemical composition of brachiaria brizantha and decumbens under conditions of good nutrient supply. The study was conducted in the city of Coruripe, East Mesoregion of the state of Alagoas, in a medium-textured dystrophic red-yellow latosol. The experimental design was randomized blocks with five replications, and the plots consisted of five furrows of five meters in length, spaced 0.60 meters apart. Phosphorus was applied at the bottom the open furrows at a dose equivalent to 50 kg of P ha-1. Nitrogen and potassium fertilizers were applied at doses equivalent to 150 ha-1 when plants were approximately 5 cm tall. Evaluations of dry matter accumulation and allocation were carried out 45 days after plant emergence, when light interception by leaves was approximately 90%. Both species showed high growth rates, with an average shoot dry matter accumulation of 5.64 t ha-1, but brachiaria decumbens was about 25% more productive than brachiaria brizantha. There was no effect of the species on the percentage of dry matter allocation and about 50% of it was allocated to in the leaves. There was also no species effect on shoot crude protein content, which had an average of 106 g kg-1, enough to ensure good ruminal fermentation. Brachiaria decumbens had higher calcium, magnesium and sulfur contents compared to brachiaria brizantha, although adequate contents of these three nutrients were also found in brachiaria brizantha.

Estimation of carbon stock in the soil plant system of the main phytophysiognomies of the cerrado of west Bahia, Brazil

The work was carried out in the western region of Bahia in five phytophysiognomies of cerrado. The regional climate is of the Aw type with rainy summers and dry winters. The main soils are Red-Yellow Latosol, Quartzarenic Neosol and Dystrophic Haplic Gleysol with texture varying from sandy to sandy loam. Soil samples were taken up to 0.40 m to determine the soil carbon and for plant biomass models already established by other authors were chosen. The total soil carbon content followed the decreasing order: VRD>CRD>CSS>CCS>CCL. This may reflect the difference in density of plants in these phytophysiognomic compartments, although there is no significant difference between the soils under the phytophysiognomies of CCS and CCL. The soils under the five phytophysiognomies, on average, presented a carbon stock of 50.63 Mg ha-1. The studied phytophysiognomies in aboveground vegetation presented carbon stocks ranging from 0.05 to 23.36 Mg ha-1.This variation is explained by the plant diversity of each phytophysiognomy. Therefore, the accumulation of carbon depends on the richness and size of species of the area. In general, the upper soil layers stored greater amounts of carbon. Aboveground biomass and in roots stand out for higher carbon production in biomass, the phytophysiognomies of CRD and CSS.

Nutrient balance in a constructed wetland system using treated domestic wastewater on ornamental sunflower crops

This study aimed to assess the nutrient dynamics of raw and treated wastewater (RWW and WW) in constructed wetlands (CW) for the irrigation of ornamental sunflowers, compared to freshwater (Fw) in Red Yellow Latosol (RYL) with (OF) and without (WF) inorganic fertilization. The study was carried out from July 10th to October 2nd of 2019. Wastewater was applied in pots with 10 kg of RYL. The amount of salts in the RWW, influent and effluent of CW and UnS (Uncultivated System), were evaluated in eleven samples. The study also assessed the following: plant height (PH), stem diameter (SD), number of leaves (NL), leaf area index (LAI), the inner diameter of the capitulum (IDc), the outer diameter of the capitulum (ODc), number of petals in the bud (NP), days after harvest (DAH), fresh phytomass in the aerial part (FPAP), dry phytomass in the aerial part (DPAP), fresh phytomass of the capitulum (FPc), dry phytomass of the capitulum (DPc), nutrient content in the aerial sunflower, and chemical composition in the RYL. The average removal efficiency of K+, Ca2+, and Fe in the CW was 34.33, 37.88, 39.82, and 45.40%, respectively. The PH (86.54 cm), SD (11.75 mm), NL (21), and LAI 3646.73 cm2) were higher in the WWOF treatment at 70 days after sowing. Treated wastewater without fertilization (WWWF) presented higher P, K, S, B, and Mn absorption. Freshwater with fertilization accumulated greater amounts of N, and WWOF accumulated greater amounts of Zn. Wastewater increased the P content and decreased K+ and Ca2+ in RYL. Irrigation with domestic WW in CW provided salts to the soil and increased the growth and quality of sunflowers irrigated with Fw

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.

Curvas de resposta do milho à adubação potássica obtidas através de experimento fatorial

The effect of this plant study was determined by the application of different nutrient solutions and increasing doses of dry mass and pots potential on aerial production of corn plants grown in a sample content of a Red-Yellow Latosol in pots under greenhouse conditions. The treatments consist of three nutrient solutions, the treatments of additional doses (K) and a solution that received neither nutrient nor K application. The root quadratic model is the most suitable among the results to describe a dry mass production of corn plants as a function of the K dose.