Search

Biological nitrogen fixation (BNF) is what makes soybean economically viable. However, the launch of cultivars, with a high-yield potential and abiotic factors that reduce BNF, raised doubts about ...

The lime (L) and phosphogypsum (G) promote changes in the chemical attributes of the soil that can alter the development of corn. The objective was to evaluate morphological and yield components of corn after liming and G and to correlate them with yield. The treatments consisted of a 2 x 4 + 3 factorial, with two methods of application of L: surface (SL) and incorporated (IL) to obtain different levels of base saturation (BS): 44, 60, 70 and 90%. Three additional treatments were evaluated involving the use of L and G applied on the surface, being: BS 60% + 3.71 Mg ha-1 of G (60G50); BS 70% + 3.71 Mg ha-1 of G (70G50) and BS 70% + 7.42 Mg ha-1 of G (70G100). Plant height (PH), ear insertion height (EIH) and stem diameter (SD) were not influenced by the treatments. The SL increased the length of the ear (LE), number of grains per row (NGR) and mass of a thousand grains (TMG) up to BS of 72, 80 and 72%, respectively. Thus, there were no advantages of higher base saturation (BS 90%). The combination of L and G promoted improvements in ear diameter (ED), NGF, LE, TMG. The yield in IL was 445 kg ha-1 higher than SL, however when combining G and L the production increased 6 to 12% in relation to BS 44% SL. BS% levels in IL did not influence any response variable. Grain yield was positively correlated to ED, TMG, LE and PH.

Nutrient leaf application is complementary to soybean nutritional management, mainly at maturity, when plants present high nutritional demand and high nutrients and photoassimilate translocation ra...

Nanoparticle (NP) use is becoming important alternative in different branches of science such as in agriculture, used as new source of fertiliser. In this study, it was tested iron (Fe) NP, applied...

Novel fertilizer stabilization technologies are needed to decrease ammonia (NH 3 -N) losses and increase nitrogen use efficiency. Duromide + NBPT is a new technology that combines two molecules, Duromide and NBPT, whose propose is to increase the efficiency of the urease inhibitor NBPT in reducing NH 3 -N loss from urea. Preliminary results showed that Duromide + NBPT can be a more effective product than just NBPT, particularly under low soil pH and high-temperature conditions. This study aimed to compare the effects of urea + Duromide + NBPT, urea + NBPT, and conventional urea on soil N losses by NH 3 -N volatilization. The field experiment was conducted on a Latossolo Vermelho Distroférrico (Oxisol) in Campo Mourão, Paraná, Brazil, using a randomized complete block design with treatments arranged in a 2 × 3 factorial, comprising two N doses (45 and 90 kg ha -1 ) and three N fertilizers (urea + Duromide + NBPT, urea + NBPT, and conventional urea). The NH 3 -N volatilization data were subjected to nonlinear regression using a logistic model. The NH 3 -N losses varied according to dose and fertilizer, reaching up to 12.4 % of the applied N in the conventional urea treatment. Urea + Duromide + NBPT was more efficient than urea + NBPT in decreasing NH 3 -N volatilization. Compared to conventional urea at doses of 45 and 90 kg ha -1 of N, urea + Duromide + NBPT reduced NH 3 -N volatilization losses by 35 and 54 % and from urea + NBPT by 15 and 33 %, respectively. The new stabilizing technology Duromide + NBPT reduced NH 3 -N losses by up to 33 % compared to NBPT alone. Ammonia volatilization was influenced by soil moisture. The volatilization peak, observed after 18-19 days of N fertilizer application, was triggered by rainfall events.

Knowing the nutrient removal by soybean grain harvest in different varieties, locations, and over time is essential to correctly adjust agronomic recommendations, update farmers’ practices, and increase nutrient use efficiency. A field-based research trial was carried out to assess macronutrients [nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), and sulfur (S)] removed in grain by modern soybean varieties from southern Brazil introduced between 2007 and 2016. We examined changes between our set of modern varieties and a dataset of historical values encompassing a wide range of varieties introduced before 2007. Moreover, we undertook a synthesis analysis using scientific literature published after 2007 to investigate nutrient removal by grain among modern Brazilian soybeans and a dataset that included field trials from Argentina, United States, and India. There were no yield gains across the years for modern soybean varieties introduced among 2007 and 2016 in Brazil, although the grain N and Mg concentrations decreased. Modern Brazilian soybeans increased nutrient removal compared with that by soybeans historically planted in Brazil, with 11.1, 26.9, 45.0, and 31.6% more N, P, K, and Mg removed, respectively. Our results indicated that soybean growing in Brazil removed 4.3% less N relative to the values reported in the literature dataset, whereas K removal was 21.4% greater. A significant difference was also recorded for high-yield soybean varieties, and Brazilian varieties removed 11.8% less N and 8.6% more K than varieties in the literature dataset. No differences were found among locations for P removal, averaging 4.9 kg Mg–1 grain. In conclusion, this study indicates that the amounts of nutrients removed by modern soybean varieties were greater relative to the historical values recorded in Brazil, excluding Ca and S. Nonetheless, in the middle to long term (10 years), a significant impact of plant breeding on grain nutrient concentration was recorded only for N and Mg. The difference in nutrient removal patterns between Brazil and other countries indicates an integrated effect of management, genotype, and environment on nutrient removal. These findings provide guidance for optimal nutrient management and specific information for plant breeding programs to understand nutrient variability.

Knowledge on the behavior of cumulative N-NH3 volatilization is important for defining the strategies to reduce the N losses, as well as increasing the efficiency of nitrogen fertilization ...

Lime application is the most appropriate technique to raise soil pH, decrease Al3+ toxicity and increase Ca2+ and Mg2+ contents in acidic tropical and subtropical moist soils. The objective of this research is to evaluate changes in chemical attributes and soybean yield in sandy soil after lime incorporation. The soil was classified as a typical Quartzipsamments cultivated with (Brachiaria decumbens Stapf) pasture, and its degradation state was classified as strong. The experimental design was a randomized block with six replicates and four lime doses (0, 2, 4 and 8 Mg ha-1). The soil in the area was prepared with one plowing and two harrowings, followed by lime application and two more harrowings to incorporate the lime up to 0.2 m depth. The dependent variables analyzed were soybean yield; numbers of pods filled, pods not filled, and total pods and soil pH in water, CaCl2 and KCl. All parameters were measured at depth of 0.0-0.1, 0.1-0.2 and 0.2-0.3 m. The increase of soil pH by the different lime rates were observed just in 0.0-0.1 and 0.1-0.2 m layers. After 6 months no changes in soil pH were observed in subsoil (0.2-0.3 m). With lower H+ and Al3+ activity and higher basic cation availability, soybean yield was also changed. The maximum soybean yield of 2,929 kg ha-1 was observed with 4.6 Mg ha-1 lime application, although pod number per plant remained constant, independent of limestone dose.

Brazil is currently the leading country in no-till (NT) farming, particularly on Ferralsols (Latossolos), the most abundant soil type. These soils are characterized by subsurface acidity that cannot be effectively corrected by surface application of additives. In this situation, the use of phosphogypsum can be advantageous. This study aimed to assess the residual effects of lime and phosphogypsum application on a clayey Ferralsol, and four soybean and two wheat yields in southern Brazil. The area has been cultivated under no-till since 1975. The soil was limed to different base saturation (BS) levels (50, 60, 70, and 90 %) by surface application (SL) or lime incorporation (IL). Three combined treatments were also studied: (i) surface liming to 60 % BS plus standard (3.71 Mg ha -1 ) phosphogypsum dose (60G1), (ii) surface liming to 70 % BS + standard phosphogypsum dose (70G1); and (iii) surface liming to 70 % BS + double (7.42 Mg ha -1 ) phosphogypsum dose (70G2). Soil samples were collected 48 months after treatment. Soybean and wheat yield was not influenced by BS levels, however IL increased soybean yield in 2012/13, but reduced soybean and wheat yield in later crops. Phosphogypsum increased wheat yield by up to 12.8 % (2012 season) and 5.2 % (2015 season), but soybean was not influenced. Incorporated liming caused a decrease in soil Al 3+ levels until 0.60 m depth, whereas SL decreased Al 3+ levels until 0.30 m depth. Surface liming increased Mg 2+ levels in the 0.40-0.60 m layer. Incorporated liming reduced soil organic matter in the surface layer. A double dose of phosphogypsum (7.42 Mg ha -1 ) had a greater residual effect in subsurface layers but caused a decrease in Mg 2+ and K + levels. Therefore, the standard phosphogypsum dose provided the best results. In the very clayey soil in subtropical environment, the effects of SL extend beyond surface layers and are preferable to those of IL, although production was not influenced by BS.

Oxisols ( Latossolos ) are widely distributed in tropical zones and generally characterized by high levels of surface and subsurface acidity. In Brazil, most Oxisols are managed under no-till conditions with surface application of acidity amendments. This study aimed to evaluate lime application strategies (incorporated and surface) for achieving the desired soil base saturation (BS%) levels (44, 60, 70, and 90 %) and the effect of phosphogypsum + lime application on soil chemical properties as well as wheat and corn yield in southern Brazil. Lime incorporation was more effective in reducing the soil acidity and increasing Ca2+ and Mg2+ despite a decrease in organic matter at the soil surface. Phosphogypsum application increased S-SO42- and Ca2+ availability throughout the deeper soil layers and reduced the Mg2+ content in the surface layer. Wheat yield under incorporated lime conditions increased with BS% up to 75, but there was no response to surface application. When phosphogypsum was applied, the wheat yield increased by 8.4 %. For corn, incorporated lime increased the yield up to 445 kg ha-1, which was equivalent to the yield after phosphogypsum application. An increase in the S-SO42- level was the main factor related to the increase in crop yields. In the short term, our results suggest that phosphogypsum applied along with lime is more appropriate than incorporating lime under no-till management conditions.

The use of Azospirillum brasilense has the potential to improve plant nitrogen (N) use efficiency, while a better understanding of alternative management practices with inoculation is necessary. The aim was to examine the effects of the leaf application of A. brasilense in association with nitrogen fertilization on the wheat crop. The experiment was conducted in Lidianópolis, Paraná, Brazil, in a completely randomized block design with four replications. The treatments included four doses of A. brasilense for leaf application (0, 200, 400, and 600 ml ha-1) and four doses of N (0, 40, 80, and 120 kg N ha-1). The nutritional content, yield components, quality, and yield of the wheat crop were evaluated. There was no interaction among the factors, nor did the treatments have an isolated effect on spike length, the number of spikelets per spike, spikes per m2, thousand grain weight, and test weight. However, doses of A. brasilense increased calcium and magnesium absorption at 283 and 380 ml ha-1, respectively. Similarly, nitrogen application increased the content of calcium, magnesium, and copper in the leaf at 61, 47, and 49 kg N ha-1, respectively. Nitrogen also increased the number of grains per spike and yield at 56 and 54 kg N ha-1, respectively. Yield correlated with the number of grains per spike and the manganese and copper content in the leaf. The results demonstrate that the inoculation of leaves with A. brasilense favored a higher absorption of divalent cationic macronutrients and that N was fundamental to increasing the yield, with the best responses observed between 47 and 61 kg ha-1.

Nanofertilizers are increasingly explored for sustainable micronutrient delivery in agriculture. Pre-treating seeds with nanofertilizers prior to planting (i.e., seed priming) reduces concerns about nanoparticle (NP) fertilizer non-target dispersion, however, priming formulations and concentrations must be carefully selected to avoid germination inhibition and toxicity. Here we investigate changes in corn seed germination and seedling development after seed priming with ZnO NPs, ZnO bulk and ZnCl2. To evaluate the effects sterile seeds were immersed in priming solutions of 0, 20, 40, 80, 160 mg L&minus, 1 Zn for the three Zn sources. Following an 8 h priming the seeds were evaluated for germination and vigor for 5 days on germination paper. Root and shoot lengths were measured as well as fresh and dry biomass. Compared to the control, the ZnO NP and ZnCl2 seed priming promoted beneficial effects. ZnO NP seed-priming exhibited a concentration dependent profile in improving seedling growth, with greatest benefit around 80 mg L&minus, 1, providing 17%, 25% and 12% higher values than control for germination, root length, and dry biomass production, respectively. In contrast, seeds primed with bulk ZnO did not differ from the control. These findings support NP-seed priming as an alternative to delivery of essential micronutrients, such as zinc, to corn seedlings.

The development of new fertilizer technologies to reduce nitrogen (N) losses from an agricultural system and to increase nitrogen use efficiency (NUE) is a global research objective. Controlled-release nitrogen fertilizers have shown great potential for reducing N losses and synchronizing N release according to crop demand, thereby improving the NUE. The objective of this study was to characterize controlled-release nitrogen fertilizers and compare them with conventional nitrogen sources in terms of N release, N loss via NH3 volatilization, and fertilizer effects on second-season corn. The field experiment was performed on an Ultisol in a randomized block design. The treatments consisted of two conventional nitrogen sources (urea and ammonium sulfate) and three brands of polymer-coated urea (PCU; Agrocote®, FortBlen®, and Kimcoat®). The variables N release and N loss by NH3 volatilization were subjected to nonlinear regression analysis using a logistic model and the Korsmeyer-Peppas model, respectively. Leaf N content and dry matter yield were subjected to the Tukey test, and the morphologies of the PCUs were observed by scanning electron microscopy (SEM). Electron micrographs revealed differences in the number of layers and the thickness of the coatings of the studied PCUs. FortBlen®, containing granules with single- or double-layer coatings with thicknesses ranging from 34.53 to 50.34 µm, promoted more gradual N release and reduced N-NH3 losses by 36.4 % compared with those observed with uncoated urea. Kimcoat® released approximately 98 % of the applied N within 24 hours, resulting in N-NH3 volatilization, and the responses in second-season corn were similar to those with uncoated urea. Although no benefits were observed in second-season corn for PCUs over uncoated nitrogen sources, some PCUs promoted more gradual N release and reduced N-NH3 volatilization, providing a promising alternative for environments prone to N loss.

Fertilizer formulation alternatives that avoid unnecessary losses and environmental impacts are being investigated in agricultural management. Seed priming with nanofertilizers prior to planting, reduces concerns about non-target dispersion; however, priming formulations and concentrations must be carefully selected to avoid undesired effects. Here, seed germination and seedling development were evaluated after seed priming with CuO nanoparticles (NPs), CuO bulk and CuCl2. The seeds were immersed in priming solutions of 0, 20, 40, 80 and 160 mg.L−1 Cu for the three Cu sources. Following 8 hours priming, the seeds were evaluated for germination and vigor (first germination count). Root and shoot lengths were measured as well as shoot and root dry biomass. The copper NP did not show any toxic effects on corn seed germination and growth, and also promoted higher biomass when compared to the other Cu sources. On the other hand, CuCl2 primed seeds exhibited Cu-toxicity in roots and shoots for all concentrations tested. Bulk Cu priming results indicated the better role of NPs size effects. These findings support NP-seed priming as an alternative to delivery of essential micronutrients, such as copper, to corn seedlings. Resumo: Alternativas para evitar perdas e impactos desnecessários no meio ambiente são alcançadas no manejo agrícola. A preparação de sementes com nanofertilizantes antes do plantio reduz as preocupações com a dispersão não-alvo; no entanto, formulações e concentrações devem ser cuidadosamente selecionadas para evitar efeitos indesejados. Aqui, avaliou-se a germinação e o desenvolvimento de plântulas após a iniciação das sementes com CuO NPs, CuO bulk e CuCl2. As sementes foram imersas em soluções primárias de 0, 20, 40, 80 e 160 mg.L-1 para as três fontes de Cu. Após 8 horas de preparação, as sementes foram avaliadas quanto à germinação e vigor (primeira contagem de germinação). Os comprimentos de raiz e parte aérea foram medidos, bem como a biomassa seca de parte aérea e de raízes. A fonte de nanopartículas de cobre não apresenta efeitos tóxicos no crescimento do milho e promove maior biomassa quando comparada às demais fontes. Por outro lado, fontes de CuCl2 mostraram alguns impactos negativos tóxicos nas raízes e parte aérea do milho para todas as doses testadas. Esses achados apoiam o tratamento de sementes com NPs como uma alternativa à entrega de micronutrientes essenciais, como o cobre.

Os efluentes das diversas cadeias produtivas industriais sao muitas vezes descartados no ambiente sem tratamento adequado. A preocupacao por uma linha de producao industrial economicamente viavel, ambientalmente correta e socialmente aceita e cada vez mais preconizada. Alguns desses efluentes apresentam carater alcalino, e podem ser utilizados como condicionadores quimicos de solos acidos, em sistemas agricolas. Objetivou-se com a realizacao do presente trabalho, avaliar alteracoes quimicas de um Latossolo Vermelho distroferrico, apos aplicacao de efluente da industria farmaceutica. O experimento foi realizado em casa de vegetacao e conduzido em tubos de PVC de 1 m de comprimento e 0,2 m de diâmetro. Nos tubos, preenchidos com solo, foram aplicadas diferentes doses do efluente. Apos 3 dias, 100 mm de agua foram aplicadas sobre cada tratamento. As colunas foram incubadas por 30 dias, posteriormente desmontadas e feitas analises quimicas nas diferentes profundidades: 0-0,2; 0,2-0,4; 0,4-0,6; 0,6-0,8 e 0,8-1,0 m. As aplicacoes do efluente fizeram com que alguns elementos do solo aumentassem significativamente sua concentracao, principalmente na camada de 0-0,2 m entre eles estao o K+, P, Mn2+, Na+, Cu2+, H+, Ca2+ e Al3+, alem do pH. Nas camadas subsuperficiais os elementos Zn2+, K+, Cu2+ e Na+ sofreram alteracoes significativas. A aplicacao do residuo da industria farmaceutica melhorou as caracteristicas quimicas do solo.

Brazilian soybean producers commonly apply maintenance potassium (K) fertilization during cultivation to restore the K taken up by plants; however, this measure can modify the morphophysiological plant characteristics, since the functions of K are closely related with plant growth and development. This study assessed the morphological changes in soybean plants in response to K rates, sowing fertilization, and the application periods of K fertilization in a Latossolo Vermelho eutroférrico (Oxisol) under a no-tillage system, located in the municipality of Floresta, Paraná. A randomized block design was used in the experiment with four replications in a fully crossed factorial design (5 × 2 × 2). The experiment was carried out in two growing seasons (2015/2016 and 2016/2017), with a total of 80 experimental units. The rates corresponded to the first factor (0, 40, 80, 120, and 160 kg ha-1 of K). The application periods (pre-sowing and post-sowing) were the second factor, and sowing fertilization (0 and 30 kg ha-1 of K) the third. The following variables were measured: shoot dry weight, leaf dry weight, stem dry weight, leaf area, specific leaf area, leaf area ratio, and leaf area index, and these biometric parameters were correlated with soybean yield. The results showed that plants well-supplied with K exploited the environment better and this may be reversed for higher yields since there were correlations between grain yield and the biometric parameters. At lower water availability, the biometric changes were more evident.

Há grande carência de informações quanto à adubação com Nitrogênio e Potássio para a produção de minimilho. Quando colhido antes do início da formação de grãos, as quantidades de nutrientes exigidas podem ser diferenciadas. Por essa razão, o presente trabalho teve por objetivo avaliar a resposta do minimilho às adubações nitrogenada e potássica em solo de textura média na região de Maringá, gerando dados que possibilitam a recomendação da aplicação de doses adequadas desses nutrientes para a cultura, evitando os desperdícios e a contaminação ambiental. Os experimentos foram conduzidos na Fazenda Experimental de Iguatemi, na safra verão 2010/2011 e safrinha 2011. O delineamento experimental para os dois experimentos foi blocos casualizados no esquema fatorial 4 x 4, utilizando-se quatro doses de nitrogênio (N) (0, 50, 75 e 100 kg ha-1) e quatro de potássio (K) (0, 20, 40 e 60 kg ha-1), aplicadas 50% na semeadura e 50% em cobertura no estádio V6 de desenvolvimento. O cultivar de milho-pipoca utilizado foi o IAC 125, híbrido triplo top cross, de ciclo precoce. Para as condições em que foi realizada a pesquisa, o potássio e a interação NK não influenciaram a altura de plantas e o comprimento das espiguetas comerciais na safra verão. A máxima produtividade de minimilho, na safra verão, foi obtida com a aplicação de 64,35 kg ha-1 de nitrogênio, não havendo incremento na produtividade com a aplicação de potássio. Na safrinha, a maior produtividade foi alcançada com a combinação das doses 60,9 e 51,23 kg ha-1 de nitrogênio e potássio, respectivamente.

Using seeds of high physiological quality is important the establishment of a crop. Practices for quality seed production include sowing in the offseason and applying foliar macro and micronutrients to supplement fertilizers applied to the soil. The aim of this research was to evaluate the soybean yield and the physiological quality and nutritional content of seeds. Foliar fertilizer (24% P, 8% Ca, 4% K and 2.5% B) was applied at 0.50, 1.0, 1.5, 2.0 and 2.5 kg ha-1 at the R3 soybean stage in a completely randomized design with six replications. The experiment was carried out at two sites. The following traits were evaluated at the R6 stage: the final stand, plant height, height of the first pod insertion, number of branches and number of pods per plant. After the soybeans were harvested, the thousand grain mass and yield were evaluated. The contents of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, zinc, iron, copper and boron were evaluated. Furthermore, the germination, first germination count, accelerated aging, modified cold, electric conductivity and emergency speed index were measured. The data were analyzed by means of joint analysis. When the foliar fertilizer rates were significant, the polynomial regression models were adjusted. The number of pods per plant and yield increased at site 1 (Rancho Alegre d 'Oeste). Application of the foliar fertilizer only influenced the emergency speed index at site 2 (Mariluz) with regard to the physiological quality of the seeds. The P content was positively affected at both sites; the K, S, Zn and B contents were only positively affected at site 2.

Burning is a common practice in tropical areas and related changes in mineralogy might affect the chemical and physical behavior of soils. Maghemite is a common iron oxide in soils formed from basic rocks in tropical regions. This mineral and hematite are the main pigments in these soils and exhibit high magnetization stemming from the precursor magnetite formed during the weathering process of primary minerals. The objective of the present study was to analyze changes in color, magnetic suceptibility values, Fourier transform infrared spectroscopy (FTIR) spectra, and available Fe and Al contents extracted with 1 mol L-1 KCl during the process of thermal transformation of synthetic Al-maghemites into Al-hematites. Synthetic substituted maghemites with different degrees of Al-substitution (0.0, 1.0, 2.0, 2.9, 3.8, 5.6, 6.7, 10.0, 12.0, and 17.1 mol% Al) were subjected to a temperature of 500 ± 10 °C for 0, 5, 10, 16, 64, 128, 192, 360, 720, 2160, 3600, 5040 and 6480 min. The color of the samples was analyzed by a Munsell system in a colorimeter. Mass-specific magnetic susceptibility (χLF) was measured at low-frequency. Available Fe and Al contents were estimated by a 1 mol L-1 KCl solution. Fourier transform infrared spectroscopy (FTIR) spectra were obtained through use of a Bruker Vertex 70X FTIR spectrophotometer at a spectral resolution of 4 cm-1. Contents of Fe and Al extracted by 1 mol L-1 KCl in Al-hematites were not detected. All samples analyzed exhibited YR hue. Hue proportion decreased with increased heating time, and color changed from brown to red. The increase in isomorphic substitution (IS) led to increased hue values from maghemite to hematite, and the latter then became yellower. The χLF values decreased with an increase in heating time, indicating transformation from a ferrimagnetic phase (maghemite) to an antiferrimagnetic phase (hematite). With increasing IS, the maghemite χLF values decreased. Bands of the initial members (time 0) in the FTIR spectra were indexed as maghemites. The end members after completion of the heat treatment were identified as hematites. The IS of Fe by Al in maghemite influenced the thermal transformation to hematite, as well as the color and χLF of the minerals. The χLF proved to be very efficient in detecting maghemites remaining after thermal processing. Fe and/or Al were not ejected from the hematite crystalline structure after heat treatment.

The effects of different commercial phosphate fertilizers [Triple superphosphate (TSP), Tricalcium phosphate (TCP), and ARAD rock phosphate) and soil aluminum (Al) saturation (86, 29, and 0%) on the mineral composition and dry mass production of corn (Zea mays) plants were studied. As soil Al saturation values decreased, pH, calcium (Ca), and magnesium (Mg) levels in the soil increased. High Ca values in the shoot resulted in the reduction in potassium (K) concentrations. The high values of P availability in the soil for the ARAD source of P did not correspond to the high values of dry mass production of corn plants. The high values of corn mass production were noticed for the TSP phosphate source, and the mass productions values were reduced as the soil Al saturation values increased.

Synthetic aluminum-substituted maghemites were characterized by total chemical analysis, powder X-ray diffraction (XRD), Mössbauer spectroscopy (ME), and vibrating sample magnetometry (VSM). The aim was to determine the structural, magnetic, and hyperfine properties of γ-Fe2-xAl xO3 as the Al concentration is varied. The XRD results of the synthetic products were indexed exclusively as maghemite. Increasing Al for Fe substitution decreased the mean crystalline dimension and shifted all diffraction peaks to higher º2θ angles. The a0 dimension of the cubic unit cell decreased with increasing Al according to the equation a o = 0.8385 - 3.63 x 10-5 Al (R²= 0.94). Most Mössbauer spectra were composed of one sextet, but at the highest substitution rate of 142.5 mmol mol-1 Al, both a doublet and sextet were obtained at 300 K. All hyperfine parameters from the sub-spectra were consistent with high-spin Fe3+ (0.2 a 0.7 mms-1) and suggested a strong superparamagnetic component associated with the doublet. The magnetic hyperfine field of the sextets decreased with the amount of Al-substitution [Bhf (T) = 49.751 - 0.1202Al; R² = 0.94] while the linewidth increased linearly. The saturation magnetization also decreased with increasing isomorphous substitution. Maghemitas sintéticas substituídas com Al foram caracterizadas por meio de análise química total, difratometria de raios-X (DRX), espectroscopia Mössbauer (EM) e magnetometria de amostra vibrante (MAV). Objetivou-se com este trabalho determinar as propriedades estruturais, magnéticas e hiperfinas de γ-Fe2-xAl xO3, conforme a variação da concentração de Al.Os resultados de DRX dos produtos sintéticos foram indexados somente para maghemita. Com o aumento da substituição de Fe por Al, o diâmetro médio do cristalito diminuiu e levou todos os picos de difração para maiores ângulos º2θ. A dimensão a0 da cela unitária cúbica decresceu com o aumento de Al, de acordo com a equação a o = 0,8385 - 3,63 x 10-5 Al (R²= 0,94). A maioria dos espectros Mössbauer foi composta de um sexteto, mas na taxa mais alta de substituição de 142,5 mmol mol-1 Al um doubleto e sexteto foram obtidos a 300 K. Todos os parâmetros hiperfinos do subespectro foram consistentes com o alto spin Fe3+ (0,2 a 0,7 mms-1) e sugeriram um forte componente superparamagnético associado com o dubleto. O campo magnético hiperfino dos sextetos decresceram com a substituição de Al [Bhf (T) = 49,751 -0,1202Al; R² = 0,94], enquanto as larguras da linha aumentaram de forma linear. A magnetização de saturação também diminuiu com o aumento da substituição isomórfica.