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The purpose of this study was to investigate the availability of the heavy metals cadmium (Cd), lead (Pb), and chromium (Cr) to soil and maize plants fertilized with different sources and doses of zinc (Zn) in a Rhodic Eutrudox soil. For that purpose, concentrations of Cd, Pb, and Cr were evaluated in leaf tissue and grains of maize plants and in 0-20 and 20-40 cm soil layers after fertilization with four doses of Zn from eight different sources of fertilizer. There was no accumulation of Cd, Pb, and Cr in maize grain and Cd and Cr in leaf tissue of the plants; nevertheless, there was accumulation of Pb in leaf tissue, showing its availability throughout different sources of Zn and consequent uptake by plants. Regarding the soil, it was observed that fertilizer from the different sources made Cd, Pb, and Cr available at increasing amounts proportional to increased Zn doses. Under experimental conditions, fertilization with Zn increased concentrations of heavy metals Cd, Pb and Cr in soil, further highlighting the importance of conducting more studies related to the application of mineral fertilizers for micronutrient supply and the availability of heavy metals.

RESUMO -Objetivou-se avaliar a qualidade fisiológica de sementes de trigo submetidas aos tratamentos com bioestimulante, triadimenol e Azospirillum brasilense. O delineamento utilizado foi inteiramente casualizado, quatro repetições, esquema fatorial 3x8, três cultivares de trigo e oito tratamentos de sementes. As cultivares foram CD-150, CD-116 e CD-104, e os tratamentos foram obtidos da combinação entre: 150 g.L -1 de triadimenol (TRI); 90 mg.L -1 de cinetina + 50 mg.L -1 de ácido giberélico + 50 mg.L -1 de ácido indolbutírico (CGA) e estirpes Ab-V5 e Ab-V6 de A. brasilense na concentração de 2,0 x 10 8 células viáveis mL -1 (AZO), organizados da seguinte forma: testemunha; TRI; CGA; AZO; TRI+CGA; TRI+AZO; CGA+AZO e TRI+CGA+AZO. Foi avaliada a germinação e plântulas anormais (%); comprimento da parte aérea, hipocótilo e raiz; diâmetro do hipocótilo; número de raiz; massa seca da parte aérea e raiz, e a relação raiz/parte aérea. Os resultados evidenciaram que: os tratamentos não influenciaram a germinação; o bioestimulante e Azospirillum brasilense isolados ou em associação proporcionaram incrementos no desenvolvimento inicial de plântulas de trigo, e o triadimenol isolado ou associado com bioestimulante ou A. brasilense proporcionou menores valores de comprimento da parte aérea, hipocótilo, raiz e número de raiz, independente da cultivar testada.Termos para indexação: germinação, reguladores, triadimenol, Azospirillum sp., T. aestivum L.Physiological quality of seeds of three wheat cultivars for different treatments ABSTRACT -The objective of this study was to evaluate the physiological quality of wheat seed treated with plant growth regulators, triadimenol and Azospirillum brasilense. The experimental design was completely randomized with four replications in a 3x8factorial: three wheat cultivars and eight seed treatments. The cultivars used were CD-150, CD-116 and CD-104, and the treatments were a combination of three different substances: 150 g.L -1 triadimenol (TRI), 90 mg.L -1 kinetin + 50 mg.L -1 giberellic acid + 50 mg.L -1 indolebutyric acid (CGA) and strains Ab-V5 and Ab-V6 of A. brasilense at a concentration of 2.0 x 10 8 viable cells mL -1 (AZO), as follows: control, TRI, CGA, AZO, TRI+CGA, TRI+AZO, AZO+CGA and TRI+CGA+AZO. Germination and abnormal seedlings (%), shoot and hypocotyl length and the diameter, length and number of roots, dry weight of shoot and root/shoot were determined. The results showed that: the treatments did not affect seed germination; the treatments did not increases the early development of wheat seedlings and triadimenol alone or in combination with A. brasilense plant growth regulator resulted in lower values for shoot, root and hypocotyl length and root number for all the cultivars.

Abstract:The objective of this work was to evaluate the removal of Cu 2+ and Zn 2+ in water by means of the adsorption process using three biosorbents derived from jatropha biomass (bark, endosperm and endosperm + seed coat). The experiments were performed in batch and evaluated the effect of solution pH, adsorbent mass, contact time, different initial concentrations of the metals Cu 2+ and Zn 2+, and the temperature of the solution during the adsorptive process. By kinetics, the adsorption isotherms and thermodynamics the mechanisms that control the adsorptive process were evaluated. The optimal conditions for the realization of the adsorptive process for both metals were: solution pH of 5.0 and 8 g L -1 of adsorbent mass per volume of solution, with a contact time between adsorbent and adsorbate of 60 min. According to the Langmuir model, the maximum adsorption capacities for the bark, endosperm and endosperm + seed coat of Jatropha were, respectively, for Cu 2+ 11.541, 20.475 and 22.910

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Achieving high productivity in agriculture is increasingly needed and requested; however, this activity should be performed in a sustainable and rational way. The use of micronutrients in the fertilization of the most diverse cultures is becoming a common practice on farms, but it is important to conduct studies in relation to fertilizers used for this supplement, including raw materials with which they are produced. Therefore, this study aimed to evaluate the phytoavailability of nutrients and toxic heavy metals Cd, Pb, and Cr; productivity; and yield components in wheat sown in soil with residue of N/P 2 O 5 /K 2 O+Zn-based fertilizer applied in previous crop. Treatments consisted of residual fertilization of five forms arranged in two doses (D1=300 kg ha −1 and D2=600 kg ha −1 ). The five types of fertilization were composed of formulated N/P 2 O 5 /K 2 O and the variation of different Zn sources. In the assessment of phytoavailability were determined levels of K, Ca, Mg, Cu, Mn, Zn, Fe, Cd, Pb, and Cr in wheat leaves. The results show that the residual effect of fertilization was not enough for there being difference between treatments at both doses used; however, it was found that the fertilizers used to Zn supply provided residual effect, providing significant levels of Pb and Cr for wheat plants.

RESUMOO correto incremento da produtividade agrícola deve estar aliado ao avanço tecnológico no conhecimento das exigências nutricionais de cada cultura, proporcionando, dessa forma, o correto uso de insumos na propriedade agrícola. Com o objetivo de estudar a resposta de plantas de soja ao zinco (Zn) em relação a diferentes doses de fósforo (P) e potássio (K), foi realizado este experimento no município de Palotina-PR. O solo foi classificado como Argissolo Vermelho-Amarelo eutrófico. Os tratamentos foram arranjados em esquema fatorial 3x3, constituindo três formas de adubação com P 2 O 5 e K 2 O: sem adubação, uma vez e duas vezes a recomendação de adubação pela análise de solo e três doses de Zn (0; 2 e 4 kg ha -1 ). Como fonte de nutrientes, foram utilizados fosfato bicálcico para P, cloreto de potássio para K e sulfato de zinco para Zn. As doses de Zn aplicadas não influenciaram, significativamente, a produtividade, não sendo justificada a sua suplementação na forma de adubação de base. Já a adubação com P 2 O 5 e K 2 O provocou significativo aumento da produtividade e aumento do número de legumes por planta, com aumento das doses desses nutrientes no solo. Termos para indexação:Glycine max, produção, adubação, micronutriente, macronutrientes. ABSTRACTThe correct productivity increment must be allied to the technological advance in the knowledge of the nutritional requirements of each culture, thus allowing for the correct use of the inputs in the agricultural property. With the objective of studying the plants of soybean reply to zinc (Zn) in relation to the different doses of phosphorus (P) and potassium (K), this experiment was performed in the municipality of Palotina-PR. The soil was classified as typic hapludalf. The treatments were arranged in a 3x3 factorial scheme, constituting three fertilization forms with P 2 O 5 e K 2 O: without fertilization, recommended dose and twice the recommended fertilization dose by the soil analysis and three Zn doses (0; 2 and 4 kg ha -1 ). Nutrient sources used were bicalcic phosphate for P, potassium chloride for K and zinc sulphate for Zn. The applied Zn doses did not significantly influence productivity, so supplementing the base fertilization form is not justified. On other hand, fertilization with P 2 O 5 e K 2 O resulted in a significant increase in productivity and an increase in the number of legumes per plant, with an increase of the doses of these nutrients in the soil.