ABSTRACT The work was intended to evaluate the effect of different organic compounds originating from the mixture of agroindustrial and urban wastes, as well as their doses in the physiology and production of cowpea. The experiment was conducted under a randomized block design, in a 4 x 5 + 2 factorial arrangement, with four organic fertilizers (3 composed obtained from of sewage sludge, green coconut shell, carnauba butt; and sewage sludge biochar), five doses (20, 40, 60, 80 and 100 t ha-1) and two additional treatments (without fertilization and mineral fertilization). We evaluated the leaf gas exchange in three phenological stages and the productive aspects. Regarding the physiological variables, the compounds with carnauba butt and green coconut shell promoted the best results and throughout the crop cycle, the gas exchange decreased. The productive aspects were increased by about 60%, especially due to the treatments with organic compounds. The PCA can confirm the univariate results, with emphasis on compounds with green coconut shell and carnauba butt. The high percentage of explanation found in axis 1 (60.49%) may be associated with the fact that the gas exchange and production variables are highly responsive to fertilization. The treatment with biochar caused a reduction in both in the physiological and in the productive aspects. The compounds with carnauba tip and green coconut shell promote satisfactory results, being viable alternatives to complement chemical fertilization with an indicated dose of 300g pot-1 or 60 t ha-1.

ABSTRACT The use of organic waste for the production of plant substrates is an important environmental and economic alternative. In this perspective, we performed a work in a greenhouse, with the aim of evaluating the effect of substrates from organic waste during growth, gas exchange and accumulation of mineral elements in ‘Sunrise Solo’ papaya tree seedlings. The experimental design adopted was completely randomized, with four treatments and five repetitions, with six plants in each repetition. The treatments consisted of four types of substrates, three from the composting of sewage sludge, green coconut shell and carnaubeira palm butt, and one was the Turfa Fértil® commercial. We evaluated biometric and physiological variables and accumulation of nutrients and heavy metals in papaya seedlings. The green coconut shell and carnaubeira palm butt substrates promoted superior results for growth, dry biomass, gas exchange and accumulation of nutrients, whereas the commercial substrate and sewage sludge produced seedlings of inferior quality considering all the analyzed variables.

RESUMEN El objetivo de este estudio fue evaluar el efecto de diferentes dosis (0,10, 20, 30, 40 y 50 t ha-1) de fibra de coco verde en sustrato de crecimiento sobre el desarrollo temprano y la fisiología de dos cultivares de soya (Pampeana 40RR y Pampeana 60RR). El experimento se llevó a cabo en un invernadero utilizando un diseño experimental completamente al azar en un arreglo factorial de 2x6 (dos genotipos y seis dosis) con cinco repeticiones. Cada repetición estuvo formada por una planta, totalizando 60 unidades experimentales. Se evaluaron variables biométricas (altura, número de hojas, diámetro del tallo, área foliar y masa seca) y fisiológicas (fotosíntesis, conductancia estomática, transpiración, carbono interno, eficiencia en el uso del agua y pigmentos fotosintéticos). Después de obtener los datos, a los 30 d después de la siembra, las medias fueron sometidas a análisis de varianza y, cuando fueron significativas según la prueba F, fueron sometidas a análisis de regresión y comparación de medias por la prueba de Tukey. A través del análisis de regresión, fue posible calcular la dosis mínima ideal para cada variable. Se observó un aumento en la altura de la planta, el diámetro del tallo, el número de hojas, el área foliar, la masa seca de hojas, masa seca de tallo y masa seca de raíces de alrededor de 51.10%, 31.60%, 52.83 %, 61.78%, 79.65%, 81.52%, y 6.06%, respectivamente, cuando comparamos los valores de las dosis mínimas con los puntos máximos encontrados en cada variable. En cuanto al intercambio de gases, el cultivar 60 RR fue superior al cultivar 40 RR. En conclusión, el compuesto de fibra de coco verde influyó positivamente en el crecimiento y fisiología de los cultivares, obteniendo la mejor respuesta con la dosis de 30 t ha-1.

ABSTRACT This study aimed to evaluate the effect of different doses (0, 10, 20, 30, 40, and 50 t ha-1) of green coconut fiber in growth substrate on the early development and physiology of two soybean cultivars (Pampeana 40RR and Pampeana 60RR). The experiment was carried out in a greenhouse using a completely randomized experimental design in a 2x6 factorial arrangement (two genotypes and six doses) with five replicates. Each replicate was made up of one plant, totaling 60 experimental units. Biometric variables (height, number of leaves, stem diameter, leaf area, and dry matter) and physiological variables (photosynthesis, stomatal conductance, transpiration, internal carbon, water use efficiency, and photosynthetic pigments) were evaluated. After obtaining the data 30 d after sowing, the means were subjected to an analysis of variance and, when significant for the F test, they were subjected to regression analysis and comparison of means by the Tukey's test. Through the regression analysis, the ideal minimum dose for each variable could be calculated. We observed an increase in plant height, stem diameter, number of leaves, leaf area, leaf dry mass, stem dry mass, and root dry mass of around 51.10%, 31.60%, 52.83%, 61.78%, 79.65%, 81.52%, and 6.06%, respectively, when we compared the values of the minimum doses with the maximum points found in each variable. Regarding the gas exchange, cultivar 60 RR was superior to cultivar 40 RR. In conclusion, the green coconut fiber compound had a positive influence on the growth and physiology of the cultivars, with the best response being obtained at the dose of 30 t ha-1.

RESUMO O estudo de cultivares de moderada tolerância ao alagamento é primordial para sua utilização na irrigação de pastagens com águas salinas. Objetivou-se avaliar a composição química do capim Panicum maximum cv. BRS Zuri sob o efeito de diferentes lâminas de água e níveis de salinidade. Utilizou-se delineamento em blocos casualizados com parcelas subdivididas com cinco repetições por tratamento. Os tratamentos foram resultantes da combinação de três níveis de salinidade na água (S1 = 0,6; S2 = 1,8; S3 = 3,0 dS m-1) e quatro intensidades de irrigação (I1 = 60; I2 = 80; I3 = 100; I4 = 120% da evapotranspiração). Avaliou-sea composição química do capim Panicum maximum cv. BRS Zuri, cortado aos 28 dias, durante dois ciclos.Houve interação entre os fatores (salinidade x lâmina x ciclo) para os teores de matéria seca (MS). Com o aumento das lâminas de irrigação, houve redução linear nos teores de proteína bruta (PB) nos dois ciclos. O teor de fibra em detergente neutro (FDN) ecelulose (CEL) aumentaram linearmenteem função das lâminas de irrigação, já os teores de lignina (LIG) reduziram linearmente com as lâminas de irrigação. Concluiu-se que os níveis elevados de salinidade causam reduções nos teores de matéria seca, em resposta ao aumentona disponibilidade hídrica e no prolongamento dos ciclos da cultivar. A redução dos níveis salinos sob baixa disponibilidade hídrica proporciona maiores teores de PB. A salinidade afeta negativamente os teores de FDN, FDA, HEM, CEL e LIG com o aumento das lâminas de irrigação.

ABSTRACT The study of cultivars with moderate flood tolerance is essential to their use in pastures irrigated with saline water. The aim of this study was to evaluate the chemical composition of Panicum maximum ‘BRS Zuri’ under the effect of different irrigation depths and levels of salinity. A randomised block design of split plots was used with five replications per treatment. The treatments resulted from the combination of three levels of water salinity (S1 = 0.6, S2 = 1.8 and S3 = 3.0 dS m-1) and four levels of irrigation (I1 = 60%, I2 = 80%, I3 = 100% and I4 = 120% of the evapotranspiration). The chemical composition of the grass, Panicum maximum ‘BRS Zuri’, cut at 28 days, was evaluated over two cycles. There was an interaction between the factors (salinity x irrigation depth x cycle) for the dry matter (DM) content. With the increase in irrigation depth, there was a linear reduction in the crude protein (CP) content in both cycles. The neutral detergent fibre (NDF) and cellulose (CEL) content increased linearly as a function of the irrigation depth, while the lignin (LIG) content decreased linearly with irrigation depth. It was concluded that high levels of salinity cause reductions in the dry matter content in response to increased water availability and extension of the cultivar cycles. The reduction in saline levels under low water availability results in a higher CP content. Salinity has a negative effect on the NDF, ADF, HEM, CEL and LIG content as the irrigation depth increases.

O cedro-australiano (Toona ciliata M. Roem var. australis) é uma espécie promissora para plantios comerciais em função da qualidade e ampla utilização da sua madeira e de seu alto retorno financeiro em um pequeno espaço de tempo. No entanto, são escassas as informações sobre o comportamento desta espécie em relação à acidez do solo. Nesse sentido, objetivou-se avaliar a influência de diferentes níveis de saturação por bases sobre o crescimento e a qualidade de mudas de cedro-australiano. A saturação por bases do substrato foi elevada para 21,3; 33,2; 47,9; 60,4 e 70,0%, através da adição de diferentes doses de calcário com teor de 12% MgO e 50% CaO (PRNT 95%) em vasos com capacidade para 3,5 dm3 que continham Latossolo Vermelho Distroférrico típico. Aos 120 dias após o transplantio foram obtidos: altura, diâmetro do coleto, matéria seca das raízes, parte aérea e total. Determinou-se, também, as relações altura/diâmetro do coleto, altura/matéria seca da parte aérea, matéria seca da parte aérea/matéria seca de raiz e o índice de qualidade de Dickson. As mudas de cedro-australiano respondem positivamente à elevação da saturação por bases. As respostas positivas das variáveis morfológicas analisadas apontam para a necessidade de se fazer a correção da acidez do solo elevando o nível de saturação por bases para 50%, no intuito de maximizar a produtividade da cultura.

The Australian cedar (Toona ciliata M. Roem var. australis) is a promising species for commercial plantations based on the quality and wide use of its wood and high financial returns in short time. However, there is little information about the behavior of this species in relation to soil acidity. In this sense, the objective of this study was to evaluate the influence of different base saturation levels on growth and quality of Australian cedar seedlings. The substrate saturation was raised to 21.3; 33.2; 47.9; 60.4 and 70.0%, by adding different doses of limestone content of 12% MgO and 50% CaO in vessels with capacity of 3.5 dm3 of a typical dystrophic Red Latosol (Oxisol). At 120 days after transplanting were obtained height, stem diameter, root dry matter, aerial parts and total. It was also determined the relationship height/stem diameter, height/aerial parts dry matter, aerial parts dry matter/root dry matter and Dickson's quality index. Australian cedar seedlings respond positively to the base saturation increase. The positive responses of morphological variables pointed to need to do the acidity correction increasing the level of saturation to 50 %, in order to maximize the crop yield.