Carlos Alberto Kenji Taniguchi

Macronutrients Use Efficiency and Phosphorus Exportation by Melon Plants in Response to Fertilization

This study aimed to evaluate macronutrients use efficiency and phosphorus accumulation, partition and partial balance in the melon hybrid Goldex F1, in response to mineral and organic fertilizers. The following fertilizations were evaluated: mineral fertilizer; bovine manure; bovine manure associated with mineral fertilizer; poultry litter; and poultry litter associated with mineral fertilizer. Plants were collected and separated into leaves, stem, and flowers and, when there were, unripe and ripe fruits for chemical analysis. Phosphorus accumulation increased along the melon crop cycle. Phosphorus partition between leaves + stems + flowers and unripe fruits + ripe fruits showed that about 80% of P was allocated to the fruits. The decreasing order of use by the plant was S > P > Mg > Ca > N > K. Only the treatment with poultry litter was within the range considered as adequate for P recovery. Mineral and organic fertilizers did not interfere with nutrient accumulation and P partition by the melon plants.

Yellow melon yield in response to mineral or organic fertilization

ABSTRACT Although current recommendations in Brazil suggest the application of mineral and organic fertilizers, there is little information regarding the interaction between them in melon plants. This study aimed to evaluate the effects of mineral and organic fertilization in the plant development, nutritional status, and fruit yield of yellow melon. The following fertilizations were evaluated: mineral fertilization; bovine manure; bovine manure associated with mineral fertilization; poultry litter; and poultry litter associated with mineral fertilization. Bovine manure and poultry litter were applied at rates equivalent to 15 m3 ha−1 and 5 m3 ha−1, respectively. Phosphorus and potassium were applied based on the results of the soil analysis and nitrogen based on the expected yield of 20 to 30 t ha−1 of fruits. Phosphate and organic fertilizers were applied at the time of preparation of the beds, while nitrogen and potassium were supplied daily through irrigation water. Goldex F1 melon hybrid seedlings were used in the experiment. Plants were collected to evaluate the dry matter production at beginning of flowering, beginning of fruiting, fruit growth, and fruit harvest. Leaves were collected at flowering stage to evaluate the nutritional status of plants. Harvest was made when the fruits reached the intense yellow coloration. Organic fertilizers alone and combined to mineral fertilizer did not affect the dry matter yield of leaves, stems, fruits and shoot, the concentrations of macro and micronutrients in melon leaves, the nitrogen accumulation in the plant, and the yield of the yellow melon. The application of bovine manure associated to mineral fertilization showed the lowest values of nitrogen recovery applied. Bovine manure application resulted in increase of nitrogen organic forms in soil.

The influence of the structural features of lignin-based polyurethane coatings on ammonium sulfate release: kinetics and thermodynamics of the process

The influence of the properties of lignin-based polyurethane (PU) coatings on the release behavior of ammonium sulfate was assessed through complete physicochemical, structural, and morphological characterization. The influence of the release medium was evaluated as well. The higher the amount of lignin in the coatings was, the lower the pore diameter and swelling degree and the higher crosslinking were. The hydrophobicity of coatings was not significantly changed by increasing the lignin content. However, the opposite behavior was observed for their biodegradability. The results of the nutrient release experiments showed that the two formulations of lignin-based PUs had very similar behavior in terms of release rates of NH4+ and SO42− in both release media, despite their different properties. However, there was a difference between their release rate constants obtained by using three different kinetic models. In addition, both PU coatings released a higher amount of SO42− than NH4+ in both media. The thermodynamic data suggest that dissolution and release processes for SO42− are more spontaneous than that for NH4+. Nevertheless, both coatings behaved in accordance with CEN standards for CRF systems, representing a potential technique for agricultural applications.

Evaluation of nutritional and chemical composition of yacon syrup using 1 H NMR and UPLC-ESI-Q-TOF-MS E

A complete characterization of yacon syrup was performed by analytical techniques, including NMR and UPLC-QTOF-MSE. The effect of the different stages of yacon syrup production on fructooligosaccharides (FOS) and chlorogenic acid (CGA) contents were also evaluated. As a result, in addition to higher levels of FOS and CGA, some mineral elements, such as K, Ca and P, and essential amino acids, such as tryptophan, valine, and threonine, were determined in yacon syrup. Twenty-five compounds were putatively identified, and the main compounds were phenolics derived from quinic and trans-cinnamic acids. Considering the different stages of yacon syrup production, the results indicate that the contents of FOS and CGA were maintained in the pulping, enzymatic maceration and microfiltration, leading to a concentration of these components in the last stage of processing (vacuum concentration). These results will be used to fortify this innovative and promising product in the area of functional foods.