The area of interest is the synthesis and study of properties of new types of hydrogels made from pelt waste, in order to recover waste from tanneries. Leather processing in tanneries results in about 500-600 kg of pelt waste from a ton of raw hides. These hydrogels are made using smart processes in order to then be applied in agriculture, for preservation of water in the soil or for controlled release of fertilizers, pesticides but also for the development of additivated agricultural film biodegradable over time (between 1 month and 6 months). Hydrogels that are based on biopolymers, compared with hydrogels based on synthetic polymers, have the advantage of biodegradability, biocompatibility, and a low level of toxicity. The paper presents the production of biodegradable polymer mixtures obtained from hydrolysis and enrichment of the resulting hydrolysate with phosphorus and potassium. Hydrogels with collagenous structure are tested using a high-performance instrumental analysis system (FT-IR-ATR, UV-Vis-NIR, SEM, EDAX, etc). The paper presents an experimental model for obtaining hydrogels with collagenous structure from pelt waste resulting from the liming process.

Siliceous natural nanomaterials (SNNMs), i.e., diatomaceous earth and natural zeolites, have a nanoporous structure with large active surfaces that adsorb cations or polarized molecules. Such nanoporous feature determines the effects related to SNNM utilization as low-risk plant protectants and soil improvers. This work used SNNMs from Romanian quarries as carriers for foliar fertilizers applied to stone-fruit trees, apricot and peach. We determined the effects of SNNMs on the physiology, yield and fruit quality of the treated stone-fruit trees. SNNM application determined impacts specific to the formation of particle films on leaves: reduced leaf temperature (up to 4.5 °C) and enhanced water use efficiency (up to 30%). Foliar fertilizers’ effects on yield are amplified by their application with SNNMs. Yield is increased up to 8.1% by the utilization of SNNMs with foliar fertilizers, compared to applying foliar fertilizer alone. Diatomaceous earth and natural zeolites promote the accumulation of polyphenols in apricot and peach fruits. The combined application of SNNMs and foliar fertilizer enhance the performance of peach and apricot trees.

Iron chlorosis represents a physiological phenomenon with negative impact on the quality and quantity of grape production in the vineyards. The bicarbonates are considered to be the main group of compounds which immobilize the iron in the soil in forms not assimilable by the plants. The grape production in conditions of iron deficiency can be improved significantly by applying foliar fertilizers. The best result in mitigating the effects of iron deficiency were obtained by the application of the fertilizers which, in addition to a complex mineral composition, also have a content of organic matter in the form of humic substances or protein hydrolysate.

ABSTRACT. This paper addresses the priority area of greening tanneries by recovering hide waste as fertilizing biocomposites. The paper presents the development of protein biofertilizers and their application in agriculture for plant growth and remediation of nutrient-poor soil. The aim was to obtain protein biofertilizers and apply them to soybean crop having the effect of stimulating the metabolism, speeding the productive phase, stimulating the defense system of the plant. We also obtained healthy plants and increases in production quality upon application of fertilizing biocomposites based on collagen hydrolysate. The highest increase of production was recorded for variants to which the protein biofertilizer was applied before sowing. KEY WORDS: pelt waste, protein biofertilizer, soil, soybeans OBTINEREA UNUI BIOFERTILIZATOR PROTEIC SI APLICAREA ACESTUIA PE SOL DEGRADAT CULTIVAT CU SOIA REZUMAT. Lucrarea abordeaza domeniul prioritar de ecologizare a tabacariilor prin valorificarea deseurilor de piei ca biocompozite fertilizante. În lucrarea de fata se prezinta obtinerea de biofertilizatori proteici si aplicarea acestora în agricultura pentru cresterea plantelor si remedierea solurilor sarace în substante nutritive. S-a urmarit obtinerea unor biofertilizatori proteici care s-au aplicat ulterior la cultura de soia având ca efect stimularea metabolismului, grabirea fazei productive, stimularea sistemului de autoaparare al plantei. De asemenea, s-au obtinut plante sanatoase si sporuri de productie de calitate superioara la aplicarea biocompozitelor fertilizante pe baza de hidrolizat de colagen. Cel mai mare spor de productie s-a obtinut la variantele la care s-a aplicat biofertilizatorul proteic înainte de însamântare.

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