RT info:eu-repo/semantics/article T1 Synthesis and characterization of a stable humic–urease complex: application to barley seed encapsulation for improving N uptake A1 Mvila, Beaufray Gilaime A1 Pilar Izquierdo, María Concepción A1 Busto Núñez, Mª Dolores A1 Pérez Mateos, Manuel A1 Ortega Santamaría, Natividad K1 Enzyme immobilization K1 Nitrogen availability K1 Plant growth K1 Seed coating K1 Seed encapsulation K1 Soil urease K1 Bioquímica K1 Biochemistry K1 Agricultura K1 Agriculture AB BACKGROUNDMost N fertilizers added to soil are not efficiently used by plants and are lost to the atmosphere or leached from the soil, causing environmental pollution and increasing cost. Barley seed encapsulation in calcium alginate gels containing free or immobilized urease to enhance plant utilization of soil N was investigated.RESULTSUrease was immobilized with soil humic acids (HA). A central composite face-centered design was applied to optimize the immobilization process, reaching an immobilization yield of 127%. Soil stability of urease was enhanced after the immobilization. Seed encapsulation with free urease (FU) and humic–urease complex (HUC) resulted in a urease activity retention in the coating layer of 46% and 24%, and in germination rates of 87% and 92%, respectively. Under pot culture conditions, the pots planted with seeds encapsulated with FU and HUC showed higher ammonium N (NH4+-N) (26% and 64%, respectively) than the control soil at 28 days after planting (DAP). Moreover, the seed encapsulation with FU and HUC increased the N uptake 83% and 97%, respectively, at 35 DAP.CONCLUSIONSeed encapsulation with urease could substantially contribute to enhancing plant N nutrition in the early stages of seedling establishment. PB Society of Chemical Industry SN 0022-5142 YR 2015 FD 2015-09 LK http://hdl.handle.net/10259/8264 UL http://hdl.handle.net/10259/8264 LA eng NO We thank the ‘Ministere de L’Enseignement Superieur de laRepublique du Congo’ for a fellowship awarded to BG Mvila. DS Repositorio Institucional de la Universidad de Burgos RD 23-nov-2024