Acrylate polymers as a novel method to deliver nutrients and enhance fertilizer and water efficiency in forestry

ESTEBAN TUBERT; VICTORIA VITALI; GABRIELA AMODEO

Iguazu

Congreso; International Congress of plant Molecular Biology; 2015

Reducing fertilizer use is one of the high-priority targets in the quest for sustainable agroforest systems. Currently, synthetic superabsorbent polymers (SAPs) are widely used to improve water efficiency by retaining moisture nearby the roots in tree species. In the present study we assessed the sustainability of Eucalyptus grandis seedlings supplied with a high molecular weight superabsorbent polymer (SAP) which was used as a vehicle of a nutrient formulation which comprises small amounts of macro and micronutrients (tBAL). As a first approach to evaluate the effects of the polymer-nutrients mix (SAP + tBAL), stomatal conductance (gsSC) and growth parameters (i.e. height, biomass, leaf area) were measured on greenhouse experiments evidencing that SAP is adequate to deliver nutrients while maintaining its drought protection ability. Likewise, under limited watering conditions the SAP + tBAL mix produced an increase in biomass and height compared to standard NPK fertilization in pellet form. In-field experiments revealed that the hydrated polymer as a carrier of specific nutrients resulted in a significant reduction of fertilizer requirements at least until 150-200 days after plantation. Moreover, plants treated with both the conventional superficial fertilizer as well as with the injected formula (SAP + tBAL), showed increased growth parameters. In summary, our results could be used to re-design current forestry fertilizing systems by promoting the combination of available SAPs and specific nutrient molecules which could be used in small amounts, contributing, as well, to a reduction in water requirements. This method could also be useful to deliver other type of molecule of interest, such as agrochemicals and growth promoters, contributing to a more sustainable forest land management.