Synthesis and evaluation of a superabsorbent-fertilizer composite for maximizing the nutrient and water use efficiency in forestry plantations

Growth promotion and protection from drought in Eucalyptus grandis seedlings inoculated with beneficial bacteria embedded in a superabsorbent polymer

“…A good quality bioinoculant should be able to promote effective contact of the PGPB with the host plant, protecting the added PGPB from the natural environment and the competing native microbial community; also, its application should be simple and cost-effective 39 . Our work shows that the superabsorbent polymer developed by our research group (SAPH 12 ), can be used as a vehicle to inoculate beneficial bacteria in the rhizosphere of eucalypt seedlings during transplantation. Moreover, the SAPH maintained the viability of the inoculum in soil for at least three months under laboratory conditions, which is the critical period for the establishment from greenhouses seedlings.…”

“…To assess the feasibility of using an acrylic-cellulosic superabsorbent polymer (SAPH 12 ) as a vehicle for the application of the selected strains, we tested the survival of bacterial cells when they were embedded in hydrated SAPH. We used cell suspensions of each strain containing 1 × 10 8 colony forming units (CFUs) per ml in distilled water, while control SAPH was hydrated with distilled water only.…”

“…Highly crosslinked acrylic-based SAPs have been shown to be very effective at reducing post-planting water deficit stress at an affordable cost and simple field application methodologies have been developed 9 – 11 . In particular, an acrylic-cellulosic superabsorbent composite (SAPH) has been employed in E. grandis seedlings in greenhouse trials, as well as in the field, and shown to be effective not only for water retention but also for nutrient delivery 12 .…”

“…In this work, we tested, as a PGPB carrier, a crosslinked acrylic-cellulosic superabsorbent composite (SAPH) which we have previously synthesized and shown to be effective for water retention and protection from drought stress and as a matrix for delivery of mineral nutrients when raising E. grandis seedlings, both in greenhouse trials and in the field 12 . We selected two bacterial strains with eucalypt growth-promoting characteristics and combined them with gelified SAPH in potted plant experiments in which we tested the performance of the gel-bacteria combination on the plant´s tolerance to two different intensities of drought stress.…”

Salt-Tolerant Superabsorbent Polymer with High Capacity of Water-Nutrient Retention Derived from Sulfamic Acid-Modified Starch

“…4 When SAPs are applied to soil, the soil surface water evaporation and water infiltration could be reduced, 5 and soil porosity and soil structural stability could be improved; 6 SAPs could also reduce soil bulk density, improve water use efficiency, and improve soil synchrony and carbon assimilation rate in the early stage of plant growth. 7 SAPs could also improve the utilization efficiency of granular fertilizer, 8,9 so that the absorbent polymers are also widely used in agriculture and forestry. Typically, water-absorbing polymers undergo swelling in three stages.…”