Matrix-Based Fertilizers Reduce Nutrient Leaching While Maintaining Kentucky Bluegrass Growth.

We tested the efficacy of matrix-based fertilizers (MBFs) to improve Kentucky bluegrass ( Poa pratensis L.) growth while reducing NH, NO₃, dissolved reactive phosphorus (DRP), and total phosphorus (TP) compared to commercial slow-release fertilizer (SRF) Polyon®, ESN®, and Avail® in greenhouse column studies. The MBFs covered a range of inorganic N and P in compounds that are relatively loosely bound (MBF6) and more tightly bound compounds (MBF7) with Al(SO₄)₃18H₂O and/or Fe₂(SO₄)₃3H₂O and with high ionic exchange compounds starch, cellulose, and lignin. The total amount of NO₃ and NH₄ leached was greater from columns receiving Polyon® and ESN® fertilizers than all other treatments. The MBF6+Avail® or MBF7+Avail® fertilizers leached 64–68% less NO₃ than Polyon® (43-0-0) and ESN® (46-0-0), and 73–76% less TDP and TP than Avail® (10-34-0). A greater amount of NO₃ was leached from the MBF6+Avail® and the MBF7+Avail® treatments than the other MBF fertilizer treatments. Shoot and root biomass were greater when plants received the Avail ®, MBF6+Avail®, and MBF7+Avail® fertilizer treatments than the other fertilizer treatments. When combined with small quantities of commercial SRFs, these new MBFs were able to maintain plant growth while reducing N and P leaching. These new MBF formulations do not depend on organic or inorganic coatings to reduce N and P leaching and with further testing and development could be effective commercial fertilizers. [ABSTRACT FROM AUTHOR]