|JEONG, KA YEON - The Ohio State University
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2018
Publication Date: 8/1/2018
Citation: Altland, J.E., Jeong, K. 2018. Initial substrate moisture content and storage temperature affect chemical properties of bagged substrates containing poultry litter fertilizer. HortScience. 53(8):1191-1196. https://doi.org/10.21273/hortsci13004-18.
Interpretive Summary: Bagged potting mixes are increasingly being sold with organic fertilizers premixed into the substrate. Organic fertilizers that are premixed into bagged potting mixes can release nutrients while the potting mix is stored in the bag. The objective of this research was to determine how moisture content of the potting mix and storage temperature affect nutrient release from an organic poultry litter fertilizer into the substrate while being stored in the bag. Poultry litter fertilizer provided a stable source of nitrogen in bagged potting mix over a range of moisture contents and storage temperatures (20 and 40 °C), with little change in total nitrogen released over time. These data show that the poultry litter fertilizer used in its commercially-available particle size, provided a suitable source of nutrients for bagged potting mixes subjected to prolonged storage before use.
Technical Abstract: Bagged potting mixes can be stored for weeks or months before being used by consumers. Some bagged potting mixes are amended with organic fertilizers such as poultry litter, although there is little knowledge about how these and other organic fertilizers release in the substrate while in storage. The objective of this research was to determine nutrient availability from an organic poultry litter fertilizer in a bagged potting substrate stored at different temperatures and with varying initial moisture content (IMC). The base substrate composed of 60 sphagnum peat : 30 bark : 10 perlite (by vol.) amended with 5.5 g·L-1 dolomitic limestone and 0.5 g·L-1 granular wetting agent. This base substrate was either not amended with additional fertilizer [non-fertilized control (NFC)], or amended with a poultry litter fertilizer (microSTART60, 3N-0.9P-2.5K) in its original pelletized form (PL-P) or ground (PL-G), or an uncoated prill fertilizer (UPF, 15N-6.5P-12.5K). Substrates had initial moisture contents (IMC) of 25%, 45%, or 65% and were stored at either 20 or 40 °C. Poultry litter particle size had no effect on any of the measured chemical properties of the stored substrates. Both PL fertilizer treatments resulted in pH similar to or lower than the NFC. The two PL fertilizers had higher EC throughout the experiment (1.59 to 2.76 mS.cm-1) than NFC (0.13 to 0.35 mS.cm-1). Poultry litter fertilizer provided a stable source of N in bagged potting mix over a range of IMC and storage temperatures, with little change in total N released over time.