Composted Turkey Litter: II. Effect on Plant Growth

Abstract Cotoneaster dammeri C.K. Schneid. ‘Skogholm’ and Hemerocallis sp. ‘Red Magic’ plants were potted into a pine bark substrate amended with 0, 4, 8, 12, or 16% (by vol) composted turkey litter and were grown under 1-, 2-, or 3-day irrigation frequencies. Root dry weight of ‘Red Magic’ daylily plants decreased with increasing compost rate while leaf dry weight was not affected by compost addition. Photosynthesis and stomatal conductance of daylily plants were enhanced when compost was added to the substrate but were decreased by the water stress associated with the reduced irrigation frequencies. Leaf, stem, and root dry weights of ‘Skogholm’ cotoneaster plants decreased with decreasing irrigation frequency. Even though compost increased container capacity and available water, there was not sufficient water in the container to maintain optimal growth under reduced irrigation frequencies. ‘Skogholm’ cotoneaster leaf and stem dry weights increased with increasing compost rate while root dry weight decreased with increasing compost rate. Decreasing irrigation frequency increased foliar N, P, K, Cu, and Zn concentrations but decreased foliar P, K, Ca, Mg, Mn, Cu, Zn, and B contents. Increasing compost rate increased foliar N, P, Mg, Mn, Cu, Fe, and B concentrations and foliar N, P, Mg, Mn, Cu, Fe, and B contents. Based on foliar nutrient response and plant growth, it appeared that compost adequately replaced the dolomitic limestone, micronutrients, and macronutrients added to the commercial substrate.