| pubs.notes | Abstracst -
For several decades, there has been environmental pressure against extracting peat for horticultural use. Peat is a key component of soil-free substrates in the greenhouse and nursery industry. However, the increasing expense of peat, negative impacts of peat mining on wetland ecosystems, and growing perception of peat havesting as unsustainable have led to an investigation for alternatives. In this study, New Zealand peat was compared to European peat in terms of its physical and hydraulic properties. A series of laboratory tests were conducted, including bulk density, gravimetric water content, particle density, porosity, saturated hydraulic conductivity and water retention to assess if New Zealand peat can be improved to the quality of European peat. Several additives (includes bark, coir, baled peat, zeolite, sphagnum moss and “Int. peat”) were selected to mix with New Zealand peat up to 10% by volume, to improve physical properties and structure. Also, a novel methodology is developed for wetting the peat materials until near saturation gradually to determine optimum water holding capacity under a horticultural setting. In conjunction with tension table measurement, a water retention curve for each treatment tells which treatment is more aligned with European peat’s physical and hydraulic properties. The result shows New Zealand peat with 10% bark, coir, sphagnum moss, zeolite have similar hydraulic properties to European peat resulting in comparable water holding capacity. The additives of bark, coir, sphagnum moss and zeolite with New Zealand peat were tested under three trials for mushroom production. Trial data showed that with bark and sphagnum moss amendment in NZ peat, mushroom yield increases. It was concluded that a replacement of 10% volume of peat, sphagnum moss and zeolite can improve the physical properties through changes in structure and particle density. | |
