Evaluation of Cow Peat as a Plant Growth Media

摘要

Almost 63% of non-CO2 greenhouse gases, mostly methane and nitrous oxide, are produced by the agricultural industry. As Livestock waste lagoons are designed to prevent the nutrient transport and treat manure, they are major contributors to the release of these non-CO2 greenhouse gases. They have to be controlled and one such way is to harness these gases by implementing anaerobic digestion. Anaerobic digestion of livestock waste has shown very good potential but, handling of digested solid end products require extensive management. One potential option is to recover fiber from the solid digestate to make a cow peat plant growth material.;Peatlands are one of the most important natural ecosystems in the world which have key values for biodiversity conservation, climate regulation and support welfare, water regulation in drylands, acts as an enormous carbon sink and also an agricultural land. But overexploitation of peatlands has led to adverse effects on the environment. Peat mosses have well defined lignified cell structure as a soil material which makes them perfect media for plant growth. All these degradations and its effects have made peat extraction unsustainable and so search for alternatives have begun over the last decade.;The fiber components of digested dairy manure (Cow Peat) have been evaluated by researchers as a suitable substitute for peat moss along with many other products such as biochar, rice husk, wheat straw, sewage waste, potato waste etc. Results have shown that the cow peat has similar physicochemical properties to peat moss and so, they have been widely used in the horticulture and floriculture industries as a replacement for peat moss.;In this study, we assessed the potential to recover cow peat from a novel multi-stage anaerobic digester that processes high solids content manure. Edible crops were grown in the digestate and cow peat for the first time, as they have been already proven in the other industry such as the growth of perennial plants, strawberries, bedding plants etc. The study has been carried out in two trails without nutrient amendment. The first experiment was conducted with bean plants and 6 soil mixes with digested manure. The performance was compared with commercially available soil mixes including peat moss. The best performing soil mixes were utilized in a second experiment assessing two more plant types, beet, and lettuce.;The results of both the experiments have revealed that digested manure (well composted digested manure solids) and fiber (component separated from manure solids by fractionation) component has produced plants with significantly similar (p > 0.05) shoot dry mass and root structure as commercially available plant media. The digested dairy fiber contains a significant amount of nutrients for the plant to germinate. Carbon/Nitrogen ratio was higher than recommended range and so may have had an adverse effect on pH and reducing the availability of micronutrients. Results demonstrate the potential for anaerobically digested fiber to replace peat moss as plant growth media providing growers with a local, renewable substitute for peat and a supplemental income for animal farm operators.;Key Words: Non-CO2 Greenhouse gases, Peatlands, Peat, Anaerobic Digestion, Digested Fiber, Plant media.