Agronomy of the energy crops Miscanthus x giganteus, Arundo donax and Phalaris arundinacea in Wales.
mesheuropmc: food and beverages | fungi
For this study, the energy crops Miscanthus x giganteus, Arundo donax and Phalaris arundinacea were planted at sites across Wales. Non-destructive methods of estimating crop yields were developed the most significant relationship for Miscanthus was between mean shoot height and mean shoot dry weight, whereas for Arundo it was between mean shoot volume and mean shoot dry weight although these estimates were over-estimates of actual crop yield when scaled up to field size. Yield estimates were obtained from destructive sampling for Phalaris and these were shown to be under estimates of whole crop yield. Crop growth data were compared in relation to soil type, soil chemistry and climatic conditions. Soil clay content and soil preparation were identified as of utmost importance to Miscanthus and Arundo success, but had no effect on Phalaris crops. Both Arundo and Miscanthus showed sensitivity to air temperatures during the growing season. Delaying harvest of both crops produced material with decreased moisture and mineral content, although results were not significant in all cases. The nitrogen, phosphorus and potassium content of leaves were higher than that in the cane, and harvest following leaf abscission was recommended. Arundo did not senesce completely during the winter period, and produced harvested material with higher mineral content than Miscanthus. Both crops required further drying to meet moisture content requirements for combustion crops. Phalaris was the only crop to meet moisture content and mineral content threshold levels, although the results were not consistent across sites. Leaf chlorophyll content was significantly correlated to above ground plant mineral content. Organic and inorganic fertilisers were applied to the three crops, and produced no response in Phalaris. Both Miscanthus and Arundo increased growth in response to high phosphorus levels, and generally in response to high fertiliser applications. At recommended application rates cattle manure showed most effect.