Production of Sugarcane and Tropical Grasses as a Renewable Energy Source. First Annual Report, June 1, 1977-May 31, 1978

摘要

Tropical grasses from Saccharum and related genera are being evaluated as candidates for intensive production of solar-dried biomass. Categories of candidate grasses include short-, intermediate-, and long-rotation species for intensive co-production with conventional food commodities. Minimum-tillage candidates are also sought for extensive production on marginal lands. The hybrid forage grass Sordan 70-A (Northrup-King Company) is the outstanding short-rotation plant tested to date. It completes both the tissue-expansion and maturation phases within 10 weeks, yielding at least 4 tons of oven-dry biomass per acre. Napier grass (var. Common Merker) is a promising intermediate-rotation crop which possibly may be exceeded by several napier grass hybrids. Interspecific Saccharum hybrids and the Saccharum species S. spontaneum and S. sinense are being investigated for both long-rotation and minimum tillage cropping. Direct comparisons of sugarcane hybrids with napier grass indicate that sugarcane is an inferior candidate for short-term production of tropical forages. Sugarcane responded well to narrow spacing for about 6 months after seeding. Napier grass failed to respond to close spacing. Both species increased yields with decreasing frequency of harvest. Fertilization rates based on conventional sugar and forage production data were inadequate to sustain maximum biomass yields. Candidate grasses have shown two discrete biomass production phases, ie , tissue expansion which is highly visible but consists mainly of water, and tissue maturation which has little visibility but yields the bulk of the plants' dry matter. Additional progress was made in sugarcane growth control with chemical growth regulators. (ERA citation 04:052801)