Bioenergy and Other Uses
The use of agricultural residues for energy, unless it occurs directly on-farm requires refineries, transportation and a distribution network. Nevertheless, especially with subsidies this method is becoming increasingly practiced at both the on-farm and regional level, and depends upon the development of local/national markets. Northern Europe, particularly Sweden has developed such an infrastructure over the past two decades, with biogas methane developed for transport and energy not only from straw and manure, but household waste. A bioenergy infrastructure does not currently exist or is not well developed in many developing country regions, although it is growing through a number of pilot projects.
Many of these involve production of pellets from stubble; including rice stubble, which is less usable for fodder and does not readily incorporate into the soil. The same holds for wood litter gathered from forest understory, which can only decompose slowly on the forest floor. Some additional investment is required both for equipment to produce the pellets, as well as to burn them (whether at the household level in cooking or heating stoves, or the larger town or district heating plants which have become a key component in EU low-carbon energy plans).
A number of academic and commercial start-ups, many of them associated with the Global Methane Initiative (GMI) and Global Alliance for Clean Cookstoves (GACC) have developed different systems that use straw, and/or biomass to produce bioenergy at the community level. The most effective systems seem to include both manure and stubble; and one of these is under active development in Punjab.
Other kinds of alternate use may be possible, in particular for rice straw given its more limited applicability for bedding and soil incorporation (below) due to its tough structure. IKEA of India has offered for example to develop ways to use rice straw in products such as bags; others have suggested use in brick manufacture; but these thus far appear to be in an early development stage.
An important consideration for both bedding/forage, bioenergy and other uses for straw and biomass is the need to leave at least some material on the fields or forest soil. Depending on the crop and soil conditions, research indicates that between 20-60% of straw or other biomass materials should remain, in order to allow for continued soil fertility and humus levels.
Bedding and Fodder
Alternative agricultural uses require livestock, either on-farm or within the community or region, with a readily available market for straw use. Many developing country regions without the need for winter silage rely on natural grasslands and pastures for animal feedstock, but these grasslands are also subject to annual open burning and education of farmers on the need for rotation and regeneration without burning is key.
Better, more appropriate technology, tools, and machinery represent the closest and easiest steps to re-incorporate this traditional harvest of straw for on-farm needs, avoiding disincentives. For example, recent changes to the list of combines available for subsidy in Nepal resulted in burning being introduced there for the first time, as the “improved” subsidized combine left stubble too high for harvest. Departure of male farm labor for paying jobs overseas, particularly in the Middle East; and a fear of rats and snakes in the higher stubble also contributed to increased burning practices. This disincentive also resulted in new costs for bedding and forage previously supplied by the stubble.