Local autonomous power supply systems are generally limited to stationary applications which, although of vital importance to farm mechanization, still represent a considerably smaller fraction of total energy than that used in mobile mechanization systems powered by tractors and other engine-driven vehicular equipment.
Soil tillage systems are predominantly concerned with the provision of an adequate seedbed to accommodate the subsequent crop seeding or planting operation and to provide an optimum environment for seed germination, plant establishment and vigorous crop growth. Traditional tillage systems involved breaking the soil crust with a human or animal powered implement or plow pushed or pulled through the soil.
Human and animal powered mechanization systems (Figures 2 and 3) are described in detail in Human and Animal Powered Machinery, EOLSS on-line, 2002. The drudgery, long hours and low pay typically associated with these systems make rural life in the developing countries an unattractive career for young men and women.Examples include herbicide application based on sensed soil organic matter content, and anhydrous ammonia application in growing maize based on sensed soil nitrate level. This is a complex technology that requires a major investment in research and development. The pay-off will derive from the savings accrued due to lower use of expensive agrochemicals, environmental protection and sustainability.The concept of timeliness recognizes that there is an optimum time to perform certain crop production operations from planting through to harvesting. If one or more of these operations is performed too early or too late, a timeliness penalty is likely to accrue, that is, yield and/or the quality of the crop is diminished, yielding a lower price to the farmer. For example, the ideal time to harvest grain is when the crop is ripe and the moisture is low (see also, Maintaining Working Conditions and Operation of Machinery).
However, although the renewable alcohols can be produced from agricultural byproducts (cereal straw, sugarcane bagasse) the economics are even more unfavorable given the complex manufacturing process that includes fermentation and distillation.