Farming strategies to fuel bioenergy demands and facilitate essential soil services

Perennial lignocellulosic biomass and food crop residues have traditionally been important resources used internally on-farm. However given the growing outlook with advanced biofuel conversion technologies, such biomass sources might be of competing greater value if sold off the farm into the bioenergy feedstock stream. Inputs of carbon embedded in above-ground plant biomass are a key biological energy source for the soil surface a zone of great importance in the success of food-feed-fiber production and ecological processes essential to environmental quality. This review of literature looks at how above-ground plant biomass contributes to soil properties and processes, water conservation and quality, on-farm forage availability, and as a harvestable biofuel component. Competing needs for this resource could cause serious environmental or economic consequences without sufficient knowledge of their potential impacts. Perennial forages and crop residues are critical for providing surface cover to protect soils against erosion and for providing the organic inputs to support below-ground ecosystem communities, properties, and processes. The amount of biomass required to maintain soil organic matter and various ecosystem services linked to this key soil property may, in many cases, exceed that needed for simple erosion control. Consequences of continuous residue harvest could be detrimental or minor, depending on the climatic and edaphic conditions, as well the type of cropping system and tillage management employed. Achieving a balanced outcome will require scientific evidence of in-field effects, a collective vision for designing landscapes of appropriate functional capacity, and well-designed government policies for crop residue and perennial biomass utilization schemes to contribute to a sustainable agricultural approach. Published by Elsevier B.V.