Short-rotation willow coppice (or SRWC) is an innovative biomass feedstock based on the cultivation of shrub willow varieties using conventional agricultural methods. The growth vigor demonstrated by these shrub varieties enables a stem harvest every two to three years over the 25 year life span of the crop. An annual harvest is therefore possible after establishing willow cuttings over a two to three year period.
Mechanized planting of willow cuttings is done from April to June at a density of 15 000 to 16 000 cuttings per hectare. A preliminary harrowing of the soil must be done down to six inches to maximize root development and consequently the survival rate of cuttings. In the fall, a cutback of the shrubs is performed to induce stem multiplication the following spring. An effective mechanical and/or chemical control of weeds is critical during the establishment year in order to minimize the length of time it takes for the plant to achieve its maximum annual yield increment.
SRWC does not require the intensive use of fertilizers and pesticides. Fertilization requirements are lower than annual cash crops and the operation is performed only during the first year of each growth cycle. Herbicide application is generally limited to the first two years of a plantation, since the vegetal canopy provides effective weed control afterwards. Insect damages are mostly observed on new sprouts rather than old stands. Again, field inspections and timely interventions are critical during the first two years of a plantation.