High technology biomass production by Salix clones on a sandy soil in southern Sweden

An investigation was undertaken to (1) determine maximum biomass production of fast-growing Salix clones on dry or nutrient-deficient land where adequate nutrients and water are supplied by irrigation and fertilization, (2) compare the efficiency of different irrigation-fertilization systems, (3) investigate the possibilities of successively increasing soil fertility by a fertilization routine adjusted to growth and uptake, (4) monitor the leakage of different nutrients to groundwater, and (5) make economic calculations with respect to the different irrigation-fertilization systems. The experimental area, which was abandoned farmland, was planted in 1982 with clones of Salix. The soil was very sandy with small amounts of organic matter. The groundwater table was 2-3 in deep. The pH of the soil at 0-15 cm depth was initially 4.8-5.5. Three irrigation-fertilization systems were used: (1) drip, (2) sprinklers, and (3) subsurface irrigation. During summer 1984 the area was irrigated and fertilized once a week for 12 weeks with a complete liquid fertilizer equivalent to 10 kg N per week. Production was about 1 kg m(-2) and 3 kg m(-2) for 1- and 2-year-old shoots, respectively. There were no significant differences between the irrigation-fertilization systems or between the species and clones, for either 1- or 2-year-old shoots.