Biomass yield and energy efficiency of willow depending on cultivar, harvesting frequency and planting density

Abstract

The study aimed at comparing the yield of dry biomass and energy efficiency of 22 willow cultivars depending on the harvesting frequency and variable plant density. The field experiment was established in 2010. The willow cultivars were planted in two densities; 13 300 and 32 500 plants per ha. Among the compared cultivars in the second year (2013) of full production, high yield of dry matter was obtained from cvs. Tordis (33.1 t/ha/year), Inger (30.4 t/ha/year) and Klara (29.0 t/ha/year). After six years of cultivation, the highest aboveground dry matter was given by cvs. Tora (27.4 t/ha/year) and Tordis (27.0 t/ha/year). The gross calorific value of willow biomass ranged from 15.2–20.1 GJ/t dry weight. Greater energy efficiency (329.3 GJ/ha/year) occurred in willow cultivars collected in a two-year cycle than in the one-year cycle (286.4 GJ/ha/year). In the two-year cycle collected in the third year after planting, energy efficiency was greater (379.5 GJ/ha/year) than in the two-year cycle harvested in the sixth year after planting (279.15 GJ/ha/year). The initial slower growth of biomass does not determine plant yielding.

Short rotation coppice of leguminous tree Leucaena spp. improves soil fertility while producing high biomass yields in Mediterranean environment

“…This trend was similar for all study taxa, yet L. leucocephala 'India' yielded significantly more biomass (p = 0.008) than L. leucocephala 'Honduras' (predicted mean (SE) were 32.0 (1.6) and 29.2 (1.6), respectively (Tables A.1 and A.2). Therefore, from the fourth to the eleventh year, annual rotations also produced more biomass than biennials, so that not only environmental conditions or genotype affect production, but also the harvesting frequency (Guidin Nissin et al, 2018;Kulig et al, 2019). At the end of the study period, we did not observe a decrease in the vigor of sprouts, despite some stumps having up to 10 cuttings.…”

Low Indirect Land Use Change (ILUC) Energy Crops to Bioenergy and Biofuels—A Review

“…Herbaceous crops were chosen because they are species that present several environmental benefits such as high nutrient and water use efficiencies, erosion control, soil stabilization, and carbon storage, they contribute to the landscape and biological diversity and have a low need for inputs, namely fertilizers and pesticides [10,[13][14][15][16][17], and help in the recycling of organic components in the soil [11]. For example, miscanthus presents an extensive and deep rooting system, a lengthy permanence in soil, and the translocation of nutrients from aerial biomass to the rhizomes at the end of the vegetative cycle, which reduces the need for high application of fertilizers to ensure growth [18].…”

“…Herbaceous crops, like the giant reed, switchgrass, reed canary grass (Phalaris arundinacea), miscanthus, and perennial ryegrass (Lolium perenne) are crop species that can be cut annually after planting and the rhizomes must be left in the ground to ensure continued growth, a procedure that can be maintained for 15 years or longer, therefore, they are also classified as perennial crops. The perennial energy crops (or multi-annual plantations) do not need the incorporation of considerable quantities of pesticides and fertilizers, they help to avoid soil erosion, present low soil fertility requirements [10], and help in the recycling of organic components in the soil [11]. The short cycle coppice like poplar (Populus spp.…”

Triploid Hybrid Vigor in Above-Ground Growth and Methane Fermentation Efficiency of Energy Willow

“…Since improving biomass yield and energy production efficiency is now a central goal ( Kulig et al, 2019 ), we have initiated a crossing program between two leading Swedish diploid cultivars (Tordis and Inger) and our autotetraploid genotypes. We postulated that a novel genetic composition based on triploidy and heterosis could result in a substantial improvement in the biology of willow plants used for bioenergy production.…”