Cut‐and‐chip harvester material capacity and fuel performance on commercial‐scale willow fields for varying ground and crop conditions

Abstract

Shrub willow (Salix spp.) is capable of producing commercially attractive amounts of biomass in short rotations, but harvesting costs and logistics remain a concern.There is a particular need for information about harvesting operations on larger, commercial short-rotation woody crop systems. Another recent issue on commercial fields in northern New York is commercial growers conducting harvests during the growing season rather than the recommended dormant season when fields may be too wet to harvest. This study evaluated and modeled the in-field performance of a cut-and-chip harvester for almost 700 wagonloads of chips operating in commercial willow fields in a wider array of crop and field conditions than have been previously reported. Analysis indicated that the time of harvest (leaf-on or leaf-off) and whether site conditions were wet or dry affected the harvester's material capacity.Mean material capacity was greatest for leaf-off, dry conditions (71.8 Mg/hr) and lowest for leaf-on harvests, which were similar for wet (30.4 Mg/hr) and dry conditions (29.7 Mg/hr). Mean crop specific fuel consumption ranged between 1.3 and 3.3 L/Mg, but can get considerably higher for standing biomasses below 40 Mg/ha.Wet ground conditions and leaf-on harvests tend to decrease material capacity and increase fuel consumption as the harvester has to divert power to forward movement and material processing. Relationships for material capacity and fuel consumption based on standing biomass, time of harvest and ground conditions will be essential for evaluating and modeling the economic and environmental impacts of commercial-scale willow operations. K E Y W O R D Sfuel consumption, harvesting logistics, leaf-on harvesting, material capacity, short-rotation woody crops, wet-weather harvesting, willow EISENBIES Et al.

Willow Biomass Crops Are a Carbon Negative or Low-Carbon Feedstock Depending on Prior Land Use and Transportation Distances to End Users

“…Harvesting accounts for 9.48 kg CO 2eq Mg −1 in all scenarios and is the second largest impact among crop management activities after fertilizer, so improvements in harvester efficiency can contribute to GHG emission reductions. This number is about 27% lower than the 13 kg CO 2eq Mg −1 value in a previous study [1] due to improvements in harvester efficiency of single pass cut and chip operations modeled in this study and improved data for harvester operation and fuel consumption that have been made over the past few years [29,46]. Site management is an integrated category including all site preparation, planting, and site maintenance processes, specifically including processes #1 to # 15 and process #20 in Table S1.…”

“…As a result, the range of EROI values in this study (8. [9]. Harvesting throughput values in our study are based on more recent data that showed a substantial improvement in harvester throughput [29,46] that results in lower energy consumption per Mg of biomass and a higher EROI. Further improvements in harvesting and chip loading operations may be possible to further lower energy inputs into the system.…”

Growing Season Harvests of Shrub Willow Have Higher Nutrient Removals and Lower Yields Compared to Dormant Season Harvests

“…In practice, commercial harvests have not necessarily occurred within the recommended window; site conditions, especially on poorly drained marginal land in the northeast U.S., may limit machine access and operators may elect to expand the harvesting window [24]. The timing of willow harvests can potentially impact coppice regeneration and regrowth, and ultimately impact the productivity and costs [19].…”

Economic Evaluation of the Production of Perennial Crops for Energy Purposes—A Review

“…The search for crops that would meet the criteria of sustainable development and make good raw material for bioenergy and bioeconomy has been the subject of numerous papers [34][35][36], many of which determined specific conditions for their cultivation [37], harvest [38][39][40][41][42][43][44][45][46][47], and factors affecting the crop per area unit [48] and the impact of cultivation on greenhouse gases (CHG) [49,50] and on the environment [51][52][53]. Mathematical methods were used by Bender et al [54], Hauk et al [55], Salles et al [56], and Sleight et al [57,58] to assess crop yields; by Havlíčková et al [59] to assess the SRC biomass price; and by Frank et al [60] to assess both the minimum selling price and net present value (NPV).…”