Search Results (19)

This study focuses on enhancing the comprehensive utilisation of rice straw by proposing a vibration-assisted compression technology, with the aim of resolving inherent issues in traditional baling, such as uneven compression and low density. This study designed a multi-point vibration-assisted compression test rig and established a vibration-enhanced compression mechanical model based on the physical properties of rice straw. By integrating discrete element method (DEM) simulations with bench testing, the optimal length-to-width ratio of 1:1 was identified for achieving superior compaction quality. A systematic analysis was conducted to evaluate the effects of vibration point configuration, frequency, and amplitude control on straw bale integrity. The results of the DEM simulations demonstrated that vibration-assisted compression significantly enhanced the compaction uniformity and stability of rice straw. The dimensional stability coefficient and pressure transmission rates of the straw bales reached 88.25% and 58.04%, respectively, validating the efficacy of the vibration-assisted compression technique. This study provides innovative concepts and theoretical foundations for optimising the design of straw baling and in-field collection equipment. It holds critical significance for advancing the resource-efficient utilisation of agricultural residues and promoting sustainable agricultural practices. Full article

Aiming at the problems of low operating efficiency and the unclear mechanisms in the bundling process of existing residual film recycling machines, this paper designs a chain network-type residual film bundling device and analyzes the motion characteristics of the film bundling process using high-speed camera technology. A mechanical analysis of the bundling process was conducted, and a test rig for the chain network residual film bundling device was built. The bundling process was studied via a high-speed camera. Field tests were carried out with the density of the film bale as the evaluation indicator and the forward speed of the machine, the rotational speed of the active film-removing roller, and the rotational speed of the film-rolling support roller as influencing factors. A Box–Behnken experimental design was used to optimize the working parameters of the device. The results show that when the machine’s forward speed is 5.8 km/h, the active stripping roller rotates at 170 rpm, the roll support roller operates at 210 rpm, and the film bale density reaches 124.44 kg/m³, with a relative error of only 1.34 kg/m³ compared to the predicted value. This verifies the effectiveness of the device and demonstrates that it can meet the requirements of mechanized residual film recycling. Full article

Agricultural machinery, particularly balers, plays a crucial role in forage management. These machines are prone to fire incidents caused by mechanical friction, heat buildup, and the accumulation of crop residues, among other contributing factors. Despite their operational importance, fire risks associated with balers remain largely understudied. This research aims to identify critical fire risk factors in large square balers through a combined analysis of survey data, temperature monitoring, and residue characterization. A questionnaire survey was conducted among 144 large square baler users to assess fire incidence and potential risk factors. Contingency table analysis and binary logistic regression were applied to identify variables significantly associated with the fire risk. Additionally, temperature data were recorded in six balers during two harvesting seasons, and residue samples were collected and analyzed to assess their ignition potential. Using a rake for windrowing was the only variable significantly associated with increased fire risk, making balers 3.4 times more likely to experience a fire (p = 0.034). Temperature analysis showed that the feeder fork brake (190.6 °C) and hydraulic pump (128.7 °C) were the hottest components, but none of the recorded temperatures exceeded the 250 °C ignition threshold of fine agricultural residues. Residue analysis showed that particles smaller than 250 µm accounted for 39% of the total material, underscoring their potential to contribute to fire propagation. This study highlights the critical influence of raking equipment on fire risk in balers and emphasizes the importance of preventive measures such as enhanced cleaning, real-time temperature monitoring, and improved mechanical design. These findings provide actionable insights for reducing fire hazards in agricultural operations and optimizing baler safety. Full article

The Loess Plateau, with a large area of marginal land, holds the potential to produce 62–106 Tg per year of switchgrass biomass; however, the economic feasibility of producing bioenergy in the region is unclear. The farm-gate feedstock production (FGFP) cost of switchgrass was calculated in a spatially explicit way by taking the geographic variation in crop yield, soil properties, land quality, and input costs into consideration in order to evaluate the economic performance of bioenergy production. Cost–supply curves were constructed to explore the energy supply potential of switchgrass feedstock. The calculations were conducted using ArcGIS in a 1 km grid and all the evaluations were conducted under different agricultural management practice (AMP) scenarios in parallel. The FGFP costs showed significant spatial variation ranging from 95 to 7373 CNY (Chinese Yuan) per tonne⁻¹ and that the most economically desirable areas are scattered in the south and southeast region. The weighted average FGFP costs are 710, 1125, and 1596 CNY per tonne⁻¹ for small bale (SB), large bale (LB), and chipping (CP) harvest methods, respectively. The projected energy supply potential is 1927 PJ (Petajoules) per year⁻¹, of which 30–93% can be supplied below the market prices of different fossil fuels according to feedstock formats. Compared to current biomass residual pricing, 50–66 Tg (Teragrams) switchgrass feedstock is competitive. The results demonstrated that the Loess Plateau holds the potential to produce bioenergy that is economically feasible. This study provides a methodological framework for spatially explicit evaluation of the economic performance of perennial energy crops. Detailed information obtained from this study can be used to select the optimal locations and AMPs to produce feedstock production at minimum cost. Full article

Diversifying agronomic production systems by combining crops and livestock (i.e., Integrated Crop Livestock systems; ICL) may help mitigate the environmental impacts of intensive single-commodity production. In addition, harvesting row-crop residues and/or perennial biomass could increase the multi-functionality of ICL systems as a potential source for second-generation bioenergy feedstock. Here, we evaluated non-CO₂ soil greenhouse gas (GHG) emissions from both row-crop and perennial grass phases of a field-scale model ICL system established on marginally productive, poorly drained cropland in the western US Corn Belt. Soil emissions of nitrous oxide (N₂O) and methane (CH₄) were measured during the 2017–2019 growing seasons under continuous corn (Zea mays L.) and perennial grass treatments consisting of a common pasture species, ‘Newell’ smooth bromegrass (Bromus inermis L.), and two cultivars of switchgrass (Panicum virgatum L.), ‘Liberty’ and ‘Shawnee.’ In the continuous corn system, we evaluated the impact of stover removal by mechanical baling vs. livestock grazing for systems with and without winter cover crop, triticale (x Triticosecale neoblaringhemii A. Camus; hexaploid AABBRR). In perennial grasslands, we evaluated the effect of livestock grazing vs. no grazing. We found that (1) soil N₂O emissions are generally higher in continuous corn systems than perennial grasslands due to synthetic N fertilizer use; (2) winter cover crop use had no effect on total soil GHG emissions regardless of stover management treatment; (3) stover baling decreased total soil GHG emissions, though grazing stover significantly increased emissions in one year; (4) grazing perennial grasslands tended to increase GHG emissions in pastures selected for forage quality, but were highly variable from year to year; (5) ICL systems that incorporate perennial grasses will provide the most effective GHG mitigation outcomes. Full article

Livestock producers often resort to either baling or grazing of crop residues due to high hay prices and reduced supply of other forages and silage in the markets. Soil-water-crop management practices can affect residue nutrient qualities for its use as cattle feedstock. A two-year study (2018–2019) was conducted to investigate the effects of irrigation (AI, all row-irrigation; ARI, alternate row irrigation; and RF, rainfed) and planting pattern, PP (SR, single row; and TR, twin-row) on soybean (maturity group IV cv. 31RY45 Dyna-Gro) post-grain harvest residue quality such as crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), acid detergent lignin (ADL), net energy for maintenance (NEM), net energy for gain (NEG), net energy for lactation (NEL), total digestible nutrients (TDN), and relative feed value (RFV). Irrigation has a significant effect on CP, ADF, NDF, and TDN while PP affected only NDF. All the above parameters were significantly affected except NEM by the contrasting climate conditions, particularly during July through August coinciding with early crop reproductive stages and maturity. The RFV values ranged from 70.4 to 81.6 and this lower range was attributable to nutrient translocation to seeds and higher lignification during plant senescence towards the grain filling stage of the crop as good quality hay records over 120 RFV. These results indicate that both irrigation and weather during soybean seed development can alter post-grain harvest residue quality parameters, thereby playing critical roles in its RFV. Full article

Shrub species play a critical ecological role in ecosystems, covering significant areas. However, with the current development of vegetation cover, conditioned by climate change, certain species have acquired a dominant role, which suffocates the other ecosystem species in a natural monoculture model. Thus, some species, such as Cytisus striatus (Hill) Rothm., have acquired preponderance, mainly due to the dense forests they establish. This situation has contributed to the increased risk of rural fires, forcing permanent actions to control the settlements. These actions entail costs that make the continuity and permanence of control unsustainable. The energetic valorization of residual biomass resulting from operations to reduce fuel load is an option that seems viable, mainly if used in the production of biomass pellets in a mixture with other biomasses, such as Pinus pinaster or Eucalyptus globulus. The laboratory characterization tests demonstrated that the residual biomass of C. striatus presents parameters that fall within limits defined by the standard ENPlus^®. The processing of this residual biomass on an industrial scale line is also feasible. However, given the configuration of the material to be processed, production lines may be necessary, especially concerning the detachment of the material. The logistical issue may also impose restrictions since the material has a low density, even when baled. Full article

The growing population worldwide will create the demand for higher cereal production, in order to meet the food need of both humans and animals in the future. Consequently, the quantity of crop by-products produced by cereal cropping will increase accordingly, providing a good opportunity for fostering the development of the sustainable supply chain of renewable solid fuels and natural feedstock for animal farming. The conventional machineries used in wheat harvesting do not guarantee the possibility to collect the chaff as additional residue to the straw. The present study investigated the possibility to equip a conventional combine with a specific device, already available on the market, in order to collect the chaff either separately (onto a trailer), or together with the straw (baled). The total residual biomass increased by 0.84 t·ha⁻¹ and 0.80 t·ha⁻¹ respectively, without negatively affecting the performance of the combine when the chaff was discharged on the swath. Farmers can benefit economically from the extra biomass collected, although a proper sizing of the machine chain is fundamental to avoid by-product losses and lower revenue. Full article

Wastes from artichoke and broccoli crops and cannery industries represent an environmental problem. A viable option to this problem is ensiling them for use as ruminants feed. The aim of this study was to characterise the ensiling process of broccoli and artichoke by-products and assess their suitability to be part of the ruminant diet, as well their minimum shelf life. Twenty-one commercial round bale silos (300 kg and 0.64 m³) of each by-product were made. Samples were analysed at days 0, 7, 15, 30, 60, and 200 to determine microbial populations, fermentation metabolites, nutritional components, and phytosanitary residues. Feedstuffs showed good suitability for ensiling, and stabilisation was achieved on day 30. The variables with the greatest significant differences among sampling times were microbial populations and fermentative components. There were no important dry matter losses, and some significant differences were observed in the nutritional composition, especially in crude protein and fibrous fractions, but they were not relevant for the loss of nutritional quality of silages. The phytosanitary residues determined on day 200 were below the maximum residue limits set by European legislation. So, ensiling these by-products in commercial round bale silos is a suitable and profitable technique that allows their preservation for a long time (200 days). Full article

The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha⁻¹), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries. Full article

In cereal crops, chaff is a valuable lignocellulosic by-product that accounts for more than 50 Mt y⁻¹ in Europe and is suitable for bioenergy purposes. Chaff is usually not collected due to the lack of combine harvesters that have the capability to handle it properly. The present two years experimental study investigated the hypothesis that the overall biomass collected in wheat crop can be increased by equipping the combine harvester with an aftermarket device. Chaff, discharged from the combine harvester-cleaning system, is collected by the turbine that delivers it either on the swath or on a lateral trailer towed by a tractor. The performance of all machines involved in the harvesting (combine harvester, tractor, baler, and trailer) were assessed. The chaff was collected in bales with the straw (A mode) and separately on a trailer (C mode). Comparisons with non-collected treatment (B mode) were performed in order to estimate the total chaff collected and the biomass losses. The results showed that 1.79 t FM ha⁻¹ per year of chaff could be collected when baled with the straw, whereas 1.27 t FM ha⁻¹ were collected separately on a trailer. Both field and material capacity were not negatively affected by the chaff collection. Therefore, our study confirmed the hypothesis that turbine technology is a valid solution for increasing the total residual biomass collected in cereal cropping for energy purposes. Full article

This work assesses the costs of exploiting the biomass feedstock chaff. Chaff is a harvest residue generated during the conventional grain harvesting process and usually remains on the field. In this paper, the costs of collecting and supplying chaff to the end user with different harvesting methods and supply chains are analyzed. The costs are estimated for a base case defining a set of general assumptions. The impact of these assumptions is analyzed in a sensitivity analysis by means of tornado diagrams. A full costing method based on the VDI guideline 2067 part 1 is applied for the cost estimation. The cost analysis reveals that ceasing the fractioning of grain, straw and chaff during harvesting and transporting them as a mixture reduces the harvesting costs significantly. The costs are decreased due to a reduction in agricultural operations and processing large amounts of material. The lowest total costs originate from the production of chaff-straw bales. Harvesting chaff as a single fraction leads to the highest costs with the investigated supply chains. Comparing the costs of chaff supply to potential revenues shows that an exploitation of the harvest residue can be economically feasible. Full article

A big amount of agricultural residues are generated from crop production and partially remain in the field after harvest. Removing the excess of residues after crop harvesting can increase farmer income, providing feedstock that could be used for industrial and energy purposes. The costs for collection and transport of straw and stalks are site- and region-specific and depend on the availability of agricultural residue and on how much of the residue is removed from any specific field or location. If the biomass is baled then it is required to upload the bales on a trailer, transport and unload all the baled biomass to the storage center. On the other hand, if a self-loading wagon is used the loose biomass collected, it must be unloaded every time the wagon is completely full. The distance and the harvesting system used influence the costs and should be analytically studied to avoid turning a possible profit into a disadvantageous business. The research represents a real case study to evaluate, which is the maximum distance to the biomass logistic center from which it is more economically convenient to gather the wheat and corn residues in bales instead of using a self-loading wagon. The results show a lower harvesting unitary cost for the self-loading forage wagon respect to the baling system. Although the study showed delivery distances over 11.4 km for wheat straw and 16.0 km for maize stalks, the use of the self-loading forage wagon is no longer convenient, and baling is the preferred harvesting system. Full article

Baled pruning residue could be a valid solution to reduce the storage surface area in thermal and electrical power station. This study aimed to analyze the storage performance of pruning residues baled by a round baler considering three orchard tree species (apple, peach, and kiwi) and three different techniques (uncovered, under roof, and wrapped). The storage parameters considered were: moisture content, dry mass, and wood energy content of the material. The initial moisture content of the tree orchard specie (apple, peach, and kiwi) was different: lower for peach (41%) and higher for kiwi (51%). At the end of the storage period, all bales (covered and uncovered) obtained similar values to that of the air (about 20%); wrapped bales have highlighted no moisture content variation. The tested tree species showed a similar initial high heating value (18.70 MJ·kg⁻¹), but a different initial low heating value: lower for kiwi (7.96 MJ kg⁻¹) and higher for peach (10.09 MJ·kg⁻¹). No dry matter losses were observed in all test. Stored pruning residues in bales show good benefits in term of “biofuel” quality independent of the techniques adopted expect for the wrapping system that do not permit adequate drying of the biomass. Full article

Generation of heat in small and medium-size energy systems using local sources of energy is one of the best solutions for sustainable regional development, from an economic, environmental, and social point of view. Depending on the local circumstances and preferences of the agricultural activity, different types and potentials of biomass are available for energy recovery. Poland is the third-largest producer of apples in the world. The large cumulative area of apple orchards in Poland and necessity of regular tree pruning creates a significant potential for agricultural biomass residues. In this paper, the LCA analysis of a new and integrated process chain focused on the conversion of cut branches coming from apple orchards into heat is conducted. Furthermore, the obtained results of the environmental indices have been compared to traditional mulching of pruned biomass in the orchard. It was shown that in terms of the LCA analysis, the biomass harvesting, baling, and transportation to the local heat producer leads to an overall environmental gain. The cumulative Climate Change Potential for pruning to energy scenario was 92.0 kg CO₂ equivalent·ha⁻¹. At the same time, the mulching and leaving of the pruned biomass in the orchard (pruning to soil scenario) was associated with a CO₂ equivalent of 1690 kg·ha⁻¹, although the soil effect itself amounted to −5.9 kg CO₂ eq.·ha⁻¹. Moreover, the sensitivity analysis of the LCA showed that in the case of the PtE chain, the transportation distance of the pruned bales should be limited to a local range to maintain the positive environmental and energy effects. Full article