A review of losses arising during conservation of grass forage: Part 1, field losses

McGechan, M.B.

doi:10.1016/s0021-8634(89)80067-8

Cited by 42 publications

(25 citation statements)

References 17 publications

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“…These values are in accordance with other studies focusing on grass storage for feed production (19,20). For willow, the storage was modeled as 'whole rods storage' which also represents a method typically applied to dry the harvested willow stems over summer (17,(21)(22)(23)(24)(25)(26)(27); this way, the storage also functions as a drying pre-treatment.…”

Section: Crop Storagesupporting

confidence: 63%

“…To this, an impact category named "Phosphorous as resource" was added, in order to reflect the benefits associated with phosphorous (P) savings, based on the Impact 2002+ method (19). Background LCA data were based on the Ecoinvent v.2.2 database, and the assessment was facilitated by the LCA software SimaPro 7.3.3 (20). Foreground LCA data essentially included Danish-specific data for agricultural and energy conversion processes, and the impacts associated with capital goods (foreground data only) as well as those related to transportation of the residues (i.e.…”

Section: Impact Assessmentmentioning

confidence: 99%

“…On field drying was thus considered and modelled based on the on field drying process traditionally used for hay: the ryegrass is left on field for a few weeks, where it is mowed and turned in order to facilitate the drying to DM content of 85%. The dry matter losses caused by microbial respiration as well as by the different operations was estimated to 20% (±10%) of the initial DM content (20,31). Biomasses undergoing anaerobic digestion require size comminution (assumed 10-50 mm); this was considered by including an electricity consumption of 7.5 kWh t -1 DM (32).…”

Section: Pre-treatments: Anaerobic Digestionmentioning

confidence: 99%

See 2 more Smart Citations

Bioenergy Production from Perennial Energy Crops: A Consequential LCA of 12 Bioenergy Scenarios including Land Use Changes

Tonini

Hamelin

Wenzel

et al. 2012

Environ. Sci. Technol.

105

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In the endeavor of optimizing the sustainability of bioenergy production in Denmark, this consequential life cycle assessment (LCA) evaluated the environmental impacts associated with the production of heat and electricity from one hectare of Danish arable land cultivated with three perennial crops: ryegrass (Lolium perenne), willow (Salix viminalis) and Miscanthus giganteus. For each, four conversion pathways were assessed against a fossil fuel reference: I) anaerobic co-digestion with manure, II) gasification, III) combustion in small-to-medium scale biomass combined heat and power (CHP) plants and IV) co-firing in large scale coal-fired CHP plants. Soil carbon changes, direct and indirect land use changes as well as uncertainty analysis (sensitivity, MonteCarlo) were included in the LCA. Results showed that global warming was the bottleneck impact, where only two scenarios, namely willow and Miscanthus co-firing, allowed for an improvement as compared to the reference (-82 and -45 t CO 2 -eq. ha -1 , respectively). The indirect land use changes impact was quantified as 310 ±170 t CO 2 -eq. ha -1 , representing a paramount average of 41% of the induced greenhouse gas emissions. The uncertainty analysis confirmed the results robustness and highlighted the indirect land use changes uncertainty as the only uncertainty that can significantly change the outcome of the LCA results.3

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Section: Crop Storagesupporting

confidence: 63%

Section: Impact Assessmentmentioning

confidence: 99%

Section: Pre-treatments: Anaerobic Digestionmentioning

confidence: 99%

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Bioenergy Production from Perennial Energy Crops: A Consequential LCA of 12 Bioenergy Scenarios including Land Use Changes

Tonini

Hamelin

Wenzel

et al. 2012

Environ. Sci. Technol.

105

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“…However, the difference in NDF content was unusually large if caused only by loss of DM in the field, especially between early harvested silage and hay. As herbage dries, it becomes more brittle and susceptible to mechanical losses (McGechan, 1989), and may account for some of the difference in NDF contents as hays were dried to less moisture content and exposed to more handling steps. In grasses, the NDF content is mainly concentrated in vascular tissues of leaves and of stems in particular and with progressing maturity the NDF is increasingly lignified.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

Schulze

Nørgaard

Byskov

et al. 2015

Animal

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The physical structure value of conserved grass/clover forages of spring harvest was evaluated by assessing effects of harvest time, conservation method, iNDF/NDF ratio and NDF intake (NDFI) per kg BW on chewing activity and fecal particle size in dairy heifers. A mixed sward consisting of ryegrass (Lolium perenne), red clover (Trifolium pratense) and white clover (Trifolium repens) was harvested in 2009 on May 9 (early) and 25 (late), and both cuts were conserved as silage and hay. The early silage, early hay, late silage and late hay contained dry matter (DM) of 454, 842, 250 and 828 g/kg, and NDF of 315, 436, 414 and 503 g/kg DM, respectively. Forages were fed as sole feed to four Jersey heifers of 435 ± 30 kg BW in a 4 × 4 Latin square experiment. Feeding level was 90% of individual ad libitum intake, divided equally across two daily meals offered at 0800 and 1530 h. Chewing activity was estimated from recorded jaw movements (JM) oscillations continuously logged for 96 h and summarized per 24 h as mean effective rumination time and eating time. Eating behavior was further observed during four 20-min test meals. Weight proportion of large feces particles (>1.0 mm) and geometric mean fecal particle size (GPS) were calculated. Potentially indigestible NDF (iNDF) was estimated by incubation for 288 h in situ. The daily DM intake (DMI) decreased with progressing maturity at harvest ( P < 0.001) while daily NDFI was unaffected by harvest time ( P > 0.05). Earlier harvest led to less rumination per kg NDFI ( P < 0.01), similar eating time per kg NDFI ( P > 0.05) and similar proportion of large particles ( P > 0.01) compared with later harvest. Rumination time per kg NDFI decreased with higher NDFI per kg BW ( P < 0.001) and with lower iNDF/NDF ratio ( P < 0.01). Content and potential digestibility of NDF was greater in hay than in silage from the same harvest probably due to field loss and therefore confounded effects of conservation method. This study of high digestibility grass/clover silage and hay showed that NDF content and NDFI per kg BW affect fecal particle size and rumination time per kg NDF, and suggests implementation of NDFI per kg BW in systems evaluating physical structure in diets.

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“…The reduction in the N-NH 3 values probably stemmed from the inhibition of proteolytic microorganisms. According to McGechan (1989), greater N-NH 3 values indicate higher intensity of proteolysis, and this is mainly due to the fermentation of the amino acid redox by the proteolytic clostridia. Therefore, Ribeiro et al (2008) consider that N-NH 3 is a product of the undesirable fermentation by Clostridium and, in well-conserved silages, the N-NH 3 levels should not exceed 10% total N. Based on these values, it is clear that the Brachiaria decumbens silages enriched with soybean hulls presented desirable fermentations.…”

Section: Resultsmentioning

confidence: 99%

Losses through gases and effluent and nutritional value of Brachiaria decumbens with addition of soybean hulls

et al. 2014

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-The objective of this experiment was to evaluate the losses of nutrient through gases and effluents, the nutrient recovery, fermentation parameters and the chemical parameters of silages of Brachiaria decumbens with the addition of soybean hulls, testing five levels of inclusion: 0, 10, 20, 30 and 40% (as is), with five replications per treatment. After the standardization cut of the forage, performed at 5 cm from the soil level, the soil was fertilized with nitrogen and potassium in the form of ammonium sulfate and potassium chloride, respectively, at 60 kg/ha. After 60 days, the grass was cut at 10 cm from the soil and ensiled. Experimental silos with capacity of 10 liters with Bunsen valve were used. Silos had 3 kg of sand conditioned at the bottom for retention of the effluents. The results show that the contents of dry matter, crude protein, acid detergent insoluble fiber and total digestible nutrients presented positive linear behavior with the inclusion of soybean hulls. In the grass silages with addition of soybean hulls, there was greater recovery of dry matter in relation to the control silage, which is a reflection of the negative linear behavior for the values of losses of gases and effluent. There was quadratic behavior in the pH values and negative linear behavior for the ammonia N values and buffering capacity with the inclusion of the additive in the grass silage. Inclusion of soybean hulls is sufficient to improve the fermentation pattern and minimize the losses through gases and effluents, contributing to the nutrient recovery, in addition to promoting overall improvement of the nutritional value of Brachiaria grass silages.

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A review of losses arising during conservation of grass forage: Part 1, field losses

Cited by 42 publications

References 17 publications

Bioenergy Production from Perennial Energy Crops: A Consequential LCA of 12 Bioenergy Scenarios including Land Use Changes

Bioenergy Production from Perennial Energy Crops: A Consequential LCA of 12 Bioenergy Scenarios including Land Use Changes

Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

Losses through gases and effluent and nutritional value of Brachiaria decumbens with addition of soybean hulls

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