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Environmental impacts of baled silage - WA0111

Big bale silage accounts for approximately 18% of grass silage made, but is currently subject to few constraints under the Control of Pollution Regulations. This study will aim to assess the risks of water pollution from big-bale silage in relation to other silage-making methods and will evaluate alternative techniques to minimise these risks. Effects of the following factors on quantity, pattern and composition of effluent released from the most commonly used big-bale system (wrapped grass silage in big bales) will be investigated: dry matter content at ensiling; height of stacking bales; season in which ensiling occurs; wrapping pattern; and use of standard balers as opposed to balers with chopping mechanisms. Effects of each factor will be studied by conducting a specific range of field experiments with groups of wrapped grass bales stacked in various combinations according to the factor under investigation. A desk study will also be undertaken to assess the effects of storage method, soil type and the siting of heaps of bales relative to water courses, on pollution risk to both ground and surface waters; this study will use data from experimental fieldwork, knowledge of alternative farm practices and existing knowledge on likely effluent flow over or through different soils or strata. Information from experimental approaches and the desk study will be collated to produce a practical guide on simple measures which farmers and contractors can adopt to minimise the risk of water pollution from big-bale silage. Data gained from fieldwork, together with up to date census figures on quantities of silage produced and ADAS data on annual trends in silage dry matter contents, will be used to refine previous ADAS estimates of effluent release on a national scale from different ensiling methods. In order to assess likely pollution risks from this released effluent, an additional desk study will be undertaken which will take account of the following: patterns of release of effluent from bales vs. clamps; estimates of farmers siting heaps relative to watercourses; estimates of the adequacy and structural condition of clamp silos and associated tanks, available from previous studies; and trends in NRA/EA pollution statistics before and during the course of the study. In addition to production of best practice guidelines, results of the study will be promoted to farmers, contractors, and film and baler manufacturers by a variety of other media, such as booklets, videos and roadshows.
Project Documents
• Final Report : Environmental impacts of baled silage   (93k)
Time-Scale and Cost
From: 1997

To: 2000

Cost: £117,920
Contractor / Funded Organisations
Fields of Study
Environmental Protection - Agriculture