MANURE MANAGEMENT Recycling organic residues and minimising environmental impacts: MANURE MANAGEMENT Recycling organic residues and minimising environmental impacts
Slide3: Estimated quantities of organic manures recycled to land in the UK Williams et al. (2000); Gendebien et al. (1999); Gendebien et al. (2001)
Manures: diffuse and point source pollution: Manures: diffuse and point source pollution Point source pollution
associated with well-defined discharges
often avoidable with good design & management
Diffuse pollution
arises from wider, often multiple sources
difficult to define
difficult to prevent or control
Major pollution incidents have reduced significantly - due to introduction of Regulations and Codes…...: Major pollution incidents have reduced significantly - due to introduction of Regulations and Codes…... Water pollution incidents due to agriculture, England and Wales (Anon, 2000)
Agriculture still accounts for significant direct water pollution: Agriculture still accounts for significant direct water pollution 11% of total incidents in 1998
55% of these caused by manures
But manures remain a poorly utilised resource: But manures remain a poorly utilised resource In terms of potential fertiliser replacement value:
Worth up to c. £200 million p.a.
£2000 p.a. for a 100 cow dairy herd
£5000 p.a. for 1000 finishing pigs
£15,000 p.a. for 50,000 laying hens
Leading to nutrient surplus, crop loss and diffuse pollution……..: Leading to nutrient surplus, crop loss and diffuse pollution…….. (e.g. lodging, yield loss, low sp weight, low HFN, slow harvest ?)
Reasons why manure nutrients have not been effectively utilised?: Reasons why manure nutrients have not been effectively utilised? Nutrient content not known
typical nutrient content values
analysis not carried out
Uncertain prediction of nitrogen availability
Spreading practices
poor management
cost of improved equipment
High perceived costs?
Still unpleasant “disposal” operation?
Lack of confidence by farmers
Poor spreading practices?: Poor spreading practices? Uncertain application rate
unknown capacity of spreader/tanker
records of loads per field poor/lacking
Excessive application rate
Poor lateral spread pattern
usually some overlap between bouts needed
Poor longitudinal (length) spread pattern
poor control discharge rate
Spreading at wrong time?
Spreading under poor conditions?
Unpleasant job given low priority?
Possible consequences of diffuse pollution arising from manures?: Possible consequences of diffuse pollution arising from manures? From recent typical manure application practice:
Estimated 32,000t p.a. NO3-N lost by leaching?
Estimated 57,000t p.a. NH3-N lost by ammonia volatilisation?
Under Pilot NSAs, greatest single contribution to reduction in NO3-N loss came from improved management of manure from intensive units
How to reduce N losses from a farming system? - scenario testing:: How to reduce N losses from a farming system? - scenario testing: (1) Transfer 50% of autumn manure applications to spring
(2) Increase proportion manures incorporated rapidly or injected (from 10 to 20%)
(3) Improve allowances by farmers for manure N to those in RB209
(4) Combination of all three strategies
Manure management strategies and estimated short and longer term N losses: Manure management strategies and estimated short and longer term N losses
Reducing N losses from a farming system: Reducing N losses from a farming system The most effective way to reduce potential for nitrate leaching loss is to increase allowance made for manure N supply
Strategies for sustainable manure recycling?: Strategies for sustainable manure recycling? What’s in it? - nutrient content & rate
Where & how? - technique & precision
What happens next? - nutrient loss & uptake
Dealing with negative effects
Delivering a clear message?
Strategies for encouraging better recycling of manures: Strategies for encouraging better recycling of manures User-friendly computer software -MANNER, PLANET, NVZ DSS
Publications (RB209; booklets)
Combined research and demonstration
Don’t forget the negative messages !
Call in ADAS/TAG/TDG?
Integrating manure and fertiliser applications on farm crops without loss of yield or quality (N Yorks, 2000): Integrating manure and fertiliser applications on farm crops without loss of yield or quality (N Yorks, 2000) (Defra LINK funded, LK0904) practical advice for land managers
Incentives for better use: Financial?
Potential savings for cereals could be > £80/ha*
and for silage grass > £50 / ha *
Need for cross compliance - loss of single payment?
Avoiding the negative effects
Legal?
Requirements of the Nitrate Vulnerable Zone Action Programme and of GAEC (good practice)
Public image?
Especially where clear ‘win-win’ for both farmers and environment Incentives for better use * as part of a well designed fertiliser plan