Land application of animal manure supplies nutrients and organic matter to raise and maintain the quality of soils for crop production. It can also be a major source of environmental pollution. Considering soil health and agronomic aspects, while applying organic fertilisers, care needs to be taken to prevent any environmental degradation like emission of odour and greenhouse gases, surface and sub-surface water contamination. Specially designed manure application machineries are important to ensure the beneficial effects by mitigating the detrimental effects.
Environmental issues related to manure application ?
Provincial and Federal Governments of developed countries are imposing regulations for practicing Best Management Practices (BMP) of manure management.
Solid Manure Spreader
The handling and land application of solid manures and organic fertilizers are the basic functions of manure spreaders. Typically, machines that are categorized as solid manure spreaders handle product having a dry matter content over 12% . Manure spreaders are generally semi-mounted trailers comprising of frame, hopper with floor conveyor, spreading devices (usually rotating mechanisms) and power transmission parts. Box spreader is the most commonly used solid manure spreader equipment that works best for cattle manure that has 70-80% moisture content. It could be truck mounted or tractor pulled.
Liquid Manure Spreader
Liquid or slurry (semi-solid) manure is land applied by spreading technique. However, this approach is not environment friendly as there is chances of runoff loss, greenhouse gas emission and loss of nutrients to the atmosphere. Presently the liquid splashing technique is being replaced by manure injectors.
Research has shown that as much as 30% of the nitrogen can be lost through volatilization. Thus, it is recommended that slurry manure be injected into the soil, reducing odour and surface runoff while minimizing the loss of valuable nutrients to the atmosphere. Generally two types of injection techniques are used:
- Sweep Injection: Injection that uses sweep type tynes and injects manure in a horizontal manner in the soil.
- No-till Injection: Injection that places manure in narrow bands and very little of the soil is disturbed.