Agricultural chemicals and waste management

Waste suitable for recycling and use in agricultural production

In the course of production activities, in addition to the main product, various types of post-production residues are often unintentionally generated. This waste is worth recycling for both economic and environmental reasons, in accordance with the waste hierarchy, if it could not be prevented

Recycling is understood as recovery whereby waste is reprocessed into products, materials or substances for the original purpose or other purposes; this includes the reprocessing of organic material (organic recycling). It does not include energy recovery and reprocessing into materials to be used as fuels or for landfilling.

We can divide manufacturing residues into:

  • by-products – understood as post-production residues, suitable for direct use without prior processing or as raw material for the manufacture of other products,
  • waste – defined as production residues requiring treatment for recovery or disposal and non-recoverable production residues and unusable objects or parts thereof.

In agricultural production, both crop and livestock, mainly natural organic residues are produced. In crop production, the predominant ones are:

  • post-harvest residues, i.e. cereal straw, rape straw, maize stalks, husks, potato peels, beet leaves, stems and leaves of root vegetables (e.g. carrot tops), roots of other vegetables (e.g. cabbages), hulls and other plant residues,
  • residues from the cleaning and storage of arable crops, e.g. cereal husks, middlings (waste grain and weed seeds), soggy or mouldy grain, undersized vegetables and root crops, rotten or frozen potatoes, beet and vegetables, spoiled haylage,
  • orchard residues, e.g. branches from tree pruning, fruit drops, etc.

A particular type of recycling is organic recycling. Plant material, where possible, should in principle be managed on site.

Animal production produces animal excreta: manure, slurry, slurry, chicken manure.

In addition to organic residues, natural mineral residues such as stones collected from fields or soil from washing and cleaning, such as vegetables, can also be generated.

Post-production non-natural residues, such as plastics, various packaging materials, agricultural spray washings, etc., are also very important in environmental terms.

In agricultural activities, many of the natural residues described above can be used in agricultural production, creating a closed cycle of matter and energy in the environment – highly desirable for agricultural sustainability.

By-products can be disposed of or used on the farm as:

  • natural organic fertilisers: manure, slurry, chicken manure, compost (made from animal excrement and waste plant matter),
  • animal bedding (e.g. cereal straw),
  • animal fodder (e.g.: beet leaves, non-food parts of vegetables, stems and leaves and other plant residues, buttress, undersized vegetables and root crops),
  • fuel or for briquette production (e.g. cereal straw, plant stalks, branch chips), which, however, is not sustainable.

Organic waste of natural origin on the farm should be used primarily to increase the amount of organic matter in the soil and improve soil fertility. These materials should be shredded, spread evenly over the field and ploughed in. It is advantageous to pour manure or slurry over shredded cereal straw, or rape and maize stalks (before ploughing), in order to maintain the right proportions of nitrogen and carbon.

In the case of waste plant matter that has already been harvested from the field or that has arisen from the cleaning and storage or spoilage of agricultural crops, it should be used for composting. The product of this process is an organic fertiliser – compost. Every farm can and should operate its own composting facility. It makes it possible, in a simple process, to manage plant waste and produce a useful fertiliser for cultivation, improving soil activity and increasing the amount of nutrients in the soil. On farms that collect manure, plant residues can be mixed with animal manure and used together as organic fertiliser.

Another type of organic recycling is methane fermentation carried out under anaerobic conditions. The products of this process are biogas (used for energy production) and digestate – a valuable organic fertiliser. Running methane digestion is a difficult process and requires specialised plant and knowledge. If your farm produces large amounts of organic waste, it is worth considering this solution, as methane fermentation allows for additional savings and income, due to the use of the generated heat for own consumption and the sale of electricity.

The following wastes can be recycled organically in biogas plants, composting plants:

  • animal faeces,
  • waste from cultivation and plant breeding,
  • grasses and garden waste,
  • food product residues,
  • fruit and vegetable leftovers,
  • under-quality, non-compliant crops (cereals, root crops),
  • under-fertilised silage. For more in the guidelines for the use of by-products and the recommended handling of waste in agriculture and the agri-food industry, see the website and documents of the Ministry of Agriculture and Rural Development.