Agricultural Waste and Pollution
As the population of the world increases so does the demand for food. This in turn leads to pressure on the agricultural sector to improve yields whilst doing so at affordable pricing. This has caused farmers to abandon traditional methods in favour of the intensive farming we witness today resulting in greater agricultural waste and pollution.
Agricultural waste is waste produced by various agricultural operations and includes organic and non-natural waste. Non-natural waste includes pesticide containers, plastics, tyres, batteries, oil etc. The Chartered Institute of Waste Management reported that plastic packaging from agricultural waste accounted for 1.5% of all plastic packaging in the waste stream in England. Approximately 135,000 tonnes of agricultural plastic waste are produced each year in the UK. It not only poses a threat to the environment but also to the health of those farm workers exposed to harmful biological materials. Biohazards include fungi, bacteria, viruses and those working in the removal of manure from animal and poultry units can be exposed to dusts resulting in respiratory problems.
Agricultural pollution is contamination of the environment and ecosystem arising from abiotic and biotic by-products of farming practices which can also cause injury to humans and affect economic interests.
Abiotic (not derived from living organisms) causes include:
- Chemical fertilisers – the use of chemical fertilisers can adversely affect the soil, surface water and groundwater. The three main macronutrients used in chemical fertilisers are nitrogen, phosphorus and potassium. Nitrogen and phosphate fertilisers have major environmental impacts. Rainfall causes the fertiliser to be washed into waterways and is a major contributor to the eutrophication of fresh water rivers, lakes etc. Nitrogen rich compounds found in fertiliser run offs are a primary cause of serious oxygen depletion in oceans, coastal areas, lakes and rivers. Only a small part of nitrogen-based fertiliser is converted to produce crops and other plant matter. The rest builds up in the soil and is lost as runoff. The runoff goes into surface water and leaches into groundwater causing water pollution. The nutrients, especially nitrates, can be a problem for habitats and human health if they are washed off the soil into watercourses or leach through the soil into groundwater. Cadmium can be found in phosphorus and a continuous use of high-cadmium fertilizer can contaminate soil and plants. Fluoride is also found in phosphate fertiliser and there is a real chance of fluoride toxicity to livestock that ingest contaminated soils. Also, of possible concern, are the effects of fluoride on soil microorganisms.
- Chemical pesticides – these embrace insecticides, herbicides and fungicides and are designed to eradicate certain pests. Unfortunately, they can also destroy those that are natural enemies of pests (i.e., insects that prey on or parasitize pests) rather than the target pests themselves. They pollute water and soil, diminish biodiversity and are harmful to beneficial insects that are pollinators, threaten fish life and destroy natural habitats.
- Other heavy metals such as mercury, lead and arsenic – these are often recycled into fertiliser because of their high zinc levels essential to good plant growth. These potentially harmful ingredients can be removed but at a high cost. Selenium occurs naturally in the soil and certain farming techniques e.g. irrigation, can lead to a build-up of selenium which can find its way into water systems through runoff, leaching etc. This build up, once in reservoirs, is toxic to wildlife, humans and livestock and is known as the Kesterton Effect named after the Kesterton Reservoir in the San Joaquin Valley, California which was declared a toxic waste dump in 1987 because of excessive levels of selenium caused by irrigation.
- Leaching, Runoff and Eutrophication – chemicals applied to the land can seep into the water table causing contamination and can be part of water runoff into rivers, streams etc. Chemicals rich in nitrogen and phosphorus once in water increase the nutrient levels causing eutrophication. Algae forms and uses up most of the available oxygen in the water leaving little for other life forms causing fish and other animals living in the water to die. Algae also restricts the amount of sunlight entering the water affecting photosynthesis of plants and prevents the restoration of oxygen levels thus causing the water being unable to support life.
- Soil Erosion and Sedimentation – A great amount of soil erosion and sedimentation is caused by intensive agricultural methods and poor land management. Soil degradation causes an irreversible decline in soil fertility on about six million hectares a year. Sedimentation in water runoff can lead to transport difficulties in navigating streams, rivers and watercourses without regular dredging. It can also limit the amount of light penetrating water thus affecting animal and plant life.
Biotic (living or once living organisms e.g. animals, plants.) causes include:
- Greenhouse gases from animal waste - The United Nations Food and Agriculture Organization predicted that 18% of anthropogenic greenhouse gases come directly or indirectly from the livestock.
- Manure - Animal waste is a major contributor to air, soil and water pollution. It is often pumped into open-air pits called ‘lagoons’ and then the liquid manure is sprayed onto fields. The amount very often is more than can be taken up leaving the rest to escape into the air or runoff into streams, rivers etc. causing serious pollution problems. Improper disposal methods are harmful to groundwater, the environment and to human health. Dangerous and offensive odours and other air pollutants are emitted causing problems for people in neighbouring areas.
- Biopesticides – these are pesticides derived from natural materials and there are concerns that they have a negative impact upon non-targeted species.
- Introduced Species - The increasing globalization of agriculture has resulted in the accidental introduction of pests, weeds, and diseases to places where they were never established and where they become an invasive species. As such they impact populations of native species and threaten agricultural production.
- Biological Pest Control (Biocontrol) – this is intended for use against insects, weeds etc and relies upon predation, parasitism and herbivory. It also requires careful and considered management. Problems can arise through side-effects upon biodiversity because of attacks on non-target species by the same mechanisms. The introduction of biocontrol can be irreversible and can include dispersal from agricultural habitats into the natural environment and host-switching or adapting to utilise a native species.
It is evident strict controls are needed in all efforts to enhance food production whilst maximising profit. This often means the environment pays the price with contaminated land, toxic seas and rivers, climate change, soil degradation etc. The ‘clear up’ problems will be enormous as will the cost and immediate action is required.
As we have seen a major problem is an over reliance upon chemicals without consideration as to the consequences. There is a clear correlation between chemicals usage and the subsequent damage caused to the environment and the fragile ecosystem. Slowly the United Nations and Governments are waking up to the situation, but it is the responsibility of us all to assist in solving the problems. At Organicco we recognise we cannot provide answers to them all, but can do all we can to make a difference. We have developed systems designed to convert organic agricultural waste into fertiliser, e.g., farm manure utilised in our system will be reduced by up to 70% in quantity and the remaining 30% will be converted into stabilised granular fertiliser which can be applied to land eliminating the damaging environmental consequences of spreading untreated manure. It also reduces the use of chemicals providing further benefits to the land and environment as the dangers posed by runoff and leaching are vastly reduced, if not eliminated. Organic fertiliser will help soil enrichment reducing problems of soil degradation.
We have a choice. We can continue without considering the future or we can try and make a difference. Organicco has made its choice and is happy to provide any further information on its products or any aspect of this report.