Agriculture faces the challenge of feeding an increasing world population, estimated to reach 9.1 billion people by 2050. This requires an overall food production increase of 70% between 2005/07 and 2050 (FAO 2009). This increase can be achieved through higher yields, increasing the area farmed, higher cropping intensity (number of crops per year) or a combination of these.
Enhancing agricultural productivity will have a key role in providing food in the future. Fertilizer will be one of a number of technologies used together to increase food production per hectare of agricultural land.
The Australian fertilizer industry recognises that intensification, including increasing fertilizer use, can harm the environment, particularly when fertilizer is used inappropriately.
Raising soil fertility with fertilizers can increase crop yield; it can also increase the risk of nutrient movement from agricultural land to waterways. The nutrients of main concern in waterways are nitrogen and phosphorus, both of which can lead to excessive algal growth. This can harm other aquatic plants and animals, including coral and fish. Algal growth can also affect the suitability of water for uses such as drinking, recreation, stock watering and agricultural irrigation.
There is national and international public focus on runoff water quality from the catchments of the Great Barrier Reef in Queensland. Nutrient levels in the waterways and estuaries of the Swan and Scott River Coastal Plains of Western Australia have also attracted public concern. The movement of nutrients from the soil store, and those applied as fertilisers, is one of a number of factors contributing to poor water quality in both of these examples.
Greenhouse Gas Emissions
The manufacture of fertilizer contributes to greenhouse gas emissions. For example, when ammonia (the base product for a number of nitrogen fertilizers) is manufactured, natural gas is consumed both as a feedstock and as an energy source. Some of the carbon dioxide liberated in the process is captured for use in the production of urea (a major nitrogen fertilizer) and other industrial products. Excess carbon dioxide is vented to the atmosphere. In the production of phosphate fertilizers, calcium carbonate is acidulated resulting in the release of carbon dioxide. Smaller amounts of methane and nitrous oxide are release from the combustion of diesel, LPG and natural gas for energy used in the manufacturing process. Grid electricity is also a major energy source used in the manufacture of some fertilizer products.
As fertilizer products are moved around the country and applied to farmland, greenhouse gases are also released via the burning of fossil fuels such as diesel, LPG and petrol.
Fertilizers stimulate crop growth which assists in removing carbon from the atmosphere and fixing it in plant cells. However nitrous oxide can be released from agricultural land, particularly when nitrogen fertilizers are applied and the soil approaches a water saturated state. Nitrous oxide is a significant greenhouse gas.
Nutrient depletion and soil erosion
Some agricultural systems remove more nutrients in farm produce than are replaced. Over time, this results in soil that is depleted of nutrients. Plant production declines and soil is more easily eroded by wind and rain. The eroded soil and any accompanying nutrients can find their way into waterways and contribute to poor water quality.
Other environmental issues
The fertilizer industry has been active in addressing other issues that have potential to cause undesirable impacts. These include:
- the use of fertilizer from organic, industrial and domestic waste streams, which can contain food and environmental contaminants;
- dust and odour at fertilizer manufacturing and distribution sites;
- water and energy use efficiency in manufacturing processes;
- stack (air) emissions from manufacturing; and
- packaging waste.
Fertilizer Australia Response
The greatest risk fertilizers present to the environment typically occur once they are applied to agricultural land. To ensure that fertilizer users receive good advice on managing these risks the industry has developed a national product stewardship program, Fertcare.
Fertcare also covers management of food safety risks related to impurities in fertilizers.
Fertcare is a training, certification and accreditation program delivered by independent third parties on behalf of the fertilizer industry. Fertcare focuses on providing high quality advice to users of fertilizers. This advice assists users to optimise productivity and minimise environmental and food safety risks.
Fertilizer Australia encourages members and agronomists to adopt the international 4R Nutrient Stewardship concept for fertilizer best management practices. The core of this simple concept is applying the right source of plant nutrients (or product), at the right rate at the right time and in the right place. This approach considers economic, social and environmental dimensions of nutrient management and is essential to the sustainability of agricultural systems. For more information on 4R Click Here.
During 2014 Fertilizer Australia commenced the Fertcare Carbon Farming Extension Program which will produce summaries of the best available scientific information on greenhouse gas emissions from fertilizer application and the best ways to manage these risks. This material will be provided to Fertcare participants through workshops and will then be included in the standard training material.
Details of how members of Fertilizer Australia are performing in managing environmental issues can be found in the Sustainability and Stewardship Report. To access the report click on the image above.
More details on Fertcare
More details on the Fertcare Carbon Farming Extension Program including science papers, regional summaries and best practice guidelines: Nutrients and fertilizer information