Agriculture is the key to America's economic foundation. It adds about $26.2 billion to Iowa’s economy from food, fuel, fiber, feed and forestry products.
Cropland includes areas used for the production of adapted crops for harvest. Two subcategories of cropland are recognized:
- Cultivated cropland comprises land in row crops or close-grown crops and also other cultivated cropland, for example, hay land or pastureland that is in a rotation with row or close-grown crops.
- Non-cultivated cropland includes permanent hay land and horticultural cropland.
Iowa has 30.6 million acres of cropland distributed over more than 85,000 farms.
Major Natural Resource Concerns for Cropland
Erosion by wind and water
Soil erosion involves the breakdown, detachment, transport and redistribution of soil particles by forces of water, wind, or gravity. Soil erosion on cropland is of particular interest because of its on-site impacts on soil quality and crop productivity, and its off-site impacts on water quantity and quality, air quality, and biological activity.
The economic impact of mitigating soil erosion significantly burdens the agri-business sector and the Nation as a whole. Dust contributions to the atmosphere and delivery of sediment, nutrients, and chemicals to water resources are primary environmental concerns addressed by public policy makers and the stewards of our working land has important long term implications for cropland sustainability, natural resource condition and health, and environmental quality.
Maintaining and enhancing soil health
Managing for soil health is mostly a matter of maintaining suitable habitat for the myriad of creatures that comprise the soil food web. This can be accomplished by disturbing the soil as little as possible, growing as many different species of plants as practical, keeping living plants in the soil as often as possible, and keeping the soil covered all the time.
Soil is managed to its maximum potential through a system of conservation practices, including no-till, cover crops, advanced nutrient and pest management, buffers and drainage systems, where appropriate. This approach results in healthy soil that reduces erosion, requires less nutrient inputs, manages the effects of flood and drought, and reduces nutrient and sediment loading to streams and rivers.
Water quality from nutrient and pesticides runoff
Water bodies require nutrients, such as nitrogen and phosphorus, to be healthy, but too many nutrients can be harmful. Many of our nation’s waters, including streams, rivers and wetlands are affected by applied nutrients to neighboring fields. The effect to a given water body depends on its location and the source of nutrients.
High levels of nitrate in drinking water can cause serious public health concerns. Additionally, increased nitrogen and phosphorus levels in water can produce excessive aquatic vegetation and algal blooms resulting in reduced dissolved oxygen, harmful toxins, and increased water temperature. In extreme cases dissolved oxygen may be so low that dead zones, known as hypoxia, exist where most aquatic life cannot survive. Algal blooms can impart an undesirable taste to potable water that is difficult to remove by water treatment. High ammonia levels are toxic to some freshwater fish species.
Managing the quantity of water available for irrigation
Inefficient use of irrigation water impacts onsite and offsite water quantity and quality. Irrigation systems and water management practices can waste water and negatively affect farm profitability.
Irrigated agriculture is essential in meeting the nation’s food and fiber production needs. Agriculture is the nation’s largest water user, accounting for more than 85% of the nation’s annual water consumption. Emerging problems that further complicate resource protection and water allocation include: serious long-term drought conditions, critical ground water declines occurring in agricultural production areas, saltwater intrusion into ground water supplies, and competition for water among a multitude of water users, including power generation, drinking water supplies, wildlife, recreation, etc.