Sustainability of Agriculture at Greenberry Irrigation District
Depending on environmental factors and cultural practices, irrigation can add or detract from the sustainability of agriculture and the environment. In areas with limited aquifers or stream flow, and in areas with certain soil types and climatic conditions, irrigation may be inherently unsustainable. In other cases, inappropriate cultural practices can exacerbate marginal situations and create unsustainable conditions, resulting in dramatic environmental deterioration. This can occur in a very short time.
Conversely, in situations where conditions and cultural practices are appropriate, irrigation can increase sustainability, and indeed provide a degree of control that gives the agriculturalist new tools to increase productivity, crop diversity, and sustainability. This is the case on the Greenberry Irrigation District (GID).
Given adequate supplies of water from the Willamette Basin Project as demonstrated in the Environmental Assessment conducted under the National Environmental Policy Act by the Bureau of Reclamation, irrigation can be used in several positive ways to increase sustainability on the GID:
Grass seed production. Perennial grass seed production can be done in the Willamette Valley without irrigation. However, the ability to irrigate reduces environmental risk and increases production. On dry springs, the ability to irrigate keeps the crop growing to maximize its potential that year. After harvest, irrigation allows the crop to be restarted in late August or early September, getting the stand well established before winter. If rain is late coming in the fall in a non-irrigated situation, it means a weak plant going into winter, which assures a low yield the next year.
Grass seed cultural practices with irrigation. With the phasing out of field burning, farmers have been forced to turn to increasingly harsh pesticides to control weeds. Now, when establishing a new stand of grass seed with irrigation, it is possible to irrigate, work the ground, sprout the weed seeds, remove the weeds mechanically through tillage or with a non-selective, less persistent herbicide such as Round-Up, and then plant the crop.
Grass seed production without irrigation. The ground would be worked with a great deal of dust, planted, wait for rain to sprout the grass seed, and then use a more toxic, selective herbicide to control the weed plants in the established grass stand.
Nutrient timing. As with pesticide use, irrigation may allow more flexibility in the application of synthetic or organic fertilizers through an associated application of water. This decreases the possibility of an unexpected weather event moving nutrients into surface water flows and into streams, a major cause of non-point source pollution.
Crop rotation. Irrigation brings the possibility of many more crops. In the section above on grass seed cultural practices with irrigation and without, it is easy to imagine that each new crop gives new opportunity to reduce environmental aspects and increase productivity when innovatively grown in rotation with a diversity of crops. Crop rotations are important from a soil quality and health aspect as well.
Irrigation efficiency. As a relatively young irrigation district, GID technology is appropriate and advanced in terms of both water and energy consumption. Where western Oregon regulations allow 2.5 acre feet of water per acre to grow a crop, GID members grow most crops on less than half that amount.
Local consumption. Many food crops consumed locally require irrigation. With our increased ability to produce food crops, over time local agriculture can be more focused on the local community as those markets develop. Many food crops now grown on the GID are Food Alliance certified for a local processor, Stahlbush Island Farms.
In summary, irrigated agriculture, while it may seem more intensive, may actually be more in tune with environmental processes and less intense in its impacts on the environment than the more limited crop choices dictated by a lack of irrigation. Irrigation helps limit both environmental and economic risk to both the farmer and the community to which they belong . This is an important genesis for the members of the GID.
