Steven Linscombe | 4/28/2016 4:20:01 PM
Sustainable agriculture is the production of food and fiber using practices that will ensure the ability to continue to do the same into the future. Sustainable agriculture is based on the principle that we must meet the needs of the present without compromising the ability of future generations to meet their needs.
In rice production huge strides have been made in sustainability over the past two decades simply from significant per-acre yield increases. U.S. rice yields have increased from 5,621 pounds per acre in 1995 to 7,572 pounds per acre in 2014. The inputs to produce the crop – including fertilizer, water, energy for pumping, pesticides and seed – have changed little in those 20 years. So, if you consider the output per unit of input, there has been a substantial improvement in sustainability.
Other sustainability considerations include the conservation of soil and water resources for rice production specifically and all agricultural production in general. Agricultural producers and industry leaders have long understood the importance of maintaining these resources. In fact, this understanding led to the creation of the Soil Conservation Service in 1935, whose main function was working with producers and landowners to minimize the effect of agriculture and forestry production on soil loss. The name of this agency was later changed to the Natural Resources Conservation Service to recognize its expanded role, especially in the areas of water conservation and quality.
Louisiana rice production can cite specific examples of improvements in conservation. Ten years ago, most southwest Louisiana rice was grown using a seeding method known as water seeding-pinpoint flooding. This method was used as a means of cultural control of the weedy relative of rice known as red rice. It involved working a seedbed in the water before seeding and then draining the field shortly after broadcast seeding, which was done with an airplane. One drawback of this system was the necessity of draining fields while the flood water still contained a large amount of suspended soil sediments that remained from the seedbed preparation in the water. This could lead to soil erosion from the rice field, as well as increasing the sediment load of the receiving water body. This practice, however, is used much less today because most producers have adopted the use of Clearfield technology, which allows for drill or dry broadcast seeding. In addition, many rice producers have incorporated minimum or no-till techniques into their production systems. This further minimizes soil loss and improves water quality.
Another area often cited in reference to sustainable agriculture is reducing the “carbon footprint” in farming. This is a general reference to the production of greenhouse gases associated with climate change, mainly carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4). In many instances, attempts are made to measure the carbon footprint of every activity associated with the production of a crop, as well as that crop’s end products. For example, in rice this would include not only the carbon equivalent production associated with the field of rice itself but also that associated with the production of the fuel, fertilizer and pesticides needed to produce, harvest and dry the crop, as well as those associated with the processing, transportation, packaging, etc., necessary to make the end product available on the grocery store shelf. In some cases in Europe, food products are being labeled with the estimated carbon footprint associated with that product.
Rice has somewhat of a negative reputation in this area because there is a fairly large amount of methane produced, primarily as a result of the aquatic nature of rice production. It is interesting to note that the amount of methane produced in an acre of rice is much lower than that produced by an acre of vegetative marsh along the Louisiana coast. This is because the rice field is only flooded a few months each year while marshland is flooded year-round. Some might consider it ironic that Louisiana rice production is being questioned because of the methane produced, while every effort is being made to maintain and expand the coastal marshes.
Rice is grown as an irrigated crop in the United States and thus must use a large volume of water. While it might be possible to modify some practices to reduce water use, this is not an area where huge changes can be made in U.S. commercial rice production while maintaining profitability.
Sustainability in agriculture is also measured by how a crop’s production affects the biodiversity of the region where it is grown. Here rice production gets a gold star. The environmental conditions under which rice is grown produce excellent biodiversity and provide habitat for a multitude of species. The co-production of crawfish in many rice fields in the fall and spring following rice harvest in Louisiana only enhances the region’s environmental quality.
Rice production in southwest Louisiana is primarily in the coastal prairies, which are just to the north of coastal marshes. It is well-documented that this region is facing a substantial problem related to the annual losses to the state’s coastal marshes, especially fresh and intermediate marsh. Thus, rice production in this area will only become more important in providing habitat to waterfowl, as well as other water birds.
In southern Louisiana many rice fields are flooded prior to planting beginning in January or February. These fields provide ideal habitat for high-priority shorebird species such as sandpipers, dowitchers, yellowlegs and stilts. These fields are also frequented by rosette spoonbills as well as egrets and herons. Later in the growing season, after the rice has been established and the plants are flourishing, this becomes excellent habitat for numerous species such as rails, gallinules and fulvous whistling ducks. The rice fields and coastal marshes of southwest Louisiana typically provide habitat for more migratory waterfowl than any similarly sized region in the continental United States. Rice fields also provide excellent waterfowl habitat in all U.S. rice-producing states. Thus, in the area of biodiversity, rice is a model crop.
Steven D. Linscombe is American Cyanamid Professor for Excellence in Plant Genetics, Breeding and Variety Development. He is also the director of the LSU AgCenter Southwest Region and the H. Rouse Caffey Rice Research Station.
(This article appeared in the winter 2016 issue of Louisiana Agriculture.)
Rice is planted using a seed drill on the Simon Farm south of Morse. Photo by Bruce Schultz
Rice seeds spread onto a field by airplane have sprouted a few days after planting. Photo by Bruce Schultz
Dustin Harrell, LSU AgCenter agronomist, plants seed on a planter pulled by a tractor driven by Research Associate Jacob Fluitt. Photo by Bruce Schultz
Steve Linscombe, LSU AgCenter rice breeder, records his observations on emerging rice plants in a date-of-planting study at the LSU AgCenter H. Rouse Caffey Rice Research Station. Photo by Bruce Schultz
Steve Linscombe is the director of the Rice Station, which holds a field day every year in late June or early July. People from all over the world have attended these field days. Photo by Bruce Schultz