I began my career with the LSU AgCenter in 1982 as the rice specialist with the Louisiana Cooperative Extension Service, a position I was in until I moved to the Rice Research Station to begin working in the variety development project in 1988. Therefore, I have had the opportunity to observe the evolution of rice production in the state over the past 33 years. The changes have been profound. First and foremost is the increased level of productivity during that time frame. In 1982, the statewide average rice yield per acre was 4,160 pounds. In 2015, the average per acre rice yield was more than 7,500 pounds. This is a phenomenal yield increase over this period and is due to a number of factors, not the least of which is improved genetics. The Rice Research Station was established in 1909 with the main mission of evaluating and then later developing superior varieties for improving the viability of the Louisiana rice industry. Through its history the station has excelled in this arena. In 1982, the varieties being grown were typically well over 40 inches in height and very susceptible to lodging (falling over prior to harvest). Most current varieties are close to 36 inches with much higher levels of resistance to lodging. Newer varieties (and hybrids over the past 12 years) also have much higher levels of inherent yield potential.
The Clearfield technology introduced in 2002 has also had a profound effect on Louisiana rice production. This technology allowed for the first time the selective elimination of the noxious weed red rice in Louisiana rice fields. Because it is a close relative, it was impossible to develop a herbicide that would kill red rice without harming the commercial crop. Dr. Tim Croughan and co-workers in the 1990s developed mutated rice lines resistant to herbicides that would kill red rice. After much additional research by many scientists, Clearfield rice technology was born. For the first time rice producers could plant a rice crop and spray it with a herbicide to kill red rice without harming the crop. Not only did this allow for red rice control, but our producers could dramatically change cultural practices. Before Clearfield, the vast majority of Louisiana rice was water-seeded using a pinpoint flood system. This entailed flooding and working fields in the water prior to planting and then draining the fields for a brief period shortly after seeding to allow the rice seedlings to anchor to the soil. The fields were then reflooded and never allowed to dry before harvest drainage. The pinpoint system provided a moderate level of control of red rice by preventing oxygen from penetrating the soil. If no oxygen is available, the red rice seeds in the soil cannot germinate and infest the field. Since the advent of Clearfield, rice producers can now dry-seed (drill or dry broadcast) with full aeration of the soil to encourage red rice seed germination because the technology now allows for the emerged red rice plants to be killed. This not only allows for control of red rice but improves cultural management, especially nitrogen use efficiency. Now nitrogen can be applied on a dry soil surface and incorporated into the soil with the establishment of the permanent flood on 4- to 5-leaf rice. This is a much more efficient system than applying nitrogen on a muddy or flooded soil early in the growing season, which is necessary in a pinpoint flood system. The dry-seeded system is also much more environmentally sound. With the pinpoint system, when fields were drained shortly after seeding, often the drain water had a very high sediment load that caused not only soil erosion but high sediment water moving into the receiving stream. Dry-seeding minimizes this.
Another major improvement has been in the consistency and productivity of the ratoon or second crop. The southwest Louisiana growing season is long enough to allow for a second harvestable crop to be produced on regrowth from the stubble after first crop harvest. Research conducted at the Rice Station has developed techniques for producers to maximize second crop uniformity, productivity and quality of the harvested crop. It was not that long ago that ratoon crop production was often a hit or miss proposition. Today, the ratoon crop is much more dependable and consistent.
Another significant change has been the use of laser-guided systems for precision leveling of rice fields. This technology has dramatically improved flood efficiency and decreased water use in Louisiana rice production. Prior to the introduction of this technology, most Louisiana rice fields had used water leveling techniques to level fields and eliminate levees. The laser technology allowed for much more precise leveling and thus much more precise water level control. Precision leveling, for the most part, eliminated potholes and hills and allowed for quicker flood establishment, with less water and a more uniform flood depth. This has had significant positive impacts on increased rice productivity.
Next month we will discuss additional important changes in Louisiana rice production through the years.
This project was partially supported by USDA National Institute of Food and Agriculture.
Permission granted April 15, 2015 by B. Leonards (LA Farm & Ranch) to republish article on www.lsuagcenter.com