Environmentally controlled cabinets in the laboratory evaluating ammonia volatilization losses of nitrogen from fertilizers.

Preflood nitrogen fertilizer application in rice production.

Applications of preflood nitrogen fertilizer on muddy ground or into a flooded field are less efficient than applications on dry ground.

Small plot research combine harvesting a water management trial.

The Rice Fertility and Agronomy Project at the H. Rouse Caffey Rice Research Station (HRCRRS) is led by Dr. Dustin Harrell. The overriding objective of the project is to provide an immediate impact on the productivity, profitability, and sustainability of Louisiana rice production and the U.S. rice industry as a whole. This is done by conducting basic and applied research which focus on subjects that have a high potential to improve nutrient and cultural management practices in rice production. Over the past decade, this project has grown and gained a highly reputable standing with the rice industry, crop consulting, and scientific communities.

A major focus of this project has been on improving nitrogen use efficiency in drill-seeded, delayed flood rice production systems. Research has identified that volatilization losses from urea fertilizers left exposed on the surface of a Crowley silt loam surface over a 10-day period could amount to anywhere from 15 to 30% of the total applied nitrogen. The project’s work with NBPT-treated urea indicated that during that same time volatilization losses from urea could be reduced to less than 5%. The efficiency of N fertilizer applications in rice production are dependent upon fertilizer source, soil conditions at the time of application, and the time the N fertilizers are left exposed on the soil surface prior to flood establishment. Current research continues to evaluate these parameters in an effort to improve N fertilizer efficiency in rice production. In addition to N fertilizer research, the Rice Fertility and Agronomy Project conducts research with phosphorus (P), potassium (K), and zinc (Zn) fertilizers in rice production systems which have led to improved soil test-based fertilizer recommendations.

Rice varieties released by the Rice Station have dominated the U.S. rice acreage over the last 20 years. The Rice Fertility and Agronomy Project has worked closely with the rice breeders at the HRCRRS. The project’s research is vital to determining and defining the nitrogen fertilizer needs of new and potential new rice varieties developed at the HRCRRS. In addition, defining the lodging potential of a new variety when pushed with elevated rates of nitrogen is a critical component of the release package of a new rice variety.

The advent of the Clearfield rice and hybrid rice technology caused a shift in rice seeding practices in Louisiana. Louisiana was once dominated with a water-seeded system; however, drill seeding is the most common practice today. This project’s research focused on refining seeding rate recommendations for the new Clearfield, drill-seeded systems. Because of this research, seeding rate recommendations were reduced by approximately 17% while still maintaining maximum rice yields and saving the farmer money.

Ratoon rice production is very important in southwest Louisiana. Current and past research has focused on improving ratoon rice crop yield by implementing stubble manipulation after the main crop harvest, improving nutrient management, and using plant growth regulators.

For more information, contact Drs. Dustin Harrell and Manoch Kongchum.