Bruce Schultz, Gould, Frances I.
The agronomy project under Dustin Harrell, LSU AgCenter rice extension specialist, is an all-encompassing series of studies aimed at improving production efficiency and increasing yields.
“We’re looking at nitrogen fertilizer requirements and optimum plant populations for soon-to-be-released varieties and hybrids,” Harrell said. “This information is extremely important, so producers will know how to manage newly released varieties.”
He said small plot trials are used across the rice-growing area of the state at eight locations. “The past two years, we’ve been looking at a new urease inhibitor,” Harrell said. “It looks like it will be a new tool for rice producers, and hopefully it will be available for the 2019 growing season.”
He said the optimal nitrogen rate, time of application and number of fertilizer applications have been studied for furrow-irrigated rice production. Work in 2018 showed that the optimal fertilizer timing was three split applications seven days apart. In addition, he said, the 2018 work showed that an additional 50 pounds of nitrogen was needed for furrow-irrigated rice compared to conventionally flooded rice.
Harrell said a drone has been used to capture reflectance data of rice fields, which was compared with data obtained from a Greenseeker sensor to find if there is a correlation between the two devices in an effort to develop a midseason nitrogen rate calculator.
“We hope to have a new midseason nitrogen fertilizer recommendation calculator using this technology within five years,” Harrell said.
He said improved ratoon management is another objective of the agronomy project. He wants to know if fertilizer recommendations need to be modified if stubble management is done. Harrell said he also is studying the use of gibberellic acid in the first crop to enhance ratoon yield. Previous work in Louisiana and in Texas has shown that gibberellic acid can increase second-crop yields in some years.
Harrell also conducts volatility studies to measure gaseous losses of nitrogen from fertilizer applications in the field. His lab also has the capability to determine gaseous nitrogen losses from different soil types.
The LSU AgCenter and the LSU College of Agriculture