Nitrogen rates for various rice lines studied

A major part of the work by Dustin Harrell, LSU AgCenter agronomist and extension rice specialist, is to evaluate nitrogen fertilizer rates and timing for new lines that could potentially become varieties.

“We also want to know the potential for lodging at these nitrogen rates,” Harrell said.

In addition, plant populations are evaluated to determine the optimal seeding rate for new lines.

“That way we can recommend an appropriate seeding rate,” he explained. “Some lines do well at low plant populations, and they tiller well, but too high of a rate can result in lodging and more disease.”

Harrell said his work also focused on furrow-irrigated rice, or row rice, to determine nitrogen rates and timing. The practice is used mostly in north Louisiana, where farmers grew about 30,000 acres of rice with this method.

He also is studying the use of nitrification inhibitors and urease inhibitors to improve nitrogen efficiency.

“One of the things we saw that worked best this year was two split applications preflood, 14 days apart, at the Rice Research Station,” Harrell said. “In general, we have seen optimum nitrogen rates tend to be a little bit higher in the furrow-irrigated system.”

He said the system seems to require 100 pounds of additional nitrogen compared to the conventional practice of growing rice in a continuous flood.

Harrell also said nitrification inhibitors make nitrogen fertilizer more efficient for row rice, but it has little benefit in conventionally grown rice.

His rice research was conducted at the H. Rouse Caffey Rice Research Station and the St. Joseph Research Station, as well as the Charlie Fontenot farm near Palmetto, the Woodsland Plantation near Monroe and the Kyle Hensgens farm near Iowa.

But Harrell said no data was obtained at the Iowa location when all trials were lost because of Hurricane Laura.

Hurricane Delta also rendered Harrell’s ratoon research unusable because the storm shattered much of the grain from the second crop grown in those plots at the Rice Research Station.

Agronomy work photoJPG

Dustin Harrell prepares a sample to be tested in a laboratory with an experimental urease inhibitor to reduce ammonia volatilization. The research uses different soils from across the state, with different temperatures and varying durations. The work is aimed at showing growers potential benefits of a urease inhibitor before flooding.

11/24/2020 9:42:19 PM
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