Nutifafa Adotey, an LSU AgCenter post-doctorate agronomy researcher,
places an acrylic chamber over an area of rice plants grown in a
semi-aerobic environment for an alternate wetting and drying project
being conducted by Manoch Kongchum, an LSU AgCenter rice researcher.
LSU AgCenter researcher Manoch Kongchum is studying nitrogen-use efficiency and yield for rice grown under three different irrigation protocols.
In the study Kongchum is comparing conventional delayed flooding with two other methods — alternate wetting and drying and semi-aerobic conditions.
Preliminary results in 2017 showed that alternate wetting and drying reduced the amount of irrigation water by 31 percent. However, this practice reduced grain yield by 4 percent.
In 2018, the alternate wetting and drying water management practice reduced irrigation water requirements by 50 percent and resulted in a 3 percent yield increase compared to conventional, delayed flooding.
The yield difference could be attributed to rainfall. The 2017 rainfall was recorded at 32 inches, but only 12 inches in 2018.
Because of the excessive rainfall in 2017, the alternate wetting and drying plot was watered only once, but in 2018 it was irrigated four times, Kongchum said.
The study used CL153 and the hybrid CLXL745 in 2018. The 2017 study used CL153 and CLXL729.
Kongchum said the project will be continued for 2019 at the AgCenter H. Rouse Caffey Rice Research Station. Then it will be conducted on a larger scale at a farm.
“The research will be continued in order to determine the best option on a large farm scale to maximize profit with less resources or water requirements,” he said.
Kongchum also is studying the differences in methane gas released from the different methods of growing rice.
The LSU AgCenter and the LSU College of Agriculture