LSU AgCenter rice specialist Dustin Harrell’s agronomy research has shown that fertilizer should be applied on dry ground to minimize nitrogen losses, but this year the ground often was too wet to follow that recommendation.
Because of the rainy spring encountered in 2015, Harrell plans to focus on the wet soil scenario in 2016 to study what should be done when fertilizer has to be applied when fields are saturated or flooded. The study will include split applications, timing and varied nitrogen amounts.
The objective will be to determine alternate recommendations for pre-flood nitrogen fertilization when the weather does not allow for fertilizer applications on dry ground. The alternate recommendations would incorporate recommendations that would possibly compensate for nitrogen losses that would be incurred by using multiple smaller applications.
Harrell also said farmers who participated in the verification program who faced flooded or wet soil spoon-fed nitrogen instead of applying the full amount at once. “We know we have to avoid large amounts if it’s going into the water.”
The agronomy work also includes investigating how much fertilizer should be used on newly released and potential new varieties as they are developed by rice breeders. Varieties are evaluated for their response to nitrogen at multiple locations across the state on an annual basis.
Harrell said farmers need to know how potential new varieties perform at different application rates of nitrogen fertilizer across different soil types and in different environments prior to their release so agronomic recommendations can be made.
Lodging is another important attribute closely looked at in these types of studies.
Harrell continues to evaluate the volatility potential of new and experimental fertilizer sources. Harrell obtained new equipment last year that will allow him to test fertilizers on multiple soil types in the lab year-round. Harrell said the data generated will help him estimate how much nitrogen is lost when fertilizers are applied on the various soil types that are found around the state.
The LSU AgCenter and the LSU College of Agriculture