Arkansas Rice Update 5-17-24

by Jarrod Hardke, Rice Extension Agronomist - May 17, 2024

Arkansas Rice Update 2024-07

May 17, 2024

Jarrod Hardke, Trent Roberts, and Bob Scott

“Won’t you give me something, something to hold onto.”

Frustrating Weather

Some areas with rice remaining to be planted were able to make headway this week, though scattered rains yesterday once again threw in a wrinkle.  Expected mid-week rains ahead my lead right into the prevented planting date for remaining acres.

Beyond trying to finish up planned acres, the wind speeds, direction changes, and rains continue to make herbicide applications difficult, and keeping those applications off surrounding fields and crops more difficult.  There is plenty of rice out there that looks great, but there is a definite uptick in the number of fields getting banged up from off-target movement.

I expected more fields to be pushed to flood this week though with the winds and erratic moisture conditions getting fields both sprayed and fertilized proved more difficult.  The weekend into early next week looks very favorable for weather to allow progress to be made (depending on how much rain was received last night).

Those in agriculture should never curse a rain, but at this point I would like to request that we save some of this for later in the summer when we can make the most of it.  Right now it just continues to be frustrating.

Let us know if we can help.

Table 1. U.S. Rice Planting Progress as of May 12, 2024 (USDA-NASS).

Fig. 1.  2012-2024 Arkansas rice planting progress by week (USDA-NASS).

Fig. 2.  NOAA 7-day precipitation forecast.

New on Arkansas Row Crops Radio:

Weeds AR Wild Series, S4 Ep 5:  Talking Rice Weed Control with Dr. Ford Baldwin

Ricing Around

Jarrod Hardke

With more growers having some acres of pureline varieties this year than they may have recently grown, there are a few items to point out to give varieties the best chance of success.

• Don’t be late on preflood nitrogen – the penalty is greater with varieties as the preflood N drives tillering and varieties aren’t as good at scavenging for soil N when you’re delayed.

• Flood management matters more – keeping adequate moisture in fields and not letting the flood subside will help protect the rice from drought stress (more prone and greater penalty than hybrid), and you risk releasing grasses – varieties can be less competitive with them.

• Varieties are just less forgiving in general. Small mistakes or ill-timed management decisions compound quickly in pureline rice fields and can lead to greater yield penalties.

• Applying urea (treated with NBPT) to drying ground can be done successfully when we allow the ground to dry after the application before flooding. The key point is that we want the soil to be as dry as possible prior to rainfall or irrigation incorporation which moves the urea into the soil.  The level of soil moisture or dryness will dictate whether urea actually moves into the soil or dissolves in the floodwater.  When urea does not move into the soil and dissolves in the floodwater we get much lower N uptake by the rice plant, greater N loss potential, and are more likely to see yield reductions or N deficiencies later in the season.  A general rule of thumb is that if soil doesn’t stick to your boots you are OK, but obviously the drier the better.

Bobbing and Weeding

Bob Scott

Scattered thoughts on weed control:

• Many calls this week on putting out grass herbicides or graminicides.

• In rice these include Provisia, Highcard, Clincher, and Ricestar.

• Most questions revolve around tank mixes as these types of products historically have antagonism issues.

• In general, you should not tank mix these products with phenoxy herbicides like Grandstand or 2,4-D.

• The ALS chemistry which includes products such as Permit, Gambit, and Newpath/Preface are less likely to cause problems.

• Residual products such as Facet, Command, and Prowl usually complement these products in tank mixes and are recommended.

• Refer to the label or MP44 for specifics.

• Especially avoid tank mixes if the grass is large and you need to be sure that the grass herbicide works.

• It’s good to put a day or two between the grass herbicide application and the broadleaf application.

The Missing Zinc

Jarrod Hardke and Trent Roberts

We regularly, and increasingly, emphasize the need for proper zinc (Zn) fertilization in rice.  However, there have been several calls this spring where Zn was left out of the preplant fertilizer mix and folks are looking for guidance on how to address that oversight.

As a quick reminder of our general Zn recommendations:

• Apply 10 lb of Zn per acre as a granular fertilizer before emergence on silt and sandy loam soils when:

  • Soil-test Zn is < 4.1 ppm and pH is > 6.0.

  • Soil-test Zn is <1.6 ppm and pH is < 6.0.

• For salvage management of Zn deficiency, apply 1 lb actual Zn per acre as EDTA chelate to drained soil and fertilize with 100 lb/acre AMS and re-flood.

So, if you are in a situation where you needed to apply 10 lb Zn per acre at planting but it was left out, our recommendations would be to apply 1 lb actual Zn per acre as EDTA chelate with your preflood herbicide application.  This will address your Zn needs for the current crop season but will not help build for the future to allow us to get away from annual Zn applications.

Nitrogen Application and Rainfall

Jarrod Hardke

Applying preflood nitrogen to rice in and around rainfall events can be tricky.  With that, conversations have turned to the possible outcomes of receiving rain shortly after applying preflood N.  Fig. 3 is a reproduced graph showing the amount of N volatility 8 days after a simulated rainfall event.  To clarify, urea was applied to dry soil, then rainfall was simulated ranging in amounts from 0.125 to 1 inch, then allowed to remain as volatility was measured.

The gist is that as long as we use urea treated with NBPT (e.g. Agrotain) our chances of significant N los to volatilization are low whether we receive any rainfall, and it is reduced even further the more rainfall we receive.  So don’t be overly concerned if you catch a shower after NBPT-urea application.  Even if you chose to not use NBPT, volatility is reduced by rainfall and urea incorporation.  Another thing to consider is that these results are from urea applied to initially dry soil.  If the soil has been moist or wet prior to urea application the ammonia volatilization loss would have been much greater.

However, the study showed that using NBPT-urea resulted in higher grain yields than untreated urea, becoming more pronounced when ½-inch or greater rainfall was received after application.

Short version – use NBPT-treated urea and have confidence in holding onto your N and rice yield potential regardless of rainfall events.

Fig. 3.  Cumulative nitrogen volatilization loss 8 days after simulated rainfall.

Chart recreated from Dempsey 2015 (UA Thesis).

CBOT September Rice Futures, 10-Year Monthly Continuation.

DD50 Rice Management Program is Live

The DD50 Rice Management Program is live and ready for fields to be enrolled for the 2024 season.  All log-in and producer information has been retained from the 2023 season, so if you used the program last year you can log in just as you did last year.  Log in and enroll fields here:  https://dd50.uada.edu.

Use the Arkansas Rice Advisor Internet App!

The Arkansas Rice Advisor site https://riceadvisor.uada.edu functions like an app on your mobile device.  There you can readily access the DD50 program, rice seeding rate calculator, drill calibration, fertilizer and N rate calculators, publications, and more.

Additional Information

Arkansas Rice Updates are published periodically to provide timely information and recommendations for rice production in Arkansas.  If you would like to be added to this email list, please send your request to rice@uada.edu.

This information will also be posted to the Arkansas Row Crops blog (http://www.arkansas-crops.com/) where additional information from Extension specialists can be found.

More information on rice production, including access to all publications and reports, can be found at http://www.uaex.uada.edu/rice.

Acknowledgements

We sincerely appreciate the support for this publication provided by the rice farmers of Arkansas and administered by the Arkansas Rice Research and Promotion Board.

The authors greatly appreciate the feedback and contributions of all growers, county agents, consultants, and rice industry stakeholders.