Arkansas Rice Update 4-7-23

by Jarrod Hardke, Rice Extension Agronomist - April 7, 2023

Arkansas Rice Update 2023-03

April 7, 2023

Jarrod Hardke and Trent Roberts

“I hear the train a’comin’, it’s rolling round the bend.”

Kick the Tires and Light the Fires?

Yet another wild week of spring weather.  Jimmy Buffett could just as well have been singing about those in agriculture when he wrote the line “if we weren’t all crazy we’d all go insane.”  We’re just into April and things have already been interesting enough to last us all of spring.

Do my eyes deceive me or is the precipitation forecast (Fig. 1) clear over Arkansas?  It has been many moons since we’ve seen a forecast like that.  Some may get a crack at things starting on Sunday in the northeast, but Monday will be a bigger moving day.  Central and southeast areas will see Monday as the earliest day and may track further into the week.

The past two days have been cloudy and cool since Wednesday’s rain, so while the wind has started some drying we’re really waiting on warmer temperatures and sun over the weekend to see just how quickly things can dry out.  As we put our foot on the gas, be mindful about where you’re planting what.  Last year we got a little ahead of ourselves during some planting windows and boxed some of our technologies in, planted too soon behind certain burndown herbicides, or in fields that would have carryover issues from the previous year.  Work your plan and avoid costly mistakes.  A coach used to tell us all the time growing up, “do it right, do it light, do it wrong, do it long!”

Let us know if we can help.

Fig. 1.  NOAA 7-day precipitation forecast.

Fig. 2.  Rice has already emerged in central Arkansas.

DD50 Rice Management Program is Live

The DD50 Rice Management Program is live and ready for fields to be enrolled for the 2023 season.  All log-in and producer information has been retained from the 2022 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.

Planting Progress

Jarrod Hardke

The Mid-South keeps trying to get going if the weather will move out of the way.  As of Monday, 4/3, Arkansas was in line with the 5-year average planting progress.  In the upcoming report on 4/10, progress should climb to 10-15%.  The northern part of the state missed some of the rains over the past week, so there’s a wide range of planting progress in different areas from 50% complete to less than 10%.  Meanwhile the central and southern portions of the state have received more rain leading to much lower progress, virtually zero in some areas, but pockets have had a little better luck.

Table 1. U.S. Rice Planting Progress as of April 2, 2023 (USDA-NASS).

Fig. 3.  2012-2023 Arkansas rice planting progress by week (USDA-NASS).

When to Sling That Fertilizer

Trent Roberts and Jarrod Hardke

Optimum timing for phosphorus (P), potassium (K), and zinc (Zn) fertilizer application all depends on your needs and your soil test values.  Spring applications, prior to or at planting, always seem to be most favorable.  This is especially true if you have low soil test values and need higher rates of P and Zn.  But let’s talk details.

We’re going to focus on spring applications since it’s spring, but let’s get the fall application topic out of the way.  Why do we lean away from fall-applied P and K?  Well, it has to do with loss and availability the next season.  For fall applications we’re worried about P being tied up and not as available in the spring when the rice needs it; and we’re worried about K being lost via leaching and runoff and not available in the spring when the rice needs it.  The further in front of the crop that we place nutrients, the more likely they are to be lost or converted to compounds that are less plant available.  The closer to plant demand that we can place nutrients, the more efficient they will be used and the larger the return on that investment.

So back to spring applications – when is the best time to apply?  Let’s go nutrient by nutrient.

If soil tests call for P, it needs to go out prior to or at planting and incorporated whenever possible.  Most of our common P fertilizers (TSP, MAP, and DAP) are water soluble and immediately plant available but it really comes down to how accessible they are to the plant for uptake.  Phosphorus is relatively immobile in the soil so surface applications and applications made in-season require more time to come in contact with the plant roots and be taken up.  Applying P later into the season reduces the likelihood that we’ll get all the P accessible for plant uptake that we need and this can be problematic on soils that test very low in P.

If soil tests call for Zn, it needs to go out as a granular zinc sulfate prior to or at planting and incorporated whenever possible.  Similar to P, Zn is immobile in the soil and surface applications of granular Zn have limited mobility in the soil and will not be accessible for plant uptake until much later in the season.  If corrective applications must be made during the season, we’re forced to rely on chelated liquid formulations (Zn EDTA) that are just as expensive as the granular form, but these liquid apps only address the deficiency and do not increase soil test levels.  Chelated liquid Zn formulations are needed for early season Zn applications when the canopy coverage is low because they increase the mobility of Zn in the soil allowing both foliar uptake as well as root uptake.

If your soil test calls for K, you have a lot of freedom in the spring in terms of application timing.  You can apply the K from prior to planting, up to planting, even up to preflood.  Because K fertilizer is very soluble and relatively mobile in the soil (compared to P), we can easily apply it during the season dropping it into the flood if we need to.

Follow the timing of the fertilizer that has the strictest requirement.  Always consider how hard a deficiency will be to correct in-season.  For instance, Zn deficiency is very hard to correct in-season so being proactive will pay major dividends.  Phosphorus is the next hardest nutrient to manage, so apply early and incorporate if you can, but also know that we can be successful with in-season applications if needed and deficiency is caught early.  There is a large window of opportunity to apply K and effectively maximize yield so the flexibility with application timing is high.  If you need P or Zn, then whatever mix you need to run should go out early and incorporated whenever possible.  If you only need K, then you can run it just about anytime, including with your preflood urea if that works for you.

Another note: There still seems to be a lot of blending of sulfur fertilizers either with the mixed fertilizer or with preflood urea.  The vast majority of our soils do not need any sulfur additions to maximize rice yield, so this is not the best use of our money.  There are sandier fields, and even clay fields with exposed sand veins or sandy areas, that do need sulfur added, but these are still rare overall.  Be smart about how and where you use sulfur to optimize your return on investment.

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.