Rains this week should essentially close the door on the 2019 rice planting season. Some areas received far less rain than anticipated, but it seems everyone received enough to put a halt to the week.
Plenty of folks noted that they may have been finished planting a certain percentage of their intended acres, but with this rain they were finished. In other words, anyone who had planted 75% of his intended acres by Tuesday became 100% planted with the rainfall.
Now the focus must turn toward managing what we have in the ground. Warm temperatures are increasing acres going to flood.
We are still surprised there aren’t more acres already enrolled in the DD50 program. Stay on top of that preflood N timing. Eyeballing the growth stage or “age” of the plant is a good way to be late with the timing.
Temperatures next week are set to be mild and very helpful for rice growth and development. We won’t be maxing out on DD50 units, but we’ll have plenty of them and the milder conditions generally mean good things for rice at this stage. Looking at DD50 unit accumulations, you might say we compare closest to 2014 at least as far as recent years.
That would be a good one to match since it still ties for the state yield record with 2013.
This hasn’t been an easy season for anyone, but a few extra thoughts toward those in the Arkansas River Valley affected by the flooding. Farms and homes are underwater and hopefully the water will recede quickly.
Urea Versus Ammonium Sulfate for N Needs in Rice
Ammonium sulfate (AMS) is a more stable fertilizer form than urea when applied to soil. However, the additional cost of AMS is not usually worth it given the low amount of N compared to urea. In some cases, such as with young rice, it may be advantageous to use AMS or even DAP to apply some N in these more stable forms than to go with urea.
When soil is dry, AMS will have less ammonia volatilization than urea. For preflood applications, we can use NBPT-treated urea to reduce the volatilization and it makes more economic sense over AMS.
When the soil is wet (muddy), then AMS is much more stable, but we can still make urea more competitive by treating it with an NBPT product. Again, comparing the cost, it’s easier to apply NBPT-treated urea and the additional N at a lower cost makes it preferable to AMS.
Now what about if we’re applying N into a standing flood, whether at 5-leaf rice or at midseason? The answer is that you should always use urea in these situations, and there is NO NEED to treat it with an NBPT product. Applications of AMS into the water show no advantage over plain urea.