Cotton producers in southwest Oklahoma are smiling about recent rainfall.
But regardless of the weather, farmers should always follow some basic requirements, according to Dr. Randy Boman, Oklahoma State University cotton program director.
"The most important piece of equipment is the planter," he says. "It is important to double check bearings, discs, chains, vacuum system, plates and in-furrow insecticide boxes to make sure everything is in excellent working condition. Badly-worn parts should be replaced to contribute to planting and insecticide application precision. Seed and in-furrow insecticide tubes can be plugged by insects, spiders and trash accumulation. It’s a good idea to make sure delivery tubes are clean and flowing freely."
Boman says 2011 stressful temperature extremes (highs and lows), drought and wind are creating critical challenges to planting this crop.
"Even in better years, we need to realize there is a significant art to planter adjustment," he says. "Each field will likely need to be assessed and, as many producers are aware, even the soil and moisture variability in a given field can result in planter adjustment concerns. Soil moisture (good seed to moist soil contact) level is critical in the zone immediately surrounding the seed. If too much dry soil is moved from the planting zone, hard crusting or "baking" behind the planter can occur, especially if high temperatures, wind and low humidity are a challenge."
Most modern planters, Boman says, have less likelihood of "baking" although it may still be a concern in some instances. He says seed should be planted in good moisture, probably not more than two inches deep, depending on the seed vigor, wind and heat forecast. Dry soil in the seed furrow or incomplete closing of the seed furrow may result in highly variable stands when difficult environmental conditions are encountered.
Boman says a good target is for soil temperatures is at least 65 degrees at the four-inch depth. Because of planting window constraints arising from the number of planters and acres to cover, this can be a nearly impossible goal.
"In 2011, we have been dealt a difficult hand of cards thus far," Boman says. "The good news is that we have good soil temperatures across the region. The bad news is, until recent rains, we had poor soil moisture, if any, under dryland conditions. Dryland no-till fields may be in better shape moisture-wise at greater depths, but for areas that did not receive rainfall recently, it is likely still too dry at the surface without a planting rain."
Most growers with center pivot irrigation opted to pre-irrigate this year to move moisture into the soil profile, Boman says. Producers with pivots could consider three-quarters to an inch of spray irrigation following planting to help insure a stand.
"Even if planted into reasonably good moisture, growers should watch their fields for moisture loss in the seed zone, especially if high winds and heat follow planting," he says. "If producers are planning to follow planting with center pivot irrigation, the seed should not be placed more than one to one-and-a-half inches deep, but make sure it is covered well with soil."
With furrow irrigation, producers have long been waiting for an excellent rainfall event. The reservoir is just under half-full at the time, Boman says, and it was initially thought that most of the available irrigation water would be expended on an "up-front" irrigation run. With the recent rainfall, it remains to be seen what will occur.
If later rainfall occurs in the North Fork of the Red River watershed area, additional irrigation may become available later in the season.
Waiting for rain
"With most of the irrigation district waiting for rainfall for quite some time now," Boman says, "all of the acres will be planted and will emerge later than normal.
"It will be important to insure a reasonably uniform distribution of this water in order to get a good stand. Planting first and then furrow irrigating is a good strategy, especially if large acreages have to be planted.
"My experience with subsurface drip irrigation (SDI) tells me it is risky to ‘water up’ dry planted cotton," he says. "The potential challenges include the amount of time and the delivery capacity of the drip tape.
"It is my understanding most of the SDI in the Lugert-Altus irrigation district was installed in an 80-inch alternate furrow pattern. This means water must penetrate the soil and move 20 inches laterally and soak the seed zone. Since none of the SDI has been pressured up and leaks located, this will have to be done rapidly. Some SDI acreage has been converted to no-till production.
“These no-till fields are likely in better condition with moisture in the soil profile, plus the ground is relatively flat."
"Based on my previous observations, this should be a plus for the SDI to be able to effectively provide moisture in the seed zone."
The clean-till fields with somewhat raised beds likely will be more of a struggle, Boman believes. With the cloddy upper soil structure, it may be important not to place the seed too deeply with the planter, but adequate soil coverage will be important.
"The good news is once the irrigation water is applied, warm air and soil temperatures typically encountered this late in the growing season should result in a rapidly growing crop," he says.