Timely Irrigation

Moisture During Podfill Is Essential For High Soybean Yields

STONEVILLE, MISS.
   “Get the water on and off quick on small beans.” That’s the message Dr. Trey Koger, Soybean Extension Specialist, delivered recently at the Delta Research and Extension Center Field Day in Stoneville, Miss.
   He spoke of situations where the ground has cracked significantly especially on heavy clay in the past spring’s environment.
   “We don’t want to let these soils get into this situation, but about all of us really saw this this spring,” Koger said. “Actually these cracks have helped us in some situations where we’ve turned the water on and were able to get the water down into those cracks, which actually served like a little bit of a trench. These cracks in some situations have helped these small beans even though we don’t want to ever get in this situation.”
   Farmers have pumped a lot of water and have watered a lot of small beans, as well as some not so small.
   “We’ve got a very, very late crop and we’ve had to manage this crop a little bit differently,” he continued. “We have been able to tell where we’ve been watering well and where we’ve not been watering well. So we have crops all over the board, some really good looking crop, and unfortunately a lot more that looks just fair; then we have some crop that looks poor that have a long way to go; but it has potential. It has a lot of potential.”
   The condition of the crop is very indicative of the planting date. Beans were planted from late March to mid-July and they’re still being planted, so the condition of the crop is all over the board.
   “One thing I would probably add is, it’s best to move to an earlier planted crop for a lot of reasons: One, to take advantage of early season moisture, and two, to avoid some late season disease and insect pressure,” he said. “That will save some money and make bigger yields. With this late planted crop we’re right back in that window where we’re going to deal with a lot of insect pressure, likely some disease pressure, but especially insect pressure. We can make really good yields, we’ve got all the tools and the thresholds to manage those. We can sweeten that if we spend a little bit of money, and that can make us a lot of money, with this year’s soybean crop especially.”
   One thing he urged farmers not to do is let the beans start wilting or going through moisture stress. That can cause upwards of 15 percent reduction in yield potential. It’s most critical to get water on soybean from the early reproductive through late reproductive growth stages from R2 through R6.
   “If we get behind watering at this time, it’s extremely difficult, almost impossible, to catch up with pivots on these beans that are going through the reproductive growth stage,” he said.
   Outside of the Delta, a lot of the crop is dryland and that’s especially in the hands of Mother Nature.
   “If we get some good showers and some good rain we’ll make a good crop,” Koger added. “If we don’t, it’s going to be a crop that’s pretty tough, pretty dismal; but if we can break this dry cycle, I think we can make a pretty good crop. We’ve just got to catch some rains.” Δ
   BETTY VALLE GEGG-NAEGER: Senior Staff Writer, MidAmerica Farmer Grower  

Dr. Trey Koger, Soybean Extension Specialist, Delta Research and Extension Center, Stoneville, Miss. discusses water on soybeans. Photo by John LaRose, Jr.