Soybean aphids, two-spotted spider mites, fungicide decisions despite little disease pressure, and the hot and dry conditions were some of the more common issues or questions Iowa State University Extension and Outreach Field Agronomists have seen or heard about in fields across the state over the last week. Read on for more specifics about what’s happening around the state.
Northwest Iowa
Dry conditions causing crop stress, herbicide carryover and drift, nutrient deficiencies induced by the dry conditions, armyworms in forages, and a frost event in NE Iowa were some of the common or big issues or questions ISU Extension and Outreach Field Agronomists heard about or received this past week. Read on for more specifics about what’s happening around the state.
North Central Iowa
The best way to break the drought is to write an article from extension about dry weather. So, here’s a stab at trying to make it rain.
Spotty rainfall and dry conditions, replanting/filling in soybean stands, weed management/herbicide application considerations, and fertilizer burn on corn roots were some of the more common concerns or questions ISU Extension Field Agronomists received over the last two weeks. Read on for more specifics about what is happening and being seen in fields across the state.
Northwest Iowa
The dry conditions are causing some to see what is known as “floppy” corn (aka rootless corn). Rootless corn is easy to diagnose – simply dig up plants that are not standing erect like they should be, then gently knock off the soil to get a look at the roots. With rootless corn you will see the seminal roots but no, or poorly developed, nodal roots.
While the warm weather has finally arrived for planting season, dry soil is becoming an increasing concern in parts of the state. In addition to concerns about subsoil moisture, some fields have had significant surface drying, particularly in areas with more tillage this spring. Dry soil conditions have put into question seeding depth. The goal here is to plant the seed into moisture to achieve uniform emergence.
Soybean seed depth considerations
The recent dry conditions across the state, carried through from the 2020 growing season, has created an environment in which field fires are of concern this spring if current conditions continue to persist. Strong winds can increase problems by acting as a catalyst, drying crop residue, enhancing the chances for a fire to be started, and increasing the scope of the fire if it’s already been ignited.
Spring planting season may come with added challenges as growers continue to deal with the effects of last August’s derecho event. Many fields through central Iowa were riddled with downed corn, and while some fields were able to be partially harvested, others were damaged so severely that growers had no choice but to till them under without harvesting any grain. In either case, there will be higher than normal residue levels in these fields this spring.
The dry conditions throughout large areas of Iowa during 2020 reminds us of Iowa’s last significant drought in 2012 and the subsequent impacts on nitrate-N levels in subsurface drainage the following spring. This article will address concerns for water quality in drought conditions and opportunities to reduce nutrient losses from fields this fall.
Chopping silage during rapid drying conditions always bring up the question of “How much water do I add?” The short answer: It is practically impossible to add enough to get to your desired moisture level.
To add one point of moisture for each ton of silage you would need to add seven gallons. For example, if the silage was 55% moisture, you would need to add 70 gallons of water per ton of silage. That would calculate out to be 16,520 gallons of water for a 9’x200’ silage bag.
