By Daniel Davidson
DTN Contributing Agronomist
This is the year farmers are faced with late planting, prevented planting and replanting decisions all in the same season.
If you couldn't get fields planted by the prevented-planting crop-insurance deadline, or if wet weather and water ponding along with saturated soils or drought conditions force you to replant, you have some tough choices to make.
For fields with drowned-out stands, consider whether the yield and economic returns from a replanted crop will exceed those of the current crop. Of course if the whole field is lost and there is no crop, the decision is easy. Most fields are a mixed bag of drowned and surviving areas. Stand assessment is critical in a these replant situations. If some of the original plants remain, do you destroy them before you replant as they will compete with the replant seedlings. And how much damage will be done to the field just getting in to replant?
Young corn plants (V5 stage or younger) can tolerate leaf damage and flooding and remain viable because the growing point remains below the soil surface. Small corn plants are not tolerant of flooding and survive only about three days in moderate, cloudy conditions. Warm, sunny days accelerate these losses. So if you experience flooding, like a frost in spring, you need to be patient and wait a few days and see if the plant survives. You can also pull up some plants and see if the base is mushy versus firm and cut it up and see if it is blackened and necrotic, which indicates the growing point hasn't survived.
Another consideration that is part of a replant decision is whether to make a hybrid change. By June, most recommendations call for reducing maturity by five days for corn planted from May 20 to June 1, 10 days for corn hybrids planted after June 1. Corn that does not reach black layer by the first hard frost will have low test weight, won't dry, will mold more easily in the field and in storage and will likey be discounted by grain buyers.
Switching to Soybeans
Typically, crop profit potential doesn't swing from corn to be in favor of soybeans until planting is delayed beyond June 10. But remember if you applied nitrogen for the corn crop you may want to stay with corn. If you also applied a residual herbicide on your corn acres the plant-back restrictions may also force you to choose corn.
Not all the issues this year are due to wet conditions. In western Ohio dry soil conditions have hurt soybean emergence, particularly in tilled fields. Before deciding to replant soybeans, dig up some seed and see if it is still healthy or the hypocotyl has emerged and hasn't broken off.
If you find seed is still healthy and germinated, but the hypocotyl isn't broken, wait and it will probably emerge, especially if the soil is moist and the surface is softened after a rain. If many of the hypocotyls are broken you probably need to consider replanting.
We're hearing that a number of farmers in northeastern Iowa and southern Minnesota are filing prevented-planting claims on corn, which is more economical this year than expected returns on soybeans, even if herbicide restrictions aren't an issue. Those vacant fields are perfect candidates for a cover crop to suppress the weeds, protect the soil, and scavenge up all the residual nitrogen into plant biomass.
What types of species work well as a cover crop this summer? Warm forage grass species such as millets (which are in short supply in 2013) and sorghum or Sudan grasses or teffgrass are excellent for scavenging nitrogen and other nutrients and producing biomass either for hay purposes or as organic matter to be returned to the soil. If you wait till August you can plant cool season legumes such as clovers or vetch or dicon/tillage radishes or oats. And by early September you can plant a winter cereal such as rye, triticale or wheat. However if you received a full indemnity payment on the prevented-planting acres, you cannot harvest these forage crops until Nov. 1 or later.
Where wet weather has also limited spraying days, winter annual weeds may already be ahead of you. Mark Loux, weed scientist at Ohio State University, said by June, winter annuals are going to die shortly. You can still beat them up, and control emerging annuals, in corn by spiking glyphosate or Liberty with 2,4-D, dicamba or Status along with atrazine. In soybeans, he says the options are fewer and suggests spiking glyphosate or Liberty with Classic.
If you had out-of-control winter annuals, you may consider applying a residual herbicide with some 2,4-D or glyphosate this fall to buy you more time in next spring.
It's fortunate that the heavy rains this spring have recharged the soil profile in many parts of the Midwest and Northern Plains after a dry winter. Those areas, where a crop has been planted, should have moisture reserves available to handle short periods of dry weather that can occur any summer.
© Copyright 2013 DTN/The Progressive Farmer. All rights reserved.