Down at the local co-op, farm store, or coffee shop, there’s always one guy who, when asked if done with planting, answers, “Yeah, at least for the first time.” Everyone chuckles knowingly because they’ve all experienced having to make the decisions surrounding replanting.
There are a host of problems that may cause one to have to replant soybeans – crusting, flooding, dry soil, insects, diseases, the list goes on. In each case, though, there are common things that need to be considered when making a replant decision.
Is the reason for considering replanting solved or has it improved?
First, replanting into conditions that have already caused reduced populations doesn’t seem reasonable. Be sure to address any emergence challenging situations prior to replanting. If it is heavy rains, flooding and saturated soil – are those rain events over with?
What’s the population of viable plants remaining, and their distribution?
Is there an even stand? Populations as low as 75,000 plants evenly distributed can compensate and provide yields close to or even exceeding your planned goal given good growing conditions. Areas with large gaps or bare ground need to be further evaluated before making the replant decision. Uneven population distribution can impact weed control as well as yield.
In the “Roundup Era,” when glyphosate was often the only post herbicide product used and it was effective, bare ground areas weren’t as much of a challenge, rescue treatments could be made if needed. With the shift in weed species and the development of herbicide resistance, it’s becoming more important to maintain a full crop canopy to prevent late germinating weed seeds from germinating, becoming established and impacting yield.
What are the economics of replanting?
Replanting has associated costs. Weighing the costs to replant with a later planting date versus the benefits of replanting is crucial when making the replant decision. Seed, fuel, additional seed treatments or tillage, and equipment and labor costs all need to be considered. Other costs can also be incurred when replanting.
If you have spots with low populations, you can cause damage to the good areas while planting the empty spots. Growers are often tempted to interplant new seed into thin spots. Research has shown that this practice seldom increases yields, though the improved crop canopy can have a positive effect on weed control.
Every growing season is unique, and all agronomy is local. Many years, even with our best thought out plans and practices, we may need to consider if, when, and how to start over and replant. Just make sure replanting yield pays the bills and gives you a reasonable yield. And in some instances, replanting becomes mandatory