Excessive water on crops can happen several different times in the year. Mother Nature has the final say on when too-wet soil conditions occur, but good soil structure and avoiding compaction can minimize the length of time roots stay submerged.
When looking at the concept of water-logging — when your plants have too much water (sorry, drought zone), the interaction between the size of the plant and the time of the year plays a big role in how large the final yield impact will be.
As discussed on episode 86 of The Agronomists, there isn’t necessarily a clear better or worse time of year for it to happen.
Dr. Mario Tenuta, of the University of Manitoba, says water-logging will most severely impact plants under warm temperature conditions.
“Those roots are more active, they need more oxygen, and also the other soil organisms need oxygen as well,” he explains. “Now, early on, when it’s cooler, soon after emergence, that drawdown of oxygen in the system takes a lot longer to occur [than] under the cool conditions.”
While the plant may be able to grow through the water-logging better in the spring, however, it brings a whole different set of concerns, with the top one being disease risk.
“When you have that early season water-logging, now you have started having a plant system that is not really suited well to defend itself, especially its very young root system, and it’s easily prone to various root rots,” Tenuta says. “So yes — they’re more tolerant of it. However, there’s this issue with diseases, so you see your treatments are going to be extremely important. And that kind of situation as well.”
Another consideration is going to be crop type when managing early season water-logging. As Dr. Dave Hooker, of the University of Guelph – Ridgetown Campus, says, when focusing on soybeans, the most critical timing for soybeans is going to be the reproductive stages, while corn is more sensitive during V6 and earlier.