Leaf structure and ear flex characteristics can help a field handle stress
Farming today is more than shooting for big yields. Instead, you must look past average field yields and realize the lower-yielding areas are holding down the average, says Farm Journal Field Agronomist Ken Ferrie.
The key to higher production — and more efficient input use — is to identify the stress in each field and manage around it. It starts with choosing the right hybrid and population for each management zone.
FIND THE STRESS IN EACH FIELD
“Most fields have yield variation, even if they look uniform through the windshield,” Ferrie says. “After a few seasons, you know where the best and worst yields are in wet, dry and normal years. Yield maps will show just how much the yield swings, and how many acres are in each zone. If you farm low-yielding areas the same as high-yielding areas, you’ll get less production from the same amount of inputs.” Answer these questions about your low-yielding areas:
- Is the stress annual or perennial? Annual stresses could include areas missed by the fertilizer applicator or affected by herbicide drift from a neighboring farm. Perennial stresses occur every year.
- Is there a (relatively) quick fix? There might be, if the problem is fertility imbalance or lack of fertility. Some stresses, such as insects, nematodes and disease, can be managed every year with pesticides and/or resistant varieties.
- Is the solution practical? Often, the solution to wet soil is to install drainage; but that involves expense and requires cooperation from landlords and neighbors.
FARM AROUND HURDLES
If stress can’t be eliminated, plan to farm around it, Ferrie says. Examples include sandy soil that can’t hold water and high-pH or alkaline soils.
That’s where hybrid selection and plant population come in. If you’re fighting high-pH soil, wet soil or a disease such as Goss’s Wilt, resistant varieties can minimize the impact.
If you’re battling dry soil, lowering plant population makes more water available to plants. Here’s the catch: While lowering population, you still must capture 97% of available sunlight to maximize yield.
So you must understand hybrid characteristics, from your own experience, your seeds rep and test plot results. Here are some examples:
For water-stressed fields, choose taller, pendulum-leaf hybrids that can flex ear size to make up for lower plant population. The pendulum leaves ensure sunlight is intercepted before reaching the ground. Ferrie calls these defensive hybrids because you are managing a stressful management zone.
Plant upright-leaf hybrids on your better, stress-free soil. These “offensive” hybrids require higher populations to capture 97% of sunlight.
Plant recommended population ranges. “Our Farm Journal studies have proven pushing population after you reach 97% light capture stresses most hybrids, but especially those with a lot of flex in ear size, and may actually lower yield,” Ferrie says. “After 97% light capture, increased yield comes not from more plants, but from practices such as fertility
management and pest management.”
Continue to choose hybrids based on yield and performance. “But also make sure they fit your field or management zone,” Ferrie says. “When you spot a high yielder in a neighborhood test plot, find out if the field and management practices that produced it were similar to your own. If not, do not expect the same results on your farm.”
Matching Hybrids to Soil Conditions Pays Off
Matching upright- and pendulum-leaf hybrids, at the appropriate population, to droughty and highly productive soil zones significantly increased return on investment in this 2021 Farm Journal Test Plot study. Figures shown are the difference in gross income with corn at $7 per bushel and seed at $300 a bag. On droughty soil, planting taller, pendulum-leaf hybrids at a lower population maximized the capture of sunlight while making more water available to each plant.
Darrell Smith works alongside Ken Ferrie to break down the systems approach to farming.
