Proper hybrid selection for each field cannot be made without considering soil type first.
When planting on heavy clay soils in high rainfall areas, saturated soil conditions are often a problem. Northern, Eastern, Late Health and Early Health genetic types show the highest tolerance to wet feet, whereas Western, Southern and High Yield genetic types perform poorly when soils are saturated.
The compact, deep-penetrating root systems found in Eastern, Northern, Early Health and Late Health Genetic Families enable growth in heavy soils by penetrating hardpan layers that the more fibrous root systems of High Yield, Western and Southern Genetic Families cannot penetrate.
Though their narrower profile and compact root systems make them more prone to root lodging during heavy winds when soils are saturated, hybrids with Eastern, Northern, Early Health and Late Health Genetic Families can produce a good crop, even if heavy clay-loam soils receive excessive rainfall. Their smaller, more drought-sensitive root systems have a difficult time absorbing enough moisture in the more porous silt-loam and sandy-loam soils, but are more tolerant to the heavier soils receiving excessive rainfall.
The more fibrous root systems of the High Yield, Southern and Western Genetic Families cannot penetrate hardpan layers found in clay soils. However, they have a broader-spreading root profile with more surface area to absorb water and therefore have better drought tolerance on silt-loam and sandy-loam soils. Because their spreading root system develops a wider base and has more surface area in contact with soil particles, these genetic families are also less likely to have root lodging problems when soils are saturated and subjected to heavy winds. Before hybrids can add value to a particular field, the genetics must be adapted to that soil type.
- Corn maturities need to be conservative on heavy soil types because plant growth and development slows down, especially when soils become saturated due to excessive rainfall.
- Corn growth and development speed up on sandy soil types, which means maturities can be stretched later. Large ear types, on sandier, drought-prone soils, with fibrous root systems—such as High Yield x Southern and High Yield x Northern—perform well, whereas Eastern types do poorly.
- The spreading, fibrous root systems of High Yield, Southern and Western types provide better drought tolerance on well-drained soils.
- Western types perform poorly on saturated soils because they are sensitive to wet feet. They tend to be short, and moisture stress on sandy soils develops plants with ears that are too low and leaf canopies that are too thin, which leads to weed-control challenges.
- Most Western-style hybrids prefer well-drained, silt-loam soils, though they do well on clay loams if tiled and not saturated.
- With a Northern x Western combination, placement is more open to positioning on many soil types.
Male Southern Genetic Families have a fibrous root system with a high surface area, enabling strong moisture absorption on well-drained silt loams and sandy loams, but leaving them prone to pancaking on heavy, tight, clay soils.
Male Eastern Genetic Families have thick, deep-penetrating roots that can grow through heavy, tight clay soils, but have a narrow base, making them susceptible to root lodging. Because they’re less fibrous, they are less drought tolerant.
Male Western Genetic Families have a fibrous root system for strong drought tolerance that is less spreading than Southern Genetic Family root systems.
The male Northern Genetic Families’ root system is an average of Southern and Eastern Genetic Families’ root systems.