Benefitting productivity and the environment: Current and future maize cropping systems improve yield while reducing...

Area of Science:

• Agricultural Science
• Environmental Science
• Agronomy

Background:

• Cereal crop yield increases enhance global food security.
• Era studies assess genetic and management impacts on crop yield.
• Environmental impacts of maize (Zea mays L.) cropping system evolution remain understudied.

Purpose of the Study:

• To evaluate changes in maize yield and nitrate losses from "Old" (1990s) to "Current" (2010s) and "Future" (2030s) cropping systems.
• To test the hypothesis that improved maize yield and nitrogen use efficiency benefit water quality.

Main Methods:

• Developed a cropping systems era study in Iowa, USA.
• Compared "Old", "Current", and "Future" maize cropping systems.
• Quantified changes in yield and nitrate load + soil nitrate.

Main Results:

• Maize yield and nitrogen use efficiency (kg grain kg^-1 N) have improved over time.
• Yield-scaled nitrate load + soil nitrate decreased by 74% from Old to Current systems.
• Yield-scaled nitrate load + soil nitrate decreased by 91% from Old to Future systems.

Conclusions:

• Advancements in maize cropping systems enhance both yield and nitrogen use efficiency.
• Modern and future maize systems demonstrate significant water quality benefits compared to older systems.
• Sustained improvements are vital for feeding a growing population and protecting ecosystem services.