Fall Newsletter 2025

More Yield with Less N

Comparison of Regional Averages

The chart below illustrates the relationship between nitrogen applied, crop yield, and nitrogen balance, comparing a regional average from 2016 with Dr. Cehrs’ management results over several years. The regional average (blue line for yield and red dashed line for nitrogen balance) shows that yield rises steadily with nitrogen application but begins to level off around 150–200 lbs/acre, while nitrogen balance (unused nitrogen in the system) continues to climb, indicating inefficiency and potential environmental impact.

This chart* compares average regional nitrogen response with Dr. Cehrs’ management system, focusing on crop yield (blue, left axis) and nitrogen balance (red/green, right axis).

In contrast, Dr. Cehrs’ results (blue squares for yield and green for nitrogen balance) show significantly higher efficiency. Careful N and irrigation management resulted in 2019 yields doubling compared to 2018 without adding extra nitrogen. At the same time, his nitrogen balance dropped by 69%, showing that his approach not only boosted productivity but also minimized waste.

The key takeaway is that careful nitrogen management can achieve higher yields and reduce environmental losses, proving that applying more fertilizer is not always the path to better outcomes.

*Source: Southern San Joaquin Valley Management Practices
(https://agmpep.com/wp-content/uploads/20240802_SSJV_MPER_FINAL.pdf)