Rain soaked fields - when to water

By Scout Nelson

Following three years of dry conditions, Minnesota farmers are now navigating the challenges posed by excess rainfall. This shift underscores the need for meticulous irrigation planning during crucial crop growth stages, especially considering the current soil moisture.

Vasudha Sharma, UMN Extension irrigation specialist, emphasizes the importance of assessing the existing moisture before further irrigating. Over-irrigation can lead to several issues, including waterlogging, which disrupts root functions and nutrient absorption, ultimately affecting yields.

By monitoring soil moisture, farmers can determine the precise water needs of their crops.

For example, sandy loam soil retains about three inches of water within the top 24 inches. Typically, irrigation is advised when this reserve depletes by half. With a corn crop planted in early May, daily water usage nears 0.15 inches by late June.

This calculation indicates a need for irrigation in 10 days if weather conditions remain dry. Rainfall can extend this interval.

Delaying irrigation offers numerous benefits:

• Water Conservation: Saves water and supports environmental sustainability.
• Reduced Leaching: Prevents nutrient washout, preserving soil fertility.
• Healthier Roots: Avoids excessive moisture that can weaken root systems and enhance susceptibility to diseases.
• Pest Control: Less standing water reduces habitats for pests and diseases.
• Cost Efficiency: Minimizes expenditure on water, fuel, and labor by optimizing irrigation times.

Practical Steps for Farmers:

• Soil Moisture Sensors: Utilize these tools for accurate moisture readings.
• Irrigation Scheduling Tools: Employ applications like the Irrigation Management Assistant to manage water usage efficiently.
• Weather Forecasts: Stay updated on weather patterns to potentially skip unnecessary irrigation.
• Regular Field Checks: Visually inspect crops and soil to verify conditions.

Strategic irrigation management is critical after a season of unexpected rainfall. By integrating technology with traditional field assessments, farmers can make informed decisions that enhance productivity, save costs, and promote sustainable practices.

Photo Credit -istock-laughingmango