Nutrient loss from floodplain soil with controlled subsurface drainage under forage production

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Subsurface drainage in forage production can increase nitrogen and phosphorus loading in surface waters.
• Limited research exists on controlled drainage (CD) versus free drainage (FD) impacts in forage systems.

Purpose of the Study:

• To quantify the effects of CD and FD on nutrient and sediment loss in tile drainage.
• To evaluate CD as a best management practice for forage production.

Main Methods:

• Comparison of CD and FD in a floodplain soil with a cereal rye-sorghum rotation and cattle grazing.
• Measurement of total suspended solids (TSS), nitrate nitrogen (NO3-N), and dissolved reactive phosphorus (DRP) in drainage water.
• Analysis of seasonal concentrations and cumulative loads.

Main Results:

• CD reduced NO3-N concentrations by 6.03-9.63 mg L-1 compared to FD.
• CD resulted in 79-90% lower TSS and DRP loads during sorghum seasons.
• CD significantly lowered cumulative NO3-N loads (0.68-6.14 kg ha-1) and discharge volumes.

Conclusions:

• Controlled drainage is effective in reducing nutrient and sediment loss from forage production systems.
• CD minimizes nitrogen and phosphorus loading into surface waters, mitigating environmental impacts.
• CD is a viable best management practice for improving water quality in floodplain soils.