Integration of Organic Amendments with Water Table Management Recycling System On Water Quality and Crop Production.

Effectiveness of manure addition and closed-loop water recycling with controlled drainage/sub-irrigation on water quality and crop production were evaluated between 2008 and 2011. Over 50% of farm lands in the Great Lakes region are tile drained. However, the agronomic and environmental effectiveness of tile drainage (TD) options can differ with nutrient management. A study was conducted to determine the impacts of organic fertilizer (i.e. solid and liquid cattle manures) vs. inorganic fertilizer (IF) on crop productivity and nutrient movement under free drainage and water table control systems in a corn-soybean rotation. Four separate reservoirs and water recycling system were used to maintain desired water table control. All treatments were added with same amounts of P and crop available N, except for the P draw-down (PDD) where only N was added. Results from the first rotation cycle showed that the IF control and PDD had the greatest corn yields. The liquid cattle manure (LCM) had the lowest corn yields. The solid cattle manure (SCM) had much higher corn yields than LCM, but slightly lower value than IF control and PDD. It was noticed that there were no differences in soybean yields for all the treatments. However, the LCM organic fertilizer treatments had the lowest total cumulative nutrient loss. The PDD inorganic fertilizer treatments had the highest total nutrient loss followed by IF control inorganic treatments. The SCM organic fertilizer treatments had a similar high nutrient loss as IF control inorganic treatments. The controlled drainage with sub-irrigation recycling system reduced total cumulative nutrient loss by 24 to 37 % relative to traditional free drainage system. This study must be continued to provide valuable knowledge for accessing the long-term cumulative effects of organic manure addition compare with inorganic fertilizer under traditional free drainage and innovative water table recycling management system on crop productivity and water quality