Sustainable High Yields on Poorly Drained Soils For presentation: Water for Food Conference Lincoln, Nebraska May 1-3, 2011 R. Wayne Skaggs
Drainage in United States (Million Ha) Total Cropland 170 Cropland Requiring Drainage 43 (25%)
DRAINAGE WORLD-WIDE(Smedema et al. 2004) Cropland NeedingDrainage 500 Million Ha (33% of Total Cropland)
CROPLAND NEEDING DRAINAGE(Smedema et al. 2004) Million Ha All Cropland 500 (33%) Irrigated Cropland 150 (55%) Rainfed Cropland 350 (28%)
Avg. annual nitrogen yieldMississippi River of streams for 1980-1996 Drainage Basin Hypoxic Zone
Nitrogen Losses in Drainage Water Increase with Intensity of Subsurface Drainage
45 40 35 30 25 20 15 10 5 0 Natural Moderate Intensive Slow Dr. TOTAL NITROGEN 42.1 20.0 13.6 3.6 Total Nitrogen (kg/ha/yr)
Potential Effect of DWM in the Midwest on N Load to Gulf of Mexico • 50,000 ton N per Year • Based on 8.3 million Ac of drained corn and soybean land in the states of Iowa, Indiana, Illinois, Ohio and Minnesota (Jaynes et al., 2008) • NRCS recently (March, 2011) announced a major initiative to promote DWM and related practices in the upper Midwest to reduce N losses to the Mississippi River and Gulf of Mexico.
Agrosphere Modeling for Producing Large Increases in Food Yield A M P L I F Y • AMPLIFY is a initiative enabling public and private sector scientists to partner with producers to achieve high yield in an environmentally and economically sustainable manner.
Hypothesis Drought stresses can be substantially reduced and yields increased by increasing root depths in poorly drained soils in humid regions
Methods to Increase Root Depth • Increase pH to > 5.5 to depths of > 60 cm • Incorporate Organic Matter • Genetic Manipulation