Dr. David L. Wright
The focus of my research and extension program has been on real world problems faced by the agricultural industry. Our projects have a strong interdisciplinary perspective and incorporate systems level strategies and objectives to develop viable farm production systems that enhance economics, sustainability, environmental services, and mitigate risks for the operation. Key areas of creative work include: Development of conservation farming systems that integrate perennial grasses/livestock into row crop rotations to enhance soil health, reduce inputs by use of recycled nutrients and utilization of N from legumes and enhancing rooting. Adoption of the sod based rotation in both small plot and farm scale projects has shown the following key findings.
1) Enhanced soil and water quality by increasing organic matter content .1 % per year which has resulted in almost 1 % increase over an eight year period making a significant impact on water and nutrient holding capacity. This has reduced irrigation needs by 50-70% and resulted in crops being grown more cheaply.
2) Increased water holding capacity by increasing organic matter content and creating an environment conducive to increased earthworm populations and better soil tilth. These earthworm holes and bahiagrass root channels allow more water infiltration deeper into the soil profile resulting in more subsoil moisture that can be utilized by crops as well as channels for the following crop to follow.
3) Reduced pesticide use (more than 50%) from having half the system in a perennial grass. We found that perennial grasses reduce plant diseases and nematode levels in the soil to levels not requiring treatment or reduced treatment levels.
4) Increased yield as a result of larger root systems and peanut yield being as much as 50% higher as compared to conventional rotations.
5) Reduced risks since half the farm is out of “cash” crops and perennial grasses can withstand drought, hurricanes, and various other stresses better than annual row crops, therefore, less money is risked each year.
6) Reduced N and K fertilizer inputs of 50% or more due to nutrients being recycled in manure and yields of cotton being improved by 200 lbs/A lint after grazing due to enhanced rooting as compared to cover crops alone.
7) Enhanced microbial populations with both cover crops and grazing during winter months along with indicator enzymes for C, N, P, and S cycling being enhanced indicating a healthier soil.
8) Improved farm income by 2 to 7 fold. With increased yield of row crops after perennial grasses as well as increased forage yields of small grains grown during winter months more profit is realized.
Management strategies for the conservation farming systems have been developed that is utilized in the conservation cropping system. The technology developed has been promoted through on farm demonstrations, short courses, county meetings, on line publications, scientific journals, extension fact sheets and other media presentations. Key findings developed used in the system include:
1) Conversion from tillage to conservation tillage with direct savings of $7-89/A in fuel and labor costs with at least $50/A enhancement in environmental services (less soil erosion, etc.) which amounts to an advantage of more than $.5 bil. to SE U.S. growers alone each year.
2) Deep tillage on Coastal Plain soils prior to planting small grain resulting in an increased yields of 12 bu/A making an economic impact of $100 mil. more income for SE growers.
3) Irrigation and nutrient management scheduling on corn resulting in 50 bu/A yield increase for SE growers or $20 mil. more income for Florida growers and $400 mil. more for SE Growers.
4) Developing management for control of hardlock in cotton which is a severe Florida problem due to humid conditions near the coast. The management with fungicides and insecticides has resulted in doubling of yields by many growers but a consistent 200-300 lbs/A lint yield increase on average for Florida growers adding $20-30 mil. to the economy of Florida growers yearly.
5) Asian soybean rust was found in the U.S. in the Fall of 2004 with the potential of costing U.S. soybean growers $3-4 bil. a year in fungicide and application costs. Over 50 man years of research was done at our location to find that would control the disease including resistant germplasm. More than 2/3rds of the scientific papers written are from our location. Sentinel plots saved U.S. growers $299 mil. the first year in pesticide costs.
6) New research is looking at carinata as a “drop-in” fuel as a winter crop that can be used in conservation cropping systems.