1a.Objectives (from AD-416)
Quantify the potential for enhanced carbon sequestration as well as possible improvements in water and nutrient uptake efficiencies as a result of specific technologies and agronomic practices in corn-soybean cropping systems.
1b.Approach (from AD-416)
Experiments will be conducted in a combination of rhizotron and growth chambers in the National Soil Tilth Laboratory. These experiments will be conducted as a series of comparisons of seed treatments and genetic material on the early growth of corn and soybean using controlled conditions of soil water, soil temperature, and air temperature.
This project is designed to quantify the potential for enhanced carbon sequestration and reduced greenhouse gas emissions due to increased water and nutrient uptake efficiencies as a result of adopting specific technologies and agronomic practices in corn-soybean cropping systems. The goal of the experiments is to develop an empirical and physiological basis for the observed responses to specific crop protection technologies and to quantify the changes in the carbon, nitrogen, or water dynamics affecting plant growth or modifying the soil carbon and nitrogen dynamics. Multiple parameters are evaluated over the course of the season that will define the potential responses of crops to both seed treatments or genetic traits and environmental parameters. These include water-use efficiency, light-capture efficiency, nitrogen-use efficiency, and plant vigor. To quantify these parameters requires the integration of a number of independent measurements collected over the course of the growing season. Studies have been conducted in growth chambers to compare the growth response of treated and untreated seed in the presence and absence of pathogens. Treated seed versus untreated seed in the absence of pathogens showed no significant difference in leaf area, height, or dry weight for corn or soybean; however, seed treatments increased soybean leaf area and shoot and root biomass in the presence of soil pathogens. Studies in the rhizotron were conducted to evaluate growth response under soil conditions and there were trends toward improving growth and water-use efficiency with seed treatments with soil pathogen and weed stressors added to the soil. An extension of these controlled environment studies is being conducted in the field in which three tillage systems with three production systems are being compared. Project progress is documented through teleconference calls, sites visits, and email exchanges, typically twice a week or more.