Location: Crop Genetics Research
Project Number: 6066-21220-014-001-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2016
End Date: May 31, 2021
Objective:
The objectives are 1) to evaluate total nutrient uptake and partitioning in commercially available technology traited soybean vs conventional soybean, and 2) determine economic productivity differences associated with choosing one technology system over the other.
Approach:
For objective one, four soybean technology traits will be evaluated and will include conventional, roundup ready, liberty link, and roundup Xtend. Each technology trait will be represented by two varieties representing a mid to late 4 maturity group. Each variety will be seeded in eight row plots (4 rows for destructive sampling and 4 rows for yield) approximately 11 m in length and 8.1 m wide. Varieties will be seeded at approximately 56,656 seed ha-1. After emergence, stand counts will be taken to determine an early (V4) and final (R8) plant population. Aboveground total biomass will be collected from each experimental unit at V4, R1, R5, R6.5 and R8 from 1 m of row to determine nutrient uptake and partitioning. Biomass will be dissected into leaves and stems for early samples and leaves, stems and yield components for samples after the onset of reproductive growth. After dissection, samples will be dried, ground, digested and analysis for nutrient composition ( N, P, K, S, Ca, Mg, Mn, B, Zn)will be determined by ICP. At R8 harvest index will be determined as well as seeds m2 and seed size. At harvest, yield will be measured with a small plot combine from the center two rows of each plot that was not sampled for biomass. If weather permits, two locations and two planting dates per year for three years will be evaluated. Each trial will be placed into an irrigated environment and arranged as a split-plot, with planting date as the whole plot and technology trait as the sub-plot. Treatments (i.e. technology trait) will be replicated four times.
For objective two, four soybean technology traits will be evaluated and will include conventional, roundup ready, liberty link, and roundup Xtend. Each variety, two per technology trait in the initial year of evaluation, will be seeded in a strip trial design and include four replicates. Inputs for each technology traited variety will be managed as needed/appropriate. That is herbicide and weed control decisions will be conducted on an as needed basis for each variety and with the proper chemical matrix for each trait. Need to include that yield will be measured. All inputs will be recorded and utilized to determine an economic advantage of choosing one system over the other. Growth stage will be recorded weekly for each variety to determine differences in crop growth among technology traits. Rate of canopy closure will be evaluated on a bimonthly basis. Mississippi State University partial budget generator excel spreadsheets for delta irrigated soybean production will be used to determine total production costs of each system.
