2018
Impact of Fertilization and Planting Dates on Cover Crops Biomass Production and Nutrient Turnover on Soybean-Corn Rotation Systems
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Contributor/Checkoff:
Louisiana Soybean and Grain Research and Promotion Board
Category:
Sustainable Production
Keywords:
AgricultureField management
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Brenda Tubana, Louisiana State University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Louisiana Soybean and Grain Research and Promotion Board
$24,000
Institution Funded:
Louisiana State University AgCenter
$24,000
Brief Project Summary:

One of the many agronomic benefits of cover crops is their ability to take up and store nutrients. Decomposing cover crop biomass then releases those nutrients in a plant-available form for future crops. This project fills gaps on information that describes the nutrient contribution of cover crops and the resulting impact on the following cash crops. It increases understanding of the relationships between cover crop biomass and nutrient recycling. Efforts quantify nutrient uptake and biomass production of cover crops at different planting dates, as well as measuring changes in soil nutrient levels. The trials used a cover crop mix of legumes, like crimson clover and hairy vetch, with tillage radish, a brassica.

Key Benefactors:
farmers, agronomists, Extension agents

Information And Results
Project Deliverables

A field trial will be established at Ben Hur Research Station with the following treatment structure: 3 plating dates (two week interval) and 2 fertilization schemes (with 0-15-15 fertilizer vs. no fertilizer). All treatments will be replicated four times on plots with a dimension of 6 rows (38 inch wide row) x 50 ft long. Using triple superphosphate and muriate of potash as source of phosphorus and potassium, respectively, fertilizer treatment will be applied and incorporated to soil prior to sowing of cover crop seeds. Cover crops species included a mixed of hairy vetch, crimson clover, and tillage radish. In several demonstration plots on producers’ fields, sub-sample areas will be identified for additional data to take from.
Before chemically burning down the cover crops, biomass samples from a known subsample area will be taken from both research and demonstration plots. Cover crops will be separated by species, counted, and weighed after oven-drying. Soil samples will be taken on the onset of reproductive stage of the following main crop. Both plant and soil samples will be analyzed for nutrient content based on nitric acid-hydrogen peroxide digestion procedure followed by ICP analysis and Mehlich-3 extraction procedure, respectively. Soil organic matter and pH will be also monitored. The nutrients removed by each of the cover crop species will be computed. Grain yield of the main crop (soybean or corn) will be determined as well.
Using PROC MIXED in SAS, analysis of variance for all measured variables will be conducted to determine the significance of treatment effect. For significant effect, contrast analysis will be performed for selected treatments.

Final Project Results

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.