2017
Tracking Cereal Rye Nitrogen Release through Soil Pools and Cash Crop Uptake
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Contributor/Checkoff:
Indiana Soybean Alliance
Category:
Sustainable Production
Keywords:
Field management Soil healthTillage
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Shalamar Armstrong, Purdue University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Indiana Soybean Alliance
$33,574
Institution Funded:
Purdue University
$33,574
Brief Project Summary:

Cover crops have re-emerged as a possible solution to reduce nitrogen (N) loading from agricultural fields. No studies have quantified the percentage of scavenged N return from cover crop residue. Data has shown successful tracking by the decomposition of cover crop residue and estimated release of N from the residue. To address the fate of cover crop residue N following termination more definitively, this project will use 15N techniques to quantify the amount of cover crop N released to the soil; and measure the amount of cover crop residue N utilized by subsequent crops.

Key Benefactors:
farmers, agronomists, Extension specialists, ag retailers, applicators

Information And Results
Final Project Results

Update:
“Tracking Cereal Rye Nitrogen Release Through Soil Pools and Cash Crop Uptake” has been successfully established at the existing Armstrong Lab Cover Crop Research Site at the Purdue Agriculture Research and Education Station on April 1, 2017. Cover crop biomass was enriched using a series of pulse labeling application on April 2, April 11, and April 24. During pulse labeling, small amounts of 15N are “spoon-fed” to the cereal rye to maximize uptake. Cereal rye was terminated on 5/10/2017 and biomass was removed on 5/15/2017.

On average cereal rye produced 2,684 kg/ha of aboveground biomass and 50.5 kg N/ha of N uptake. Cereal biomass was refrigerated until it could be applied to correct micro-plots following corn and soybean planting. Corn and soybean were planted in micro-plots on 5/16/2017 at a rate of 32,000 seed/acre and 150,000 seed/acre respectively. Corn micro-plots received 30 lbs N/acre as starter at planting. A side-dress N application of 150 lbs N/acre as urea was applied at the V5 growth stage. Vegetative growth stages were successfully sampled on 7/7/2017 (Corn, V5) and 7/17/2017 (Soybean, V6). Reproductive growth stages tissue samples for both corn (R4) and soybean (R5) were collected on 8/23/2017. Reproductive tissue samples were separated into stover and grain samples. All tissue samples were dried and ground for analysis of total N and 15N stable isotope analysis. At each plant sampling date, 30cm soil samples were also collected for analysis.

Corn and soybean are expected to mature in early October, and a third tissue sample will be collected at maturity to determine 15N content. The 15N analysis will be conducted on all samples during the winter 2017-Winter 2018, and we expect the preliminary analysis to be available by early 2018.



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.