2018
Maximizing Yield and Quality of Mid-Atlantic Soybean Production with Soil Sulfur Management
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Contributor/Checkoff:
Maryland Soybean Board
Category:
Sustainable Production
Keywords:
GeneticsGenomicsSeed quality
Parent Project:
Maximizing Yield and Quality of Mid-Atlantic Soybean Production with Soil Sulfur Management
Lead Principal Investigator:
Raymond Weil, University of Maryland
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Maryland Soybean Board
$26,031
Institution Funded:
University of Maryland
$26,031
Brief Project Summary:

This research significantly adds to the knowledge of the sulfur status of soybean crops in Maryland and the management potential alleviate S deficiency and increase soybean yield and quality. It addresses practical questions related to the agronomic management of S enhance soybean seed protein-amino acid balance by increasing the proportion of S-containing methionine and cysteine amino acids. Research investigates economical methods of S application, including soil application of gypsum, foliar application of Epsom salts and integration of brassica cover crop mixes. It also aims to evaluate soil tests to find one to predict on which soils crops will benefit from S applications.

Key Benefactors:
farmers, agronomists, Extension agents

Information And Results
Project Deliverables

• In November 2018 we presented a paper to the American Society of Agronomy that we believe was the first report of substantially improved protein quality on soybean achieved by sulfur fertilization (Weil and Notto, 2018).
• We also presented the preliminary results from 2018 soil test evaluations at the November 2018 American Society of Agronomy meeting

Final Project Results

Update:
Field experiments were conducted at the Central Maryland Research and Education Center (CMREC) at Beltsville on two double crop soybean fields and two full season soybean fields. All fields were conducted as randomized complete block trials with four treatments (1) Epsom sprayed at a rate of 77 lbs/acre at first flower, (2) gypsum broadcast at a rate of 500 lbs/acre at planting, (3) combined gypsum and Epsom, and (4) control. Soil samples were collected around planting time from each control plot at 3 different depths (0-10 cm, 10 – 20cm or bottom of A, and 20 cm or bottom of A – 30 cm). Seed samples were collected by hand and yield measurements were collected from the combine. Yield results from 2018 Beltsville experimental fields under extremely wet early season and very dry mid-season conditions indicated that only double crop soybeans responded to sulfur (S) addition. A 14% increase (4 bushels/acre) in yield was observed on double crop soybeans where S was added.

Three different soil tests were evaluated to determine which would most effectively predict crop response to applied S. Three extractants--0.01M calcium chloride, 500 ppm calcium phosphate and Mehlich 3--were used to extract soil S from 138 samples from research sites at CMREC Beltsville and on farm collaborator fields. The extracted samples were sent to Penn State University for ICP analysis. We found S in the top 30 cm of the soil vs. soybean yield in bu/ac showed the strongest correlation with the calcium phosphate extraction. The critical level for that extraction was around 3-4 ppm extractable S as determined by ICP analysis. Extractable S in the subsoil (bottom of A – 30 cm) showed the strongest correlation with the calcium phosphate extraction as well. The critical level for that extraction was approximately 3-4 ppm extractable S as determined by ICP analysis. Only a limited number of sites have been analyzed for yield response and S response, but for these samples the calcium phosphate extraction was the only extraction that trended in the expected direction.

View uploaded report Word file

Addition of sulfur to soils resulted in a 14% increase (4 bushels/acre) in yield on Maryland double crop soybeans in 2018 (a year with an extremely wet early season and a very dry mid season). Good results were obtained using a 500 ppm calcium phosphate extractant to extract sulfur from soil samples and then relate resultant soil sulfur levels to crop yield.

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.