Location: Dairy Forage Research
Project Number: 5090-21500-002-012-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2021
End Date: Sep 14, 2026
Objective:
1. Evaluate the nutritional status of alfalfa in Wisconsin by conducting a plant tissue and soil sampling survey.
2. Summarize previous Wisconsin studies of alfalfa response to phosphorus (P), potassium (K), sulfur (S), and lime application and contribute to the Fertilizer Recommendation Support Tool (FRST).
Approach:
A survey of the nutritional status of alfalfa in Wisconsin will be conducted during the 2022 and 2023 growing seasons. Each year 50 fields will be sampled with field selection based on the representativeness of soil series used in alfalfa production and cover a range of management practices. Field agronomists will be asked to assist in identifying fields and perhaps collect some samples. Within each field alfalfa tissue samples will be collected at bud to first flower prior to second cutting. Soil samples with be collected to a depth of 15 cm within this same area. Biomass samples may be collected to assess yield. Information about the field such as age of stand, crop and soil management practices, past nutrient applications, and variety will be collected. Data will be summarized and evaluated to determine percentage of fields that have potential nutrient deficiency and if nutrient sufficiency status is related to various soil or management practices. Data will be compared to data collected in 2010 and 2011 to determine if there have been any obvious changes in alfalfa nutrient sufficiency status over the past decade. If time, funding, and potential collaborations allow, up to 20 additional fields may be sampled in Minnesota and Michigan.
Data from alfalfa phosphorus(P), potassium (K), sulfur, and lime response trials from the past 30 years in Wisconsin has been published primarily in conference proceedings, extension bulletins, and reports. These data will be compiled and summarized. The P and K response data will be added to the FRST database.
