The decision to utilize late-summer planted forage crops as a feed source may be necessary when in-season crop yields fail to meet expectations or opportunities exist in the current crop rotation. One should evaluate the decision to plant and harvest late-summer planted forage crops carefully. The following steps can help determine your need and ability to plant late-summer planted forage crops.
- Conduct a forage inventory (https://livestock.extension.wisc.edu/files/2020/09/forage-inventory-and-needs.xlsx) to determine your forage needs including a reasonable estimate of known feeds yet to be harvested (e.g. corn silage, corn stalks, etc.).
- Contact your crop insurance agent to determine if a late-summer planted forage crop affects your coverage.
- Determine any potential restrictions as a result of herbicide or other crop protection products previously applied.
- Consult your nutritionist to determine how the forage will be used in the ration.
- Determine that a late-summer planted crop provides a return on investment (https://cropsandsoils.extension.wisc.edu/article-topic/economics-budgets-financial/).
These are the major considerations for a late-summer planted forage crop:
1. Species Selection
Determine if you have fall or spring forage needs. Consider selecting a forage that will provide the level of quality desired for the animals being grown.
- Fall forage needs can be met by a late-summer seeded oats. Fall seeded oats are higher in quality than spring seeded oats: (https://fyi.extension.wisc.edu/forage/fall-grown-oat-forages-cultivars-planting-dates-and-expected-yields/)
- Warm season annuals (sorghum-sudangrass) or forage cocktail mix for mid-October harvest. (https://fyi.extension.wisc.edu/forage/sorghums-sudangrass-and-sorghum-sudan-hybrids/)
- Spring forage needs can be met by planting cereal rye or winter triticale for harvest. (https://fyi.extension.wisc.edu/forage/files/2017/06/Rye_090507_final-1.pdf)(https://fyi.extension.wisc.edu/forage/fall-forage-rye-for-dairy-heifers-and-dry-cows/)
2. Planting Date(s) and Potential Dry Matter (DM) Yields
- Late-summer seeded Oats/Oats and Peas should be planted in the northern half by Aug. 10-15th or September 1st in the southern part of Wisconsin.
- Annual Warm Season Grasses (Sorghum-sudangrass) or Cocktail Mixes should be planted by August 10th Northern, August 15th Southern.
- Cereal Rye and Winter Triticale should be planted for forage purposes ideally in mid-September – Oct. 1st. Plantings can occur later, understanding yield potential will be lower.
- Yields of late summer planted forage crops will vary based on species, planting date, soil fertility, precipitation, growing degree days (GDD’s) accumulated, and the stage of maturity.
|Table 1. Late-Summer and Spring Planted Forage Options for Wisconsin
|Fall oats and peas
|Winter cereal grain
|Spring oats and peas
|Fall oats + Winter cereal grain
|Late-Oct. & Mid-May
|Italian Ryegrass-Legume Mix
|Source: Steve Barnhart, retired ISU Extension forage specialist
Additional information at: https://fyi.extension.wisc.edu/forage/alternative-forage-crops/
3. Soil Test Levels and Plant Nutrient Needs
Fertilization requirements, nutrient uptake, and removal with harvest vary by forage species and soil-test levels. Results from three Wisconsin studies for winter rye, rye and triticale, Italian ryegrass, and Italian rye-legume mixtures are shown in Table 2. Studies showed optimum N fertilization rates of 40 to 85 lb N/a (per cutting) depending on the forage (Table 2). Removal rates did not vary widely between studies with 17 to 18 lb P2O5/a, 81 to 84 lb K2O/a, and 4 to 5 lb S/a removed per ton of dry matter across all forages.
Fertilization guidelines and estimated nutrient removal with harvest for selected summer forages are shown in Table 3. Values shown in Table 3 are for soils with 2.0 to 9.9% soil organic matter and optimum soil-test P and K. Fertilization requirements are based on soil-test level and estimated removal. Fertilization planning for 2024 crops should consider removal of summer-planted forages in addition to guidelines provided by UWA2809. Soil sampling after forage harvest and planting subsequent crops is advised.
Table 2 shows dry matter yield, nutrient uptake (pounds per acre), and nutrient removal (pounds per ton of dry matter) for Wisconsin alternative forage studies.
Table 3 shows dry matter yield, nutrient uptake (pounds per acre), and nutrient removal (pounds per ton of dry matter) for Wisconsin alternative forage studies.
4. 90-Day Precipitation and Temperature Outlook
NOAA (National Oceanic Atmospheric Administration) 90-day outlook maps: https://www.cpc.ncep.noaa.gov/products/predictions/90day/.
5. Weather Conditions at Harvest Time- Plan accordingly
- Fall Harvest – Short days and heavy morning dew may limit your ability to wilt forage to 60% moisture. Have a plan to segregate from other forages if needed.
- Spring Harvest –Spring weather conditions will influence your harvest timing. Monitor weather forecasts and patterns for planting of the next crop.