Jason Hartschuh, Extension Field Specialist, Dairy Management and Precision Livestock, The Ohio State University
Spring is an exciting time of the year as we get to start rewriting any mistakes we made last year in forage production to set our farm up for lower feed costs and higher production potential. However, without proper planning, you may be rolling the dice or even hedging towards poor feed quality when it comes to cereal grain forages. The first decision that can still be made for cereal grain forages is the spring nitrogen rate, followed by harvest timing decisions. Spring nitrogen application can increase both yield and crude protein, depending on fall nitrogen application rate and soil nitrogen.
Nitrogen for Yield Increases
We have been conducting a project at the North Central Research Station in Fremont, Ohio to evaluate the effects of spring and fall nitrogen rates on cereal rye yield and quality when the rye was harvested in the boot stage. In both years, spring nitrogen application increased yield when 60 lb./acre or less of fall nitrogen was applied. In 2024 (Figure 1), the yield was maximized when 75 lb./acre of spring nitrogen was applied if fall nitrogen application was 60 lb./acre or less. However in 2025 (Figure 2), if 25 lb/acre of nitrogen or more were applied in the fall, yield was maximized with 30 additional lb/acre of spring nitrogen. Our highest fall nitrogen rates of 75 lb/acre in 2025 or 90 lb./acre in 2024 experienced no yield increase from additional spring nitrogen from 0 to 90 lb./acre. For a stand that received no fall nitrogen, an early application as soon as the crop turns green may provide the greatest increase in tillering to increase yield.
Figure 1. 2024 Cereal rye yield harvested in the late boot stage comparing multiple fall and spring nitrogen rate combinations. Treatments with the same letter above them had the same statistical yield.
Figure 2. 2025 Cereal rye yield harvested in the late boot stage, comparing multiple fall and spring nitrogen rate combinations. Treatments with the same letter above them had the same statistical yield.
Increasing Crude Protein
Forage crude protein is directly linked to plant-available nitrogen during rapid spring growth. Spring nitrogen is much more critical than fall nitrogen for crude protein content. Both years, even when 75 lb./acre or more of fall nitrogen was applied, 60 lb./acre of spring nitrogen was needed to maximize crude protein. When no fall nitrogen was applied, crude protein was maximized with 75 lb/acre of spring nitrogen in 2024 and 90 lb/acre in 2025. As acid rain continues to decline, sulfur applications may someday increase crude protein, as sulfur is a critical component for plants to produce the amino acids cysteine and methionine. In certain soil types like sandy soils or soils with organic matter content of less than 1%, this may already be true. Conducting an on-farm trial with forage analysis is the best way to determine if a sulfur investment is needed on your farm. Manure typically contains some sulfur. At the research farm in Fremont with no manure history, a two-year trial in 2022 and 2023 did not find a yield, crude protein, energy, or digestibility increase from 20 lb./acre of spring sulfur as ammonium sulfate.
Harvest Timing
Harvest timing has the greatest impact on the digestibility and crude protein content. Winter annual cereal grains follow the grass quality curve, with digestibility declining as the crop matures from the early vegetative stage through mid-stem elongation. During this time period, there are only minor declines in digestibility. From flag leaf early emergence through boot stage, there is a major increase in NDF and about a 10% decrease in 48-hour digestibility of NDF (NDFD%). The NDFD% rapidly decreases as the head emerges and grain fill begins. An economic analysis from 2019 showed that high-quality rye, harvested just as the flag leaf emerged, had the highest income over feed cost (IOFC) of $9.80/cwt of milk for any analyzed corn silage, alfalfa, or rye silage combination when fed at 72% corn silage, 28% ryelage, and 0% alfalfa silage. Average quality rye, which would be harvested when the head was in the late boot stage and some plants had heads just started to emerge, resulted in a decline in IOFC to about $9.20/cwt of milk at the same ration inclusion percentage. The most profitable IOFC with average quality rye was 0% rye, 64% corn silage, and 36% alfalfa. The economics of low-quality rye are even worse, with an IOFC of only $8.50/cwt of milk. Chop length should be determined based on other feeds and the total ration inclusion rate of the forage. The ideal chop length for small-grain silage is ½ to ¾ of an inch; however, in some instances, it may be appropriate to chop as long as 1 ½ inches. The longer the chop length, the more difficult it is to pack silage completely, which can lead to spoilage.
Start planning now to have high quality small grain silage to feed this year. Applying spring nitrogen can increase yield if no fall nitrogen is applied, but it is necessary to maximize crude protein. When spring and fall total nitrogen applied is less than 100 lb/acre, our research showed that more nitrogen was removed by the forage than was applied. If using manure as the nitrogen source, it can be applied through Feeks 7 without damage from the drag hose; tractor tires remain visible after Feeks 5. Be sure mowers and choppers are ready as soon as cereal grains begin stem elongation. To maximize quality, it is better to start harvest early when weather conditions are favorable, rather than try to maximize yield and quality when the crop is in the boot stage and rain showers delay harvest until heading. Delayed harvest, causing lower quality forage, can reduce farm profitability for the next year.