Evaluating Alfalfa Stands: Stand Counts
Were you expecting more from last year’s alfalfa yields? Did your plants get enough time to winterize in the fall? Do you have concerns about stand winter kill? Evaluating your alfalfa stand in the spring is key to planning management and setting expectations for this year.
As stands begin greening up, alfalfa stand assessment can be completed using a hay square as a quick and easy way to look at the overall stand health. While we call it a hay square, square or circle shapes work equally well. A 17x17-inch square or 19 inch in diameter circle are the size needed.
Next, determine what to count. There are two options when evaluating your stand: 1) by the number of plants per square foot (typically recommended for new stands, planted last fall) and 2) by the number of stems for established stands. Stem count will more accurately predict yield compared to plant number. However, either method will provide information for making management decisions.
Randomly select four to five areas in your field to sample. Then count the plants or stems that would be harvested, typically anything over 6 inches, to determine your count. Then divide those numbers by two to get stems or plants per square foot. For established stands, having four to five healthy plants per square foot or 55 stems per square foot would warrant a productive and healthy stand. Fields with stem counts below 55 see a significant decrease in dry matter production.
For stands planted last fall, you will see more plants per square foot compared to stems. Remember, a good rule of thumb is, for every pound of seed planted, expect three to five plants. New plantings that contain fewer than 12 plants per square foot may need to be reseeded.
Fertilizing Cool-Season Grass
Fertilizing cool-season grass pastures or hayfields is something producers do each year while accounting for forage needs, the value of the forage, and fertilizer costs. With high fertilizer costs this year, many producers are reconsidering this practice or reducing the amount that is applied. Very important to remember is that adequate precipitation is needed to realize the grass response to the fertilizer.
Fertilization of smooth bromegrass pastures should occur in spring through early May. If the nitrogen is a single application, usually between 80 to 100 lbs of actual N per acre is suggested for eastern Nebraska. The recommended application rate declines westward across the state with about 30 to 40 lbs N per acre suggested for the Panhandle.
If doing split applications, usually it's two-thirds in the spring and one-third in the fall when growth resumes on the cool-season grasses. With fertilized pasture, be sure to include a rotational grazing plan that will effectively harvest the extra forage and provide the greatest return on the fertilizer investment. Also remember that adequate moisture is needed with fertilizer applications.
Soil tests could also be conducted to determine more exact amounts needed, particularly for any phosphorus, potassium or sulfur that could be applied.
Research conducted in eastern Nebraska has shown a 30% increase in forage yield with fertilization and the economic optimum rate is between 80 to 120 lbs per acre. A crude protein increase from 16 to 20% was seen with fertilizer applications up to 160 lbs. That is a lot of fertilizer, but it did increase crude protein and organic matter digestibility while decreasing NDF or neutral detergent fiber. Always be aware when applying fertilizer, especially in pastures and fields near water sources such as ponds.
Brome pastures are hardy, and we can and do graze them hard in Nebraska. Haying or grazing operations can benefit if managed correctly with fertilizer.
Spring Flash Grazing
As pastures green up this spring, there may be an opportunity for producers to get some early forage and manage weeds by flash grazing. This can be particularly beneficial for early weeds like cheatgrass or downy brome. Especially problematic in the western parts of the state, cheatgrass greens up early, outcompetes native species, and creates fine fuels that increase wildfire risk.
Targeted flash grazing — short-duration, high-intensity grazing — can suppress cheatgrass if timed right. The best window is during the elongation phase, just before seed set. This is when animals prefer it, nutritional value is fairly high, before it robs your pastures of moisture and nutrients, and most importantly, before it reseeds itself for the next year.
Flash grazing doesn’t have to be limited to cheatgrass. In eastern Nebraska, pastures hit by drought last year can expect a flush of spring and summer weeds. Flash grazing offers a chance to control those weeds while providing valuable early forage — especially if you're delaying full pasture turnout to allow for regrowth.
Similarly in native pastures being invaded by cool-season introduced species like smooth brome and Kentucky bluegrass, flash grazing can be a useful tool. Turn out early, before warm-season species begin their growth (before late May) and graze hard. The cool-season grasses will be targeted, and warm-season natives will have a chance to better compete for resources later.
Strategic spring grazing won’t solve every weed problem, but it can jumpstart your pasture’s productivity.
