Consider establishing alfalfa in August and September

In 1994 we were coming off a record rainfall year. The excessive moisture of 1993 caused many alfalfa stand failures. Back then, I wrote an article designed to increase the interest in establishing alfalfa acreage. A decade later, we have a different set of circumstances that make it an excellent time to increase base alfalfa acreage. Beef, dairy and most row-crop prices are relatively good. Our region still ranks high nationally in beef production. We still have a strong dairy presence. Horse numbers have constantly increased in the past decade. Comparatively, our alfalfa acreage remains small. Considering its excellent feed quality in both hay and grazing systems, we should be producing more alfalfa. Mid-August to mid-September is a very good time to plant alfalfa.

 There are non-manageable conditions such as excessive rainfall, periods of severe summer drought and poor soils that make lower Midwest forage producers leery of alfalfa. Manageable alfalfa production factors in our region are low soil pH, high nutrient demands, timely harvesting and more intensive pest management compared to other forage crops. With a little effort, these concerns can be addressed.

A major component of alfalfa success is stand persistence.

Physiologically, alfalfa does not like wet feet. It is a crown feeder with nutrient uptake occurring from the upper root zone. Lack of oxygen severely affects alfalfa’s root activity. Alfalfa has a deep taproot system that can pull moisture from deeper soil depths, which gives the crop good drought tolerance. Whenever possible, choose well-drained sites for alfalfa establishment.

Alfalfa fields need to be weed free before, during and after establishment. As a stand matures, producers have several herbicide options during the growing and dormant seasons. Generally, with optimum weed control, alfalfa growers can expect an extended stand life. Late summer planting generally has less weed pressure compared to spring planting.

A major reason for alfalfa stand reduction is disease infestation. The most common alfalfa diseases in our region are: bacterial wilt, phytophthora root rot, fusarium wilt, crown rot, sclerotinia, anthracnose, rhizoctonia, leaf spots, black stems, downy mildew and alfalfa mosaic virus. It is not always possible to identify these diseases, but knowing the conditions when they occur will help growers reduce and slow their pressure. Unlike mid-season weed problems, there are no economical disease control options once alfalfa becomes infected. However, knowing the diseases present in a field/ region can help decide which crop rotations and disease-resistant alfalfa varieties are needed. WL brand alfalfa varieties have the best overall disease package in the industry. Please review disease tolerance before selecting an alfalfa variety. Disease pressure is generally lower in late summer compared to early spring-established alfalfa seedlings.

Similar to weeds and diseases, we generally observe less seedling insect pressure in late summer compared to early spring-planted alfalfa. The two most damaging alfalfa insects in the Midwest are the alfalfa weevil and potato leafhopper. Other important insects include aphids, cutworms, grasshoppers and plant bugs. Labeled rates of insecticides applied when insects reach an economic threshold are required for maintaining alfalfa stands in our region.

Fertility is important for producing and maintaining alfalfa. One ton of alfalfa removes 12 to 15 pounds of phosphorus and 50 to 60 pounds of potassium. Depending on soil tests, producers need to apply at least removal amounts of these nutrients annually. Many producers apply all nutrients to alfalfa once, usually after the first cutting. Alfalfa, like many crops (and many of us), is capable of consuming more food than it requires. For this reason, I recommend splitting fertilizer applications, with one-half of the yearly total applied after the first cutting and third cutting. Sulfur and boron should be applied to alfalfa, preferably during the first cutting fertilization. Zinc and magnesium are important and should be applied based upon soil tests. Do not attempt to establish alfalfa unless the soil pH is at least 6.5.

Harvest management is important for maintaining an alfalfa stand. Generally, harvesting at the bud stage produces exceptional quality alfalfa. However, this practice reduces potential stand longevity by 2 to 3 years. By delaying harvest to early bloom, producers may sacrifice some quality but increase persistence. Many agronomists recommend against cutting or grazing alfalfa between Sept. 15 and Nov. 1. This “rest” allows the buildup of root carbohydrates and other root reserves needed for winter survival and rapid crop growth next spring.

Given its feed quality and the number of forage operations in our region, let’s consider spending more time and dedicating a few more acres to this high quality forage. Provided there is enough soil moisture for seed germination and early seedling vigor, I feel late summer is the optimum time to establish alfalfa.