What is the appropriate time to rotate an alfalfa crop rotation stand? “Rotation” is best understood as a revitalization of the alfalfa plant and its surroundings. According to alfalfa specialists, a healthy stand should have at least twenty-five shoots from two plants per square foot for dryland alfalfa and forty shoots from three plants per square foot for irrigated alfalfa in order to be considered fit for rotation. I use the general rule of thumb that most alfalfa stands yield 20 to 24 cuts per stand.
Alfalfa fields should preferably be planted with another crop for a least of one year, but ideally for two years. It is best to avoid planting alfalfa directly after another because studies have indicated that this can lower yields by as much as 30% during the first year of the new alfalfa stand’s life. Apart from getting rid of an old, worn-out alfalfa plant, what other advantages may alfalfa rotation offer? Paul Vincelli and Ray Smith of the University of Kentucky state in Managing Diseases of Alfalfa that since most alfalfa diseases cannot live in the absence of a host plant, switching to a different crop for a few years can help lower pathogen numbers in the field.
How soon can alfalfa crop rotation be planted following alfalfa?
For Oklahoma, small grains are a wise choice. There aren’t many suitable alfalfa rotational crops in Oklahoma. After alfalfa, cereal crops and annual forage grasses are the greatest rotational crops. The nitrogen that’s produced after alfalfa is ploughed can help small grains. Alfalfa could be followed by corn and sorghum in regions with sufficient rainfall or access to irrigation. It has long been known that cereal crops planted after alfalfa increase in yield. Alfalfa’s fixation of nitrogen has a major role in all of this. The season and quantity of nitrogen-rich top growth present at the time of ploughing determine how much nitrogen is ploughed down. The following crop year recovers around 25% of the integrated N that was lost when alfalfa was ploughed under.
Most likely, the crop that comes before alfalfa is more important. Enough time should be available to prepare a good seedbed. In September, alfalfa can be planted after the seedbed has been sufficiently prepared by harvesting a small grain crop in June. Alfalfa can also be sown in the fall, after soybeans and early corn. However, field issues (fertility, drainage) must be resolved quickly, and sufficient rainfall is needed to restore soil moisture. To prevent the rush, it’s often best to harvest summer crops and wait until the following year to sow alfalfa. It is normally best to avoid using legumes such as soybean, peanut, or other species immediately before or after alfalfa, as they do not effectively reduce the build-up of disease organisms.
Can I thicken up my thin alfalfa crop rotation stand?
Sometimes very thin first-year stands can be made a little thicker. Old thin stands are difficult to thicken. When alfalfa is sown into thin, ancient stands, few of the new seedlings typically grow into productive plants. A thin stand should have its causes assessed and fixed before being reseeded. In established stands, pests that accumulate in and on older plants might affect seedlings. Mature plants have an advantage over seedlings when it comes to light, water, and nutrients. An older stand should be burned and the field cycled to another crop for a few years before reestablishing alfalfa if it has thinned to the point where it is no longer profitable.
Drowned-out locations: Replanting in “drowned-out” spots is tempting. Only if the causes of the damp areas are addressed is this justified. Alfalfa can be successfully established after enhancing drainage and creating a healthy seedbed. If the issue is not fixed, attempting to replace damp areas with fresh alfalfa typically leads to further stand collapse. Thin seedling stands: Autotoxicity issues are unlikely to arise in thin stands that are younger than a year old. If inadequate seedbed preparation, delayed planting, or wash-out (or blow-out) caused the narrow stand from a fall-sown stand, then early spring overseeding into thin patches could thicken sections with less than 5 plants/ft2.
The right requirements are satisfied and a cautious process is adhered to. All of the requirements for no-till seedbed preparation are the same as for conventional seedbed preparation: a pH that is suitable and sufficient soil fertility; good drainage both internally and externally; sufficient control of weeds and insects; and enough moisture for alfalfa seedling germination and growth. A minimum amount of plant residue on the soil’s surface is necessary for no-till planting in order to prevent shade for seedling alfalfa. Moreover, a no-till drill that is designed to plant alfalfa must be used for planting.If any of these parameters are not met, no-till alfalfa establishment is likely to fail, resulting in the loss of expensive investments in fertilizer, seed, and other supplies.
The best time to establish no-till alfalfa is in the fall, when fertility issues and drainage issues have already been resolved, with little grain stubble. Controlling weeds in the summer before planting and managing insects on alfalfa seedlings will be the two main issues. If there is no left-over row effect, planting no-till alfalfa alongside early-planted soybeans should also be successful. It is feasible, but not guaranteed, for alfalfa to establish itself in grass sod before then. The main issues are that alfalfa seedlings are shaded and cannot compete with other plants for soil moisture. After planting, the likelihood of success rises if herbicide-treated sod strips are dead and there is an abundance of rainfall or irrigation.
Indeed, in fields where persistent herbicides like GLEAN and AMBER were applied for weed management in wheat the previous spring, damage (stunting) of newly planted alfalfa has been noted. In certain Oklahoman fields, the application of sulfonylurea herbicides (such GLEAN and AMBER) on the wheat crop prior to alfalfa planting has left the alfalfa seedlings severely stunted. This has been especially noticeable in the summers after herbicide application that are dry. Always read pesticide labels carefully and abide by crop restrictions for your own safety. This involves accurately documenting the following: Which chemical was used; When it was applied.
The extent of the application. There are presumably numerous instances of herbicide carry-over causing harm to alfalfa every year. Poor alfalfa stand establishment is frequently attributed to weather, weeds, or variety when, in reality, it is the result of herbicide overuse, such as forgetting when, what, or how much herbicide was given to prior crops.