Producers of alfalfa may be asking whether it’s time to rotate their alfalfa production to another crop. The value of each crop produced should be considered before the decision is made for the 2011 crop, suggests Phil Kaatz, Michigan State University extension forage educator.

Research at the University of Wisconsin shows that shorter rotations of alfalfa means greater profit per acre for the entire farm because of greater alfalfa yield, higher forage quality, reduced pesticide use, greater nitrogen credits and increased corn yields.

Annual yield has the largest impact on alfalfa profitability because inputs, including harvesting cost, change little as yield increases. On-farm measurements of alfalfa yield and inputs showed that yield was the single most important factor determining profit. The relationship is so strong that farmers should do all they can to remain in the high-yield-range with their alfalfa, says Kaatz.

One of the challenges to alfalfa profitability is declining yield with stand age. The declining yield is due to environmental stresses, wheel traffic and diseases. One of the main culprits for thinning stands is alfalfa crown rot. Crown rot may be caused by a complex of up to four types of fungi: Rhizoctonia; Stagnospora; Colletotrichum; and Fusarium. Plant death due to crown rot is often blamed on winterkill, but several studies have revealed greater stand loss in the growing season.

Excessive wheel traffic, especially when fields are wet, will result in compacted soils that reduce air circulation within the soil which results in poor nutrient utilization.

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Source: Michigan State University