Fertility Management of Winter Wheat Grown after Alfalfa

Forage hay crops remove large amounts of nutrients from the soil, because of this, levels of available phosphorous, potassium and sulfur are often marginal for crops following forages.

IPNI-1997-CAN-MB10

24 May 2001

Justification

    Forage hay crops remove large amounts of nutrients from the soil; about two to three times as much as annual seed crops. Because of this, levels of available phosphorous, potassium and sulfur are often marginal for crops following forages. While levels of available soil nitrogen are elevated when forage legumes are included in the rotation, some additional N fertilizer to following crops is warranted to maximize yield potential. Another factor to consider in N management after alfalfa is stand termination technique; some stand termination techniques may result in increased need for N in following crops.

    Recently, Cl has been identified as an important element for maximizing yield potential (and reducing leaf spot) in winter wheat cultivars, including the current western Canadian standard, CDC Kestrel. Because Cl uptake is suppressed by high concentrations of soil nitrate, Cl deficiencies in winter wheat crops following alfalfa may be more severe than in winter wheat crops following non-N fixing crops.