Nutrient Management & Application Planning Flashcards

A nutrient management plan must be updated when which of the following occurs on the farm?

Answer: Land use, crop rotation, or yield goals change significantly

Nutrient management plans must be updated when significant changes occur in land use, crop rotation, livestock numbers, or yield goals that affect nutrient needs.

Zinc deficiency in corn typically causes:

Answer: White striping on young leaves and shortened internodes ('white bud')

Zinc deficiency in corn produces characteristic white or yellow striping on young leaves and shortened internodes, sometimes called 'white bud' in severe cases.

Under which soil condition is phosphorus availability to plants generally LOWEST?

Answer: Very acidic soils (pH below 5.5) or very alkaline soils (pH above 7.5)

Phosphorus availability is lowest at extremes of pH — fixed as iron/aluminum phosphates in acidic soils and as calcium phosphates in alkaline soils — with maximum availability near pH 6.5.

When interpreting a manure analysis report for nutrient management planning, which value is used to determine the plant-available nitrogen in the first year of application?

Answer: The sum of ammonium-N and a fraction of the organic N

First-year plant-available nitrogen from manure is estimated as the ammonium-N (immediately available) plus a mineralizable fraction (typically 20–40%) of the organic N.

For a field with a documented history of high crop yields and adequate soil test levels, which nutrient management strategy is most appropriate?

Answer: Use maintenance/replacement rates to replace nutrients removed by the crop

Maintenance fertilization replaces nutrients removed in the harvested crop, maintaining soil test levels and supporting continued high yields without over-application.

Which of the following is the BEST indicator that a nutrient management plan is protecting water quality?

Answer: Nutrient application rates do not exceed crop removal plus buffer amounts

Ensuring that applied nutrient rates do not substantially exceed crop removal plus acceptable soil-building amounts minimizes the excess nutrients available for water quality impairment.

When fertilizer is placed in direct contact with seed at planting (pop-up or in-furrow placement), the MAIN risk to avoid is:

Answer: Salt injury or 'fertilizer burn' to the germinating seed

Fertilizers placed directly with seed can cause osmotic stress and salt injury to germinating seeds, limiting safe rates especially for nitrogen and potassium products.