Nutrient Management Research Database

This paper covers the "four Rs" of nutrient management as they relate to pecan orchards.

The "four Rs" refer to applying the Right amount of fertilizer of the Right kind, at the Right time, in the Right place.

A brief section on soil-building practice is also included.

Right Kind

• While no form of nitrogen is better than one another, ammonium sulfate is often suggested for use as it decreases pH and can increase availability of zinc, iron and magnesium.
• Zinc chelates are recommended over zinc sulfate, since they release zinc slowly and steadily. This limits the ability of soil to "hold on" to zinc and increases plant availability.

Right Time

• Nitrogen timing depend on a number of factors including fertilizer type, tree age, and crop demand.
• Zinc should be applied in the early part of the season. For mature trees, around sprays are needed. The first at leaf burst (when leaves are unfolding), the second 7 days later, the third 14 days after the second spray, and the fourth 14-21 days after the third spray. Young trees receive additional sprays every two weeks until July.
• Potassium is rarely deficient, so annual applications are only needed on sandy soil when test results show a deficiency.
• Phosphorus can be deficient in lighter textured soils or in high pH soils, and should be incorporated into soil when applied.

Right Place and Right Amount

• Readers should refer to the source for detailed descriptions of fertilizer placement and applications rates.