Fertilization of Dry Beans
1) Dry beans respond to fertilizer. You need to closely monitor your Nitrogen, Phosperous, Potassium, and Zinc levels.
2) Choose a yield goal that fits
3) Soil Testing. It is recommended that you soil test your dry bean fields prior to planting. (See Recommendation Tables here ). With your soil test results in hand; you will be able to make fertilization decisions based on numbers instead of guessing. By following the soil test recommendations; a cost effective fertilization program can be developed. An effective fertilizer program will help to maximize yield.
4) Fertilizer Applications. Most growers choose to broadcast their fertilizer if a large quantity is needed. Ideally, this should be plowed down or worked in, so it will be mixed into the plow layer. If your fertility levels are adequate to meet your yield goals; a starter fertilizer application can be used to help establish the young bean seeding. When a starter fertilizer is used; never place the seed in direct contact with the fertilizer. One should place the starter fertilizer 2 inches to the side of the seed and by 2 inches below the seed. Note: A starter fertilizer with phosphates can intensify zinc deficiency, especially during cool - moist soil conditions in the spring. Some zinc should be added to the fertilizer to avoid this problem.
5) The nutrients of major concern for dry beans;
A) NITROGEN - The nutrient dry bean needs more than any other is nitrogen. Nitrogen is needed for cell division and reproduction. If too much Nitrogen is applied, plant maturity can be delayed and conditions for white mold enhanced. Nitrogen is a mobile element in the plant. Deficiency symptoms first appear on the lower leaves. The lower leaves first turn a uniformity pale green color. These leaves will later turn yellow. Lack of nitrogen will lower yield.
B) PHOSPEROUS - Phosphorous within the plant supplies the energy to grow and maintain the plant. Phosphorous is an element that is not very mobile in the soil but is very mobile within the plant.
C) POTASSIUM - Potassium helps plants regulate its many functions. Potassium is readily available in the majority of this areas soils. Very rarely does one encounter a dry bean field with potassium deficiency in the MN/DAK area.
D) ZINC - Zinc is a micro nutrient than is very essential for dry bean production. Generally navy beans are more zinc sensitive than pinto beans. Zinc deficiency hinders the development of the plants growing point. This causes the internodes to shorten and the plant to become stunted. The younger leaves of zinc deficient plants become yellow and/or exhibit intervenial chlorosis. zinc deficiency delays the plants maturity and will lower yield.
Soils with pH's of 7.0 or greater need to have the levels of zinc closely monitored. ( see Zinc table here ). Zinc deficiency problems can be corrected with either zinc sulfate, chelated since, or sequestered zinc. Zinc Sulfate can be used to correct the deficiency problem and help build zinc levels in the soil. The chelated or sequestered zinc ( liquids ) can correct the deficiency for the year but provides little or no zinc residual. Some growers will apply liquid zinc with their preplant herbicide to correct deficiencies. A minimum rate of 0.4 to 0.8 lbs of actual zinc per acre should be applied with the herbicide. If zinc deficiencies arise during the growing year can be foliar fed, but it is better to correct the problem before the symptoms show up. When foliar feeding a minimum of 0.2 lbs/acre of actual zinc should be applied. NOTE: Do not tank-mix a Zinc product with either Pursuit or Raptor. Zinc deficiencies can occur early in the growing season if soil temperatures have remained cool and you have a high level of soil phosphorous. When following sugar beets or corn in the rotation, you need to want zinc levels closely.