Dry Bean Rooting Depth and Water Use
March 30, 2007
Dry bean roots typically grow laterally 8 to 12 inches and downward to a depth of 3 feet or more, although root distribution is concentrated near the soil surface about 90% of the roots will be found in the top 2 feet. Over the course of a growing season, only about 10% of the water used by the beans will be obtained from the soil below 2 feet. Average dry bean water use rates will increase from about 0.05 inches per day soon after emergence to over 0.25 inches per day during pod development.
Dry Bean Planting Rates
Planting rates vary from 40 to 65 pounds per acre, depending on row spacing, plant type and percent pure live seed. Navy beans range from 2,200 to 2,500 seeds per pound. Planting rates suggested for navy beans are 40 to 45 pounds per acre of pure live seed. Studies conducted at various plant populations do not indicate any significant advantage to having populations greater than 90,000 plants per acre for Type I navy beans. Slightly higher planting rates are advised under irrigation.
Pinto beans range from 1,200 to 1,500 seeds per pound. Planting rates suggested for pints are 50 to 65 pounds per acre of pure live seed. Populations of 70,000 plants per acre for Type III (Pinto) beans have been found to be adequate. In some instances, reduced yields were observed when plant populations were below these recommendations. Under irrigation, some lodging has been observed in the Type I cultivars at extremely low plant populations. No relationship between spacing and plant population was found in studies conducted in North Dakota.
Rates should be adjusted for low germination or cool, wet planting conditions. To obtain desired plant populations, overseed live seed by 10 to 15 percent to compensate for losses during emergence. The normal planting depth is about 2-2 1/2 inches. Seed should not be planted deeper unless the topsoil is dry. Plant seeds in moist soil if possible. Growers should test their planter on a hard surface and in the field at normal planting speeds to ensure proper depth and seeding rate.
From the NDSU ProCrop Database:
NDSU Crop Production Page -- With links to 2007 NDSU Herbicide, Fungicide, and Insecticide Guides, as well as other crop production bulletins and NDSUs weekly crop/pest report: www.ag.ndsu.nodak.edu/cropprod.htm
University of Minnesota Extension Service -- Click on the Farm link. www.extension.umn.edu
Pesticide Labels -- Excellent resource on all current pesticide and adjuvant labels, with links to pesticide manufacturers: www.cdms.net/manuf/default.asp
Ontario Dry Bean Production Info -- www.omafra.gov.on.ca/english/crops/field/beans.html
Northarvest Bean Growers Association Research & Production Library -- www.northarvestbean.org/html/research.cfm