For maximum uniformity of emergence and subsequent maturity, all areas of the field must be well drained and prepared with no crusted, cold or wet areas. Snap beans prefer a well drained soil with a pH of 5.5 to 6.0 but the pH can be as low as 5.0 if Mn or Al are not present in toxic concentrations. Liming to a pH of 6.0 makes fertilizer usage more efficient, however. Beans are sensitive to boron and may experience toxicity problems in fields where boron is naturally high or where it has been added to meet the requirements of cole crops such as cabbage or broccoli. If little or no nitrogen is available in the field, snap beans will nodulate and form symbiotic associations with N-fixing bacteria in the soil even without artificial inoculation.
Modern cultivars require fertilizer nitrogen for best performance, however.
Plants fixing their own N often get off to a slower start in cool spring weather and are less uniform in bloom time and subsequent number of days to harvest, however. Inoculating bean seed with N-fixing bacteria has not been shown to increase yields or even provide nitrogen to snap beans. If not the proper strain, the N-fixing bacterium will be ineffective and possibly parasitic. Fertilization of beans is particularly difficult in sandy soils because the risk of salt injury to snap beans is high. High salt levels cause shriveled or desiccated areas on the foliage which often resemble cold injury.