Fertilizers for chemical-free burley production

Source from:  tobaccofarmer.com By Traci Bratcher Missun  06/07/2004

North Carolina State University Conducts a Two-Year Study to Evaluate Fertilizer Sources. Producers growing chemical-free and organic burley can use only certain fertilizers on their crop. In 2002 and 2003, North Carolina State University researchers evaluated tobacco yield response to several of these approved fertilizers. Greg Hoyt, Extension soil science specialist, and Laura Overstreet, an N.C. State graduate student, evaluated nitrate of soda (16-0-0), soybean meal (7-1.2-1.5), cottonseed meal (6-3-1.5), composted chicken processing waste (9-3.5-1) and composted chicken litter (3.4-2.5-2.4). Tests were conducted at N.C. State's research stations in Laurel Springs, N.C., and Waynesville, N.C. TESTS AND RESULTS Fertilizers were applied with and without trickle irrigation. Hoyt says nitrate of soda provides readily available nitrogen, but organic sources of fertilizer do not. Organic fertilizers require water to promote microbial decomposition. This activity breaks nitrogen down from organic sources into a usable form. "Cost for trickle irrigation was about a penny per plant," Hoyt says. "While it wasn't needed last year, it was definitely needed under 2002's drought conditions." Soil and plant samples were analyzed to determine nitrogen availability and uptake. With adequate water available, all fertilizers except chicken litter produced good yields (see charts). The tobacco irrigated and fertilized with chicken litter yielded 1,837 pounds per acre in 2002, compared with the use of sodium nitrate yielding 2,289 pounds per acre. In 2003, the chicken litter yield was 2,856 pounds per acre, compared with sodium nitrate at 3,356 pounds per acre. Hoyt says the lower yields for chicken litter were because only 40 to 50 percent of the nitrogen in the litter was available to tobacco. "If litter is inexpensive, it may be cost-effective to apply more litter to get the needed nitrogen." He recommends testing litter because nitrogen content varies. SIGNIFICANCE Besides dealing with restrictions on fertilizer and pesticide use, chemical-free and organic tobacco production systems also require different field management, harvesting, storage and handling practices. For example, organic production and most chemical-free production systems require storing leaf in completely separate facilities from those for traditionally produced tobacco. Overstreet says certified organic tobacco guidelines by the U.S. Department of Agriculture require planting in soil that has not received chemical applications for at least three years. One of the advantages of growing certified organic tobacco is that it sells for about twice the price of traditional leaf. The three-year wait doesn't mean these fields have to be taken out of production. "During this transition, growers can use this ground to produce chemical-free tobacco and sell it at a premium," she says. Chemical-free tobacco production guidelines, determined by the company purchasing the tobacco, originated as a way for growers who used fewer pesticides to market their tobacco in a specialized niche. The advantage is that chemical-free leaf producers receive a price premium for their product without adhering to the more stringent guidelines for producing certified organic leaf. Overstreet says chemical-free tobacco leaf sells at a premium of 25 to 50 percent more than traditional leaf prices. Both Hoyt and Overstreet feel chemical-free tobacco is another viable way for growers to sell leaf. "Many traditional growers feel they're being phased out, and there are some who don't want to grow on the scale they used to," Overstreet says. "This is an option for growers who don't mind a little extra manual labor in exchange for premiums of 25 to 50 percent above average leaf price." Enditem