Wednesday, November 15, 2006

Crop Nutrient Availability from Sugar Factory Spent Lime: First Two Years after Field Application.

Albert Sims, 2900 University Ave., University of Minnesota, University of Minnesota, ARC Building, Crookston, MN 56716, Carol E. Windels, Univ. of MN- ARC Bldg., 2900 University Ave., 2900 University Ave., Crookston, MN 56716, United States of America, and Carl A. Bradley, North Dakota State University, Walster Hall 306, Box 5012, Fargo, ND 58105-5012.

Spent lime is a by-product generated during the processing of sugar beet for sugar.  Impurities in the beet juice are precipitated with the formation of spent lime; the purified juice is processed into crystal sugar.  Historically, spent lime has been stockpiled, resulting in large mounds of material near each factory location.  Recent evidence indicates that field application of spent lime may reduce Aphanomyces root rot, a disease increasing in prevalence in sugar beet producing regions.  Chemical analysis of spent lime obtained from factories in Minnesota and North Dakota reveal many compounds containing potential nutrients to growing crops.  Primary focus was on phosphorus (P) and concentrations ranged from 3500 to 7000 mg P kg-1.  Land application of 22 metric tons spent lime (dry weight) ha-1 would apply from 77 to 154 kg P ha-1.  One year after spent lime application in two field experiments, soil test P levels of the surface 7.5 cm soil depth increased linearly 1.7 to 1.9 mg P kg-1 for each 1.0 metric ton of spent lime applied.   Growers will need to adjust fertilizer P rates to account for P applied in the spent lime.

Handout (.pdf format, 3485.0 kb)