Document Type


Publication Date



nitrate acid, pussic acid, representative sample

Extension Number

ExEx 8145


Plant Science


If you have drought-stressed crops and still want to use them, there are two options: (1) Bale the crop, or (2) ensile it. In either case, the forage should be evaluated for crop hazards like nitrates or prussic acid (also called hydrocyanic acid, HCN) that are potentially toxic to livestock. Nitrates: Baling will not lower the nitrate levels in a stressed crop once it is cured. In contrast, ensiling generally lowers nitrate levels about 35% once fermentation is complete. To determine nitrate levels in the drought-stressed plants you need a representative sample for testing. To collect a representative field crop sample, define the sample area, determine a sample height, and note the time of day the sample is obtained.


Updated June 2006.