Soil Fertility Status and Degradation of Munitions Constituent Contaminated Soil.

The United States and other military forces use artillery ranges to practice with and test various types of large caliber ammunition. Often, these munitions do not completely detonate, leaving behind significant quantities of TNT and RDX, which is absorbed into the surrounding soil. These contaminants can possibly move into water supplies. Curiously, some soils seem to effectively bioremediate themselves through microbial degradation of the munitions constituents (MC). These MC are relatively high in nitrogen (N). Studies show that microbes acquire this N as they degrade the MC, especially if the surrounding soil is relatively low in other forms of N. It is hypothesized that this is a driving force behind MC degradation or lack thereof. Nevertheless, plant based nutritional relationships are known to be multifaceted—with growth often limited by nutrients other than N. Microbial “yield” is likely impacted in a similar way. As TNT and RDX are available N sources, microbes utilize these molecules to metabolize carbon. Eight soils were collected from U.S. military installations and thoroughly characterized for N, phosphorus (P), and potassium quantity (Q) and intensity (I) relationships. Additionally, these soils were characterized for various fractions of these nutrients, as well as for basic plant based soil tests. Results show that the relationships between degradation of MC and fertility are more complex than any one simple soils test and that further work needs to be accomplished in order to predict which soils are likely to degrade MC and which will not.