Conditions which favor volatile losses of nitrogen as ammonia include what factor?

The correct answer is high temperature. High temperatures can increase the rate of nitrogen volatilization as ammonia, particularly in the presence of urea or ammonium fertilizers. When the temperature rises, it enhances the chemical processes that contribute to ammonia volatilization. This is primarily because warmth increases the activity of urease enzymes in the soil, which convert urea to ammonia more rapidly. Additionally, higher temperatures can lead to faster evaporation of water in the soil, further concentrating nitrogen compounds and facilitating their release into the atmosphere as ammonia gas.

While the other choices may influence nitrogen dynamics in the soil, they do not specifically enhance the volatilization process to the same extent. Low humidity can actually reduce the rate of volatilization as there is less moisture to support the chemical reactions involved. High soil pH can also promote volatilization but primarily in conjunction with specific types of fertilizers. Excess rainfall typically leads to nitrogen leaching rather than volatilization by washing nitrogen out of the root zone. Thus, high temperature is the most significant factor favoring volatile losses of nitrogen as ammonia.