The concentration of ammonia and nitrate in rain water over Israel in relation to environmental factors

Abstract

Ammonia in monthly composite rain water samples from seven stations in Israel shows marked dependence of concentration on soil temperature. The mean concentration during the cool winter months is 0.17 e.p.m. NH+4, while in spring it rises to at least four times higher. Release of pedogenic ammonia from calcareous soils, which becomes accelerated at the beginning of the warm spring, is considered to be the major source of the ammonia. Losses from fertilization with ammonium containing fertilizers may be a contributing factor.

Nitrate concentration is less variable and averages 0.04 e.p.m. NO−3 during the winter months.

Total seasonal washout by rain ranged from about 4 to over 20 kg NH4-N per hectare depending on precipitation or on the average 40 g NH4-N per hectare for each mm rain.