Levels of some free organic acids in soils and effects of their addition on nitrification

摘要: Summary The presence of volatile, non-volatile (alkendienoic), phenolic and fatty acids in free form natural cultivated soils composts was found most evidently where the environmental conditions nitrifying microflora were less favourable for growth, i.e. Ap horizons (rice paddy). soil tests on inhibitory action these acids, to which added (9,10-dihydroxystearic acid), showed that aliquots capable significant far higher than those types composts. Of organic tested, only exerted effect more 95% at highest concentration tested (833.3 μg × g−1 soil), followed by valeric isovaleric with inhibitions around 50%, propionic acid 36%, 9,10-dihydroxystearic 24.5%. causes contributing inhibition nitrification are anomalous physicochemical characterize type this phenomenon occurs. This does not lead a greater number but also production ammonia, as result abnormal growth ammonifying microflora.