LOSS OF NITROGEN

Timaru Herald, Volume CXLVII, Issue 21449, 13 September 1939, Page 3

LOSS OF NITROGEN

TENDENCY OF SANDY SOILS Light and sandy loams are more apt to suffer loss of nitrogen than heavier soils, due partly to their loose and open character which favours leaching and partly to their favourable condition for bacterial activity. The organic matter content of the soil and its nitrogen are closely associated. Just as the organic matter is dissipated <as by excessive working under certain seasonal conditions), so the nitrogen disappears. On the contrary, methods which increase the organic matter tend to increase the soil’s percentage of nitrogen. Summer-fallowing, a cultural operation frequently necessary in order to eradicate weeds, tends to destroy the organic matter of the soil and thus dissipate its nitrogen. The removal of plant food in crops under irrational systems of farming in which there is continuous cropping and no attempt made to return the elements of fertility, is perhaps one of the most serious factors leading to decreased productiveness of the soil. When the greater part of the crop is fed on the farm, as in dairying and stock-raising, a large proportion of the elements are returned to the land in the form of manure, provided the latter is properly preserved, and steps taken to prevent losses of plant food through fermentation and leaching.