SOME CARBOHYDRATE FRACTIONS OF A GRAY WOODED SOIL AS INFLUENCED BY CROPPING SYSTEMS AND FERTILIZERS

Abstract

A study was made to determine the long-term effect of two cropping systems and various fertilizer treatments on organic carbon, nitrogen and some of the carbohydrate constituents in Breton plot soils.Organic carbon, nitrogen, hexose, pentose, uronic acid, hexosamine and hexosamine-N contents were significantly greater in soils from plots in a five-year rotation of grains and legumes than in a wheat–fallow sequence. The proportion of organic carbon in the form of hexose did not differ significantly in either of the cropping systems, but the values for pentose, uronic acid and hexosamine were markedly greater in the five-year rotation plot soils.The contents of organic carbon, nitrogen and carbohydrate materials in soils increased considerably following the manure and fertilizer applications, whereas lime had no effect. Manure and fertilizer treatments also appeared to increase markedly the proportion of organic carbon present as hexose and hexosamine.