Ml. Burle et al., EFFECT OF CROPPING SYSTEMS ON SOIL CHEMICAL CHARACTERISTICS, WITH EMPHASIS ON SOIL ACIDIFICATION, Plant and soil, 190(2), 1997, pp. 309-316
The soil under intensive cultivation and low addition of crop residues
is exposed to erosion and reduction of organic matter. Increases in s
oil organic matter, cation exchange capacity (CEC) and nutrient availa
bility may occur in no-till systems with legumes and with large additi
ons of organic residues. Nevertheless, some legumes may increase soil
acidification through the carbon and nitrogen cycles. An experiment wa
s carried out over 10 years, with 10 cropping systems on a Dark Red Po
dzolic soil (Paleudult) to evaluate the effect of no-till cropping sys
tems on soil chemical characteristics. Legume cropping systems resulte
d in the greatest soil organic C gain and the highest ECEC to a depth
of 17.5 cm. The increase was greatest at 0 - 2.5 cm layer. Clover syst
ems resulted in the highest soil acidification at 2.5 - 7.5 and 7.5 -
17.5 cm depths. The rate of soil pH decrease at 2.5 - 7.5 cm depth und
er clover+ Spergula/maize system was 0.1 unit year(-1). Differences in
soil acidification affected soil ECEC. Soil exchangeable cation data
indicate that nitrate leaching increased soil acidification. Maize yie
lds were greatest in legume systems due to increased N supply.