Mc. Manna et Mv. Singh, Long-term effects of intercropping and bio-litter recycling on soil biological activity and fertility status of sub-tropical soils, BIORES TECH, 76(2), 2001, pp. 143-150
On-farm field experiments were carried out at two sites having 38- and 10-y
ear-old orchard cropping systems under sub-tropical climatic regions to eva
luate changes in organic carbon accumulation and chemical and microbiologic
al properties of the soils. Under a system of different intercropped fruit
trees, the cultivation of coconut (Cocos nucifera L.) intercropped with gua
va (Psidium guajava L.) enhanced the soil microbial activity approximately
2-fold after 38 yrs over 10 yrs of the same intercropped system. Soil organ
ic carbon increased from 3.4 to 7.8 and 2.4 to 6.2 g kg(-1) after 38 and 10
yrs, respectively, following the establishment of orchards. The increase w
as attributed to greater recycling of bio-litters. Levels of dehydrogenase,
phosphatase and soil microbial biomass under field conditions generally de
pended more on the nature of the cropping system than on soil types. Simila
rly, average carbon inputs of bio-litter to the soil in monocrop (0.98 Mg h
a(-1) yr(-1)) was less than intercropped fruit trees (2.07 Mg ha(-1) yr(-1)
). The average level of soil microbial biomass carbon was 1158 kg ha(-1) (0
-0.15 m depth) and the organic carbon turnover rate was 8.5 yr(-1) after 38
yrs of intercropped fruit trees, which resulted in a lower ratio (1.81) of
carbon inputs to soil microbial biomass carbon. (C) 2000 Elsevier Science
Ltd. All rights reserved.