3.1.Soil physico-chemical properties
The rhizosphere soils from the eight different treatments differed
significantly in terms of physico-chemical characteristics (Table 1).
Mulberry rhizosphere soils showed a higher pH value than alfalfa
rhizosphere soils; pH was lower in the intercropped system compared to
the monocultures (P < 0.01). Nitrogen application
resulted in increased pH values in the monoculture system, but lower pH
values in the intercropping system. Soil organic matter (OM) contents
were significantly decreased in mulberry and alfalfa rhizosphere soil
with added nitrogen, while in intercropping systems, this trend was
alleviated. In the mulberry treatments, OM contents were significantly
higher than in the corresponding treatments of alfalfa, except for the
monoculture system without nitrogen addition. Available nitrogen (AN)
contents were significantly higher in alfalfa rhizosphere soil than in
mulberry soil, and the application of nitrogen increased AN values in
both systems (monoculture and intercropping). The soil water content
(SWC) was considerably higher in mulberry rhizosphere soil than in
alfalfa soil. Nitrogen application and intercropping resulted in
increased SWC in mulberry soil, but in decreased values in alfalfa soil.