In this study, a special rice-energy willow/poplar agroforestry system was used to
analyze the effects of reused water irrigation and mulching on soil salinity, earthworm
biomass and abundance, soil organic matter (SOM) content and weed coverage in treerow-dependent
habitats. After three-year-irrigation, we investigated the woody line (WL), the buffer
zone (BZ) and the crop line habitats (CL). Between 2019 and 2021, we collected data
on the distribution of soil-specific electrical conductivity (EC), ammonium-lactate
soluble sodium (AL-Na) and exchangeable cations (Na+, K+, Ca2+, Mg2+) and soil NO2−
+ NO3−-N contents from CL habitats irrigated with effluent water from an intensive
catfish farm. Based on our results, significantly greater earthworm abundance (274
pc m−2) and earthworm biomass (54.0 g m−2) values were measured in WL than in BZ or
CL habitats. There was no significant difference in weed coverage between the CL (0.61%)
and BZ (1.91%), but weeds were significantly denser on the WL (12.3%). In the third
year, the EC, AL-Na and ESP values were lower, but the SOM was higher in mulched soil
(183.1 mS cm−1, 253.1 mg kg−1, 4.4 ESP% and 4.597%, respectively) than in un-mulched
soil.