The treatments were: (1) CK (unfertilized control); (2) CF
(inorganic nitrogen applied at a rate of 300 kg ha1 and 180 kg ha1
respectively in each rice and wheat season); and (3) CP (manurebased
compost applied at the same total nitrogen amount as CF in
each rice and wheat season). In the CF treatments, inorganic
nitrogen was applied as urea and the application rates were
calculated from local farming habits. The manure-based composts
used in CP treatments were produced from pig or dairy manure
mainly, and their total nitrogen contents were 1.52–2.04%.
Treatments were arranged in a randomized block design with
three replicates. Nine plots were built, and each plot was 30 m2
(5.0 m
6.0 m) with a neutral zone of 0.5 m for each neighboring
plot.