In this experiment, four treatments were designed and
applied: (1) a flat plot with no mulching (CK), (2) straw mulching
with 4500 kg/ha wheat straw in the first season and maize stalks
in other seasons (SM), (3) alternating ridges (60 cm wide and
15 cm high) and furrows (60 cm wide) with only the ridges
mulched with white plastic film (PM), and (4) alternating ridges
(60 cm wide and 15 cm high) and furrows (60 cm wide) with the
ridges mulched with white plastic film and straw mulching in the
furrows (2250 kg/ha) (PSM). A sketch showing the ridge and
furrow system is presented in Fig. 1.