2.1 | Study site
The experimental site is located in the city of Sanyuan, Shaanxi
province, in the southern Loess
Plateau (34°36′N, 108°52′E). This region has a sub-humid, warm-temperate
continental monsoon climate with a mean annual temperature and mean
annual precipitationof12.9°C and 527 mm, respectively. The soil is
termed as Lou soil (manural loess soil) and classified as Eum-Orthic
Anthrosol (Udic Haplustalf in the USDA system). The basic soil
properties (0–20 cm depth) are shown in Table 1.