In this area, the following normal cultivation and field
management practices in the TLR are usually adopted in the ricewheat
rotated paddy fields. Firstly, approximately 240–300 and
200–250 kg N ha−1 of chemical N fertilizers are routinely applied
to the soil to grow rice in summer and wheat in winter, respectively.
Secondly, direct sowing and surface fertilizer application
are employed due to convenience and economic costs in practice.
Thirdly, the current standard water regime is popularly practiced.
During rice seasons, flooded water was mostly maintained
at a depth of 3–5 cm in the field except for drainage before sowing,
several midseason aerations and final drainage events. At the
beginning of each wheat season, drainage ditches (15 cm in depth
and 10 cm in width; were usually spaced 1.5–2 m apart) were
opened mechanically in the field (Fig. 2). In addition, a local crop
grower controlled above-mentioned normal cultivation and field
management practices in the experimental field (Table 1). Thus,
the results of the study were expected to be appropriately representative
of the paddy fields under conventional farming in the
TLR.