*2.3. Crop Establishment Methods (CEMs)*

The details for CEMs of rice and wheat are mentioned in Tables 1 and 2. In order to have the same crop growth duration in all three methods of cultivation, sowing of rice in main field for ARS and sowing rice in nursery for transplanting in both PTR and SRI was performed on the same date. The PTR is traditionally followed by the CEM in which rice is grown in standing water. The level of standing water is maintained by reduction in soil infiltration rate through soil cultivation in standing water before transplanting (puddling) and applying irrigation at frequent intervals. The level of water is maintained at 2–3 cm during vegetative growth stage and increased up to 5 cm during flowering and grain filling

stage. In SRI [30–32], soil puddling is carried out the same as that of PTR and soil water level is maintained at saturation. The seedlings at13–14 days old were transplanted with 1–2 healthy seedlings per hill at a spacing of 20 cm × 20 cm. The ARS is growing of rice in unsaturated, unpuddled and arable soil conditions [33]. The soil is maintained at field capacity and direct sowing of pre-soaked rice grain was conducted through seed-drill. In case of wheat, drill-sowing of wheat is mostly followed in India in which row sowing of seed at 22.5 cm with seed drill is performed, while SWI [34–36] is a new CEM involving dibbling or transplanting of young seedlings at 20 cm × 20 cm spacing. The ZTW is gaining acceptance in Indo-Gangetic plains (IGPs) by the farmers due to energy and cost saving [12] and timely sowing [7].
