Table 11.
Effect of crop establishment techniques and nutrient management options on phosphorus (P) (NaHCO3-extractable) (kg ha−1) content in soil in RWCS.
| Treatment | Initial NaHCO3-extractable P | P applied through fertilizer | Total initial P present in soil | Cropping system P uptake | Balance after completion of cropping cycle | Actual P present in soil after completion of cropping cycle | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2013–14 | 2014–15 | 2013–14 | 2014–15 | 2013–14 | 2014–15 | 2013–14 | 2014–15 | 2013–14 | 2014–15 | 2013–14 | 2014–15 | |
| Crop establishment techniques | ||||||||||||
| PTR–CDW | 17.0 | 22.5 | 51.6 | 51.6 | 68.6 | 74.1 | 26.9 | 26.6 | 41.7 | 47.5 | 22.5 | 20.3 |
| SRI–SWI | 17.0 | 22.4 | 51.6 | 51.6 | 68.6 | 74.0 | 26.9 | 26.7 | 41.7 | 47.3 | 22.4 | 19.8 |
| ARS–ZTW | 17.0 | 20.7 | 51.6 | 51.6 | 68.6 | 72.3 | 27.8 | 27.4 | 40.8 | 44.9 | 20.7 | 17.2 |
| SEm ± | – | 0.13 | – | – | – | 0.13 | 0.10 | 0.11 | 0.10 | 0.23 | 0.13 | 0.53 |
| CD (P = 0.05) | – | 0.50 | – | – | – | 0.50 | 0.38 | 0.41 | 0.38 | 0.91 | 0.50 | 2.07 |
| Nutrient management options | ||||||||||||
| Control | 17.0 | 10.7 | 51.6 | 51.6 | 68.6 | 62.3 | 22.4 | 21.7 | 46.2 | 40.6 | 10.7 | 8.6 |
| RDN | 17.0 | 23.0 | 51.6 | 51.6 | 68.6 | 74.6 | 28.0 | 27.6 | 40.6 | 47.0 | 23.0 | 22.7 |
| RDN* + Zn** | 17.0 | 21.6 | 51.6 | 51.6 | 68.6 | 73.2 | 29.1 | 28.9 | 39.5 | 44.3 | 21.6 | 20.0 |
| 75% RDN | 17.0 | 16.7 | 51.6 | 51.6 | 68.6 | 68.3 | 25.8 | 25.8 | 42.8 | 42.5 | 16.7 | 11.4 |
| 75% RDN + Zn | 17.0 | 16.2 | 51.6 | 51.6 | 68.6 | 67.8 | 26.4 | 26.2 | 42.2 | 41.6 | 16.2 | 10.5 |
| 75% RDN + MC1 | 17.0 | 28.0 | 51.6 | 51.6 | 68.6 | 79.6 | 27.4 | 27.2 | 41.2 | 52.4 | 28.0 | 26.3 |
| 75% RDN + MC1 + Zn | 17.0 | 26.4 | 51.6 | 51.6 | 68.6 | 78.0 | 28.8 | 28.5 | 39.8 | 49.5 | 26.4 | 23.4 |
| 75% RDN + MC2 | 17.0 | 27.8 | 51.6 | 51.6 | 68.6 | 79.4 | 27.6 | 27.5 | 41.0 | 51.9 | 27.8 | 25.8 |
| 75% RDN + MC2 + Zn | 17.0 | 26.3 | 51.6 | 51.6 | 68.6 | 77.9 | 28.9 | 28.6 | 39.7 | 49.3 | 26.3 | 23.2 |
| SEm ± | – | 0.19 | – | – | – | 0.19 | 0.15 | 0.16 | 0.15 | 0.36 | 0.19 | 0.78 |
| CD (P = 0.05) | – | 0.55 | – | – | – | 0.55 | 0.42 | 0.47 | 0.42 | 1.02 | 0.55 | 2.22 |
| Interaction | – | Sig | – | – | – | Sig | Sig | Sig | Sig | Sig | Sig | Sig |
PTR, Puddled transplanted rice; SRI, System of rice intensification; ARS, Aerobic rice system; CDW, Conventional drill-sown wheat; SWI, System of wheat intensification; ZTW, Zero tillage wheat; RDN*, Recommended dose of nutrients [120 kg nitrogen ha–1 and 25.8 kg phosphorus (P) ha–1 per crop); Zn**, 5 kg Zn ha–1 through ZnSO4.7H2O per crop; MC1, Anabaena sp. (CR1) + Providencia sp. (PR3) consortium; MC2, Anabaena–Pseudomonas biofilm; Sig, Significant; NS, Non-significant; Potassium (K) was applied uniformly in all treatments @ 49.8 kg K ha–1 per crop.