Table 4.
Nitrogen remobilization efficiency (%) and contribution to grain nitrogen (%) in maize as influenced by year, cultivar, and levels of NPK.
| Treatments | N remobilization efficiency | Contribution to grain N by N remobilization | ||
|---|---|---|---|---|
| Leaf | Stalk | Leaf | Stalk | |
| Year | ||||
| Year 1 | +10.5a | +60.3a | 7.6a | 33.7a |
| Year 2 | −11.9b | +47.7b | −2.1b | 26.4b |
| Cultivar | ||||
| P3522 | +20.5a | +64.4a | 11.1a | 33.8a |
| P3396 | −17.0b | +50.2b | −5.0c | 27.1b |
| Rajkumar | −5.5b | +47.4b | 2.1b | 29.2b |
| Levels of NPK | ||||
| N100P30K30 (50% RDF) | −17.7de | +51.0cd | −1.4cd | 22.0d |
| N150P45K45 (75% RDF) | −0.1bcd | +53.7c | 3.1bc | 27.0bcd |
| N200P60K60 (100% RDF) | +5.4bc | +56.2bc | 2.7bc | 32.9b |
| N250P75K75 (125% RDF) | +0.5bcd | +52.5cd | 0.4cd | 32.4b |
| N300P90K90 (150% RDF) | −20.3e | +43.8d | −7.1d | 30.1bc |
| P60K60 (100% RDF–N) | −16.1de | +48.0cd | −3.1cd | 24.3cd |
| N200K60 (100% RDF–P) | +12.0bc | +63.1bc | 10.0a | 33.7b |
| N200P60 (100% RDF–K) | +30.9a | +70.6a | 18.2a | 45.5a |
| Control (–NPK) | −0.6bcd | +47.2cd | 1.7bcd | 22.3d |
| Source of variation | ||||
| Year | * | ** | * | ** |
| Cultivar | ** | ** | * | * |
| Levels of NPK | ** | ** | ** | ** |
| Year × cultivar | ns | ns | ns | ns |
| Year × levels of NPK | ns | ns | * | ns |
| Cultivar × levels of NPK | ** | ** | ** | * |
| Year × cultivar × levels of NPK | ns | ns | ns | ns |
Year 1 and year 2 represent winter 2012–13 and 2013–14, respectively. Within year, cultivar, and levels of NPK, numbers followed by different letters indicate significant differences at p ≤ 0.05 (otherwise statistically at par). ns, non-significant (p > 0.05). *Significant at p ≤ 0.05. **Significant at p ≤ 0.01, + and − sign represent the situations when the tissue is acting as a source and sink, respectively.