Effects and interactions of phosphorus and sulphur on a mown white clover/ryegrass sward 3. Indices of nutrient adequacy
| Autor: | Ken G. Dodds, J. D. Morrison, A. G. Sinclair, L. C. Smith |
|---|---|
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | New Zealand Journal of Agricultural Research. 40:297-307 |
| ISSN: | 1175-8775 0028-8233 |
| DOI: | 10.1080/00288233.1997.9513249 |
| Popis: | Relationships were examined between relative yields of pasture with respect to phosphorus (P) and sulphur (S) applications, and clover herbage P and S concentrations and P/nitrogen (N) and S/N ratios in a P x S factorial fertiliser trial on a mown clover/ryegrass sward. The relationships between the yield of a treatment relative to the maximum yield obtainable with high rates of P alone (RY[P]) and both % P and P/N were affected by the application rate of S. S deficiency generally lowered the % P required for any given RY[P] but raised the P/N required. This latter effect was because S deficiency markedly lowered clover herbage N concentration. P deficiency had a similar but smaller effect on % S and S/N required for any RY[S]. S/N was much less sensitive to changes in clover S status than P/N was to changes in clover P status. This resulted from the strong stimulatory effect of S on clover % N. Relationships were also established between clover P and S adequacy indices and RY[PS] which is the he... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|