A unifying concept for the dependence of whole-crop N: P ratio on biomass: theory and experiment
2008
Greenwood, Duncan J. | Karpinets, Tatiana V. | Zhang, Kefeng | Bosch Serra, Àngela D. | Boldrini, Ariadna | Karawulova, Lyudmila
An equation was derived between N:P ratio of the plant and its dry biomass per unit area, based on the decline during growth in the proportion of biomass that consisted of growth related tissue. The relationship was validated using 365 measurements of N:P ratios and plant mass of crop species in 38 field experiments, by 176 advisory estimates of optimal N and P values in plants derived from the literature and by 503 measurements of N and P concentrations from a survey of natural leaves. The results indicate that N:P ratios of growth related tissue remain almost constant throughout growth and are similar for widely different species. The high N:P ratio of the plant tissues related to reproduction and an increase in the proportion of this tissue underlies the negative relationship between the N:P ratio of the whole plant and its biomass during growth.
显示更多 [+] 显示较少 [-]We thank Professor D. Kerkhoff of Kenyon College, Gambiier, Ohio, USA for providing us with his original data on herbage plants and permitting us to publish them. Funding for this work was partially provided by the UK Department for the Environment, Food and Rural Affairs through project HH3507SFV.
显示更多 [+] 显示较少 [-]