Abstract
Grasslands are a major form of agricultural land use worldwide. Current and future declines of phosphorus (P) inputs into production grasslands necessitate a shift towards selecting grass species based on high efficiency under suboptimal, rather than optimal P conditions. It is therefore imperative to identify key root traits that determine P acquisition of grasses in soils with a low P status. In a 9-month greenhouse experiment, we grew eight common grass species and cultivars on a soil with a low P status and related root morphological traits to their performance under P-limiting conditions. We applied (P1) or withheld (P0) P fertilization while providing adequate amounts of all other nutrients. Omitting P fertilization greatly reduced yield and nutrient acquisition for the various grass species. Biomass production differed significantly (P < 0.1%) among species and P fertilization treatments, varying from 17.1 to 72.1 g pot−1 in the P0 treatment and from 33.4 to 85.8 g pot−1 in the P1 treatment. Root traits were species-specific and unresponsive to P fertilization, but overall we observed a trade-off between root biomass and specific root length. Structural equation modeling identified total root length as key factor with respect to resistance to P deficiency, especially when roots explored the subsoil. Optimizing root length and subsoil exploration could be the key to maintaining high productivity of production grasslands with decreasing P availability. This is relevant for both plant breeding programs and for composing seed mixtures.
Original language | English |
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Pages (from-to) | 323-335 |
Journal | Journal of Plant Nutrition and Soil Science |
Volume | 181 |
Issue number | 3 |
DOIs | |
Publication status | Published - Jun 2018 |
Keywords
- P acquisition
- root characteristics
- root length
- structural equation modeling
- yield