Dry mass partitioning and nitrogen uptake by Eucalyptus grandis plants in response to localized or mixed application of phosphorus

Abstract

Plants respond to nutrient rich patches by changing root morphology and physiology. The aim of this paper was to analyze shoot and root growth of Eucalyptus grandis plants fertilized with the same amount of phosphorus applied in two different ways: thoroughly mixed in the soil or localized in a single hole near the plant. Localized fertilization increased root mass in the zone where fertilizer was applied, but total root mass was not altered by the type of fertilization application. With mixed fertilization plant growth was less than with localized fertilization, and plants showed nitrogen deficiency. Nitrogen uptake was measured in a split-root hydroponics system where phosphate was applied to the whole root system or in part of it. Growth of plants receiving phosphorus in the whole root system was limited by nitrogen uptake, as was revealed by low leaf N and low nitrate uptake. In conclusion, the positive effect of localized application of phosphorus must be ascribed not only to higher phosphorus but also to sustained nitrogen assimilation.

Hydraulic properties of Eucalyptus grandis in response to nitrate and phosphate deficiency and sudden changes in their availability

“…As a model species, we selected Eucalyptus grandis , a fast growing tree species, yet one that has evolved in infertile soils and is considered to have low nutrient requirements ( Grove et al, 1996; McLaughlin , 1996). Although E. grandis is a fast growing tree, its relative growth rate (mass) at seedling stage is 0.05 d −1 ( Graciano et al, 2009), lower than crop species that were analyzed in previous works that grow 0.20–0.35 d −1 for Solanum lycopersicum (tomato) and Zea mays (maize), respectively ( Cramer et al, 2009; Górska et al, 2010). Eucalyptus grandis has also a low N demand because N uptake is around 1 µmol NO $ _3^ - $ h −1 g −1 FW (data recalculated from Graciano et al, 2009), while N uptake of tomato and maize plants is around 3.3 and 4.1 µmol NO $ _3^ - $ h −1 g FW −1 ( Górska et al, 2010).…”

“…Although E. grandis is a fast growing tree, its relative growth rate (mass) at seedling stage is 0.05 d −1 ( Graciano et al, 2009), lower than crop species that were analyzed in previous works that grow 0.20–0.35 d −1 for Solanum lycopersicum (tomato) and Zea mays (maize), respectively ( Cramer et al, 2009; Górska et al, 2010). Eucalyptus grandis has also a low N demand because N uptake is around 1 µmol NO $ _3^ - $ h −1 g −1 FW (data recalculated from Graciano et al, 2009), while N uptake of tomato and maize plants is around 3.3 and 4.1 µmol NO $ _3^ - $ h −1 g FW −1 ( Górska et al, 2010). Despite its low nutrient demand, E. grandis develops a set of responses to improve acquisition of nutrients from soil or internal utilization of growth‐limiting nutrients in its native environments, especially of P ( Atwell et al, 2009).…”

Effects of localized nitrogen supply treatments on growth and root parameters in Pinus massoniana families under phosphorus deficiency

“…根数量的增加以及总根长的提高 (Drew, 1975;Officer et al, 2009) (Mou et al, 1997;Zhou & Shangguan, 2007;Graciano et al, 2009) Li et al, 2014) (Weligama et al, 2008;Jing et al, 2010;Li et al, 2014)。马尾松作为木本植物, 其对土壤养分 异质性分布的响应可能因树种和土壤养分组成的不 同而差异较大 (Einsmann et al, 1999;Guo et al, 2002;梅莉等, 2006;杨青等, 2011)…”

The spatial distribution of phosphate in the root system modulates N metabolism and growth in Eucalyptus grandis young plants

“…Seeds were obtained from a clonal seed orchard of the INTA breeding program, Argentina (Marco ánd White 2002). When plants were 2 months old, they were transplanted to a split-root system developed by Graciano et al (2009). The root system was kept intact and manually placed in two 1-L black plastic pots: one pot contained the main root and lateral roots, while the other pot contained only lateral roots.…”

“…In E. grandis plants growing with low N availability, a tenfold increase in the concentration of phosphate in soil solution had a depressive effect in growth and in N uptake (Graciano et al 2009). Surprisingly, the depressive effect was reverted when the same amount of phosphate was held to the plant in a different spatial distribution: only part of the root system was fed with a very high phosphate solution, while the other part was fed with a very low concentration of phosphate.…”