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Yield and nitrogen use efficiency of wheat increased with root length and biomass due to nitrogen, phosphorus, and potassium interactions
Author(s) -
Duncan Elliott G.,
O'Sullivan Cathryn A.,
Roper Margaret M.,
Palta Jairo,
Whisson Kelley,
Peoples Mark B.
Publication year - 2018
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.201700376
Subject(s) - shoot , phosphorus , potassium , nitrogen , biomass (ecology) , agronomy , nutrient , chemistry , plant nutrition , biomass partitioning , yield (engineering) , horticulture , biology , organic chemistry , materials science , metallurgy
Abstract Balanced applications of nitrogen (N), phosphorus (P), and potassium (K) are known to increase grain yield of wheat but the impact of the interactions among N, P, and K on root growth and nitrogen use efficiency (NUE) have not been proven. The aim of this study was to investigate the effect of balanced applications of N, P, and K on the rooting patterns and NUE of wheat. Two glasshouse experiments were conducted. A rhizobox study was used to assess the impact of interactions among N, P, and K fertilisers on total root length, biomass, specific root length, root length density, N use efficiency (NUE), and N uptake efficiency of the shoots (NUpE shoot ) and N nutrition index. In a separate pot study, plants were grown to maturity to confirm the effect of the observed changes in root growth on NUE, NUpE grain , and grain/biomass yield. In the rhizobox experiment when plants were supplied with N+P+K, total root biomass increased approximately six‐fold relative to plants grown with N alone or with no fertiliser. Plants exposed to N+P+K had NUpE shoot and NUE values that were five and ten times higher, respectively, than plants that received just fertiliser N. Plants supplied with N+P or N+P+K had N nutrition indices close to one (N‐adequate), while plants that only received N had an index of 0.62 (N‐deficient). The pot study confirmed that the changes in root length and biomass in plants exposed to N+P+K resulted in significant increases in NUE, NUpE grain , shoot biomass, and grain yield at maturity. Interactions among fertiliser N, P, and K played a critical role in influencing root biomass and length, which was associated with increases in NUE, NUpE shoot and NUpE grain .