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Changes in Phosphorus Requirement with Increasing Grain Yield for Winter Wheat
Author(s) -
Zhan Ai,
Chen Xinping,
Li Shiqing,
Cui Zhenling
Publication year - 2015
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj15.0089
Subject(s) - agronomy , phosphorus , anthesis , yield (engineering) , fertilizer , zoology , grain yield , human fertilization , biomass (ecology) , shoot , nitrogen , biology , chemistry , cultivar , materials science , organic chemistry , metallurgy
Overestimation of the P requirement has been a driving force in the overuse of P fertilization in intensively managed agricultural systems and the resulting extensive environmental pollution. A database comprising 2157 measurements was developed from 2000 to 2013 using 45 on‐farm and station trials to evaluate the relationship between aboveground P uptake and grain yield with different P fertilizer (P f ) treatments and to quantify P requirements per megagram of grain at different grain yield levels. Winter wheat ( Triticum aestivum L.) yield ranged from 0.9 to 11.7 Mg ha −1 . The P requirement per megagram of grain yield (P req ) increased with P f supply from 4.1 kg under the treatment without P f to 4.8 kg under the P f surplus treatment. These results imply that excessive P application generally does not lead to greater P use efficiency and poses a potential environmental threat. Under the optimal P f (P f = Opt) treatment, the average P req was 4.5 kg, and it declined from 4.7 kg in the yield range of <4.5 Mg ha −1 to 4.2 kg in the yield range of >9 Mg ha −1 due to the increasing harvest index (from 45.7 to 48.2%) and the diluting effect of declining grain P concentrations (from 3.8 to 3.2 g kg −1 ). The largest variation in shoot biomass and P accumulation under P f = Opt treatment occurred from the stem elongation to anthesis growth stages, suggesting that, in addition to P f supply, crop management during the early growth season is also important for achieving higher yields.