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Plant Soil (2013) 372:6580 DOI 10.1007/s11104-013-1735-8
REGULAR ARTICLE
Localized application of NH4+-N plus P at the seedlingand later growth stages enhances nutrient uptake and maize yield by inducing lateral root proliferation
Qinghua Ma & Fusuo Zhang & Zed Rengel & Jianbo Shen
Received: 2 November 2012 /Accepted: 16 April 2013 /Published online: 28 April 2013 # Springer Science+Business Media Dordrecht 2013
AbstractBackground and aims Localized supply of P plus ammonium improves root-proliferation and nutrient-uptake by maize (Zea mays L.) at seedling stage, but it is largely unknown how localized supply of nutrients at both early and late stages influences maize-growth, nutrient-uptake and grain-yield.
Methods A 2-year field experimentation with maize was conducted with localized application of P plus ammonium as diammonium phosphate (LDAP) or ammonium sulfate plus P (LASP) at sowing or jointing stage, with broadcast urea and P (BURP) or no nitrogen (F0) as controls.
Results Localized supply of P plus ammonium significantly increased root-proliferation, shoot dry-weight and nutrient-uptake at seedling stage. The positive effect disappeared at 53 days after sowing. However, plant-
growth and nutrient-uptake increased again after the second localized application of P plus ammonium at jointing. The density and average length of the first-order lateral roots in local patches increased by 50 % in LDAP and LASP compared with F0 and BURP. Maize-yield increased by 810 % compared with BURP. Agronomic N efficiency and N-use efficiency increased by 4148 % and 2557 % compared with the BURP. Conclusions It is suggested that enhanced root-proliferation in the nutrient-rich patches with localized supply of ammonium and P at sowing and jointing stages is essential for improving nutrient-uptake and ultimately grain-yield.
Keywords Ammonium . Phosphate . Localized nutrient supply. Root proliferation . Nutrient-use efficiency. Maize yield
Introduction
Plants show plasticity in shoot and root growth to adapt to heterogeneous and changing environments (Hodge 2004). The root plasticity to the spatio-temporal environmental variation is one of the main mechanisms to increase nutrient uptake and achieve higher productivity (Lynch 1995; Rengel and Marschner 2005). Many studies suggested that improved root development might represent an important strategy to enhance nutrient efficiency and crop yield required for the second green revolution (Lynch 2007).
Responsible Editor: Peter J. Gregory.
Q. Ma : F. Zhang : J. Shen (*)
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