TY - JOUR

T1 - Fertilizer ammonium

T2 - nitrate ratios determine phosphorus uptake by young maize plants

AU - Pedersen, I.F.

AU - Sørensen, P.

AU - Rasmussen, J.

AU - Withers, P.J.A.

AU - Rubæk, G.H.

N1 - This is the peer reviewed version of the following article:Pedersen, I. F., Sørensen, P. , Rasmussen, J. , Withers, P. J. and Rubæk, G. H. (2019), Fertilizer ammonium : nitrate ratios determine phosphorus uptake by young maize plants . J. Plant Nutr. Soil Sci.. doi:10.1002/jpln.201800553 which has been published in final form at https://onlinelibrary.wiley.com/doi/full/10.1002/jpln.201800553 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.

PY - 2019/4/4

Y1 - 2019/4/4

N2 - We investigated the interacting effects of inorganic nitrogen and the main inorganic phosphorus form in dairy manure (dicalcium phosphate, CaHPO 4 ) on growth, nutrient uptake, and rhizosphere pH of young maize plants. In a pot experiment, three levels of CaHPO 4 (0, 167, and 500 mg P pot −1 ) were combined with nitrogen (637 mg N pot −1 ) applied at five NH 4 -N : NO 3 -N ratios (0 : 100, 25 : 75, 50 : 50, 75 : 25, and 100 : 0) and a nitrification inhibitor in a concentrated layer of a typical acid sandy soil from Denmark. 15 N-labeled NH 4 -N was applied to differentiate the role of nitrification and to partition nitrogen uptake derived from NH 4 -N. Among treatments including nitrogen, shoot biomass, rooting and phosphorus uptake were significantly higher at the five-leaf stage when CaHPO 4 was applied with NH 4 -N : NO 3 -N ratios of 50 : 50 and 75 : 25. In these treatments, rhizosphere pH dropped significantly in direct proportion with NH 4 -N uptake. The fertilizers in the concentrated layer had a root-inhibiting effect in treatments without phosphorus supply and in treatments with pure NO 3 -N or NH 4 -N supply. Increased nitrogen uptake as NH 4 -N instead of NO 3 -N reduced rhizosphere pH and enhanced acquisition of applied CaHPO 4 by young maize plants, which may have positive implications for the enhanced utilization of manure phosphorus.

AB - We investigated the interacting effects of inorganic nitrogen and the main inorganic phosphorus form in dairy manure (dicalcium phosphate, CaHPO 4 ) on growth, nutrient uptake, and rhizosphere pH of young maize plants. In a pot experiment, three levels of CaHPO 4 (0, 167, and 500 mg P pot −1 ) were combined with nitrogen (637 mg N pot −1 ) applied at five NH 4 -N : NO 3 -N ratios (0 : 100, 25 : 75, 50 : 50, 75 : 25, and 100 : 0) and a nitrification inhibitor in a concentrated layer of a typical acid sandy soil from Denmark. 15 N-labeled NH 4 -N was applied to differentiate the role of nitrification and to partition nitrogen uptake derived from NH 4 -N. Among treatments including nitrogen, shoot biomass, rooting and phosphorus uptake were significantly higher at the five-leaf stage when CaHPO 4 was applied with NH 4 -N : NO 3 -N ratios of 50 : 50 and 75 : 25. In these treatments, rhizosphere pH dropped significantly in direct proportion with NH 4 -N uptake. The fertilizers in the concentrated layer had a root-inhibiting effect in treatments without phosphorus supply and in treatments with pure NO 3 -N or NH 4 -N supply. Increased nitrogen uptake as NH 4 -N instead of NO 3 -N reduced rhizosphere pH and enhanced acquisition of applied CaHPO 4 by young maize plants, which may have positive implications for the enhanced utilization of manure phosphorus.

KW - nitrogen form

KW - rhizosphere

KW - soil acidification

KW - starter fertilizer

KW - Zea mays

U2 - 10.1002/jpln.201800553

DO - 10.1002/jpln.201800553

M3 - Journal article

JO - Journal of Plant Nutrition and Soil Science

JF - Journal of Plant Nutrition and Soil Science

SN - 1436-8730

ER -