title: Improving phosphorus uptake and wheat productivity by phosphoric acid application in alkaline calcareous soils.
abstract: BACKGROUND
  Low phosphorus (P) efficiency from existing granular fertilisers necessitates searching for efficient alternatives to improve wheat productivity in calcareous soil.
  
  
  RESULTS
  Multi-location trials have shown that phosphoric acid (PA) produced 16% higher wheat grain over commercial P fertilisers, i.e. diammonium phosphate (DAP) and triple superphosphate (TSP). Methods of P application significantly influenced grain yield and the efficiency of methods was observed in the order: PA placement below seed > PA, DAP or TSP fertigation > DAP or TSP broadcast. The sub-surface application of PA produced highest grain yields (mean of all rates), i.e. 4669, 4158 and 3910 kg ha(-1) in Bagh, Bhalwal and Shahpur soil series, respectively. Phosphoric acid at 66 kg P2 O5 ha(-1) was found more effective in increasing gain yield over that of control. Trend in grain P uptake was found similar to that observed for grain yield. Maximum P uptake by grain was recorded at the highest P rate and the lowest at zero P. The significant increase in P uptake with P rates was generally related to the increase in yield rather than its concentration in grain. Phosphorus agronomic efficiency (PAE) and phosphorus recovery efficiency (PRE) were found higher at lower P rate (44 kg P2 O5 ha(-1) ) and decreased with P application. However, PA applied by the either method resulted in higher PAE and PRE compared to DAP and TSP.
  
  
  CONCLUSIONS
  Phosphoric acid is suggested as an efficient alternative to commercial granular P fertilisers for wheat production in alkaline calcareous soils. © 2015 Society of Chemical Industry.
authors.affiliation: Soil Science Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Akhtar
authors.affiliation: Soil Science Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Yaqub
authors.affiliation: Soil Science Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan.
authors.forename: Asif
authors.initials: A
authors.lastname: Naeem
authors.affiliation: Agricultural Mechanization Research Institute (AMRI) Division, Faisalabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
authors.affiliation: Colegio de Postgraduados - Campus Montecillo, 56230 Montecillo, Mexico.
authors.forename: Vicente Espinosa
authors.initials: VE
authors.lastname: Hernandez
mesh_terms: D000383:Agriculture / Q000379:methods*; D018533:Biomass; D002523:Edible Grain / Q000254:growth & development / Q000378:metabolism*; D005308:Fertilizers; D006801:Humans; D010710:Phosphates / Q000378:metabolism; D010756:Phosphoric Acids / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D014908:Triticum / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D010710:Phosphates; D010756:Phosphoric Acids; D012987:Soil; C024788:ammonium phosphate; D010758:Phosphorus; C030242:phosphoric acid
keywords: methods of application; phosphoric acid; phosphorus efficiency; soil series; wheat yield