title: Effect of synthetic and natural water-absorbing soil amendments on photosynthesis characteristics and tuber nutritional quality of potato in a semi-arid region.
abstract: BACKGROUND
  The effect of water-absorbing soil amendments on photosynthesis characteristics and tuber nutritional quality was investigated in a field experiment in a semi-arid region in northern China in 2010-2012. Treatments included two synthetic water-absorbing amendments, potassium polyacrylate (PAA) and polyacrylamide (PAM), and one natural amendment, humic acid (HA), both as single amendments and compound amendments (HA combined with PAA or PAM), and a no amendment control.
  
  
  RESULTS
  Soil amendments had a highly significant effect (P ≤ 0.01) on photosynthesis characteristics, dry biomass, crop root/shoot (R/S) ratio and tuber nutritional quality. They improved both dry biomass above ground and dry biomass underground in the whole growing season by 4.6-31.2 and 1.1-83.1% respectively in all three years. Crop R/S ratio was reduced in the early growing season by 2.0-29.4% and increased in the later growing season by 2.3-32.6%. Soil amendments improved leaf soil plant analysis development value, net photosynthesis rate, stomatal conductance and transpiration rate by 1.4-17.0, 5.1-45.9, 2.4-90.6 and 2.0-22.6% respectively and reduced intercellular CO2 concentration by 2.1-19.5% in all three years.
  
  
  CONCLUSIONS
  Amendment treatment with PAM + HA always had the greatest effect on photosynthesis characteristics and tuber nutritional quality among all amendment treatments and thus merits further research.
authors.affiliation: Oat Scientific and Technical Innovation Team, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, 010019, China.|Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada.
authors.forename: Shengtao
authors.initials: S
authors.lastname: Xu
authors.affiliation: Institute of Economic Crops, Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, 650205, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada.
authors.forename: Neil B
authors.initials: NB
authors.lastname: McLaughlin
authors.affiliation: Oat Scientific and Technical Innovation Team, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, 010019, China.
authors.forename: Junzhen
authors.initials: J
authors.lastname: Mi
authors.affiliation: College of Agronomy, Northwest A&F University, Taicheng Road 3#, Yangling, Shaanxi, 712100, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Oat Scientific and Technical Innovation Team, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, 010019, China.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Liu
mesh_terms: D002681:China; D003889:Desert Climate; D006801:Humans; D009753:Nutritive Value; D010788:Photosynthesis; D035281:Plant Tubers / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D011198:Solanum tuberosum / Q000254:growth & development* / Q000378:metabolism; D014867:Water / Q000737:chemistry*
chemical_list: D012987:Soil; D014867:Water
keywords: crop root/shoot ratio; dry biomass; photosynthesis characteristics; soil amendments; tuber nutritional quality