Effects of K+ and Ca2+ supplement during fertigation on leaf gas exchange and salt tolerance of cotton at full and deficit irrigation regimes

Research output: Contribution to journalJournal articlepeer-review

  • Yingying Ma
  • Zhenhua Wei
  • Jie Liu
  • Xuezhi Liu
  • Jingxiang Hou
  • Liu, Fulai
Modulation of K+ and Ca2+ levels could enhance salt tolerance in crops, yet the underlying mechanisms remain largely elusive. The objective of this study was to investigate the effects of K+ and Ca2+ supplement during fertigation on leaf gas exchange in cotton plants subjected to salt stress and deficit irrigation regime. The leaf gas exchange parameters, leaf nitrogen concentration, chlorophyll content, plant water status, abscisic acid concentration in leaf ([ABA]leaf), K+ and Na+ concentration in leaf, as well as water use efficiency were evaluated. The results showed that: stomatal conductance (gs), transpiration rate (Tr) and net photosynthetic rate (An) were significantly decreased by 150 mM NaCl stress, whereas K+Ca treatment significantly alleviated the negative impact of salt under full irrigation. The relative water content and leaf water potential (Ψ1) was significantly decreased by salt stress. At full irrigation, K+Ca treatment further decreased Ψ1 in the salt-stressed plants than the non-K+Ca treatment. K+ and Ca2+ addition had a more positive effect on gs and Tr than on An, resulting in significantly lowered intrinsic and instantaneous water use efficiencies in salt-stressed plants at full irrigation. K and K+Ca treatments significantly increased the content of K+ and the ratio of K+/Na+ in leaf under salt stress and deficit irrigation. Salinity induced-reduction in gs was associated with high [ABA]leaf and a lower Ψ1, whereas, the alleviation of gs and An in the salt-stressed plants at full irrigation upon K+ and Ca2+ addition could be attributed to osmoregulation and increased concentration of K+ and the ratio of K+/Na+ in leaf. In conclusion, at full irrigation, K+Ca treatment notably alleviated the salinity-induced depression in gs and An, ameliorating plants performance under salt stress condition. These results provide useful information for better irrigation and fertilization management in a future water-limited and salinity-affected soil environment.
Original languageEnglish
Article number104435
JournalEnvironmental and Experimental Botany
Volume186
ISSN0098-8472
DOIs
Publication statusPublished - 2021

ID: 257924964