Drip irrigation improves spring wheat water productivity by reducing leaf area while increasing yield

Research output: Contribution to journalJournal articleResearchpeer-review

  • Danni Yang
  • Sien Li
  • Mousong Wu
  • Hanbo Yang
  • Wenxin Zhang
  • Ji Chen
  • Chunyu Wang
  • Siyu Huang
  • Ruoqing Zhang
  • Yunxuan Zhang

To mitigate the climate change-induced water shortage and realize the sustainable development of agriculture, drip irrigation, a more efficient water-saving irrigation method, has been intensively implemented in most arid agricultural regions in the world. However, compared to traditional border irrigation, how drip irrigation affects the biophysical conditions in the cropland and how crops physiologically respond to changes in biophysical conditions in terms of water, heat and carbon exchange remain largely unknown. In view of the above situation, to reveal the mechanism of drip irrigation in improving spring wheat water productivity, paired field experi-ments based on drip irrigation and border irrigation were conducted to extensively monitor water and heat fluxes at a typical spring wheat field (Triticum aestivum L.) in Northwest China during 2017-2020. The results showed that drip irrigation improved yield by 10.3 % and crop water productivity (i.e., yield-to-evapotranspiration-ratio) by 15.6 %, but reduced LAI by 16.9 % in contrast with border irrigation. Under drip irrigation, the lateral development of spring wheat roots was promoted by higher soil temperature combined with frequent dry-wet alternation in the shallow soil layer (0-20 cm), which was the basis for efficient absorption of water and fer-tilizer, as well as efficient formation of photosynthate. Meanwhile, drip irrigation increased net radiation and decreased latent heat flux by inhibiting leaf growth, thereby increased sensible heat, causing a higher soil temperature (+1.10 degrees C) and canopy temperature (+1.11 degrees C). Further analysis proved that soil temperature was the key factor affecting yield formation. Based on the above conditions, the decrease in leaf distribution coef-ficient (-0.030) led to the decrease in evapotranspiration (-5.7 %) and the increase in ear distribution coeffi-cient (+0.029). Therefore, drip irrigation emphasized the role of soil moisture in the soil-plant-atmosphere continuum, enhanced crop activity by increasing field temperature, especially soil temperature, and finally improved yield and water productivity via carbon reallocation. The study revealed the mechanism of drip irri-gation for improving spring wheat yield, and would contribute to improving Earth system models in representing agricultural cropland ecosystems with drip irrigation and predicting the subsequent biophysical and biogeo-chemical feedbacks to climate change.

Original languageEnglish
Article number126710
JournalEuropean Journal of Agronomy
Volume143
Number of pages12
ISSN1161-0301
DOIs
Publication statusPublished - 2023

Bibliographical note

CENPERM[2023]

    Research areas

  • Drip irrigation, Energy balance, Root water uptake, Carbon allocation, Water productivity, CLIMATE-CHANGE IMPACTS, USE EFFICIENCY, WINTER-WHEAT, DEFICIT IRRIGATION, SOIL-MOISTURE, GRAIN-YIELD, ROOT-GROWTH, AGRICULTURE, MANAGEMENT, RATIO

ID: 334400782