Shi, J., Department of Soil and Water Sciences, China Agricultural University
, Key Laboratory of Plant-Soil Interactions, Ministry of Education, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Beijing 100193, China
Yasuor, H., Plant Sciences, Agricultural Research Organization, Gilat Research Center, Mobile Post Negev 85280, Israel
Yermiyahu, U., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile Post Negev 85280, Israel
Zuo, Q., Department of Soil and Water Sciences, China Agricultural University
Ben-Gal, A., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile Post Negev 85280, Israel

Temporal responses to drought and nitrogen stresses were studied on wheat (Triticum aestivum) seedlings subjected to drying and re-watering cycles. Growth traits were monitored in a soil column experiment conducted with two water and two nitrogen levels. Leaf area, dry weight, carbon and nitrogen mass, root/shoot ratio, specific leaf nitrogen, photosynthesis, transpiration, and water and nitrogen use efficiencies dynamically responded to water and nitrogen stresses as a function of the degree of specific stress over the growing period. Specific leaf nitrogen was critical for improving photosynthetic activity, and influenced water use efficiency positively but nitrogen use efficiency negatively, indicating a distinct trade-off between water and nitrogen use efficiencies. Subsequent to irrigation and the immediate alleviation of severity of water and nitrogen stresses, photosynthesis and transpiration recovered gradually over a period of 3-4 days. Extent of recovery was influenced by the degree of stress prior to re-watering and the re-watering cycles. Ignoring the dynamics of recovery from stress led to notable errors in numerical simulations of the dynamics of soil water and plant transpiration. © 2014.