Effects of controlling soil moisture regime based on root-sourced signal characteristics on yield formation and water use efficiency of winter wheat
| Autor: | Wei-Qiang Zhang, Ai-Wang Duan, Shou-Chen Ma, Tong-Chao Wang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Irrigation
0208 environmental biotechnology Deficit irrigation Soil Science 04 agricultural and veterinary sciences 02 engineering and technology 020801 environmental engineering Animal science Soil water 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Environmental science Dry matter Water-use efficiency Respiration rate Agronomy and Crop Science Water content Earth-Surface Processes Water Science and Technology Transpiration |
| Zdroj: | Agricultural Water Management. 221:486-492 |
| ISSN: | 0378-3774 |
| Popis: | The upper and lower limits of soil water content (SWC) determine the quota and time of regulated deficit irrigation (RDI). The drought resistance of plant varies with growth stages. Therefore, it is very difficult to determine the appropriate upper and lower limits of soil water under different growth stages. This study was first conducted to quantify the non-hydraulic root-sourced signals (nHRS), hydraulic root-sourced signals (HRS) and photosynthetic rate (PN) characteristics of winter wheat in progressively drying soil. Based on the characteristics of root-sourced signals and PN in plant, 3 water control modes were designed: CK (full irrigation, SWC when nHRS occurs was used as the lower limit of irrigation), W1 (SWCs when nHRS occurs and PN decreases significantly were used as the upper and lower limits of irrigation, respectively) and W2 (SWCs when PN decreases significantly and HRS occurs were used as the upper and lower limits of irrigation, respectively). The results showed that W1 and W2 both lowered plant height and leaf area of wheat. W1 had similar PN to CK, but W2 had significantly lower PN compared with CK. W1 and W2 lowered transpiration rates (Tr) and increased leaf instantaneous water use efficiency (WUEleaf) of plant compared with CK. After flowering, W1 lowered root respiration rate and increased accumulated dry matter after flowering (ADM) and pre-flowering dry matter remobilization (DMR) of wheat, and W2 had lower ADM compared to CK. At maturity, W1 had similar yield and higher harvest index compared to CK, but W2 reduced them. W1 significantly reduced irrigation water and improved WUE compared with W2 and CK. In conclusion, controlling suitable soil moisture (W1) based on root-sourced signal characteristics of plant helps to regulate the consumption and distribution of water and photosynthate, thus increasing water use efficiency (WUE) and irrigation water use efficiency (IWUE) of winter wheat. |
| Databáze: | OpenAIRE |
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