| Water production function and optimization in irrigation schedule of potato with mulched drip irrigation under water deficit in oasis region |
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| DOI：10.7606/j.issn.1000-7601.2017.01.24 |
| Key Words: oasis potato mulched drip irrigation water deficit optimal irrigation schedule yield water use efficiency |
| Author Name | Affiliation | | DU Jia | College of Engineering, Gansu Agricultural University, Lanzhou, Gansu 730070, China | | ZHANG Heng-jia | College of Engineering, Gansu Agricultural University, Lanzhou, Gansu 730070, China | | ZHANG Ming | Flood River Management Office of Minle County, Minle, Gansu 734500, China | | BA Yu-chun | Flood River Management Office of Minle County, Minle, Gansu 734500, China | | YANG Xiao-ting | College of Engineering, Gansu Agricultural University, Lanzhou, Gansu 730070, China | | HE Peng-jie | College of Engineering, Gansu Agricultural University, Lanzhou, Gansu 730070, China | | LI Xuan-zhen | College of Engineering, Gansu Agricultural University, Lanzhou, Gansu 730070, China |
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| Abstract: |
| A field experiment was conducted to test the potato periodic evapotranspiration and its influencing factors with mulched drip irrigation under water deficit regulation (WDR) in oasis irrigation region. Crop water production function based on Jensen model was established, and the optimal irrigation schedule for potato was determined. The results showed that the sensitive index was found the largest at the tuber bulking stage, followed by the tuber initiation stage and relatively small at the establishment and potato starch accumulation stages. Potato yield was not decreased by low WDR plots during tuber initiation (P>0.05), but was significantly decreased in the medium WDR plots during tuber initiation and low and medium WDR plots during tuber bulking (P<0.05). The water use efficiency (WUE) was maintained in low WDR potato during tuber initiation, significantly improved by 6.2%, 8.3% and 6.7% from that in medium WDR plots during tuber initiation, low WDR plots during tuber bulking and full irrigation plots (CK), respectively. With the increase of crop evapotranspiration, the potato bulb yield became increased, while the water use efficiency was decreased. Crop evapotranspiration was increased by 22.4%, the potato bulb yield was increased by 20.4% and the WUE went decreased by 15.7%. The optimal irrigation system established by genetic algorithm with crop water production function showed that the highest potato bulb yield (43.86 t·hm-2) could be achieved when the irrigation depth was up to 225 mm in the Hexi oasis, and irrigation WUE was 19.5 kg·m-2. The recommended amount of irrigation is 30～40, 130～140, 170～190 mm and 25 mm at the stages of establishment, tuber initiation, tuber bulking and potato starch accumulation, respectively, and the irrigation intervals are 7 days. Therefore, when WDR under mulched drip irrigation reduces potato water consumption, the water use efficiency can be enhanced. Low WDR does not affect the potato yield during tuber initiation, reaching water-saving purposes. |
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