PROGRESS IN GEOGRAPHY ›› 2012, Vol. 31 ›› Issue (5): 646-654.doi: 10.11820/dlkxjz.2012.05.014

• Original Articles • Previous Articles     Next Articles

Characteristics of the Root of Drip Irrigated Elaeagnus angustifolia with Different Irrigation Amounts in Extremely Arid Areas

ZHAO Xinfeng1, XU Hailiang1,2, LIU Xinhua1, ZHANG Peng1, LIU Zhiyou3, HONG Hui4   

  1. 1. Xinjiang Institute of Ecology and Geography, CAS, Key Laboratory of Oasis Ecology and Desert Environment, Urumqi 830011, China;
    2. Water Balancing Test Station of Chinese Academy of Sciences, Aral 843300, Xinjiang,China;
    3. Station of Forestry Management, Korla 841507, China;
    4. Xinjiang Administration of Tarim River Basin, Korla 841000, China
  • Received:2011-06-01 Revised:2011-10-01 Online:2012-05-25 Published:2012-05-25

Abstract: Distribution of the roots of drip irrigated Elaeagnus angustifolia with different irrigation amountswere investigated and the influence of root on soil water content was analyzed in extremely arid areas on Kalamijioasis in the lower reaches of the Tarim River. Three treatments were: 18 L, 30 L and 48 L each time onetree. This paper conducted a study on root biomass density and roots quantity. The results are shown as follows.(1) After long-term use of drip irrigation, most of Elaeagnus angustifolia root is distributed in the shallow soillayer (0~40 cm), and root branching ability reduces with the increase of soil depth. The root biomass of Elaeag?nus angustifolia in the 0-60 cm soil is up to 86% in the cumulative percentage. (2) The higher amount of irrigation resulted in enhancement in the total root biomass, but did not lead to the development of the root system inthe deep layer. Therefore, by using the irrigation quota of 48 L formed a deeper layer of soil moisture, the abilityof striking-root did not show an increasing trend with the larger irrigation amount, namely, the capacity of deepeningand depth of the roots did not increase with the increased irrigation amounts. In treatment 48 L, the ratioof soil root content in the layers of 20~40 cm/0~20 cm is small (only 0.6), and biomass is mainly concentrated in the surface; in treatment 30 L, the ratio of soil root content in the layers of 20-40 cm/0-20 cm is larger (0.75).(3) Roots of ≥5 mm increases with the increase in the amount of drip irrigation. In treatment 30 L, roots of 5mm≥φ ≥2 mm occupy the largest part of all. In treatment 18 L, there are the smallest numbers of thick roots(φ≥5 mm) and fine roots (φ≤2 mm). It is proposed that, to achieve the sustainable development of shelterbelt system in the extreme arid areas, large-scale irrigation of shelterbelt system should be taken in a variety of irrigation measures: to take the appropriate deficit irrigation in the season of competition for water between cottonand shelterbelt (from May to July), and the irrigation quota can be increased or the irrigation can be done 1-2times after August.

Key words: Elaeagnus angustifolia shelterbelt, different irrigation amounts, drip irrigation, root, the lower reachesof Tarim River