| Jujube-cotton intercropping pattern is a reasonable agroforestry mode with one plant is taller, another is shorter, in Xinjiang Oasis agroecosystems. It not only improves the economic benefits of fruit trees, and to achieve the intensive cultivation in temporal and spatial at the same time. But the jujube-cotton intercropping interaction is not clear. Through the orientation field plot test for two consecutive years,experimental is designed 5 treatments(T1 is sole jujube, T2~T4 is the jujube-cotton intercropping mode for different irrigation treatments, T5 is sole cotton), study the jujube-cotton root spatial distribution characteristics, changes of physiological and ecological index characteristics on the ground, moisture temporal and spatial variation characteristics, to explore the interaction of jujube-cotton, to prove physiological characteristics of jujube-cotton agroforestry systems, define the relationship of jujube-cotton agroforestry systems.providing a basis regulation and management theory for this agroforestry systems for sustainable development, improve the economic benefits of jujube-cotton intercropping system, promote actively agricultural production practices. The main experimental results are as follows:(1) The Pn(the photosynthetic rate)、Ci(intercellular CO2 concentration)、WUE(the mean water use efficiency) of monoculture jujube leaves were greater than the intercropping jujube. But the Pn、WUE of monoculturecotton leaves were greater than the intercropping cotton, intercropping promotes the photosynthesis capacity of cotton, represses the photosynthesis capacity of jujube. Under different irrigation treatments, At theT2 treatment, the Pn、Ci、Tr(transpiration rate)of jujube and cotton were greater than the T3 and T4 treatments, achieve high photosynthetic; The mean water use efficiency WUE of jujube in T4 treatment is the maximum one in all treatments, achieve high water use efficiency; The Tr of jujube in T3 treatment is the minimum one, achieve low transpiration rate.(2) The monoculture jujube tree root length density are more than intercropping jujube during the year and the different years. But the biomass aboveground are opposite, intercropping is greater than monoculture. Cotton is affected by jujube culvation. In the first year of planting jujube, the growth index aboveground are opposite with root length density of cotton, intercropping is greater than monoculture. In the secend year, except T4 restrictions by irrigation, the growth index aboveground are consistency with root length density, intercropping is greater than monoculture.(3) Jujube-cotton intercropping competition between species is slightly different for each year. In 2014,the competition area between jujube and cotton is at the lateral of 0.1~0.3m, vertical of 0.3~0.5m,inerspecific competition is fierce underground, cotton-jujube competitiveness index greater jujube-cotton,cotton as the dominant species have stronger competitions; With the jujube cultivation age increase, In2015, the competition area between jujube and cotton is at the lateral of 0.3~0.7m, vertical of 0.2~0.5m,jujube competitiveness is stronger than cotton, as the dominant species, it has obvious advantages of intercropping.(4) At the different irrigation treatments of jujube-cotton intercropping system, the fine root length density of jujube and cotton are effected by interspecific relationship, distribution presents reciprocal composite relationship. the fine root length density of jujube in T2 treatment is the maximum, the fine root length density of cotton in T2 treatment is the minimum; But the T3 treatment is opposite, the fine root length density of jujube is the minimum, the fine root length density of cotton is the maximum.(5) At the different irrigation treatments of jujube-cotton composite systems, the effects of soil moisture in the bud stage、blooming period of cotton is negative, jujube impacted cotton of soil moisture incomposite systems, and showed that there exist soil moisture competition in the jujube-cotton agroforestry system. |
