土壤水分胁迫对新疆大叶苜蓿的生长及生物量的影响

The effect of water stress on growth and biomass of Medicago sativa cv.Xinjiangdaye

采用盆栽法研究了不同土壤水分胁迫(田间持水量的90%,70%,40%,20%)对新疆大叶苜蓿的生长及生物量积累的影响。结果表明,土壤水分含量为田间持水量的70%时,苗高、地径、分枝数及侧根数均高于其他处理,叶片、茎、主根鲜生物量和干生物量均最大,最适宜新疆大叶苜蓿生长;土壤水分含量过高(田间持水量的90%)或过低(田间持水量的20%,40%)时,均不利于新疆大叶苜蓿生物量的形成;土壤水分胁迫抑制了新疆大叶苜蓿的生长发育,随着水分胁迫的加剧,苗高和地径生长速度均减慢。该结果为进一步了解新疆大叶苜蓿对水分胁迫的响应规律并为其在干旱区节水灌溉农业中的推广和种植以及为建立持久稳定高产的畜牧业草业生产体系提供理论依据。

The effects of growth and biomass accumulation under different soil water stress（90%of field capacity,70%,40%,20%）on Medicago sativa cv.Xinjiangdaye were studied in the pot method.The results showed that height,diameter,number of branches and lateral roots were higher than other treatments,fresh biomass and dry biomass of leaves,stems,root were the largest.When soil moisture content was 70%of field capacity and it was the most fitted for the growth of M.sativacv.Xinjiangdaye.It was not conductive to the formation of M.sativacv.Xinjiangdaye biomass when the soil moisture content is too high（90% of field capacity）or too low（20%,40%of field capacity）.Soil moisture stress inhibited growth of M.sativacv.Xinjiangdaye.Height and diameter growth rates were slowed with water stress intensification.The results helped to understand the response of M.sativacv.Xinjiangdaye to water stress and provided a theoretical basis for the spreading and cultivation of M.sativacv.Xinjiangdaye under water-saving irrigation in the arid zone agriculture as well as establishing lasting,stable and high-yielding grassland production system.