枝条覆盖对平茬花棒生长特征和浅层土壤水分的影响

Effects of branch mulch on growth characteristics and surface soil moisture of clipping Hedysarum scoparium

为了综合评价枝条覆盖对不同立地(平地、丘顶、丘间低地)平茬花棒(Hedysarum scoparium)生长特征和浅层土壤水分的影响,以吉兰泰荒漠-绿洲过渡区平茬花棒为研究对象,于2017年4-10月对覆盖与无覆盖平茬花棒物候期、土壤容积含水量、土壤储水量和生长指标等相关指标进行测定。实验结果表明:(1)枝条覆盖有利于平茬花棒提前萌芽,较无覆盖提前5 d以上。(2)枝条覆盖使不同立地平茬花棒生长初期和生长末期0-100 cm土层平均土壤容积含水量增加20.12%以上,且土壤含水量变异系数随土层深度增加变化减缓;土壤储水量在生长初期和生长末期枝条覆盖较无覆盖增加27%以上。(3)枝条覆盖使平茬花棒株高、新生枝数、基径、冠幅较无覆盖增加10.91%以上,同时其生物量鲜重和干重较无覆盖分别增加4.45%-24.17%和3.78%-18.93%。尤其丘间低地平茬花棒生物量增加效果更加明显(P>0.05)。但枝条覆盖不能改变平茬花棒生物量分配格局;(4)枝条覆盖和平茬对花棒生长均具有积极作用,枝条覆盖对丘间低地平茬花棒生长促进作用最好。

The aim of this study was to comprehensively evaluate the effects of branch mulch on growth characteristics and surface soil moisture of clipping Hedysarum scoparium at different sites(flat land, hilltop, and interdune lowland). The study was carried out from May to October 2017 at the clipping H. scoparium plantation in the desert-oasis ecotone of Jilantai. The phenological period, soil volume water content, soil water storage and growth index of clipping H. scoparium were measured under conditions of mulching and no mulching. The results showed that:(1) branch mulch was beneficial to the early germination of clipping H. scoparium, which occurred more than 5 days earlier than those not mulched;(2) the average soil volume water content increased > 20.12% at the beginning and the end of the growth of 0-100 cm under different site conditions, and the variation coefficient of soil moisture content decreased with increasing soil depth. Soil water storage of mulching increased > 27% compared with no mulching at the beginning and end of growth;(3) the height, number of new branches, base diameter, and crown width of clipping H. scoparium increased > 10.91% with branch mulching. In particular, increased clipping H. scoparium biomass was more obvious in the interdune lowland than in other areas. However, branch mulch did not change the biomass allocation pattern of clipping H. scoparium(P>0.05);(4) branch mulching and clipping played an active effect on the growth of H. scoparium, with the most enhanced growth of clipping H. scoparium in interdune lowland.