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

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.