采用遮荫试验模拟林地不同光照强度,研究紫花苜蓿地上生物量和C、N、P、K化学计量特征,为撂荒地林下间种苜蓿提供科学依据.结果表明:苜蓿地上生物量与光照强度呈显著正相关,遮荫处理显著降低了苜蓿地上生物量;62%遮荫处理下全C、N、P含量最高,分别为373.73、34.38和5.47 g·kg-1,并且显著高于对照.遮荫对苜蓿地上部分K含量影响不显著.除72%遮荫处理下C/N显著高于对照外,其他各处理与对照差异不显著.N/P、C/P随遮荫强度增加呈先降低后升高的趋势. The shading test was used to simulate different light intensities of the forestland, and to study the aboveground biomass and C, N, P and K stoichiometry characteristics of alfalfa, and provide scientific evidences for the alfalfa under the forestland in fallows.The results showed that aboveground biomass and light intensity The shading treatment significantly reduced the aboveground biomass of alfalfa. The content of total C, N and P was the highest under 62% shading treatment, which was 373.73, 34.38 and 5.47 g · kg-1, respectively, which was significantly higher than that of the control. Shading had no significant effect on the K content of alfalfa, except for 72% of shading treatments, C / N was significantly higher than that of control, but no significant difference was found between other treatments and the control.N / P and C / P increased with shading intensity First reduce the trend after the rise.