关中地区紫花苜蓿生物量累积及土壤水分利用规律的研究

Studies on Aboveground Biomass Accumulation and Water Utilization rule of Alfalfa in Guanzhong Area

以关中紫花苜蓿为材料研究了杨陵地区紫花苜蓿地上生物量、土壤水分及它们之间相互关系。结果表明，3年生紫花苜蓿株高与产量呈极显著正相关，盛花期刈割时，鲜草产量达到40970kg／hm^2；紫花苜蓿生长的地上生物量以第1茬最高，水分利用率以第2茬最高，第3茬最小；紫花苜蓿0～2m土壤水分变化与降水及苜蓿不同发育期的吸收特性相关。

The aboveground biomass and soil water content and their correlation for alfalfa in Yangling area was studied with Guanzhong alfalfa as material. The plant height and forage yield in alfalfa at 3 year ages had very significantly positive correlation. When clipping at stage of fitll bloom stage the fresh yield was 40 970 kg/hm^2. The aboveground biomass was highest in 1st cut,. WUE was highest in the 2nd cut and lowest in the 3rd cut. The water changes in 0 - 2 m soil layer during alfalfa growth stage was related with the precipitation and absorption characteristics of alfalfa in different development periods.