The invention discloses an
irrigation method for increasing the yield of
medicago sativa under
water deficit. The
irrigation method comprises the following steps of 1,
medicago sativa planting, wherein strip
sowing with the row spacing being 20 cm, the
sowing rate being 20 kg / ha and the
sowing depth being 5 cm is adopted, and 2,
medicago sativa
irrigation is conducted, wherein the irrigation rate is kept twice a week from sowing to the
seedling stage, and the total irrigation amount is 50 mm.
Water deficit irrigation is started in the alfalfa branching period, the irrigation amount is calculated according to the local actual
crop evapotranspiration amount, the moderate
water deficit and the severe
water deficit are 2 / 3 and 1 / 3 of the actual
crop evapotranspiration amount respectively, and the irrigation frequency is one time per week. And (3) irrigation
system: when an underground
drip irrigation system is designed, a
drip irrigation belt is buried at a position 20cm underground before alfalfa is sown. The alternate subsurface
drip irrigation comprises a subsurface drip irrigation
system 1 and a subsurface drip irrigation system 2. One set of underground drip irrigation system is used for one-time irrigation, and the other set of underground drip irrigation system is used for next-time irrigation. The alternate underground drip irrigation method is an effective way for improving the yield of alfalfa under the condition of water deficiency.