ObjectiveIn order to improve the survival rate and coverage of desert vegetation, a field experiment by adding fresh seaweed bio-enzymatic liquid organic fertilizer on the Atraphaxis bracteata located in the southwest of Mu Us Desert, Ningxia of northwestern China, was carried out to study its effect on soil physicochemical properties, growth and community species diversity of Atraphaxis bracteata in desert ecosystems.

MethodUsing a different gradient of fresh seaweed bio-enzymatic organic fertilizer to conduct a one-year test on Atraphaxis bracteata, the soil moisture was measured by soil moisture meter, soil total nitrogen was measured by Kjeldahl method, soil organic matter was measured by potassium dichromate titration, and species diversity was calculated by formula method.

Result(1) Fresh seaweed biological enzyme liquid organic fertilizer can increase soil moisture content in 0-10 cm layer effectively, and the soil moisture content of flush fertilization was 10.6% higher than that of foliar fertilizer application area. (2) The content of soil total nitrogen and organic matter in 0-20 cm layer increased with the increase of fertilizing amount and reached peak value when the fertilizing amount was 15 mL/m², and there was significant difference compared with control (P < 0.05). The content of organic matter treated with foliar fertilizer was much higher than that of flush fertilizer. (3) The fresh liquid organic fertilizer promoted the growth of Atraphaxis bracteata effectively, the growth of its ground diameter, plant height and new shoot all increased first and then decreased with the increase of fertilizing amount, and reached peak value when the fertilizing amount was 6 mL/m², and there was significant difference compared with control (P < 0.05). The effect of flush fertilization was better than foliar fertilizer. (4) The fresh seaweed bio-enzymatic liquid organic fertilizer increased the species composition, Margalef species richness index, Simpson dominance index and Shannon-Wiener diversity index of Atraphaxis bracteata.

ConclusionFresh seaweed bio-enzymatic liquid organic fertilizer can increase the content of soil moisture and nutrients in Mu Us Desert, promote the growth of Atraphaxis bracteata, contributes to the restoration of vegetation in Mu Us Desert, and then the vegetation can give better play to the ecological benefits.