Abstract：Excessive application of nitrogen fertilizer will reduce crop quality and harm environment．
How to reduce the nitrogen fertilizer applying dosage without reduction of output has become an issue urgently
to be solved for agriculture development．Arbuscular mycorrhizae fungi（AMF） plays a positive role in
promoting plant nutrient absorption，growth and development，and yet has the potential of replacing nitrogen
fertilizer．Taking lettuce（Lactuca sativa L. var. ramose Hort.） and spinach（ Spinacia oleracea L.） as research
objects，this experiment set up 8 treatments with different nitrogen fertilizer dosage and 5 treatments with
different AMF use level，respectively．This experiment screened out the best dosages of pure nitrogen fertilizer
for lettuce and spinach growth being 6.0 kg · hm-2 and 8.0 kg · hm-2，respectively and the best use level of
AMF were 200 g · kg-1 and 175 g · kg-1，respectively．Then AMF was used to replace the nitrogen fertilizer in
different proportions．Afterwards，the paper studied the effect of AMF on reducing nitrogen fertilizer dosage
in lettuce and spinach．The results showed that under the condition of substrate cultivation and on the premise
of not reducing lettuce and spinach fresh weight，adding 200 g · kg-1 and 175 g · kg-1 AMF，respectively could
reduce 40% and 60% nitrogen fertilizer dosage in lettuce and spinach production，respectively．That is，the
nitrogen fertilizer dosages were 3.6 kg · hm-2 for lettuce and 3.2 kg · hm-2 for spinach，their plant growth were
unaffected．The experiment result provided a new way for reducing nitrogen fertilizer application in lettuce and
spinach and for high-quality cultivation as well．
