A long-term experiment was used to investigate the effects of fertilizers and fertilization on both soil nutrients and crop yield of winter wheat grown in dry highland from 1984 to 1992. The trial treatments was as follows

CK

M，N

P

NP and NPM. Results showed that crop yield was increased stably under the treatment of long-term applying manure (M)

nitrogen and phosphours (NP) and NPM fertilizer with a range. from 49.4%to 141.6%. The most significant effect of the treatments on yield increase was NPM. The rate of yield increase was 75% and 50% for N and Papplication respectively. Contents of soil organic matter

total N

available N and P went up after M and NPM fertilization. However

use of N and p individually could only inlarge the amount of the relevent element in soil

but not the organic matter

It is suggested to use NPM mixture in agricultural production pratice and to apply NP mixfure when manure is shortage

which can assure to achieve the aim of high yield and fertile soil.