In order to explore the effects of salt and drought stress on the distribution of nitrogen in the soil and cotton growth

the distribution of total nitrogen

nitrate nitrogen and ammonia nitrogen in the soil and the growth of cotton under drought conditions under different salinity conditions in drip irrigation areas were studied through test pit tests. The experiment set up three water salinity levels with conductivity (EC) of 3 (T1)

6 (T2)

9 (T3) dS/m respectively

and three irrigation volumes of 2 700 (W1)

3 600 (W2)

4 500 (W3) m

3

/hm

2

resp

ectively (4 500 m

3

/hm

2

was the local recommended irrigation amount). The results showed that when the soil salinity was greater than 3 dS/m

the total soil nitrogen accumulation was significantly higher than the lower salinity (P

<

0.05)

and soil salinity had a greater impact on the growth of cotton during flowering. In addition

the volatilization of ammonia nitrogen in the soil was directly proportional to the soil salinity gradient. The leaching loss of soil nitrate nitrogen was proportional to the amount of irrigation water. Compared with the nitrate nitrogen leaching loss of normal irrigation amount

the impact of water stress on cotton yield was more serious (P

<

0.01). As the depth of the soil layer increased

the soil alkaline nitrogen decreased at a rate of 8% per 20 cm soil layer. The

15

N residue rate in the soil of each treatment was 11%~40%

which increased with the increase of soil salinity

and decreased with the increase of irrigation amount

which was proportional to the total nitrogen content of the soil and was inversely proportional to the cotton yield. To sum up

T1W3 was more conducive to the utilization of nitrogen fertilizer in cotton and the improvement of yield. It is recommended that the soil salinity of cotton in the drip irrigation area should be less than 3 dS/m

and the irrigation volume be 4 500 m

3

/hm

2

. The amount of fertilization could be appropriately increased during the flowering period to stabilize the yield.