EFFECT OF SOIL SALINITY ON NITROGEN TRANSFORMATION IN SOIL WITH NITROGEN FERTILIZER APPLICATION

In order to study the effect of soil salinity on fertilizer nitrogen transformation, a laboratory culture experiment was conducted with six salinity levels (soil salt content was: 0.17%, 0.99%, 1.64%, 2.32%, 2.91%, 3.79%, respectively) and 6 fertilizer treatments (no fertilizer (CK), low (UPL), medium (UPM) and high three urea phosphate doses (150 kg N/hm(2), 300 kg N/hm(2) and 600 kg N/hm(2)), low (URL) and high urea doses (URH) (300 kg N/hm(2) and 789 kg N/hm(2))). With the increase of soil salinity, the average ammonia volatilization loss rate increased from 1.07% to 9.17%. The average of cumulative ammonia volatilization under different fertilization treatments basically followed the order: URH > URL > UPH > UPM > UPL > CK. With the increase of soil salinity, the average net nitrated nitrogen under different fertilizer treatment was 52.66, 43.06, 68.86, 43.18, 31.10, 22.66 mg/kg in order. Soil inorganic nitrogen transformation increased with the increase of fertilizer application. The net nitrated nitrogen and inorganic nitrogen transformation of soils with different salinity under UPM treatment were higher than those under UR(L )treatment.

Automated summary

This laboratory culture experiment investigated the effect of soil salinity on fertilizer nitrogen transformation. The results showed that with the increase of soil salinity, the ammonia volatilization loss rate increased and the cumulative ammonia volatilization and net nitrated nitrogen content varied with different fertilizer treatments. Soil salinity had a greater influence on the net nitrated nitrogen and inorganic nitrogen transformation under urea phosphate treatment.