
TY  - JOUR
A1  - McGarity, JW 
A1  - Myers, RJK 
T1  - Seasonal trends in the content of mineral nitrogen in solodized solonetz soil
JF  - Australian Journal of Experimental Agriculture
JO  - Aust. J. Exp. Agric.
Y1  - 1973
VL  - 13
IS  - 63
SP  - 423
EP  - 429
KW  - 
UR  - https://doi.org/10.1071/EA9730423 
N2  - Fluctuations of mineral nitrogen were studied for three years in two solodized solonetz soils at Narrabri, New South Wales, under a wheat summer-fallow management system. Changes in mineral nitrogen were related to plant uptake, soil environment characteristics (water, temperature and oxygen), and climate. NO3-N was the major form of soil mineral nitrogen, generally exceeding NH4-N with NO2-N occurring only occasionally (<1 ¦g N g-1). NO3-N accumulated during fallow to 67-111 kg N ha-1 in the profile just after sowing. Crop growth depleted NO3-N to 0-11 kg N ha-1 at flowering. Several significant falls in soil NO3-N (11-27 kg N ha-1) could not be accounted for by plant uptake, and were apparently caused by denitrification. Decreases due to leaching (including lateral leaching) were not detected. Redistribution of NO3-N down the profile was observed, the efficiency of leaching increasing with increased intensity of rainfall. NH4-N generally amounted to less than 25 kg N ha-1. Fluctuations in NH4-N which occurred within the profile, could not be related to observed factors and are unexplained. The effect of a drought year, 1965, was to inhibit mineral nitrogen accumulation, lessen the depth of leaching of NO3-N and depress plant uptake of nitrogen. 
ER  -

