
TY  - JOUR
A1  - Doughton, JA 
A1  - Mackenzie, J 
T1  - Comparative effects of black and green gram (mung beans) and grain sorghum on soil mineral nitrogen and subsequent grain sorghum yields on the Eastern Darling Downs
JF  - Australian Journal of Experimental Agriculture
JO  - Aust. J. Exp. Agric.
Y1  - 1984
VL  - 24
IS  - 125
SP  - 244
EP  - 249
KW  - 
UR  - https://doi.org/10.1071/EA9840244 
N2  - A field trial was carried out on a black earth (Waco series) at Cambooya on the Eastern Darling Downs to compare the effect of black gram, green gram, grain sorghum and a summer fallow on soil mineral nitrogen (NO3-N + NH4-N) and the yield of grain sorghum grown in the following summer. The initial sorghum treatment severely depleted soil mineral nitrogen to 120 cm; even after a 173-d fallow, there was still 34 kg/ha less nitrogen present than initially in this treatment. Black and green gram also reduced levels of soil mineral nitrogen during crop growth, but these recovered to exceed pre-trial levels by 29 and 42 kg N/ha, respectively, after a winter fallow. The fallow treatment accumulated 100 kg N/ha of mineral nitrogen between January and October, but mineralization was markedly reduced from August to October. Sorghum grown on all plots in the second summer responded markedly to prior treatments, and grain yields and responses to nitrogen applied at 0, 34 and 68 kg N/ha reflected mineral nitrogen levels at planting. Yields of sorghum grain obtained without fertilizer after black gram, green gram and fallow were 8333, 7477 and 9663 kg/ha, respectively, compared with 4658 kg/ha after sorghum. Prior crops of both grams increased sorghum yield as much as a fertilizer application of 68 kg N/ha. 
ER  -

