The response to inoculation of the three chromosome races of Trifolium ambiguum sown with and without a companion grass. II. The effect of the method of inoculation on the clover and grass

The inoculation of legumes is often carried out using skim-milk as the carrier for the nodule bacteria. Increased germination due to inoculation has often been reported but in this investigation the effects of the skim-milk and the bacteria have been separated. The results indicate that the early establishment of T. ambiguum was stimulated by the skim milk rather than the nodule bacteria. The mechanism of this effect is thought to be due to extra N present in the milk and possibly to an enhanced nitrogen-cycle in the inoculated soil and evidence is produced of increases in certain freeliving nitrogen fixing and nitrifying microorganisms.