44, QUEENSLAND AGRICULTURAL JOURNAL. [1 Jan., 1898. 
pretty clearly demonstrated that this peculiar property is due to bacterial life 
found in the nodules or little knots on the roots. Consequently the more 
numerous the nodules, the greater the capacity for collecting nitrogen and 
enriching the soil. At the Louisiana Station (says Orange Judd Farmer) it 
was found that cow peas planted 2 and3 inches deep produced the greatest 
number of roots and tubercles. Below 3 inches the root system was less 
extensive and the plant less vigorous. Roots penetrating directly downward 
were generally free from tubercles at a depth of 10 or 12 inches, or soon 
after the root gets into compact clay. The nature of the soil has much to do 
with tubercle formation. In cultivated soil the nodules will be found on all 
the roots, while in a compact field they will be confined to roots near the 
surface. They are also found at a greater depth in a sandy than a clay soil, 
and where deep cultivation is practised than where shallow prevails. 
Other experiments indicated that each plant, or at most each genus of 
plant, will support but one kind of parasitic organism capable of developing 
tubercles on its roots. For example, a peculiar organism must be present in 
the soil to produce nodules on alfalfa. Any quantity of cow peas or other 
_ leguminous plants will not furnish that organism. ‘The cow pea likewise has 
its peculiar parasite. The organism to produce the tubercle must be in the 
soil before the seedis sown. Just why they are present in some places and 
absent in others, is not quite clear. Tests are being made to determine the practic- 
ability of inoculating the soil with special organisms or germs, thus making it 
possible to grow legumes on land heretofore unproductive for this particular 
crop. Results so far indicate that this is one of the possibilities, but more 
investigation is necessary before a definite statement can be made. 
