LUCERNE CULTURES

Wanganui Chronicle, Volume 75, Issue 13, 16 January 1932, Page 20 (Supplement)

LUCERNE CULTURES

DISTRIBUTION IN ENGLAND Some years ago the Rothamsted Experimental Station made arrangements for supplying British farmers with cultures of the necessary organisms to inoculate the soil for the growing of lucerne. The demand during 1930 was more than three times that of the previous year, enough cultures be’ug distrllii'ted to inoculate between 4000 and 4500 acres. The Ministry’s returns show that the acreage of lucerne in the country increased by over 4000 acres in spite of th? fall in acreage of arable land. Experiments are in hand to see whether seedsmen can inoculate tho seed bef»ro sale- This will save much trouble both in distribution and on the farm. Meanwhile scientific work has continued on the relation between the organism and the plant. It was shown in oue report that nodules do not appear on the roots of the young plant till the first leaf appears. As soon as that opens a substance is exuded from the root which enables the bacteria to attack and enter. The first visible sign of attack is the curling of the root hairs. This also is determined in part by a root excretion, and, like tho entry of the bacteria, can be brought about before the true leaf appears if the seedling is growing among rather older plants on which the leaves have opened. 1 Thus it appears that the excretion | from one plant can serve for others as well as for itself. The curling, however, is determined by an excretion from the bacteria, though tho relations between the excretions from the plants and the bacteria cannot yet be stated. Tho bacterial excretion is effective on plants other than those which the bacteria can enter, e.g., lucerne bacteria can curl the root hairs of peas, but they cannot enter. The various. leguminous bacteria do not live at peace with each other in the soil; lucerne bacteria reduce the number of nodules formed on clover roots by clover bacteria, though they cannot themselves enter the clover • root. Something happens to the organ--1 isms in the soil after the soil has been cropped with the leguminous plant for a time- Clover growing on a soil that had carried clover every fourth year had fewer nodules than clover growing ’ on adjacent soil where no clover had 5 been grown for 80 years, and this Mi • true whether there was i not.