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Show Influence of Inoculation and Green Manures on the Protein of Legumes J. E. Greaves and L. W. Jones Properly inoculated legumes may be considered nitrogen fixing factories in which atmospheric nitrogen is combined with carbon, hydrogen, and oxygen. In this way elementary, inert, valueless nitrogen is transformed into combined, active, valu able compounds. For this to occur the legumes must have root nodules in which the Rhizobium fixes the atmospheric nitrogen. When the soil is unsuited to the growth of the Rhizobium or its host, the condition must be remedied. In other cases the soil supply of nitrogen may be sufficient to meet the needs of the growing legume, hence it is not forced to use atmospheric nitro gen, but feeds as do non-legumes on soil nitrogen. More often the Rhizobium is absent from the soil or present in insufficient numbers to parasitize properly the growing plant. When this is the case the seed should be inoculated with the proper Rhizo bium. Such an inoculation may manifest itself by (1) an in crease in total crop yield. ( 2) a more uniform maturity of the crop. The present work was planned to learn the influence of inoculation on the nitrogen content of legumes when grown under controlled conditions on soil with and without green manure. METHOD OF EXPERIMENTATION Two-qallon pots were filled with soil from the experimental farm at North Logan. The soil had not previously grown legumes and was believed to be devoid of Rhizobium. It is a highly cal careous silt loam, low in nitrogen, and fairly well supplied with the other plant nutrients. Care was taken to insure a uniformity of soils in the various pots. They were seeded withi the following legumes: alfalfa, crimson clover, cow peas, Canadian field peas, soybeans, garden beans, and lupines. One half of the pots were seeded with uninoculated seed, the others with carefully inocu lated seed. The crops were grown in the greenhouse. They were harvested when in bloom, air dried, weighed, and analyzed for total nitrogen. Crop residues were returned to one half of the pots. Hence each legume entered into the following system: ... 1. Legume uninoculated, crop removed from the soil. 2. ,Legume uninoculated, crop returned to the soil. 3. Legume inoculated, crop removed from the soil. 4. Legume inoculated, crop returned to the soil. 101 |
