It is very important to study the behavior of trace element~ in soils and plants in relating to animal nutrition. The authors dealt with some trace elements contents of soils distributing in Chugoku district where granite, volcanic ash and alluvial soil were found as three typical soils.
The total Cu content was highest in the alluvial soil and lowest in the volcanic ash soil in which the content of available Cu was also trace.
The total Co content was more in both the volcanic ash and the granite soil, but less in the alluvial. And the available Co was found only a trace in the granite soil. Generally, the total Co or the available Co content was lower in the soils distnbuting Chugoku area.
There will be some possibility of the occurrenece of Co defficiency in animals in this district.
The total Mn was found as considerable amounts in the soils, however, the available Mn was rather lower in all soils.
The total Zn content was more in the volcanic ash soil and less in the granite soil.
The B content was 14.9 to 29.2 ppm as the total and was 0.1 to 0.5 ppm as the available in all soils.
Dallisgrass (Paspalum dilatatum, Poir.) and Russian comfrey (Borraginaceae, Symphytum asperrinum, Sims.) were cultivated in pots or earthen pipes which were filled with the alluvial or the granite soil and applied with (NH,h SO, or NaNO,, supper phosphate and K 2SO,, 1.2 kg per acre respectively.
Trace elements were applied in the followings, 4 kg of CuSO4, 2 kg of CoCl2, 6 kg of MnCl2, 2 kg Na2MoO4, 2 kg of ZnCl2 and 6 kg of H3BO3 per hectare each.
Dallisgrass increased 10 to 20% in its length and 10 to 30% in its weight with Mo, Co and B, but decreased around 10% in both with Cu, Mn and Zn.
The Russian comfrey was better in growth with (NH4 ) 2 SO4, than NaNO3, and increased 30% with Co, Mo and B but decreased with Mn.
There were seasonal fluctiations in the trace elements contents in plants.
Co contents in dallisgrass was fortified about five times with NaNO, as with (NH4) 2 SO4. The application of trace elements increased, of course, their contens in the plants, and it was more remarkable in the case of Co and Mo.
Organic constituents of plants were also influneced with the application of trace elements.
Among the indispensable amino acids in dallisgrass, His contents were increased with all trace elements tested except Co, Arg with Cu, Mn and Zn, Phe with Zn and B, Met with Mn and Zn, Leu and Ileu with Zn, and Val with Mn and Zn. Lys and Thr were decreased with Zn. The content of basic amino acids in Russian comfrey was much higher in the case of (NH4h SO, than that of NaN03, but other amino acids contents were higher with NaN03 than with (NH4 ) 2 SO,.
The content of Pro was increased with Cu, Co and B. Ileu with Cu and Met with Cu and B, and Lys with Co and B. However, Arg was decreased with Mn and Mo, Phe with Mn, and Asp, Thr, Ala, Leu, and Tyr were decreased with Mo.