Occurrence of potassium deficiency in barley (Hordeum vulgare L.) grown on volcanic ash with long term application of sewage sludge
1999
Miah, Y.M. | Wang, M.K. | Hayashi, H. | Chino, M.
Beginning in 1978, 2 kinds of sewage sludge compost, one consisting of sewage sludge and saw dust (S) and the other consisting of sewage sludge and rice husks (H) were applied separately to 2 plots (S and H) of a field of volcanic ash (Ando soil). Crops were grown twice a year (corn in summer and barley in winter). From the summer of 1978 through the winter of 1996, the sludge composts were applied twice a year (10 tons ha-1). The control plot received chemical fertilizer. Depressed plant growth with nutritional disorder symptoms resembling potassium deficiency was noticed beginning in 1988, so the changes in the concentrations of extractable potassium in the sewage sludge-treated and control soils were studied. Compared with the control values, extractable potassium levels decreased significantly (p < 0.05) from 1989 to 1996 in the surface soil of the S plot but not the H plot, although plant growth was repressed in both the S and the H plots during the time. However, the difference in extractable K concentration between these S and H plots was insignificant (p > 0.05). These findings suggest that the potassium concentrations of the sewage sludge-treated Ando soil had decreased to below the normal level within 10 y.
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