抄録
Soil dressing with Pumice Flow Deposit (PFD) has been widely practiced in Abashiri district of Hokkaido. Soil physical properties was improved in this operation, but concentration of nutrients in soil were declined because of dilution. To solve this problem, we studied the effect of simultaneous application of organic matter with soil dressing of PFD. Application of 80 Mgha'1 barnyard manure increased CEC, available phosphorus, and exchangeable cations. The available nitrogen value also increased, but these values were still under the value recommended. a-glucosidase activities in PFD as an index of soil microbial activities was very low in PFD, therefore this activities declined in the soil dressed with PFD. However, decrease of aglucosidase activities were less than the value estimated by soil dilution ratio when the soil physical properties were well improved by dressing. a-glucosidase activities recovered to the same level of original soil with simultaneous application of barnyard manure. As a result, we can quickly recover soil chemical and biological properties in the dressed soil by simultaneous application of organic matter with PFD.
