A Study on the Recycling of Sludge to Farmland

Recycling to The Paddy Field of Gray Lowland Soil

Abstract

Hiezu, Daisen and Saihaku in Tottori Prefecture, have been practicing the field tests jointly since 1995 in order to compost the sludge produced from the three communities and recycle it to farm lands. This paddy field test in gray lowland soil is scheduled to be continued for about 10 years. The interim results gained from tests of past 4 years are summarized as follows.(I) Yields of rice and tulip increased by using the composted sludge. Gains of rice and tulip increased too.(2) Shipment rate of tulip increased with increase of quantity of the inputted compost.(3) Content of heavy metals in crop did not increase.(4) The accumulation of heavy metals in soil could not be found even 4 years after test began.