Disease-inducing soils are soils where the percentage of fusarium, with filamentous bacteria, in the soil is high (over 15% to 20%). When living organisms with a high content of nitrogen applied as manure, odors are given off, maggots appear and a variety of harmful insects swarm. Since insects frequently appear, manure application with living organisms become harmful. More than 90% of soils today comprice the putrescent type; inorganic nutrients become insoluble, the soil is hard and physically poor. In rice fields, methane gas emission is high.
From: Agricultural Utilization Of Microorganisms For Environmental Conservation. D.r Teruo Higa. Pg 17.