[Comparison in vitro between farm-yard manure and liquid manure (author's transl)].

Spreading of liquid manure in a grassland ecosystem, stable since a long time when treated with farm-yard manure, brings out a great unbalance in the soil. In comparison of farm-yard manure, the liquid manure involves -- a decrease of C and N in the soil, -- a deterioration of the soil structure, -- a dangerous change in the CEC for K+ and Na+, -- an excessive stimulation of the microflora. In brief, through its composition the liquid manure involves a hyperactivity of the microglora. This heterotropic microflora is particularly mineralizing and breaks down the organic matter. The result is a temporary increase in fertility. But this stimulation of the soil life disbalances the eco-system in which -- the pool of organic matter decreases without replacement, -- the content in Ca++ and Mg++ decreases to the benefit of K+ and Na+.