Beneficial Effects of Organic Fertilization and No-Tillage on Fine-Textured Soil Properties Under Two Different Forage Crop Rotations

A 2-year field study was established to study the effects of tillage (conventional tillage [CT] vs. no-tillage [NT]) and fertilization (mineral fertilization vs. organic fertilization [O] with cow slurry) on a variety of physical, chemical, and biological properties of a fine-textured soil under two different forage crop rotations (maize and ryegrass, maize and triticale + pea). Four treatments were studied in each rotation for two consecutive years: NT + O, NT + inorganic fertilization [I], CT + O, CT + I. The effects of these agricultural practices on forage yield and nutritive value were determined. Conventional tillage resulted in lower compaction of the soil top layer as compared with NT, with values of soil cone index of around 2.5 MPa in the first 20 to 25 cm for NT plots. Fertilization with cow slurry, particularly in combination with NT, corrected soil acidity and increased microbial biomass and activity, as well as earthworm abundance. The combination of NT and O had the lowest impact on soil function as compared with a control native meadow located next to the experimental field. Apart from their potential as early indicators of the effects of disturbances on soil function, soil biological properties are also valid indicators of crop yield. Economically speaking, the combination of NT and I seemed to be the least profitable option. Interestingly, from the beginning of the transition from CT to NT, the combination of NT and O was a profitable alternative to the conventional practice (CT + I).