The Main Physical and Chemical Characteristics of Chernozems in the Southern Oltenia

Soils originated from the long-term arable plots at the Experimental Station of the Institute of Soil Science and Plant Chernozems are soils with a high natural fertility due to several favorable features on the whole depth of the soil profile, namely: loamy texture, optimal content of water and air, good capacity for nutrient supplying, intense microbiological activity, etc. Humus and nutrient supply is high due to their genesis conditions that have been among the best ones. With most chernozems, almost two thirds of humus reserves are within first 50 cm while phosphorus reserves are relatively evenly distributed on soil profile, although upper layer is richer in this nutrient. Although these soils have a good humus and nitrogen supply and their nitrification capacity is high, chernozems do respond well to organic fertilization as well as to nitrogen fertilization. Yet, because of rainfall scarcity, the effect of fertilization is reduced and, sometimes, uncertain. As regard potassium supply, the researches have shown a good supply with this nutrient and this is why background chemical fertilization with potassium has a low efficiency.