a. Proto-base and topography b. Living organisms c. Climate and weather
d. All of the above
The formation of a 30-centimetre layer of soil takes:
a. Up to 100 years b. From 100 to 1,000 years
c. From 1,000 to 10,000 years
d. Over 10,000 years
The average weight of soil organisms (bacteria, fungi, earthworms, springtails, mites, isopods, spiders, etc.) found in the top 30 centimetres of one hectare of soil is about:
a. 100 kilograms b. 1,500 kilograms c. 15 tonnes
d. 25 tonnes
Erosion and compaction are the biggest threats to the soil. The percentage of European land affected annually is:
a. Less than 1 percent b. About 5 to 10 percent
c. About 15 to 20 percent
d. About 40 to 50 percent
In optimal conditions, the rate of a pesticides' transformation by the soil into non-toxic compounds is:
a. More than 99 percent
b. About 80-90 percent c. About 50 percent d. Up to 25 percent
Loss of biological activity and animal species in the soil may be caused by:
a. Removal or burning of vegetation b. Excessive application of fertilisers and agrochemicals c. Acidification from atmospheric pollution
d. All of the above
The percentage of European land covered by constructed areas is:
a. 1 percent
b. 2 percent
c. 5 percent d. 10 percent
Water erosion affects crop production by decreasing plant rooting depth, removing plant nutrients and organic matter, and uprooting plants and trees. The agricultural production losses from this may reach:
a. 5 percent b. 10 percent
c. 30 percent
d. 50 percent
The level of heavy metals in the soil is constantly increasing due to:
a. Industrial and waste-incineration activities b. Combustion of fossil fuels (power production), and road traffic c. Agriculture (irrigation with polluted water and use of mineral fertilisers)
d. All of the above
The use of pesticides may lead to:
a. Destruction of the soil micro-flora and fauna b. Severe yield reduction in crops c. Leaching of toxic chemicals into groundwater
d. All of the above
The irrigation of Hungarian plain has caused salinisation in:
a. More than 20 percent of the land
b. About 5 to 10 percent of the land c. About 3 to 5 percent of the land d. Less than 3 percent of the land
Soil properties may be improved by applying the following approaches:
a. Once the threat is removed, soil quality could improve by itself b. Application of soil excavation, washing and disposal c. Treating soil pollutants with immobilising additives
