In agriculture, calcium oxide is used as sterilizer and neutraliser of soils’ acidity, often caused by various and complex phenomena. The soil’s acidity excess has a remarkable influence on the development of crops; on the other hand, the addition of lime favours the perfect assimilation of the main nutritive substances.
Calcium is useful in the plants’ physiology because it acts in the:
• cellular relaxation and division processes;
• resistance of tissues and formation of pollen;
• development of the roots.
Magnesium, instead, acts in the:
• composition of the chlorophyll molecule;
• mechanisms that prevent water drop.
STRUCTURE OF THE SOIL
The presence of lime in the soil has a positive influence also on the physical and mechanical properties of it, facilitating the structural aggregation phenomena, improving permeability to water and allowing to bring the pH value close to the neutral value, that is pH 7. In most cases an adequate treatment of the soil with lime determines a valuable increase in crop production, and the value of this increase highly exceeds the cost of manure and its laying.
GROWTH OF MICRO-ORGANISMS
The biological conditions for the presence of useful micro-organisms are present only in soils rich of lime. Therefore, the addition of lime in soils influences the growth of bacteria and formation of nitrate, which can be seen from the quick increase of CO2 formation, nitrogen content and formation of enzymes. The grain structure of the soil is favoured by annelids, in particular worms, whose galleries favour water distribution by deviating excess rain water in the sub-soil.
PHENOMENA CAUSED BY LIME DEPLETION
In all agricultural soils lime is depleted due to erosion and constant harvests.
If these lacks are not compensated, phenomena caused by lime depletion will occur in a short period of time, mainly at the beginning of the growth period, when there is the maximum absorption of nutritive substances.
In light soils said phenomena occur first of all as acid damages, while in uniform soils as structural damages.
Lime depletions are not only due to the aforementioned causes, but also to specific mineral manures, that boost the acidity in the soil.
Therefore, prior to carry out the process of manuring, the soil must be carefully evaluated.
To create or preserve favourable growth conditions for useful plants, lime depletions must be quickly re-integrated.
The quicklime required for manuring must be used in granules of 2-6 mm, since this format is more soluble and therefore it reacts quicker.
The manuring period with quicklime is not strictly related to a specific time, but spreading
the product prior to the vegetation period, in mid spring, improves the soil’s structure significantly.
Other lime applications in agriculture are: use of limewash or lime water to disinfect cellars and stables after adding pesticides; paint the trunks of orchards to protect the plants from sun rays during the summer and from frost during the winter, and to increase protection against the aggression of parasites; favour decomposition and disinfection of carcasses, in addition to recover and reclaim contaminated soils.
ITALCALCE has improved its systems to produce granular lime of 2-6 mm, characterised by a total lack of powder that makes it suitable for spreading for agricultural use, also during windy days.