Soil liming
The main goal of this operation is to reduce the acidity of the soil and bring it to the neutral state, if possible. The introduction into the soil of various calcareous materials transforms the chemical and biological nature of acidic soils, improves their fertility.
Lime materials
Natural origin:
types of limestone;dolomites;marl;
natural dolomite flour.
Waste industry with high lime content:
shale ash;
white sludge;;cement dust;
;ground blast furnace slags.
The neutralizing basis of almost all calcareous materials is chalk or calcium carbonate. The proportion of its content in various calcareous materials varies from 100 to 15 96. The necessary dose of lime is determined depending on the acidity of the soil, its structure and composition, the degree of moisture, and also on the types of crops for which this soil is intended. The need for soils in the liming of is considered strong at pH less than 3.5, medium - at pH 4.3, weak at pH 4.5.With an acidity index of pH 5, the need for liming is eliminated. With the strong soil requirement in liming, the following amount of calcareous materials should be added in terms of dry chalk( g / m2):
Strong demand 300
Average requirement 200
Weak requirement 100
The data is adjusted according to the soil type and acidity level to be achieved by liming
Chalk doses for different soil types
| Soils | Chalk doses( r / i | and 2) with pH, up to | ||||
| 5.4-5.5 | ||||||
| 4.5 | 4.6 | 4.8 | 5.0 | 5.2 | ||
| Sandy | 300 | 250 | 200 | 150 | 100 | 100 |
| Sandy loam | 350 | 300 | 250 | 200 | 150 | 150 |
| Light loam | 450 | 400 | 350 | 300 | 250 | 250 |
| Medium loam | 550 | 500 | 450 | 400 | 350 | 300 |
| Heavy loam | 650 | 600 | 550 | 500 | 450 | 400 |
| Clay | 700 | 650 | 600 | 550 | 500 | 450 |
It should be noted that these data are given for soils of normal moistening. On excessively moistened soils, to achieve the optimum level of acidity, the chalk dose should be increased by 150 g / m2.Liming is usually done: on medium soils every 4-5 years, on the lungs - every 3-4 years, on heavy soils - every 5-6 years. It is best to apply lime to cultures that respond well to liming. Especially good are the liming of cabbage, beetroot, onion, garlic, spinach, celery, as well as cucumbers, beans, turnips, cauliflower and carrots.
Calcareous materials can be applied for autumn soil cultivation along with dry organic fertilizers, evenly distributing them on the surface of the site.
Attention! Slaked lime, cement dust, slate ash can not be applied simultaneously with manure, because as a result of their interaction, a lot of free nitrogen is released, which can damage plants.
Ground limestone, dolomite flour, tuff, marl, vegetable ash is applied to the soil together with manure. First, the lime material is spread evenly over the surface of the area, then the manure is spread and the soil is immediately digested.
Content of chalk content
in lime materials,%
| Ground limestone, | ||
| or calcium carbonate | 75- | -100 |
| Dolomite powder | 55- | -100 |
| calcareous tufa | 75- | -95 |
| headed lime | 80- | -100 |
| Quicklime | 17- | -18 |
| Hydrated lime | ||
|
| -15 | |
| Wood ash | 30- | -40 |
| Peat ash |
If it is necessary to significantly increase the acidity of the soil, it is better to apply lime gradually, in several steps and in small portions so that it can be fully digested and processedtana soil. With prolonged systematic lime application, the soil acidity level should be checked regularly and, if necessary, the liming procedure should be continued.
When applying lime to the soil, take the necessary precautions: wear rubber gloves and goggles, never dissipate lime on a windy day. To smell lime in the soil, it is convenient to use forks.
It should also be noted here that different types of soils retain a constant acid reaction to varying degrees. Most soils are characterized by a gradual tendency to oxidation. Even after the measures taken to return the soil to the neutral area of acidity, a gradual process of its oxidation can begin. This is particularly true of sandy soils, which generally do not differ in stability in maintaining constant indicators. Chemical indicators change rapidly in sandy soils, as they are unable to retain nutrients and chemical elements. This also applies to the level of acidity, so lime in sandy soils should be regularly added in small portions to maintain a constant stable level of acidity.