Investigation of Causes and Influences of Soil Acidity on Crop Yields in Kozova District, Ternopil Region

The paper covers the causes of occurrence and the methods of investigating soil acidity in Kozova destrict, Ternopil region. It is a highly topical issue, since increased soil acidity negatively influences the growth and the development of most cultivated crops and affects favourable microbiological soil properties. Soil acidity is caused by hydroions that are formed under the dissociation of acids and hydrolytic acid salts and are absorbed by the smallest soil particles – colloids, which can go into interstitial water. The increased soil acidity, which is a limiting factor for the biodiversity of a particular area and interferes healthy plant development, is an important agricultural problem. It can cause the decrease of crop yields as well as plant diseases. That is why, farmers should be aware of the type and the peculiarities of the soil present on their lots and take into account and regulate pH values when cultivating various agricultural crops. Soil acidity is considered to be acceptable for the healthy growth and development of plants, if it falls within the limits of рН 6.5–7.5. It has been determined that the application of mineral fertilizers without limestone materials causes acidification of typical black soils. If there is a long-term use of the increased amounts of mineral fertilizers, there is an increase of the active acidity observed. The application of nitrogenous fertilizers increases soil active acidity even more compared to the use of phosphate potassium fertilizers. Soil exhaustion prevention techniques have been substantiated. The methods of determining soil acidity have been considered. A potentiometric method is the most wide-spread in terms of determining soil acidity level, since it is highly sensitive and accurate. Soil acidity has been experimentally determined by potentiometry using TsINAO method (GOST 26483–85) and hydrolytically using Kapenn method (GOST 26212–91). Statistical data processing has been performed. The weighted-average acidity index pH salt. is 6.3 and the hydrolytic acidity is 1.77 mg–acs/100g of soil, pH salt. is 5.9 and hydrolytic acidity is 1.92 mg–acs/100g of soil. It shows that plants can grow and develop well in this soil. Scientific and production experience suggests that the yield from acid soils decreases for 15–20%. The scientific agro-ecological approach, that is the calculation of the balance of nutrients and humus depending on the kind of the cultivated crop as well as physical, chamical and bil