BIOENERGY ON DEGRADED SOILS IN THE MOUNTAINOUS PART OF LVIV REGION: POTENTIAL AND CHALLENGES

Abstract

The article analyses the potential and challenges in the development of bioenergy on degraded soils in the mountainous part of Lviv region. Increasing the capacity of renewable energy sources is one of Ukraine's strategic goals in achieving energy independence and climate neutrality. One of these is bioenergy, which can use degraded and unproductive soils. Due to significant soil degradation, a large proportion of the land has become unfit for agriculture. That is why bioenergy crops can be grown on such lands. Such bioenergy crops include energy willow, poplar (Populus L.), black acacia (Acacia melanoxylon R.Br.), miscanthus (Miscanthus giganteus), fast-growing millet (switchgrass) (Panicum virgatum L.) etc. Each bioenergy crop has its own favourable growing conditions. In particular, conditions with annual precipitation of less than 650 mm per year and an average annual temperature of more than 6°C are considered favourable for growing bioenergy crops. The potential of bioenergy development is considered on the example of the mountainous part of Lviv region. According to the scheme of agro-soil zoning of Lviv region, the mountainous part is located within the Carpathian mountain forest-meadow (‘brown earth’) zone, within which the following agro-soil districts are distinguished: Starosambirskyi, Turkivskyi, Volovetskyi and Pidpolonynskyi. The area of mountain-forest brown earth soils within Lviv region is 181.1 thousand hectares, or 8.3% of the total area of the region. These soils are characterised by a low humus content. The pH is between 2.8 and 4.6. Such acid-base properties are quite favourable for growing bioenergy crops. It should be noted that a large part of the brown earth has been degraded due to deforestation. The limiting factor for growing bioenergy crops within the Ukrainian Carpathians is the steepness of the slopes, as a significant proportion of hillsides are not suitable for growing black acacia, miscanthus and switchgrass due to their high steepness, which can sometimes exceed 15%. This factor is not limiting for energy willow and poplar. However, the region has unfavourable conditions for their cultivation, as it has been established that poplar and energy willow plantations require moist, humus-rich, well-drained sandy loam or loamy soil. The pH value should be in the range of 5–7. Total nitrogen should be at least 15.0 mg/100 g of soil. After analysing the prospects for growing bioenergy crops in the mountainous part of Lviv region, it can be concluded that most of the territory of the mountainous part of the region is unsuitable for growing bioenergy crops due to the peculiarities of agroclimatic and soil conditions.