N. Poushkarov Institute of Soil Science was founded in 1947. Since 1961 it has been in the system of the Academy of Agricultural Sciences, which was re-organized in a NationalCenter for Agrarian Sciences in 1999.

The staff of the Institute consists of 178 permanent positions including 94researchers, 4 of which have Dr.Sci and 85 - PhD degree; 11 are senior research associates I grade, 64 are senior research associates II grade and 19 are research associates I - III grade. There are also 10 post-graduate students studying in the Institute. In regard with the various multidisplinary scientific research and experimental field activities the personnel has different specialty in: agronomy, soil science and agrochemistry, melioration, biology, microbiology, ecology, chemistry, physics, engineering, mathematics, economy and etc.

The Institute carries out and co-ordinates national and international (FAO, UNEP, EC, USDA, EC) research projects in the field of soil science, agrochemistry, agrophysics , agroecology and environmental radioecology in the following areas: genesis and geography of Bulgarian soils; characteristics of the modern soil formation processes; methodology for large-scale soil survey; physical and mechanical soil properties; soil mineralogical composition; soil organic matter – its role in soil formation and soil fertility; ion exchange capacity and chemical soil melioration; content, forms and nitrogen balance in soil; content, forms and regime of K, Mg, P, trace elements and micro-fertilization; microbiological processes in soil depending on the soil type, management and stress factors; tillage and crop rotation as factors of soil fertility; soil erosion monitoring and risk assessments; technologies for soil erosion prevention and remediation of eroded and deteriorated lands; investigation of polluted soils (heavy metals, oil products, radio-nuclides, pesticides, herbicides) and recommendations for appropriate land use, and agricultural use of industrial and agricultural wastes. The main activities are concentrated in soil monitoring, geographic databases -and information systems on the soil resources in Bulgaria at different scales.

Some of the most important research tasks and recent contributions of the researchers can be formulated as follows:

Morphological, mineralogical, chemical, physico-chemical and physical criteria for soil diagnostics and classification, and assessment of the soil susceptibility to degradation, carbon sequestration and reduction of green house gas emissions; Remediation of lands deteriorated from coal, ore and mineral extraction activities – technologies and initial soil-formation processes; Methodologies for land evaluation.

Monitoring of the factors and the rates of soil erosion at diverse climate, landscape, soil, vegetation and management conditions; Studies on the soil behavior under water erosion conditions using simulated rainfalls; Validation of models for assessing the soil erosion factors and rates; Development of agronomical practices, machines, aggregates and technologies for soil erosion prevention measures in rainfed and irrigated agricultural lands; Development of data bases and geographic information systems for soil erosion and deflation risk assessments.

Ecotoxicology – soil and plant pollution; Monitoring of the pollution; Effect of heavy metal, radionuclides, organic pollutants and oil products in food chain soil-plant-water-animal-human; Experimental study of the migration of men-made and natural radionuclides in soil, their accumulation in plants and development of procedures for reduction of their transfer from soil to plants.Monitoring and valuation of the radioecological status of soils, plants, water and other environmental objects around Nuclear Power Plants and other hazardous regions; Development and application of contemporary procedures for determination of specific activities of different alpha-, beta- and gamma- emitting radionuclides in environmental samples;Phytoremediation by typical and gene-modified plant species and cultivars; Chemical amelioration by classic (liming of acidic soils) and alternative amendments (zeolite- natural and modified type, coal powder, Fe-hydroxide etc.); Evaluation of waste materials and composts for (i) agricultural use, (ii) remediation of deteriorated lands, and (iii) assessment of their impact on soil quality.

Soil microbiological indicators for evaluation of ecological stress effects (drought, waterlogging, salinization, acidification, heavy metal pollution, organic pollutants and pesticides etc.).

Rhizosphere ecology, especially bacteria for leguminous and non-leguminous plants, bacteria producing plant growth promoting substances and mycorhizal fungi.

Utilization of agricultural and forest plant residues by their composting.

Microbial aspects of soil formation processes; Enzymatic activity of soils and composts.

The Institute maintains the unique gene-collection bank of typical and introduced Bulgarian strains of N₂ fixing and other microorganisms, used in different experiments and agroecological situations; The collection is a member of the World Cultures Collection.

Conservation agricultural practices for soil degradation prevention (compaction, pollution), organic and low-input cropping systems, integrated systems for weed control, soil tillage and crop rotations for sustainable agriculture, energy-saving technologies, environmentally friendly cropping and intercropping systems for different soil and climatic conditions.

Scientific basis for managing of soil water status, formation of crop yield and environment protection; Soil - plant root characteristics and physical interactions; Physical aspects of soil degradation; Heat and water regimes of the soil-plant-atmosphere systems.

Soil fertility monitoring and optimization of fertilizer use; Soil acidity and amelioration of acidic soils; Organic and biological agriculture; Spatial variability of nutrients and pollutants in soils – geostatistical analyses.

Monitoring and sustainable management of water and nutrient cycle in the atmosphere-plant-soil-groundwater system at plot/field/watershed scale; Critical loads of nitrogen for soil and water; Food quality of cereals and vegetables; Waste water utilization.

Project design and automatization of improved surface irrigation; Modelling on water and nutrients losses in furrow irrigation; Surge irrigation; Impact of climate variability (incl. consequences of droughts and floods), soil type and land use scenarios (including irrigation scheduling and fertilization) by application of CERES models (CERES-maize and wheat); Optimization of integrated management strategies for cereals for mitigation the consequences of extreme hydrological events.

Applied statistics and system analysis (studies, transfer and application of statistical and simulation methods and models for data analysis in agro-environmental and soil science): Statistical data analysis and transformation of primary soil data to input data for simulation; Evaluation of long-term effects of agricultural land management (LM) on soil quality characteristics; Statistical methods and models for assessment of soil quality; Methods and tools for environmental and production risk assessment and risk management; Development criteria and application of statistical methods for assessment of LM sustainability, etc.

The Institute includes 9 scientific departments working on the above mentioned basic soil processes and anthropogenic impacts, green-house and 23 field experimental sites in different soil-climatic conditions representative for the whole country’s territory, modern laboratories for physical, chemical and biological analyses, library, secretariat. Personal computers and Internet connection are available.