Abstract
Soil salinization is typically widespread on plains and in desert areas and it can lead to significant yield losses. Presently, about 50% of irrigated land in Uzbekistan is saline, 16.9% of which reached medium and high degree. Out of 13 provinces only in three ones salinization has limited distribution. Soil salinization has a severe impact on the productivity of agricultural crops; e.g. cotton crop losses due to salinity ranged from 15% to 30-40% and even to 60-80% (at low, medium and high salinity, respectively). Soil salinity combined with low moisture is mostly dangerous. Under such conditions, plants suffer double stress. The presence of salts in the soil solution leads to additional negative pressure soil moisture, a so-called osmotic pressure. This creates a difficulty in the selection of moisture the plant roots. According to Uzbek researchers, the total pressure in the root zone during the period between the first and forth cotton development phases should not exceed 4 atm. Irrigation duration for agricultural crops should consider effect of both moisture and soil salinity. In order to monitor these indicators and determine irrigation based on maximal value of osmotic potential, a simple and user-friendly methods and devices, which indirectly take into account both indicators, need to be developed.Application of electrical conductivity for soil salinity monitoring allows determining stress state of plants in practice and initiating prompt action to reduce crop losses by carrying out irrigation of plants at due time.
