INFLUENCE OF PRECIPITATION UPON DRAINAGE DISCHARGE IN TWO DIFFERENT CLIMATIC REGIONS

The goal of three-year investigations was to determine the influence of precipitation upon the drainage discharge in two different climatic regions (Croatia and Lithuania) at two different pipe drainage spacing in each region (first region with 15 m and 20 m drainage spacing and second region with 12 m and 24 m drainage spacing), to calculate the soil water balance according Thornthwaite's method and compare the measured drainage discharge and the calculated surplus of water in soil. Investigations were carried out at the experimental amelioration sites in the central Sava River Valley (Croatia) on hydroameliorated Gleyic Podzoluvisol soil and in Middle part of Lithuania on hydroameliorated Hypogleyic Luvisol soil in the period 2009 - 2011. The research results showed that the drainage discharge and its duration depended on the amount and distribution of the precipitation during the study period. There isn't difference in the total drainage discharge between the tested drainpipe spacing in each investigation year, but there are differences in the duration of the drainage discharge both on an annual scale and depending on drainpipe spacing. In each year, the duration of drainage discharge was smaller at the 12-15 m drainpipe spacing than at the 18-20 m drainpipe spacing. The calculated surplus of water followed the monthly amounts of precipitation, but in all years was higher than the drainage discharge. The 12 to 15 m pipe spacing is more efficient for draining the surplus water from drained soils, since the surplus of water from soil is drained in a shorter period of time and better water-air relationships in soil are created faster, which is a prerequisite for timely application of agricultural management practices on hydroameliorated arable areas

COMPARISON OF WATERMARK SOIL MOISTURE CONTENT WITH SELYANINOV HYDROTHERMAL COEFFICIENT

Agricultural producers to determine irrigation scheduling practices for crop‘s waterrequirement better when the soil water content of their fields is known. SelyaninovHydrothermal Coefficient (HTC) coefficient is used for identifying droughts duringthe active vegetation period, based on the water balance equation. For farmers tomake measurements of soil moisture is simply with humidity sensors, for exampleWatermark type. Soil humidity values established using Watermark type humiditysensors, value interpretations are based on manufacture indications, however theyhave not been adapted to Lithuanian conditions. Soil moisture was measured withWatermark soil moisture sensors placed at 20 and 50 cm depths. After analysingthe values taken throughout the whole period and summarizing the results it hasbeen identified that plant growth condition period evaluation according to HTC andfactual soil humidity reserves (W) differs by 20%. HTC meaning dependenciesduring vegetation period using Watermark measured humidity, strong or averagelystrong interrelation is determinate, in most cases – statistically significant. Whenevaluating soil humidity reserves based on soil texture, it is recommended to keepthe critical Watermark level in light texture soil (sands) at 80 cbar, and in all othertypes of soil - at 150 cbar. The results clearly indicate that soil composition couldbe factors limiting the success of identifying droughts in agriculture carried byWatermark type humidity sensors

STRONTIUM CONTENT IN SANDY SOILS IN AGRICULTURE FIELDS (CASE STUDY: MOUNDOU, CHAD)

During evaluation of physical and chemical properties of sandy soils and theirfertility in Southern part of Republic of Chad it has been revealed that some soilshave very high content of strontium. Its content varies from 10 to 270 mg/kg ofsoil depending on type of soil, depth of soil layers, clay and organic content.Strontium content negatively correlates with total content of calcium andphosphorus in layers of soil. Low CEC (CEC - Cation-exchange capacity) of soilmay be a reason of possible translocation of strontium from higher to lower layersof soils. Strontium content in soils do not relates with level of radioactivity of soilmeasured. The highest content of strontium has been found in soils developed onsome eolian and colluvio-alluvium deposits. Some researchers hypothesize thatsome endemic and chronic diseases such as Kashin-Beck disease, `Dysostosisenchondralis endemic`, endemic hoiter, osteoarthritis might be caused by highcontent of strontium in water and plant foods contaminated with it. Absence ofconsensus on etiological factors of these diseases confirms that it is worthconsidering necessity of further studies of different affects of high content ofstrontium in water and foods on human health directly or indirectly throughcausing misbalance in mineral nutrition

INFLUENCE OF AGROCHEMICAL REHABILITATION ON THE HEAVY METAL MIGRATION TO THE WATER

Soil plays the main role in the sustaining life of Earth ecosystems –it is thefundamental foundation of agriculture resources, food security, economy andenvironmental quality. The heavy metal pollution has been increasing inagricultural soils worldwide. For example, Cu is widely used as a pesticide againstfungal and bacterial diseases in crops or as a contaminant in organic amendments,or for irrigation as pig manure or sewage sludge. Soil and water pollution have thegreat impact on food safety and to human health: polluted soils have direct healthrisks, and secondary risk is connected to contamination of water supplies. Thearticlepresents the lysimetric experiment with the chemical composition results.This exploratory study aims to evaluate the influence of agrochemical rehabilitationon the heavy metal migration to the water. The chemical composition of intrasoil water has shown that contaminated black soil has a high absorption capacity ofheavy metals. The bulk of heavy metal brought about in a form of water-solublesalts wasabsorbedand converted by soil colloids of podzolized chernozemintorelatively stable compositions. Results of the analytical research showed thatorganic and organic-mineral systems, where phosphates were used in the averagevolume of 60 kg of Р2О5per hectare a year, reduced intake of cadmium in thesubsurface water. Mineral systems also impeded migration of zinc and copper tothe ground water. On the contrary, high doses of superphosphate in the fertilizersystem increased the leaching of Cd, Pb and Cu to the infiltration waters

Abstracts of The Second Eurasian RISK-2020 Conference and Symposium

This abstract book contains abstracts of the various research ideas presented at The Second Eurasian RISK-2020 Conference and Symposium.The RISK-2020 Conference and Symposium served as a perfect venue for practitioners, engineers, researchers, scientists, managers and decision-makers from all over the world to exchange ideas and technology about the latest innovation developments dealing with risk minimization