Proceedings Volume 2010 (format .pdf) - SimpBTH

On the basis the positive results obtained from vegetation studies the mostappropriate melioration rates for field conditions have been determined. Anexperimental plot was established on an area of 4 acres on meadow alkaline soil inthe experimental base in the village of Belozem, Plovdiv region. The agriculturalactivities are carried out and different standards of gypsum processing are tested -2,0 t / dka; 2,5 t / dka; 3,0 t / dka; 4,0 t / dka and 5,0 t / dka. 2 cultures are grown –vetch-barley mixture and wheat. The biological yield of green mass is reported andthe agrochemical evaluation of vegetable production is made. Periodically, soilsamples were taken from various variants and the characteristic of melioratedsalted soils is made to establish the changes in the salinity extent and waterdeterminingphysical parameters.RESULTS AND DISCUSSION1. /The results of vegetation and field experiments show that the gypsum of SCI inthe three-component mixture has a negative impact on the growth, development and yield ofcrops grown. According to the chemical characteristics the resulting production meetsenvironmental requirements. Heavy metals are not in high concentrations, which could have adetrimental impact on humans and animals when using the plants for food.Newly created three-component mixtures with gypsum 3% and 5% have ahigh content of soluble salts - 1.25% and respectively 1.14% in bulk area, which,according to Bulletin 27 of the MAF of 1994, defines them as salted. The values ofheavy metals are under the limit values and do not represent an environmentalhazard. The environment reaction does not modify /Table 1/. No detectablemovement of sulfates in profiles depth under 50cm layer. According to scientificresearch and practical knowledge, these soils can be attributed to so called gypsumbearingsoils, which are characterized by insufficient favorable agrochemical andphysical and mechanical properties. Soil conditions restrict the choice ofappropriate crops, which requires a special approach to the organization of croprotation.Best results were obtained in anthropogenic "soils" with gypsum 3% and5% and humus cover. Humus soil layer leads to significant improvement of thenutrient regimen, structural condition and physic-mechanical properties to 50cmdepth. It is rich in organic matter and creates a favorable environment formicrobiological activity. This reflects favorably on the growth, development andquality of crop production. The obtained grain yield of barley in variants withhumus layer exceeds double the yield in variations with humus without coverage.Statistically is proven that in variation with 5% + humus layer the yield obtained ishighest - 323 kg / dka. Soil layers below the humus horizon are characterized byphysical and chemical properties identical to those without humus coverage. Thehighest yield of pea-barley mixture’s green mass is obtained also in variants withhumus cover - 295-300kg/dka.200