خصوصيّات شيمي خاك، در ايجاد و پيشرفت فرسايش گالي در منطقه ي دشتياري - چابهار

خصوصيّات شيمي خاك، در ايجاد و پيشرفت فرسايش گالي در منطقه ي دشتياري - چابهار

در اين تحقيق روي 14 نمونه ي برداشت شده از مناطق فرسايش يافته و فرسايش نيافته، و از مناطق با و بدون پوشش گياهي، آزمايشات فيزيكي و شيميايي از قبيل، اي سي (EC)، او ام (OM)، سار(SAR) ، اي اس پي (ESP)، پ هاش (pH)، اس پي(SP) و تي ان وي (TNV) انجام شدند. براساس نتايج برّرسي هاي صحرايي و آزمايشگاهي، خاك اكثر نقاط منطقه ي مورد مطالعه، لوم سيلتي مي باشد. روند تغييرات اس پي (SP) بين 3/60-2/32، پ هاش(pH) بين 92/7-2/7 و تي ان وي (TNV) بين 4/11-5/14 به دست آمد. نتايج آزمايشات مربوطه نشان داد، كه اي‌سي (EC) خاك در مناطق زياد فرسايش يافته، 5/62 و در مناطق كم فرسايش يافته 69/0 و مقدار سار (SAR) و مقدار اي‌اس‌پي(ESP) مشابه آزمايش اي‌سي(EC) مي باشند. ميزان كاتيون موجود در خاك جداره ي گالي 1196، نسبت به كف گالي و سطح زمين 338، بيشتر است. متوسّط ميزان كاتيون در منطقه ي فرسايش نيافته با پوشش گياهي 8/23، نسبت به منطقه ي فرسايش يافته و فرسايش نيافته بدون پوشش گياهي 4/215، كمتر است. ميزان او ام (OM) خاك بين 59/0- 17/0 به دست آمد.

In the initial phase of the study, testing procedure of soil was considered necessary. And the testing process on the soil of 14 samples from the area which has gully erosion, as well as from the area, which has no gully erosion (with and without plant coverage) was carried out. The achieved results were very interesting. The EC, OM, SAR, ESP and pH and T.N.V. tests were carried out on the soil. According to the test, the soil of the majority of the area is silty loam. Silt is considered as the most sensitive soil, reacting to the erosion. The process of changes of pH, SP and T.N.V. was small. The obtained results from the changes in the tests of SAR, ESP and EC, more or less in the whole area of study, were the same. The scale of salt contaminations, existing in the soil of the wall of the gully, comparatively to the floor of the moat and surface of the land is higher. The quantity of sodium of the soil is high. Therefore, the quantity of SAR and ESP of the soil is high However, the quantity of salts in the area which has no gully erosion and with plant coverage is considerably less than in the erosion area and other non-erosion area without plant coverage. Still this erosion is high in this area and whenever the plant coverage of the locality die dies, the danger of erosion will start. The quantity of OM in the soil is approximately in low quantity. This can be considered one of the effective factors in erosion and its development. With the above mentioned tests, it can be concluded that soil is one of the effective factors in erosion in Dashtyari area. Key words: Gully erosion, Dashtyari, silty loam, Chabahar.