تاثير قرق بر برخي خصوصيات شيميايي و آلي خاك (مطالعه موردي: حوضه گنبد شهر همدان)

Effects of Rangeland Exclosure on Chemical and Organic Properties of Soil (Case study: Gonbad Area)

ﯿﻨﻪ و ﻫﺪف: ﭼﺮاي دام ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از آﺷﻔﺘﮕﯽ ﻫﺎي اﮐﻮﻟﻮژﯾﮏ ﺑﺎﻋﺚ ﺗﻐﯿﯿﺮ در ﺧﺼﻮﺻﯿﺎت ﺧﺎك و ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ ﻣﺮاﺗﻊ ﻣﯽ ﺷﻮد. ﻫﺪف از اﯾﻦ ﺗﺤﻘﯿﻖ ﻣﻄﺎﻟﻌﻪ اﺛﺮ ﻗﺮق ﺑﺮ ذﺧﺎﯾﺮ ﻣﯿﮑﺮوﺑﯽ زي ﺗﻮده و ﺑﺮﺧﯽ ﺧﺼﻮﺻﯿﺎت ﺧﺎك ﻣﺮاﺗﻊ ﺣﻮﺿﻪ ﮔﻨﺒﺪ ﺷﻬﺮ ﻫﻤﺪان اﺳﺖ. ﯾﮑﯽ از اﯾﻦ ﻣﻨﺎﻃﻖ ﺗﺤﺖ ﻗﺮق 20 ﺳﺎﻟﻪ اﺳﺖ و ﻣﻨﻄﻘﻪ دﯾﮕﺮ در ﺧﺎرج از ﻣﻨﻄﻘﻪ ﺣﻔﺎﻇﺖ ﺷﺪه ﺗﺤﺖ ﭼﺮاي دام اﺳﺖ. روش ﺑﺮرﺳﯽ: ﻧﻤﻮﻧﻪ ﮔﯿﺮي ﺧﺎك ﺑﺮ اﺳﺎس روش ﺳﯿﺴﺘﻤﺎﺗﯿﮏ- ﺗﺼﺎدﻓﯽ اﻧﺠﺎم ﺷﺪ. ﭘﻨﺞ ﺗﺮاﻧﺴﮑﺖ 1000 ﻣﺘﺮي ﺑﺎ ﺟﻬﺖ ﺷﻤﺎﻟﯽ-ﺟﻨﻮﺑﯽ ﺑﻪ ﻃﻮر ﺗﺼﺎدﻓﯽ در ﻫﺮ ﻣﻨﻄﻘﻪ )ﻗﺮق و ﭼﺮا ﺷﺪه( ﺑﻪ ﺻﻮرت ﺟﺪاﮔﺎﻧﻪ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪ. ﻧﻤﻮﻧﻪ ﺑﺮداري ﺧﺎك در ﻫـﺮ 100 ﻣﺘـﺮ ﺑﺒـﺎ روش ﺳﯿﺴﺘﻤﺎﺗﯿﮏ- ﺗﺼﺎدﻓﯽ و در اردﯾﺒﻬﺸﺖ ﻣﺎه ﺳﺎل 95 اﻧﺠﺎم ﮔﺮﻓﺖ. ﻋﻨﺎﺻﺮ ﻣﺲ، آﻫﻦ، ﭘﺘﺎﺳﯿﻢ، ﻣﻨﯿﺰﯾﻢ، ﻣﻨﮕﻨﺰ و روي ﺑﻪ وﺳﯿﻠﻪ ﻃﯿﻒ ﺳﻨﺠﯽ ﺟﺬب اﺗﻤﯽ، اﺳﯿﺪﯾﺘﻪ ﺑﺎ دﺳﺘﮕﺎه pH ﻣﺘﺮ، وزن ﻣﺨﺼﻮص ﻇﺎﻫﺮي از روش ﮐﻠﻮﺧﻪ اي، ﻧﯿﺘﺮوژن ﮐﻞ از روش ﮐﺠﻠﺪال، ﮐﺮﺑﻦ آﻟﯽ و ﻣﺎده آﻟﯽ ﺧﺎك از روش اﮐﺴﯿﺪاﺳﯿﻮن ﺗﺮ واﻟﮑﯽ ﺑﻠﮏ و زﯾﺘﻮده ﻣﯿﮑﺮوﺑﯽ ﮐﺮﺑﻦ ﺑﻪ روش ﺗﺪﺧﯿﻦ- اﺳﺘﺨﺮاج ﻣﺤﺎﺳﺒﻪ ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﭘﺲ از اﻧﺠﺎم ﺗﺠﺰﯾﻪ و ﺗﺤﻠﯿﻞ ﻫﺎي آﻣﺎري ﻣﺸﺨﺺ ﺷﺪ ﮐﻪ ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ ﭘﺘﺎﺳﯿﻢ و روي در ﺧﺎك ﻣﻨﻄﻘﻪ ﻗﺮق و ﻏﻠﻈﺖ ﻋﻨﺼﺮ ﻣﻨﯿﺰﯾﻢ در ﺧﺎك ﻣﻨﻄﻘﻪ ﭼﺮا ﺷﺪه اﻓﺰاﯾﺶ ﻣﻌﻨﯽ داري در ﺳﻄﺢ 5 درﺻﺪ داﺷﺘﻪ اﺳﺖ. اﺳﯿﺪﯾﺘﻪ ﺧﺎك در ﻣﻨﻄﻘﻪ ﭼﺮا ﺷﺪه از 7/01 در ﻣﻨﻄﻘﻪ ﻗﺮق ﺑﻪ ﻣﻘﺪار 7/23 اﻓﺰاﯾﺶ ﯾﺎﻓﺖ. رﻃﻮﺑﺖ ﺧﺎك در ﻣﻨﻄﻘﻪ ﭼﺮاﺷﺪه ﮐﺎﻫﺶ ﻣﻌﻨﯽ داري ﯾﺎﻓﺘﻪ و از 27/11 درﺻﺪ در ﻣﻨﻄﻘﻪ ﻗﺮق ﺑﻪ ﻣﻘﺪار 18/12 درﺻﺪ رﺳﯿﺪه ﺑﻮد. ﺟﺮم ﻣﺨﺼﻮص ﻇﺎﻫﺮي ﺧﺎك ﻧﯿﺰ در ﻣﻨﻄﻘﻪ ﭼﺮاﺷﺪه 1/16 ﮔﺮم ﺑﺮ ﺳﺎﻧﺘﯽ ﻣﺘﺮ ﻣﮑﻌﺐ ﺑﻮد ﮐﻪ در ﻣﻨﻄﻘﻪ ﻗﺮق ﮐﺎﻫﺶ ﻣﻌﻨﯽ داري داﺷﺘﻪ و ﺑﻪ 0/98 ﮔﺮم ﺑﺮ ﺳﺎﻧﺘﯽ ﻣﺘﺮ ﻣﮑﻌﺐ رﺳﯿﺪ. زي ﺗﻮده ﻣﯿﮑﺮوﺑﯽ ﮐﺮﺑﻦ در ﺧﺎك ﻣﻨﺎﻃﻖ ﻗﺮق و ﭼﺮا ﺷﺪه ﺗﻔﺎوت ﻣﻌﻨﯽ داري داﺷﺖ. ﻣﻘﺎﯾﺴﻪ ﻣﯿﺎﻧﮕﯿﻦ زي ﺗﻮده ﻣﯿﮑﺮوﺑﯽ ﮐﺮﺑﻦ در ﺧﺎك ﻣﺮاﺗﻊ ﮔﻨﺒﺪ ﻧﺸﺎن داد ﮐﻪ اﯾﻦ ﭘﺎراﻣﺘﺮ از 0/83 ﮔﺮم ﺑﺮ ﮐﯿﻠﻮﮔﺮم در ﻣﻨﻄﻘﻪ ﭼﺮا ﺷﺪه ﺑﻪ ﻣﻘﺪار 0/95 ﮔﺮم ﺑﺮ ﮐﯿﻠﻮﮔﺮم رﺳﯿﺪه و اﻓﺰاﯾﺶ ﻣﻌﻨﯽ داري داﺷﺘﻪ اﺳﺖ.

Background and Objective: Grazing as one of ecological disturbances causes changes in soil characteristics of rangelands. This study was carried out to study the effect of Grazed pasture on plant cover, microbial deposits and some soil characteristics of Gonbad in Hamedan. Method: Five transects of 1000 meters were considered separately for soil characteristics in each region (grazed and ungrazed). Systematic sampling of soil was performed every 100 meters in May 2016. The elements of Cu, Fe, K, Mg, Mn and Zn were measured by atomic absorption spectrometer, acidity with pH meter, bulk density from clavicle method, total nitrogen from Kjeldahl method, organic carbon and soil organic matter by the oxidation method of Walkybak and Zeitous Carbon microbial was calculated by quenching-extraction method. Findings: After analyzing, it was determined that the concentrations of K and Zn in the soil of the sample area and the concentration of Mg in the soil of the control area increased significantly at 5% level. Soil acidity in the control area increased from 7/1 in the sample area to 7/23. Soil moisture content decreased significantly in the control area and from 27.11% in the sample area reached 18.12%. Soil bulk density in the control area was 1.16 g / cm3, which decreased significantly in the sample area and reached 0.98 g / g / cm3. The carbon microbial biomass was significantly differed in the soil of grazed and control areas. The comparison of the mean microbial carbon content in studied rangelands showed that this parameter ranged from 0.83 g / kg in the control area (grazed) to 0.95 g / kg and increased significantly. Discussion and Conclusions: The exclosure area has been enclosed with exclosure, soil characteristics in the path of sequencing and achieving ideal conditions, but it still needs attention and continued conservation.