تاثير كاربرد كود مرغي حاوي انروفلوكساسين بر تنفس، بيوماس ميكروبي و جمعيت برخي باكتري‌هاي مفيد خاك

Effect of chicken manure containing enrofloxacin on soil respiration, microbial biomass, and population of some beneficial bacteria

ﻏﻠﻈﺖ آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ ﻫﺎ در ﺧﺎك ﺑﺮ اﺛﺮ اﺿـــﺎﻓﻪ ﮐﺮدن ﮐﻮد ﻣﺮﻏﯽ آﻟﻮده ﺑﻪ آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ اﻓﺰاﯾﺶ ﻣﯽ ﯾﺎﺑﺪ و ﻣﻤﮑﻦ اﺳـــﺖ ﺟﺎﻣﻌﻪ ﻣﯿﮑﺮوﺑﯽ ﺧﺎك را ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﻗﺮار دﻫﺪ. ﻫﺪف اﯾﻦ ﭘﮋوﻫﺶ ﺗﺎﺛﯿﺮ اﺿﺎﻓﻪ ﻧﻤﻮدن ﮐﻮد ﻣﺮﻏﯽ ﻣﺤﺘﻮي اﻧﺮوﻓﻠﻮﮐﺴﺎﺳﯿﻦ ﺑﻪ ﺧﺎك ﺑﺮ ﺟﻤﻌﯿﺖ .Pseudomonas fluorescens ، Azotobacter spp و Pseudomonas putida و ﻫﻤﭽﻨﯿﻦ ﺑﯿﻮﻣﺎس ﻣﯿﮑﺮوﺑﯽ و ﺗﻨﻔﺲ ﻣﯿﮑﺮوارﮔﺎﻧﯿﺴﻢ ﻫﺎي ﺧﺎك اﺳﺖ. ﯾﮏ آزﻣﺎﯾﺶ در آزﻣﺎﯾﺸﮕﺎه ﺑﻪ ﻣﺪت 45 روز ﺑﺎ 7 ﺗﯿﻤﺎر و ﺳﻪ ﺗﮑﺮار اﻧﺠﺎم ﺷﺪ. اﯾﻦ آزﻣﺎﯾﺶ ﺷﺎﻣﻞ ﮐﻮد ﻣﺮﻏﯽ ﺗﺎزه و ﮐﻤﭙﻮﺳﺖ ﺷﺪه ﻣﺤﺘﻮي آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ در دو ﺳﻄﺢ ﻏﻠﻈﺘﯽ ﺑﺎﻻ ) 1-26/2 mg kg( و ﭘﺎﯾﯿﻦ )1-4/23 mg kg( و ﮐﻮد ﻣﺮﻏﯽ ﺑﺪون آﻧﺘﯽﺑﯿﻮﺗﯿﮏ ﺑﺮ ﻣﺒﻨﺎي ﻃﺮح ﮐﺮتﻫﺎي ﺑﻪﻃﻮرﮐﺎﻣﻞ ﺗﺼـــﺎدﻓﯽ اﻧﺠﺎم ﺷـــﺪ. ﻧﺘﺎﯾﺞ ﻧﺸـــﺎن داد ﮐﺎرﺑﺮد ﮐﻮد ﻣﺮﻏﯽ ﺣﺎوي آﻧﺘﯽﺑﯿﻮﺗ ﯿﮏ ﻣﻨﺠﺮ ﺑﻪ ﮐﺎﻫﺶ ﺟﻤﻌ ﯿﺖ .Pseudomonas fluorescens ،(28%) Azotobacter spp )%73( و Pseudomonas putida )%14/6( در ﺧﺎكﻫﺎ ﺷــﺪ. ﮐﻤﭙﻮﺳــﺖ ﮐﺮدن ﮐﻮد ﻣﺮﻏﯽ ﻧﯿﺰ اﮔﺮﭼﻪ اﺛﺮ ﻣﻨﻔﯽ آن را ﮐﻤﺘﺮ ﮐﺮد اﻣﺎ ﻫﻤﭽﻨﺎن ﮐﺎﻫﺶ ﺟﻤﻌﯿﺖ وﺟﻮد داﺷﺖ. ﮐﺎرﺑﺮد ﮐﻮد ﻣﺮﻏﯽ ﺗﺎزه ﺑﺪون آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ ﺳﺒﺐ اﻓﺰاﯾﺶ 127 درﺻﺪي ﺗﻨﻔﺲ ﻣﯿﮑﺮوﺑﯽ ﺧﺎك ﻧﺴﺒﺖ ﺑﻪ ﺷﺎﻫﺪ ﺷﺪ اﻣﺎ ﺑﯿﻦ ﺳﺎﯾﺮ ﺗﯿﻤﺎرﻫﺎي ﻣﺨﺘﻠﻒ ﮐﺎرﺑﺮد ﮐﻮد ﻣﺮﻏﯽ ﺗﻔﺎوت ﻣﻌﻨﯽ دار دﯾﺪه ﻧ ﺸﺪ. ﮐﺎرﺑﺮد ﮐﻮد ﻣﺮﻏﯽ ﺑﺪون آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ ﮐﺮﺑﻦ ﺑﯿﻮﻣﺎس ﻣﯿﮑﺮوﺑﯽ را ﺑﻪ ﻃﻮر ﻣﻌﻨﯽداري اﻓﺰاﯾﺶ داد )%95(. وﺟﻮد آﻧﺘﯽﺑﯿﻮﺗﯿﮏ در ﮐﻮد ﻣﺮﻏﯽ ﺗﺎﺛﯿﺮ ﻣﻨﻔﯽ ﺑﺮ ﻏﻠﻈﺖ ﮐﺮﺑﻦ ﺑﯿﻮﻣﺎس ﻣﯿﮑﺮوﺑﯽ داﺷـــﺖ. ﺑﻪ ﻃﻮر ﮐﻠﯽ رﻫﺎﺳـــﺎزي و اﻧﺘﺸـــﺎر آﻧﺘﯽﺑﯿﻮﺗﯿﮏﻫﺎ در ﺧﺎك ﺑﺮ اﺛﺮ اﻓﺰودن ﮐﻮد ﻣﺮﻏﯽ ﺑﻪ ﻣﺰارع ﺣﺘﯽ اﮔﺮ ﻗﺒﻞ از ﻣﺼـــﺮف ﮐﻤﭙﻮﺳﺖ ﺷﺪه ﺑﺎﺷﺪ، ﺑﺎﻋﺚ ﮐﺎﻫﺶ رﺷﺪ ﮔﺮوهﻫﺎي ﺑﺎﮐﺘﺮﯾﺎﯾﯽ ﻣﻔﯿﺪ ﺧﺎك ﺷﺪ.

The concentration of antibiotics in the soil increases with the addition of fresh or composed chicken manure containing antibiotics and may affect the microbial community of the soil. The purpose of this study was to evaluate the effect of adding enrofloxacin containing chicken manure to soil on the population of Azotobacter spp, Pseudomonas putida and Pseudomonas fluorescens, as well as microbial biomass and respiration of soil. An experiment was conducted in a laboratory for 45 days with 7 treatments and three replications including fresh and composted chicken manure containing enrofloxacin in two levels of high (26.2 mg kg-1) and low (4.23 mg kg-1) concentrations and manure without any antibiotic based on a completely randomized design. The results showed that the application of chicken manure containing enrofloxacin reduced the population of Azotobacter spp (28 percent), Pseudomonas fluorescens (73 percent) and Pseudomonas putida (14.6 percent) in the soils. However, the composting of chicken manure, although reducing its negative effect, still led to a decline in population. Application of fresh chicken manure led to a 127 percent increase in microbial respiration of the soil compared to control but between other treatments there was no meaningful difference. The use of chicken manure without antibiotic significantly increased the microbial biomass (95 percent). The presence of high concentration of enrofloxacin in poultry manure had a negative effect on the microbial biomass increase, especially at the beginning of the period.