عنوان :
مقايسه تجزيه پذيري بقاياي گياهي برخي گونه هاي مرتعي در خاك
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان،دانشكده منابع طبيعي
صفحه شمار :
دوازده،84ص.:مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
مهدي بصيري،فرشيد نوربخش
توصيفگر ها :
گياهان مرتعي , معدني شدن نيتروژن , معدني شدن كربن , معادله سينتيكي رده اول , كيفيت بيوشيميايي بقاياي گياهي
تاريخ نمايه سازي :
16/12/88
استاد داور :
محمدرضا وهابي،مژگان سپهري
تاريخ ورود اطلاعات :
1396/09/28
دانشكده :
مهندسي منابع طبيعي
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Comparative Evaluation of Range Plants Residue Decomposition in Soil Elaheh Vahdat elahehvahdat@yahoo com 20 October 2009 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Mehdi Basiri Email address Basirim@cc iut ac ir Farshid Nourbakhsh Email address Farshid@cc iut ac irAbstractCarbon cycling in soil has attracted many attentions because of the increasing focus on global warming Plantresidue decomposition in soil is of great importance because of its direct and indirect effects on nutrient bio availability Carbon mineralization in soil provides the required carbon dioxide for photosynthesis On the otherhand excessive amounts of CO2 would contribute to enhancement of global temperature The objectives of thisstudy were to 1 investigate the effects of plant residues quality on carbon and nitrogen mineralization rates and2 evaluate non limiting nitrogen condition in soil on carbon mineralization kinetic Soil samples were collectedfrom 0 15 cm depth at Chahartagh closed rangeland Chaharmahal va bakhteiari Eight predominant range plantincluding Melilotus officinalis L Lam Astragalus gossypinus Fischer Astragalus adscendensBoiss Haussak Medicago sativa L Hordeum bulbosum L Bromus tomentellus Boiss Poa pratensis L Agropyron trichophorum Link K Richt were sampled To determine carbon mineralization kinetics and netnitrogen mineralization immobilization soil samples were incorporated with plant residues at a rate of 10 gresidue C kg 1 soil and incubating at 50 water holding capacity and 25 C for 45 and 90 days respectively Results indicated that on a general basis leguminous plants possessed greater concentrations on N and lowervalues of C N and Lig N compared to those of non legume plants All results of CO2 C evolution from plantresidue treated soils conformed well to a first order kinetics equation The total amount of CO2 C Cm evolvedfrom plant residue treated soils ranged from 2166 8 mg C kg 1 soil for bulbous barley to 3057 5 mg C kg 1 foralfalfa The values of Cm were highly correlated r 0 958 n 8 P 0 001 with C N ratio Net nitrogenmineralization occurred in all treatment and ranged between 3 5 mg N kg 1 soil for bulbous barley to 342 4 mg Nkg 1 for alfalfa N mineralization was highly correlated r 0 993 n 8 P 0 001 with C N The critical valuefor net N mineralization was 42 8 so that greater values of C N can be expected to cause net N immobilization We observed that N supply as ammonium nitrate increased the fraction of cellulose in the plant residues Thecorrelation between short term C mineralization and net N mineralization seemed to be time dependen and themaximum value of the correlation coefficient was observed after 2 days Overall we conclude that the Cmineralization kinetics in the soils receive range plant residues is a function of the initial composition of theplants and that C and N mineralization are functionally related so that N mineralization can be successfullyestimated from short term values of C mineralization Key words Range plants Nitrogen mineralization Carbon mineralization First orderkinetics Biochemical quality of plant residues
استاد راهنما :
مهدي بصيري،فرشيد نوربخش
استاد داور :
محمدرضا وهابي،مژگان سپهري
