اثر گونه‌هاي اهلي و وحشي گلرنگ بر برخي ويژگي‌هاي فيزيكي و شيميايي خاك تحت تنش خشكي

چكيده انگليسي :

Effect of cultivated and wild species of safflower on selected soil physical and chemical properties under water stress Maryam Zare maryam zare @ag iut ac ir January 14 2019 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 IranSupervisor Mohammad Reza Mosaddeghi mosaddeghi@cc iut ac irAbstractIt is critical to identify crops with an acceptable yield under low input conditions which are alsotolerant to water shortage and could maintain good soil quality Therefore this study was carriedout in soil columns to investigate the effect of cultivated and wild safflower genotypes and theirselected generations on some soil physical and chemical properties i e dispersible clay content water repellency structural stability indices of high energy moisture characteristic HEMC organic carbon content percent of water stable aggregates basal microbial respiration and totalnitrogen in soil columns under drought stress treatments in outdoor condition Drought stresstreatments were applied based on maximum allowable depletion MAD including mild stress MAD of 50 moderate stress MAD of 70 and severe stress MAD of 90 Nine safflowergenotypes including one cultivated genotypes two wild ones and six genotypes as their generationswere used Plant morphological physiological and root characteristics were studied in theexperimental treatments as well The experiment was conducted in a factorial arrangement oftreatments in completely randomized design with three replicates in hydro flume After eightmonths the plants were harvested and soils and roots were extracted for further analyses Theresults showed that wild genotype Belong to the species of Carthamus oxyacanthus had the highestnumber of seeds per capitulum The cultivated genotype C tinctorius C111 in the severe stresslevel had the lowest leaf water potential but genotypes of C palestinus and F2cp had lowerresistance to drought stress Drought stress significantly increased the leaf proline content The wildgenotype C oxyacanthus had the highest proline content Greatest mean values of root surface area i e 0 71 m2 m3 soil and root length density i e 89 9 m m3 soil were observed in this genotypeas well However the lowest mean values of root surface area and length density i e 0 45 m2 m3and 50 4 m m3 respectively were observed in genotype F4co Dry weight of root was highest at themoderate stress level but decreased to its lowest value at the severe stress The highest ratio of dryshoot weight to root weight was observed in the moderate stress Mean comparisons of soil organiccarbon content among the drought stress levels showed that the highest organic carbon content inthe rhizosphere was measured in the moderate stress level presumably due to greater root exudates The highest soil basal microbial respiration was measured in the moderate stress level The waterstress increased the soil carbohydrates so that they were significantly greater in the moderate andsevere stress levels compared to the mild stress level Genotype drought stress and their interactiondid not significantly affect the soil water repellency index and related parameters Similarity ofHEMC curves of fast and slow wetting conditions for the rhizosphere soil of wild genotype C oxyacanthus was higher in the moderate stress condition compared to mild and severe stress levels 98

زارع، مريم

اثر گونه‌هاي اهلي و وحشي گلرنگ بر برخي ويژگي‌هاي فيزيكي و شيميايي خاك تحت تنش خشكي

پايداري ساختمان خاك , ترشحات ريشه‌اي , تنش خشكي , منحني مشخصه رطوبتي پرانرژي , گلرنگ اهلي و وحشي , كربن آلي