M. Kerim Gullap

Plant Growth-Promoting Rhizobacteria (PGPR) and Phosphorus Fertilizer-Assisted Phytoextraction of Toxic Heavy Metals from Contaminated Soils

Phytoremediation is a remediation technique that involves the use of plants to extract, sequester, and/or detoxify pollutants through physical, chemical, and biological processes. The use of phytoremediation is expanding due to its cost-effectiveness compared with conventional methods. This study was conducted to investigate the effects of autumn and spring application of plant growth-promoting rhizobacteria (PGPR, 108 cfu mL−1 Bacillus megaterium var. phosphaticum sprayed at 250 mL plot−1) and phosphorus (P) fertilizer (0, 11, 22, 33, 44 kg P ha−1) on dry matter yield and heavy metal uptake by plants in soils contaminated with heavy metals. Field experiments were conducted using a randomized complete block design with four replications between 2004 and 2007. The results of the study indicated that P fertilization, but not PGPR application, significantly affected dry matter yield. Application of PGPR increased heavy metal availability in soils and the heavy metal uptake of meadow plants. The heavy metal content of the meadow plants resulting from PGPR application was 4–6 times higher for the spring application than the autumn application. Approximately 16, 30, 10, 10, and 3 growing seasons without PGPR are necessary to remove all lead (Pb), nickel (Ni), boron (B), manganese (Mn), and zinc (Zn), respectively, from polluted soil. The time required for Pb, Ni, B, Mn, and Zn removal could be further decreased to approximately 4, 6, 3, 3, and 1 growing seasons, respectively, with 33 kg phosphorus pentoxide (P2O5) ha−1 and 108 cfu mL−1 PGPR applications at rates of 250 mL plot−1 in the spring season.

The effect of bovine saliva on growth attributes and forage quality of two contrasting cool season perennial grasses grown in three soils of different fertility

The aim of this study was to determine the response of Dactylis glomerata L. (Orchardgrass) and Festuca ovina L. (Sheep fescue), to bovine saliva application in a loamy soil (most fertile), a sandy loam and a sandy soil (least fertile). The effects of cutting and cutting + saliva on relative height growth rate (RHGR), above- and belowground biomass and forage quality attributes [crude protein, NDF (neutral detergent fibre) and ADF (acid detergent fibre)] were investigated. The results showed that the cutting and cutting + saliva treatments resulted in greater RHGR than the control, but only with D. glomerata in the sandy soil did the application of saliva increase the RHGR. However, saliva applied after cutting increased the aboveground biomass averaged over all species and all three soils. Saliva applied to D. glomerata increased the belowground biomass in the sandy loam and sandy soils but decreased it in F. ovina in the sandy soil. The application of saliva had no effect on the crude protein or the NDF content of either species in any of the soils. On the other hand, the application of saliva after clipping increased the ADF of F. ovina but decreased that of D. glomerata averaged over all three soils. Averaged over both species, the ADF was increased by the addition of saliva in the sandy soil, had no significant effect in the sandy loam (P > 0.05) and was slightly increased in the loam.

EFFECTS OF DIFFERENT IMPROVEMENT TREATMENTS ON BOTANICAL COMPOSITION AND SEDIMENT MOVEMENT ON GRAZED AND ENCLOSED RANGE SITES

This study was carried out on heavily grazed rangelands in Erzurum, during the years 2006-2009, for 4 years period. In this study, four treatments that included artificial pasture, oversowing, fertilization and control were applied on grazed and enclosed rangeland sites. A mixture of Crested wheatgrass (Agropyron cristatum), alfalfa (Medicago sativa) and smooth brome (Bromus inermis) was used for rangeland seeding. Ammonium sulfate and Triple Super Phosphate was applied on fertilization plots in sites grazed and enclosed site. Botanical composition was determined by line intercept methods. After each erosive rain event, the amount of soil (sediment) was determined in each plot. Across of four years, fertilization increased the grass proportion, decreased other species proportion and sediment yield in both sites. Under grazing, over sowing increased the grass proportion, and decreased other species proportion. Lower grass, higher legumes, higher other species proportion and higher sediment yield determined in the third year compared to other years in both sites. The enclosed site had higher grass, lower legumes, other species proportion and sediment yield than the grazed one. Results of this study showed fertilization and oversowing treatment can be effective for soil protection in enclosed and grazed rangelands, similar to this study area. Also, combined with short term enclosure treatment the other improvement treatments can recommend for rangeland restoration and soil protection.

Farklı Cins Hayvan ile Otlatılan Meraların Sağlık ve Ekolojik Alan Sınıflaması

Meralar ekolojik faktorlerin yonlendirmesine bagli olarak kendisini yenileyebildigi gibi geriye gidis de sergileyebilir. Kullanim ozelliklerine bagli olarak olumlu, olumsuz veya mevcudu muhafaza eden seklinde davranis sergilemektedir. Bu calisma sigir, koyun ve sigir ile koyunun birlikte otlatildigi meralarin saglik ve ekolojik alan siniflamasini belirlemek amaciyla Erzurum ili Kargapazari daglarinda yurutulmustur. Bitki ortusu, toprak ve su ozellikleri yonunden incelenen mera kesimlerinde onemli farkliliklar gozlemlenmistir. Sonuclar bir butun olarak degerlendirildiginde, kisa boylu bugdaygillerin hakim oldugu yuksek rakimli bozkir meralarinda kontrolsuz koyun otlatmanin kontrolsuz sigir otlatmaya gore bitki ortusu ve iliskili kaynaklari daha fazla tahrip edici oldugunu ifade etmemiz mumkundur. Ancak koyunlarin genis yaprakli turleri baski altina aldigi goz ardi edilememelidir. Sonuc olarak bozkir meralarinin surdurulebilir kullanimi acisindan otlatma mevsimi ve kapasitesine uymak sartiyla sigir ve koyun surulerinin karisik otlatilmasinda fayda vardir.