Ömer Lütfü Elmaci

The central role of microbial activity for iron acquisition in maize and sunflower

Abstract Maize (Zea mays L.) and sunflower (Helianthus annuus L.) grown on a calcareous soil showed poor growth and/or were chlorotic in spite of abundant Fe in the roots. It has been hypothesized that microbial siderophores chelate Fe (III) in the soil, and that in this form Fe is transported towards the root apoplast. On the calcareous soil, total and apoplastic root Fe concentrations were high, probably because of a high apoplastic pH depressing Fe (III)-reductase activity and thus the Fe2+ supply to the cytoplasm. On the acidic soil, total and apoplastic root Fe concentrations were low, probably because of a low apoplastic pH favouring Fe (III) reduction, hence plants showed no Fe-deficiency symptoms. The main objective of the present work was to investigate the role of microbial soil activity in plant Fe acquisition. For this purpose, plants were grown under sterile and non-sterile conditions on a loess loam soil. Plants cultivated under non-sterile conditions grew well, showed no Fe-deficiency symptoms and had fairly high Fe concentrations in the roots in contrast to plants grown in the sterile medium. Low root and leaf Fe concentrations in the axenic treatments indicated that the production of microbial siderophores was totally suppressed. Accordingly, sunflowers were severely chlorotic and this was associated with very poor growth, whereas in maize only growth was drastically reduced. In maize under sterile conditions, root apoplastic and total Fe concentrations were not as low as in sunflowers, which may have indicated that phytosiderophores produced in maize partly sustained Fe acquisition, but due to poor growth were not as efficient in supplying Fe as microbial activity under natural conditions. It may be therefore assumed that in natural habitats soil microbial activity is of pivotal importance for plant Fe acquisition.

Ammonium fixation properties of some arable soils from the Aegean region of Turkey

Abstract This study was carried out in soils of province Izmir in the Aegean Region, which are of high importance for Turkish agriculture. In these soils, the amount of native fixed NH 4 N, its relationship with other soil properties and their reactions to fix the applying NH 4 fertilizer (fixation capacity) were investigated. For this purpose, 23 soil samples were taken from each of two depths (0–20 and 20–40 cm) from the agricultural soils of Izmir (11 from Ege University, Faculty of Agriculture Research, Application and Production Farm, nine from Rural Services Research Institute Fields and three from Ege University Faculty of Agriculture, Department of Soil Science Research Fields). The NH 4 fixation capacity with the application of N [100 mg N kg −1 soil as (NH 4 ) 2 SO 4 ] fertilizer was determined after 4, 8 and 12 days incubation period in all soil samples from 0 to 20 cm depth. In the soil samples of 0–20 cm depth, the amount of native fixed NH 4 N ranged from 60 to 231 mg kg −1 soil and made up 7 to 49% of the total-N. In the soil samples of 20–40 cm depth the related amounts were between 49 and 235 mg kg −1 soil and 10 to 49% of the total-N respectively. The native fixed NH 4 N has a significant negative correlation with the sand ( r =−0.591*) and a positive correlation with the silt ( r =0.672*) and plant available K ( r =0.586*) in samples from 20 to 40 cm depth. The results of an incubation experiment indicated a significant negative correlation ( r =−0.763**) between the native fixed NH 4 N concentration and NH 4 fixation capacity of soils. The first group of soils (No.: 2, 6, 9, 10) that have high native fixed NH 4 N did not show any fixation from added NH 4 N after 12 days of incubation. The second group (No.:1, 4, 5, 7, 22, 23) reached maximum NH 4 fixation capacity after 4 days incubation and in some soils (No.:1, 4, 5, 21, 22) the capacity approached to approximately 100% after this time. The third group of soils (No.:8, 11, 13, 16, 17, 18, 19) attained maximum NH 4 -fixation capacity after 8 days of incubation. Only two soil samples (No.:3, 14) reached their maximum after 12 days. The last group of soils (No.:12, 15, 20, 21), which were low in native fixed NH 4 N due to their high fixation capacity, showed increasing NH 4 N fixation (over 100 mg kg −1 soil added N) after the incubation time, this being evidence that these soils have high mineralization potential and that NH 4 from other N sources could be included in the soil NH 4 reservoir.

Fertility status, trace elements and heavy metal pollution of agricultural land irrigated from the Gediz River

The effect of the Gediz River, polluted by industrial and domestic wastes, on fertility status and trace elements and heavy metal pollution of agricultural land irrigated from this river was investigated. For this purpose, soil samples were collected in August 1998 between the source of the Gediz River (Murat Mountain) and its mouth (Aegean Sea). Soil samples were collected from 12 different sites along the length of the river basin from 0-30 cm depth. The soils were slightly alkaline, with no salt problem and were poor in organic matter. Total N and available P, K, Mg, Fe and Zn levels were low or average, whereas available Ca, Na, Cu, Mn were present at good and sufficient levels. Thirty three per cent of soils had available B and S of soils had total B levels above the phytotoxic lower boundary. Because of the geographical/geological structure, soil samples from the Gediz source (Sample Site 1) had high amounts of total Fe, Zn, Mn, B, Cd, Ni, Cr and Co. At the second sampling site, total Ni content was also higher than is acceptable according to the national standards set. In addition, in some soil samples the amount of total Cd was above the lower phytotoxic boundary value.

A NEW STRATEGY TO ENRICH CALCIUM NUTRITION OF FRUIT: SYNERGISTIC EFFECTS OF POSTHARVEST FOLIAR CALCIUM AND BORON SPRAYS

The objective of the study is to investigate the role of calcium (Ca) and boron (B) synergy in higher maintenance of Ca in fruit buds during senescence. To study the hypothesis, an experiment was conducted for two years in two ‘Starking Delicious’ apple (Malus domastica Borkh.) orchards established on seedling rootstocks in Banaz, Usak, Turkey. Treatments composed of postharvest foliar sprays of Ca at rate of 15.13 kg h−1, B at rate of 2.47 kg h−1 and their combination (Ca+B) compared with control trees sprayed with water. Fruiting spurs, flower ovaries, young and mature fruits were sampled and analyzed for their Ca, B, potassium (K) and magnesium (Mg) contents. Fruit were stored for six months and quality attributes were studied. Results put forth that Ca+B treatments significantly increase fruit Ca and B concentrations and firmness. The results displayed that postharvest B spray improves Ca nutrition of fruits through synergism of Ca+B on Ca translocation.

Review of spatial variations in water quality in the Gediz River

The Gediz River is one of the most important and main water source for the Gediz Basin of the Aegean region and Turkey. In this study, 18 water samples were collected from the source to the end of the river. Change in water quality, some trace elements and heavy metal contents of the Gediz River were determined. Analysis of the Fe, Cu, Mn, Zn, Pb, Cr, Co, Cd and Ni showed that the quantity of Fe in the eighth sample, taken before the meeting point of the Alasehir tributary-Gediz River and the quantity of Cr in the eighth sample were above the critical level. Overall, the study indicated that the quality of the water of the Gediz River deteriorated (along the river) from the source to the end. It was also determined that the N/P ratio diminished from the source to the end which is an indicator of domestic pollution. To preserve the soils and plants of the Gediz Basin, the Gediz River and its tributaries should be protected from garbage and effluents.

Does the Ammonium Fixation Capacity of Soils Have a Significant Effect on the Nitrogen Nutrition of Wheat

Pot experiments were conducted on three soils differing in their ammonium (NH4 +) fixation capacity [high = 161 mg NH4-nitrogen (N) kg−1 soil; medium = 31.5 mg NH4-N kg−1 soil; and no = no NH4-N was additionally fixed], and the effect of N fertilizer forms and doses on wheat (Triticum aestivum L.) was investigated. Grain yields responded to almost all forms of N fertilizer with 80, 160, and 240 kg N ha−1 in the high, medium, and no NH4 + fixing soil process, respectively. Agronomic efficiency of applied N fertilizers was significantly greater in the no NH4 + fixing soil. Thousand grain weights (TGW) of wheat grown on the high and medium NH4 + fixing soil decreased with increasing N. Grain protein increased with increasing NH4 + fixation capacity. Nitrogen doses and the forms of N fertilizers affected grain protein at a significance level. The combination of urea + ammonium nitrate (NH4NO3) was most effective in increasing grain protein content.

Does the potential ammonium fixation of soils have an impact on the optimum nitrogen fertilizer rate

ABSTRACT Field experiments were conducted to determine the effect of nitrogen (N) fertilizer forms and doses on wheat (Triticum aestivum L.) on three soils differing in their ammonium (NH4) fixation capacity [high = 161 mg fixed NH4-N kg−1 soil, medium = 31.5 mg fixed NH4-N kg−1 soil and no = nearly no fixed NH4-N kg−1 soil]. On high NH4+ fixing soil, 80 kg N ha−1 Urea+ ammonium nitrate [NH4NO3] or 240 kg N ha−1 ammonium sulfate [(NH4)2SO4]+(NH4)2SO4, was required to obtain the maximum yield. Urea + NH4NO3 generally showed the highest significance in respect to the agronomic efficiency of N fertilizers. In the non NH4+ fixing soil, 80 kg N ha−1 urea+NH4NO3 was enough to obtain high grain yield. The agronomic efficiency of N fertilizers was generally higher in the non NH4+ fixing soil than in the others. Grain protein was highly affected by NH4+ fixation capacities and N doses. Harvest index was affected by the NH4+ fixation capacity at the 1% significance level.

The Effects of Organic Wastes on Soil and Cotton Quality with respect to the Risk of Boron and Heavy Metal Pollution

The effects on soil and cotton quality of organic wastes from medicinal and aromatic plant factories were investigated with regard to the risks of boron and heavy metal pollution. Oily cumin, oregano, oilless oregano wastes, and mineral fertilizers were applied to cotton in two field experiments performed in the years 2003 and 2006. The Pb content of the soil differed significantly in the 2003 experiment and oregano wastes had significantly decreasing effect. Boron of soil to which oily cumin wastes had been applied reached a toxic limit value in 2006. Boron in soil adversely affected long fibres; B in leaves had a positive effect on the fineness of fibres in 2006. Soil Ni adversely affected plant height in 2006 and seed cotton yield in 2003. Leaf Ni had an adverse effect on fibre elasticity in 2006. Soil Co increased ginning out-turn and Cr decreased the fibre fineness of cotton in 2003.

Residual effect of agro-industrial wastes on soil properties and Zea mays (L.) nutrition

The residual effect of agro-industrial wastes previously used for potato growing was investigated for soil characteristics and maize nutrition. The soil pH increased and organic matter decreased during maize growth. Nitrogen and K were generally low, but statistically higher almost in waste-applied soils. Soil phosphorus was greatest in the ‘Only Wastes’ and ‘Min.P + Wastes NK’ treatments. N, P, K and Ca decreased significantly in the soil of ‘Only Wastes’ during maize growth, as did the organic matter content. ‘Only wastes’ generally produced a maximum maize growth parameter. Zinc and Mn were low in soils and no pollution risk arose with respect to heavy metals. Nitrogen, K, Zn and Mn of leaves were below adequate levels. Lead and Cr in plants decreased with the chelating effect of increased organic matter. Phosphorus in wastes gave significantly the highest yield, and P in kernel had the effect of increasing some yield parameters in maize.

Organik ve Kimyasal Gübrelemenin Sanayi Domatesinde (Lycopersicon lycopersicum L.) Verim, Bazı Kalite Özellikleri ve Besin Element İçeriği Üzerine Etkisi

B u arastirma, acik tarla kosullarinda yetistirilen sanayi domatesinde 0, 3, 6, 9 t/da sigir gubresi ile onerilen (25:12:12 ve 3,8 kg/da Ca) ve onerilenin yarisi miktarlarda kimyasal gubre uygulamalarinin verim ve kaliteye olan etkisini belirlemek amaciyla yapilmistir. Calisma sonucu, sigir ve kimyasal gubrelerin domates bitkisinin toplam verim, meyve eni, meyve boyu, meyve agirligini kontrole gore istatistiki olarak onemli duzeylerde arttirdigi belirlenmistir. En yuksek toplam verim ve meyve eni, boyu, ortalama meyve agirligi degerleri 6 t/da sigir gubresi ve onerilen kimyasal gubrenin yarisinin uygulandigi parsellerden elde edilmistir. Suda eriyebilir kuru madde degerleri en yuksek miktarlara sigir gubresi uygulamalarinin 6 ve 9 t/da dozlari ile onerilen ve onerilen ½ kimyasal gubre uygulamalari ile ulasmistir. Vitamin C uzerine uygulamalarin etkisi onemsiz bulunmustur. Ayrica meyve orneklerinin N, Ca, K, Mg, Zn, ve Cu iceriklerinin de sigir ve kimyasal gubre uygulamalari ile arttigi belirlenmistir