La résorption foliaire de quelques macro- (N, P, S) et micronutrients (Fe, Zn, Cu, Mn dans les forêts de Pterocarya fraxinifolia (Poiret) Spach en Turquie

Pterocarya fraxinifolia (Poiret) Spach a une distribution plutôt restreinte en Turquie dans les forêts marécageuses. La résorption foliaire de quelques macro- (N, P et S) et micronutriments (Fe, Mn, Zn, Cu) a été étudiée dans des populations de P. fraxinifolia du nord et du sud de la Turquie. Comparativement aux populations méridionales, les populations nordiques ont montré une résorption de l’azote (NRE) plus efficiente mais une résorption du phosphore (PRE) plus faible. Les populations tant nordiques que méridionales se sont montrées P-proficientes alors que seules les populations nordiques se sont révélées P-proficientes. Des valeurs négatives pour ZnRE et MnRE ont été trouvées dans les populations méridionales. SRE s’est révélée plus élevée que celle d’autres espèces décidues. Des ratios NRE/PRE > 1 ont été trouvés dans les populations nordiques mais 1 in northern populations, while <1 in southern populations

Paleovegetation Researches Based on Fossil Pollen Analysis in Akgöl (Sakarya): Preliminary Results

Fosil polen analizleri göl çökelleri, turbalıklar, akarsu ve deniz sedimanları, buzullar, linyitler ve taş kömürleri gibi çeşitli ortamlardan elde edilen polenlerin_x000D_ araştırılmasını kapsamaktadır. Kuvaterner dönemine ait palinolojik çalışmaların önemli veri kaynaklarından biri de göllerdir. Araştırma alanı olarak seçilen_x000D_ Akgöl, Sakarya ilinde, Ferizli ilçesinin Gölkent mahallesinde bulunmaktadır. Gölün yüzölçümü 3,5 km2_x000D_ ve maksimum derinliği 8 m’dir. Bu çalışmanın amacı:_x000D_ gölün dip sedimanlarında fosil polen analizleri yaparak gölün çevresinde son 1000 yılda meydana gelen vejetasyon değişimlerini ortaya çıkarmaktır._x000D_ Akgöl’den karot alımında İTÜ EMCOL Araştırma Uygulama Merkezi’nin 4x4 m. platformlu piston karotiyeri kullanılmıştır. İstanbul Üniversitesi-Cerrahpaşa,_x000D_ Orman Fakültesi Orman Botaniği Anabilim Dalında bulunan Palinoloji Laboratuvarı’na getirilen karot üzerinde her 5 cm’de bir 2 cm3_x000D_ lük sediman örnekleri_x000D_ alınmıştır. Bu örneklerde “klasik yönteme” göre fosil polen analizi yapılmıştır. Hazırlanan polen preparatlarında her bir bitki taksonu için polen yüzdesi_x000D_ değerleri hesaplanmış, odunsu ve otsu taksonlara ait yüzde grafikleri TILIA adlı programda çizilmiştir. Polen diyagramından elde edilen ilk bulgulara göre;_x000D_ Akgöl ve çevresinde son 1000 yılda yaprak döken orman vejetasyonu hâkimdir. Bu doğal orman varlığının içine son yıllarda Gymnospermae taksonlarından_x000D_ sahil çamları da dikim yoluyla getirilmiştir.Fossil pollen analyzes include research of pollen grains from various environments such as lake sediments, peatland, river and marine sediments, glaciers,_x000D_ lignite and coal. Lakes are one of the important data sources for Quaternary palynological studies. Akgöl, which is selected as a research area, is located in Gölkent district of the Ferizli township in the provincial city of Sakarya. Its surface area is 3.5 km2_x000D_ and its maximum depth is 8 meters. The aim of this study_x000D_ was to investigate vegetation changes around Akgöl in the last 1000 years using fossil pollen analysis in the bottom sediments of the lake. The Piston corer_x000D_ of ITU EMCOL Research Centre was used for recovering sediment cores from Akgöl. Sediment samples of 2 cm3_x000D_ were collected every 5 centimeters on one_x000D_ of the cores at the Palynology Laboratory of IUC. Fossil pollen analysis was performed according to the “classical method”. The pollen percentage values_x000D_ were calculated for each plant taxa and relative abundance graphs were plotted in the TILIA program. According to preliminary results of the pollen_x000D_ diagram; deciduous forest vegetation has been predominant in the last 1000 years around Akgöl. Maritime pine was introduced into this natural forest by_x000D_ plantation in the recent year

Effects of humic acids from different sources on sodium and micronutrient levels in corn plants

The use of activated humic acids (HAs) in agricultural applications is a relatively recent development. Corn (Zea mays L.) is a major food and silage crop in Turkey and yields are reduced in calcareous soils by sodium (Na) toxicity and carbonate (CO3 ) induced deficiencies of some micronutrients. In this study, the effects of two HAs extracted using the wet-alkali technique and activated with nitrogen (N2 ) and oxygen (O2 ) gases, on the Na and micronutrient (iron (Fe), manganese (Mn), zinc (Zn), copper (Cu) and boron (B)) concentrations in the homogenised stems and leaves of corn plants were investigated. The experiment was conducted with a completely randomized design with factorial arrangement (2 HA types × 2 fertilisation regimes × 5 HA concentrations), with three repetitions, in a calcareous soil in pots in a greenhouse. The humic acid was applied at 100, 200, 400, and 800 mg/kg of soil before sowing the corn seed. The variance analysis showed that increasing HA levels decreased the Na concentration in the corn plants. The lowest plant Na concentrations were obtained with the addition of HA activated with N2 and O2 to both the fertilised and unfertilised treatments. The highest Zn and Cu uptakes, and Fe, Mn, and B uptakes, were associated with wet alkali extraction and gas activation, respectively. Overall, HA extracted with N2 /O2 was more effective under unfertilised conditions and wet extracted HA was more effective under fertilised conditions

Terme Yöresi alüviyal arazilerde yetiştirilen çeltiğin bazı fiziko-kimyasal toprak özellikleriyle besin element kapsamı arasındaki ilişkiler

The rice is one of the most important yields, which has valuable income for regional economy. In order to obtain optimum yield from rice cultivation, it should be known soil properties and nutrition content of land in which rice has been grown. Otherwise, it can be faced with deprivation of yield due to misuse or applications for rice land management. The objective of this study was to determine relationships between physic-chemical properties of soil located on alluvial lands and nutrient elements in Terme district of Samsun province. For this purpose, 64 soil samples collected from the study area was statistically evaluate. The clay, silt and sand content of soils varied between 19.8-67.7%, 14.5-32.0% and 1.7-65.7%, respectively. In addition, organic matter, salt, pH and lime content were found as 0,63- 4,87%, 0.8-1.66 dS/m, 5.16-7.45 and 0.58-1.94, respectively. Moreover, micro and micro nutrient element contents were determined as 5.30-46.90 ppm, 45.0-635.0 ppm, 5.03-212.30 ppm, 6.11-91.32 ppm, 0.03-1.36 ppm, 3.83-15.90 ppm and 0.02-1.24 ppm for available P, exchangeable K, available Fe, Mn, Zn, Cu and B, respectively. It was found that there were significantly important relationships between clay content of soils and silt, sand, organic matter and Mn contents. Besides, there are significant relationships between sand and OM, and Mn content. Another significant relation was also determined between OM and Cu content. Other significant relations are between salt and K content; between pH and P, K, Mn and Cu contents, and between P content and K, Zn, Cu content and between K content and Zn, Cu content. Consequently, it should be given some suggestions such as application of fertilizers including P, K, Zn and B by taking into consideration of salinity level of soils and enrichment of organic matter in the paddy fields. Also, it was recommended to apply lime against potential Fe and Mn toxicity that may occur in the future, due to the fact that a large majority of soils have low pH values

Çeltikte (Oriza Sativa L.) Tuz Stresinin Azaltılmasında Silisli Gübrelemesinin Rolü

Toprak tuzluluğu bitki verim ve kalitesini olumsuz yönde etkileyen en önemli abiyotik stres faktörlerinden birisidir. Silisyum (Si) bitkilerde stres faktörlerini azaltan bir element olarak bilinmektedir. Bu çalışmanın amacı, tuz x Si interaksiyonunun çeltik dane verimine, tuzlulaşmanın toprakların yarayışlı Si kapsamına ve tuz stresinin önlenmesinde Si’un etkilerini incelemektir. Bu amaçla Samsun yöresi çeltik topraklarından 5 adet toprak örneği alınmıştır. Topraklarda farklı tuz düzeyi oluşturmak için 9:5:5:1 oranında Na2SO4:NaCl:CaCl2:MgSO4 tuz karışımından 1, 2, 3, 4 ve 5 no’lu topraklara EC değeri sırasıyla, 10.27, 3.55, 10.98, 5.75 ve 7.22 dS m-1’ye ulaşacak şekilde uygulanmıştır. Topraklarda faktöriyel deneme desenine göre (2 x 5) 3 tekerrürlü sera denemesi kurularak çeltik bitkisi yetiştirilmiştir. Her tuz seviyesinde (tuzsuz ve tuzlu) topraklara 0, 50, 100, 200 ve 400 mg Si kg-1 silisik asit (H4SiO4) verilmiştir. Ayrıca bütün topraklara toprak analizine göre yarayışlı NPK seviyeleri eşitlenecek şekilde gübreleme yapılmıştır. Silisyum gübrelemesiyle çeltik dane veriminde sağlanan ortalama artışın EC’si 3.55 dS m-1 olan toprakta % 55.5 ile EC’si 10.98 dS m-1 olan toprakta ise % 2.31 arasında olduğu tespit edilmiştir. Tuz x Si interaksiyonu 4 toprakta önemli olduğu ve optimum Si dozunun toprakların tuz seviyelerine göre değiştiği belirlenmiştir. Toprakların EC seviyeleri arttıkça yarayışlı Si kapsamında ve Si gübrelemesinin çeltik dane veriminde sağladığı artışlarda azalma görülmüştür. Silisyum çeltik danesinin Na içeriğini genellikle azaltırken; K içeriğini artırmış; Ca, Mg ve P içeriğinde ise belirgin bir eğilim gözlenmemiştir. Çeltiğin dane verimi ile Na içeriği arasında çok önemli negatif ilişki (R = - 0.664) elde edilirken, silisyumlu gübreleme danenin K/Na, Ca/Na, Mg/Na ve P/Na oranlarını genellikle artırmıştır. Sonuç olarak, tuzlu topraklarda yetiştirilen çeltik bitkisine uygulanacak optimum Si dozunun 200 mg kg-1 olduğu ve çeltik yetiştiriciliğinde silisyumlu gübrelemenin toprakta tuzluluk ve alkaliliğin zararlarını azaltan pratik bir uygulama olabileceği kanaatine varılmıştır

Response of Paddy Soils to Silicon Fertilization

Silicon (Si) is of nutrient element required very large amounts by rice plant. Thus silicon deficiency can commonly observed in paddling soils. In this study, silicon status and reponse to the silicon fertilizer of Bafra and Terme districts of Samsun for rice cultivation were investigated by means of a pot experiment set up in completely randomised design with three replications. For this purpose, 18 paddy soil samples were taken. Rice plants were grown in a pot filled with 2 kg of oven-dry soil and fertilized with 0-50-100-200 and 400 mg Si kg-1 as silicic acid (H4SiO2), 75 mg N kg-1 ammonium sulfate (21%) and 60 mg P2O5 kg-1 tripl superfosfate (42%) before sowing. Initially fifteen germinated seeds of Osmancık 77 rice cultivar, were planted into each pot. Rice grains with husk were harvested after 142 days from planting. The results showed that rice grain yield (1.56 - 45.85%) significantly increased (P&lt;0.01) by silicon fertilization in 83% of the paddy soils in the region. It was found that paddy soils require different doses of Si (50-200 mg kg-1) and averagely 87 mg kg-1 of optimum Si dose for the region soils. Also, a critical concentration of 17.11 mg of available Si is required to obtain a relative grain yield of 85% in the experimental soils and below this level silicon deficiency limits grain yield

The Characterization of the Arifiye peat

There is a fortune of the peat resources in Turkey, particularly around Lake Sapanca in Sakarya. There has been increasingly attention to peatlands in technological uses and agricultural applications. The Arifiye peat is a new resource. It needs to be elucidated by characterization of its chemical and physical properties. The objective of this study was to characterize a number of samples collected from fifteen different profiles of the peat (sapric) by measuring cation exchange capacity, water holding capacity, humic acid, fulvic acid, organic matter, organic carbon. In addition, the spectroscopic analysis suggested that the functional groups and molecular structure of the Arifiye peat resemble those of peatlands described previously in the literature

ENZYME ACTIVITIES OF PADDY SOILS AND RELATIONSHIPS WITH THE SOIL PROPERTIES

This study was carried out to determine the effect of soil properties on enzyme activities of paddy soils, the sample of which were taken from Üçpınar, Harız, Doğancı, Kaygusuz, Emenli, Sarıköy and Gelemenağarı villages where rice cultivation is an intensive agricultural system. In this study, soil properties having effects on urease, phosphatase, ß-glucosidase and catalase enzyme activities were setforth. Urease enzyme activities of soil samples varied from 24.12 to 39.03 mg N 100 g dry soil -1 . Significant correlations were determined between urease enzyme activities and organic matter (r = 0.89**), extractable Mn (r = 0.74**), exchangable K (r = 0.73**) and total P content of soil (r = 0.81*). Acid phosphatase enzyme activity varied between 3.00-17.44 mg phenol 100 g dry soil -1 , alkaline phosphatase enzyme activity between 12.00-25.53 mg phenol 100 g dry soil-1 . Exchangable Mg (r = 0.71*) and extractable Cu (r = 0.74*) were found to have positive effect on acid phosphatase enzyme activity and pH (r = 0.73*), exchangable Ca (r = 0.74*), exchangable Mg (r = 0.71*), exchangable total basic cations (r = 0.79*) and extractable Cu (r = 0.70*) had positive effects on alkaline phosphatase enzyme activity, whereas total P (r = - 0.84**) affected the activity negatively. ß-glucosidase enzyme activity was measured to vary between 1.12-3.64 mg salingen 100 g dry soil -1 . It was also observed that extractable Zn content of soil samples (r = - 0.97**) had negative effect on ß-glucosidase activity, wheras total exchangable acidic cations (r = 0.70*) affected the activity positively. Catalase enzyme activities of soils changed between 5.25 - 9.00 mg O2 5 g dry soil -1 . Significant correlations were found between catalase activities and fraction of soils and extractable Fe content. Positive correlations, however, were determined between catalase activities and clay fraction (r = 0.82*) and salt content (r = 0.83**) of samples