Turkish Journal of Field Crops

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DETERMINATION OF NITROGEN LEVELS BASED ON SPECTRAL REFLECTANCE VALUES IN SHEEP FESCUE (Festuca ovina L.)

Yaşar ÖZYİĞİT, Mehmet BİLGEN

Abstract

The objective of this study was to determine nitrogen levels in sheep fescue (Festuca ovina L.) using spectral reflectance data. Reflectance measurements were undertaken using a portable spectroradiometer measuring the wavelength range of 325-1075 nm of the electromagnetic spectrum. The treatments consisted of different concentrations of nitrogen, phosphorus and potassium for pots and plots. Spectral reflectance values were measured in both canopy level and single-leaf in the field and greenhouse studies. According to result of the study, the better results were obtained in greenhouse conditions. Nitrogen levels were affected reflectance values of blue region which located in the range of 400-500 nm. The results have shown that spectral reflectance data (especially blue region) could be used to estimate the N concentration in sheep fescue.

Keyword: Nitrogen, reflectance, remote sensing, sheep fescue ,

Effects of Different Water Stress Levels on Biomass Yield and Agronomic Traits of Switchgrass (Panicum virgatum L.) Varieties under Semi-Arid Conditio

Erdal GONULAL, Suleyman SOYLU, Mehmet SAHIN

Abstract

A field experiment was conducted in the Wielkopolska region at the Gorzyń Research Station, Poland (52.34°N, 15.54°E) in Central Europe. The study was conducted over a 3-year period (2017, 2018, 2019) as a two-factorial design with four replications in the RCBD. The aim of the research was to determine the effect of the cultivar (‘Bolero’, ‘Tytan’) and the inoculation (Nitragina–seeds inoculation, Nitroflora I–seeds inoculation, Nitroflora II–soil inoculation, HiStick® Lupin–seeds inoculation) on plant development, seeds chemical composition and yielding of narrow-leaved lupin. The weather conditions and experimental factors significantly influenced on productivity of narrow-leaved lupin ‘Tytan’. Drought during the growing season reduced seeds and protein yields. After inoculation of HiStck the seeds yield was significantly greater by 12.4% (p < 0.01) and the protein yield after application of Nitroflora I or HiStick by 13.9% (p < 0.01) and 19.2% (p < 0.01), respectively. Correlation coefficients showed strong relations between number of pods and seeds per plant in both cultivars regardless of the inoculation variant, however the strongest relations in both cultivar were proved on HiStick treatment.
Keyword: Biological nitrogen fixation, chemical composition, legumes, protein efficiency, yielding