Investigating the effect of different sources of nitrogen fertilizer and the type of cultivation medium on the growth and performance of Madagascar periwinkle under green roof conditions

Subject Areas : Morphophysiological

Fatemeh Kazemi ¹ , Maliheh Rabbani Kheir Khah ² , Mansoure Jozay ³

1 - Department of Horticulture and Landscape, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
2 - Departmenr of Horticulture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
3 - Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran,

Received: 2024-01-31 Accepted : 2025-01-17 Published : 2025-04-03

Keywords: green roof, nitrogen, nutrition, growing medium, plant.,

Abstract :

Choosing the right growing medium and plant nutrition is one of the key aspects of a green roof in order to achieve its important ecological functions. This experiment was conducted on the morpho-physiological traits of Catharanthus roseus in the spring and summer of 2022 under the green roof conditions of Mashhad in a factorial manner in a randomized complete block design with 3 replications. The first treatment was nitrogen fertilizer (ammonium sulfate and sulfur urea in three doses of zero, 25 and 50 grams per square meter) and the second treatment was the type of culture medium (containing soil and without soil). The results showed that Madagascar periwinkle does not show a noticeable reaction to the presence or absence of soil in the cultivation growing medium. But the use of nitrogen fertilizer significantly improves plant growth and performance. The lowest salinity (about 1 decisiemens per meter) and the lowest acidity of the culture medium (about 7) were observed with the application of all concentrations of two nitrogen fertilizers, and the reduction of the acidity of the culture medium by the fertilizer leads to better absorption of nutrients by the plant and improvement of physiological traits, including an increase in leaf water content. (up to 100%), decreased electrolyte leakage (up to 90%), increased chlorophyll (up to 2.5 μg/mg) and improved photosynthesis. Subsequently, the highest number of flowers (53 per plant), growth index (12000 square centimeters), fresh and dry weight of shoots (120 and 26 grams, respectively), fresh and dry weight of roots (4.5 and 1.3 grams, respectively) in Urea sulfur treatment was seen. 25 grams per square meter of ammonium sulfate and urea-sulfur fertilizers and both types of growing medium are recommended for growing Madagascar periwinkle plants on the green roof.