Effect of Some Organic Amendments on Lettuce Production under Urban Conditions


  • M.S.A. Emam Central Laboratory for Agricultural Climate, Agricultural Research Centre, Giza, Egypt.
  • A.M.H. Hawash Central Laboratory for Agricultural Climate, Agricultural Research Centre, Giza, Egypt.
  • Abul-Soud M.A. Central Laboratory for Agricultural Climate, Agricultural Research Centre, Giza, Egypt.


Azolla, Mitigation, Roof garden, substrate culture, vermicomposting


Promoting the urban and rural horticulture and top roof garden through reduce the cost of used substrate on the environmental and economic scales to present sustainable horticulture production via applied azolla and vermicompost to the substrate mixtures in pot system. The study conducted out during two successive winter seasons (2019 and 2020) under urban conditions at Central Laboratory for Agricultural Climate (CLAC), Giza, Egypt. The effect of vermicompost and azolla (fresh and dry) as a substrate amendment in different proportions (10 and 20 % v/v) with peat moss: perlite (1:1 v/v) on substrate properties and lettuce yield were investigated. Iceberg lettuce type cv. Robinson F1 hybrid was cultivated in complete randomized blocks design with three replicates. The physical and chemical properties of different substrate mixtures beside vegetative and yield parameters were measured.The obtained results indicated that the top-roof garden application had a positive impact on heat urban island by decreasing the ambient maximum temperature by an average range 2 – 4.5 oC beside the strong contribution in food security and production. Azolla culture and vermicomposting conserved the organic carbon and essential nutrients beside their application as a substrate amendment that presented a significant effect on lettuce yield through enhancing the physical and chemical properties of substrate and support plant nutrition.The implement of vermicompost by different ratio 10 and 20 % led to increase the bulk density, water hold capacity and EC of substrate while increasing the total pore space and air porosity were bone by dry azolla application to substrate. The vegetative growth and yield of lettuce plants improved significantly by dry azolla and vermicompost application as a substrate amendments. The treatment of substrate mixed 20 % vermicompost (v/v) followed by 20 % dry azolla (v/v) recorded the highest vegetative characteristics and yield of lettuce while the lowest gave by standard substrate peat moss: perlite (1:1 v/v).The study is highly recommended sequestrate CO2 through growing azolla and recycling urban organic wastes via vermicomposting for mitigating greenhouse gases (GHG's) emission and save natural resources as well as achieving sustainable food production through simple substrate culture in top roof garden technique.