International Science and Technology Journal

Soil fertilization is one of the most important means to compensate soils from the loss of necessary nutrients for plant growth, and improving soil properties, which leads to increase crop production. In this study Lettuce has been chosen because it is one of the most productive and consumed leafy vegetables in different parts of Libya due to its high nutritional value, while the sandy soil was chosen due to its light texture, good ventilation and moderate alkalinity. The aim of this study was to determine the effect of adding coffee powder as fertiliser on soil properties and growth rate of lettuce plants. The soil was grouped into three groups, the first group was without fertilisation, the second was fertilised with coffee residue powder and the third was fertilised with fresh coffee powder. Lettuce was planted in 8 replicated pots for each group. The germination period lasted about 10 weeks, and pots were placed in the conditions of the external environment. Different studies were applied for the used soil including morphofield aspects of morphological description (the type of horizon and hue), the physical analysis (Texture, Structure and bulk density) and the concentration of calcium CaCO3. Moreover, soils were chemically analysed for (PH, EC, N, P and K). Growth parameters such as (Plant height, number of leaves, fresh and dry weight) of lettuce were measured. The results showed that the addition of coffee powder as fertiliser caused noticeable changes in soil characters, which clearly affected the growth stages of lettuce plant. The best growth rates were obtained with unfertilised sandy soil compared with the other types of soil. The soil fertilized with fresh coffee resulted in decreased number of the leaves, while coffee residue powder resulted in significant decrease in plant height, which subsequently, stopped growing and died. Comparatively, growth of plants seeded soil without additives increased in a noticeable way. Therefore, this study suggests that fertilising with coffee powder may have a negative effect on some of soil properties and consequently the growth rate of the lettuce plant. Keywords: sandy soil, fertilisation, coffee residue, lettuce, nutrient elements.