The coir is a natural fibrous material and during its use as substrate in soilless cultures, is partially disintegrated, consisted by 56% of organic matter, and contain nutrient elements. The effects of addition of this residue on soil biological and chemical properties were studied by two ways, firstly with an incubation experiment of 15 weeks and secondly by a greenhouse tomato crop.(In vitro experiment): Into 50 g of soil of the studied greenhouse were added 0, 2.204, 4.410 and 6.610 g from the coir residue, containing 0, 1.25, 2.5 and 3.75 g of organic matter respectively. The treatment of soil with the larger rate showed a higher biodegradation of the total (SOM) about 35%. Nitrification was ensured, a significant increase in available forms of P, K, Zn, and Mn observed for all the treatments, salinity of soil did not show any significant increase and sodicity did not reached hazardous values for plants.(In vivo experiment): In a greenhouse with elevated soil salinity, 280 kg from the coir residue replacing basic and top dressing fertilization were applied in the area of 100 m², where tomato crop was established. The monitoring of soil fertilization was based on soil electrical conductivity, the (SOM) decomposed about 15%, soil salinity was maintained at tolerable levels, and tomatoes plants developed normally. The coir previously used as substrate in hydroponical cultivation is proved a valuable material for soil amendment in greenhouse crops, improving the soil chemical and biological properties, while constitutes a useful practice for environment protection.