Studies were conducted in the glasshouse of Department of Soil Cultivation and Fertilization of Horticultural Plants, University of Life Science in Lublin. The tomato of Admiro F1 cultivar was grown in the period from 10th February to 21st October 2008 and from 4th February to 15th October 2009 for 22 clusters at the density of 2.4 plants for 1m2. The following substrata were examined: 1) triticale straw, 2) triticale straw + high peat (3:1 v:v), 3) triticale straw + pine bark (3:1 v:v), 4) rockwool (100 × 20 × 7.5 cm = 15 dm3). Straw was cut into pieces (2–3 cm) and placed in rectangular boxes 14 cm high, bottom width: 8 cm and capacity 15 dm3. During the growing period about 70% straw has been decomposed. Evaluation of straw decomposition was done by comparing the weight of air dry weight of straw before the experiment with the mass after the experiment (after removal of roots). In each box/slab two plants grew. The experiments were conducted with the use of complete randomization method in seven repetitions