*3.3. Activity of Soil Enzymes*

Study results demonstrated the highest enzymatic activity in the soil sown with Lh and Lp (Table 5, Figure 10), and the lowest one in the control soil. Activities of all enzymes were expressed in activity units per dry matter of 1 kg of soil within 1 h, and so the activity of dehydrogenases ranged from 10.292 μmol TFF (triphenyl formazan) in the soil sown with Lh to 0.654 μmol TFF with Pr; that of catalase, from 0.205 mol O2 in the soil sown with Pr to 0.091 mol O2 in the control soil; that of urease, from 0.880 mmol N-NH4 in the soil sown with Pp to 0.302 in the control soil; that of acid phosphatase, from 1.302 mmol PNP (p-nitrophenyl) in the soil sown with Lp to 0.785 mmol PNP in the control soil; that of alkaline phosphatase, from 0.397 mmol PNP in the soil sown with Lh to 0.138 mmol PNP in the soil sown with Fr; that of β-glucosidase, from 0.348 mmol PNP in the soil sown with Lh to 0.298 mmol PNP in the soil sown with Pr; and that of arylsulfatase, from 0.164 mmol PNP in the soil sown with Pp

to 0.082 mmol PNP in the control soil. The average enzymatic activity of soil sown with fodder grasses was 161% higher than in nonsown soil, and of soil sown with lawn grasses was 83% higher than in nonsown soil. Generally, the enzymatic activity of soils sown with fodder grasses was higher (by 30%) than that of the soils overgrown with the lawn grasses. The lowest enzymatic activity was determined in the control soil not sown with grasses (Figure 10); there was a significantly higher one in the soils sown with Pr, Fr, and Fa; and the highest one was in the soils sown with Lh, Lp, and PP.


**Table 5.** Enzymatic activity in 1 kg d.m. of soil per 1 h.

Homogeneous groups were calculated separately for each enzyme groups denoted with letters (a–f) were calculated for the species of grass and groups denoted with letters (x–z) were calculated for the type of grass. C—unsown soil; Lh—*Lolium* x *hybridum* Hausskn; Fa—*Festuca arundinacea*; Pp—*Phleum pratense*, Lp—*Lolium perenne*, Pr—*Poa pratensis*; Fr—*Festuca rubra.*

**Figure 10.** Activity of soil enzymes presented with the principal component analysis (PCA) method. Deh—dehydrogenases; Cat—catalase, Ure—urease; Pac—acid phosphatase; Pal—alkaline phosphatase; Glu—β-glucosidase; Aryl—arylsulfatase. C—unsown soil; Lh—*Lolium* x *hybridum* Hausskn; Fa—*Festuca arundinacea*; Pp—*Phleum pratense*, Lp—*Lolium perenne*, Pr—*Poa pratensis*; Fr—*Festuca rubra.*
