The type of lawn to be created also determines the amount of seeds to be sown. The highest seeding standards apply to garden lawns (carpet) and most sports lawns. Smaller amounts are used on park lawns.
The sown amount of seeds is usually greater than the theoretically determined, because not all seeds are capable of germinating, and therefore, that contaminants may be among them. The actual Wu value in use of seeds is calculated by the formula:
wherein:
Sk - the actual germination power of seeds,
C - real cleanliness.
Germination power and purity are always stated on the label attached to the marketed seeds.
Example. We want to calculate the actual amount of seeds to be sown per m² of the following mixture:
30% common bent (Agrostis thin) about the power of germination 92% and cleanliness 90%,
70% red fescue (fescue rubra) about the power of germination 95% and cleanliness 92%.
Number of seeds for sowing bract - 3 g/m², and the fescue - 5 g/m².
We calculate the real value in use of Wu and the actual amount of seeds to be sown:
a) common bent
Wu=(92 · 90)/100 = 82,8 %
lack: 100 – 82,8 = 17,2 %
already 1 m2 should be added:
(17,2 · 3)/100 = 0,52 g
amount of seeds per 1 m2
3,0 + 0,52 = 3,52 g
because, however, the broom does 30% mixtures, thus the actual amount of seeds to be sown per m² is
(30 · 3,52)/100 = 1,05 g
b) red fescue
Wu = (95 · 92)/100 = 87,4 %
lack: 100 – 87,4 = 12,6 %
already 1 m2 should be added:
(12,6 · 5)/100 = 0,63 g
amount of seeds per 1 m²
5,0 + 0,63 = 5,63 g
fescue poses 70% mixtures, so the actual amount of seed to be sown on 1 m² is:
(70 · 5,63)/100 = 3,94
The amount of mixture seeds needed to sow 1 m² is:
1,05 + 3,94 = 4,99 g
However, the number of seeds in 1 we get a gram of the mixture by adding up the products: the actual amount of seeds to be sown, actual use value and seed count in 1 g, calculated on each of the components of the mixture:
mietlica 1,05 • 82,8 • 16000 = 13900
fescue 3,94 • 87,4 • 1000 = 3450
Total seeds in the mixture 17350 sztuk na 1m2