The percentage of energy transferred from one trophic level to the other is called ecological efficiency.
The efficiency of energy transferred from one trophic level to another varies from 5% to 20%. In the terrestrial ecosystem only 10% of energy on an average is transferred from one trophic level to another. This means 100 kg of grain is needed to produce 10 kg of meat. This is due to the fact that not all the organisms present at one level are easily available as food for the consumers at higher level. Predators may not be able to capture all the prey available. Those organisms which escape the predators eventually die and they provide food for the decomposers.
As the ecological efficiency is low the capacity of the ecosystem to support organisms at the higher trophic level is limited.