Qatar Airways accepts any sporting equipment as checked baggage as part of the passenger's free checked baggage allowance mentioned on the ticket. Any sporting equipment which exceeds the free allowance will be subject to excess baggage rates.
Excess baggage rates for sporting equipment can be found in the link below
When purchased at the airport, regular excess baggage rates apply. https://www.qatarairways.com/en/baggage/excess.html
NOTE: Occupational safety rules require that the checked baggage weight for passengers does not exceed 32 kg (70 lb) per piece. It should be noted that this 'physical' baggage weight limitation is an issue relating to Occupational Health Safety and is not related to baggage allowance and charges, which is a separate subject matter.
For contact details of Qatar Airways cargo offices, please visit the link below