If the natural background is not fully optimal, you can use a photo background. This Lastolite photo background weighs just 4.3 kg, so it should be easy to carry.
From WEX Photo Video
Manfrotto Vintage Collapsible Reversible Background 1.5 x 2.1m - Ink / Sage
DigiBroadcast
Lastolite By Manfrotto Vintage Collapsible 1.5 x 2.1m (5’ x 7’) Ink/Sage