Our reporter Carl Gierstorfer has finished filming for his upcoming report on sustainable rice crops in the Philippines. Read his latest post from the field:

"The Filipinos call them the 8th world wonder, UNESCO lists them as a world heritage site: the rice terraces of the Cordillera mountains in northern Luzon. The Ifugao people started to carve them into the hillsides 2000 years ago, at a time when iron hadn't been discovered in their part of the world. Instead they used hardwoods collected in the forests; they built complex irrigation systems and transformed these mountainous forests into a rice growing region.

One cannot stop wondering about why the Ifugao people, apparently feared headhunters, took so much effort to grow rice. Were the forests hunted empty? Was it prestigious to grow rice? What's for sure is that the climate here, even in the present cooler and drier season, is not pleasant. It's damp, wet, and pretty cold at night. The terraces are still farmed today, the plots of land handed down the generations. It is tough work. During the rainy season landslides destroy many rice paddies. Small wonder, then, that more and more of the fields are being abandoned; young people move to the cities, get jobs in the tourism industry. After all, it takes almost a year's work to harvest rice that will last for only a few months. As spectacular as these rice terraces are, there is nothing romantic about farming them. One can only hope that after 2000 years there will be at least some people left who will maintain this 8th wonder of the world.

We have finished filming and head back to Manila. There is lots of material – so now it's all about choosing the most interesting bits for the report."