Dirt! did a good job of touching on important issues facing soil today - monoculture, artificial fertilizer, soil erosion, desertification, slash and burn, etc - as well as some solutions for better soil care and conservation - compost, polyculture. What it did a poor job of was presenting how all the issues are interrelated through physical and biological processes (e.g. nitrogen cycle, life and death). The formation and roles of soil were sadly under-explained. The viewer is left with a scattershot impression of trouble but the big picture is woefully incomplete.
My sense is that the documentarian wanted to emphasize the spiritual and emotional rather than the scientific or even economic aspects. This bias makes it a good film for the uninitiated - those who need to be impressed with the value of the 'skin of the Earth' - but those who keep abreast of ecological disasters-in-the-making would probably prefer a film with a more compelling, cohesive, substantive narrative.
Too bad, because soil is an extremely important resource, and everyone should know its value and the consequences of mismanagement. Dirt! delivers the right message, but if only it would deliver it more persuasively...
