The land in West Oakland where Eric Maundu is trying to farm is covered with freeways, roads, light rail and parking lots so there's not much arable land and the soil is contaminated. So Maundu doesn't use soil. Instead he's growing plants using fish and circulating water.
It's called aquaponics- a gardening system that combines hydroponics (water-based planting) and aquaculture (fish farming). It's been hailed as the future of farming: it uses less water (up to 90% less than traditional gardening), doesn't attract soil-based bugs and produces two types of produce (both plants and fish).
Aquaponics has become popular in recent years among urban gardeners and DIY tinkerers, but Maundu- who is trained in industrial robotics- has taken the agricultural craft one step further and made his gardens smart. Using sensors (to detect water level, pH and temperature), microprocessors (mostly the open-source Arduino microcontroller), relay cards, clouds and social media networks (Twitter and Facebook), Maundu has programmed his gardens to tweet when there's a problem (e.g. not enough water) or when there's news (e.g. an over-abundance of food to share).
Maundu himself ran from agriculture in his native Kenya- where he saw it as a struggle for land, water and resources. This changed when he realized he could farm without soil and with little water via aquaponics and that he could apply his robotics background to farming. Today he runs Kijani Grows ("Kijani" is Swahili for green), a small startup that designs and sells custom aquaponics systems for growing food and attempts to explore new frontiers of computer-controlled gardening. Maundu believes that by putting gardens online, especially in places like West Oakland (where his solar-powered gardens are totally off the grid), it's the only way to make sure that farming remains viable to the next generation of urban youth.