Community urban permaculture gardens would help people become independent from the corporate petrochemically driven wage labor hamster wheel that keeps people working long hours just to buy petrochemically derived pesticide/herbicide sprayed/GMO food from agribusiness corporations..
Corporate petroleum dependency is responsible for the US military occupation of Iraq. Plastics, fertilizer, pesticides, herbicides are all manufactured from crude oil petroleum, much of which comes from Middle East countries like Saudi Arabia, Iraq, Syria, etc..
Non-GMO/non-pesticide "organic" food is still very expensive and out of reach for most working people. This is not the fault of the small time organic farmer, they are just trying to survive in the corporate capitalist system where pesticide/GMO using agribusiness corporations are subsidized by government at taxpayer's expense..
Eating healthy food without pesticide/GMO is a human right for ALL PEOPLE on Earth. Making this a reality involves growing our own food in sustainable community gardens. Beginning a community garden in a public "waste space" of unused land is a challenge, especially when the soil of that land may be contaminated with some pollution..
There are different types of pollutants;
1)Toxic heavy metals like lead (Pb), cadmium (Cd), selenium (Se)
2)"organic" pollutants like pesticides and herbicides, benzene and other petrochemical residues
This article will focus on toxic heavy metal contaminants, specifically lead. Heavy metals like lead are dangerous to have in the gardens, so it is usually good to test the soil first. This could be done by collecting a sample and having a friend test it at the local community college chemistry department. If there is a large amount of lead or other heavy metal present in the soil, there are ways to take the metal out using certain plants, called phytoremediation..
"Brassica juncea" or Indian mustard green is known to accumulate heavy metals in its tissue, called phytoextraction. A few cover crops of this plant could remove a great deal of the heavy metal contaminant from the soil. Of course these plants should not be eaten, after they finish growing or die they could be brought to a toxic waste disposal so the lead can be removed from the ecosystem..
Heavy metal accumulation by Brassica juncea is a defense method that keeps insect pests from eating too much of the leaves. The difference is seen in plants that grow in soils with toxic heavy metal presence compared to those without. The caterpillars usually don't last as long when they eat the leaves that contain accumulated toxic heavy metals. Brassica juncea is healthy to eat if the soil doesn't contain excess toxic heavy metals, as it accumulates essential (beneficial metal) elements that animals and humans need like iron, magnesium, zinc, etc..
To increase the uptake of lead for phytoextraction, the lead needs to be loosened from the soil, especially if it is high clay content. Chelates (ex. EDTA) are compounds added to soil that sequester heavy metal ions like lead and increase their uptake into the phytoextractor plant..
Lead polluted soils form insoluble lead phosphate unavailable to plants, so plants will be nutritionally deficient in phosphate. Phosphate needs to be added to the plant leaves for availability..
Certain biotech corporations are attempting to use genetic engineering for "improving" phytoremediation. This is not needed as the plants are already quite good at sequestering heavy metals. Their evolutionary strategy of heavy metal bioaccumulation benefits them by keeping insects from devouring their leaves. Humans cannot improve on what exists in the plant by tampering with their DNA. However, biotech corporations could attempt to make a profit by selling a genetically altered "improved" phytoextractors to gullible consumers similar to "Round-up Ready" or Monsanto's Bacillus thuringiensis "Bt" corn..
Mother Nature is perfection, we don't need biotech corporations tampering with DNA..
Let's overgrow the corporate system..
for more info;
"Plants that Hyperaccumulate Heavy Metals" edited by RR Brooks published by CAB Intn'l 1998
websites;
Permaculture as a Design Modality for Healing and Regeneration: Design with a Deeper Agenda;
http://www.patriciamichaeldesign.com/PCHeal.htm Ecological Engineering Group, LLC;
http://www.ecological-engineering.com/defs.html PHYTOREMEDIATION OF CADMIUM FROM
NEW ZEALAND SOILS;
http://soils-earth.massey.ac.nz/phyto_cd.htm