Industrial agriculture. Think about this oxymoron. In its name, companies set out to produce food without farmers, and eventually to crowd the farmers out of the fields. Today we’re taken with the idea that fields can be cultivated without any food being produced: agriculture without nourishment. It’s a form of agriculture based solely on profit and speculation that manages to turn bad everything that could be good: food, fertile soils (though less and less so), and even clean and renewable energy. Like photovoltaics. Like biogas.

We have already debated how photovoltaics can become a machine that gobbles up land and food resources. Now it's the turn of biogas plants, which convert biomass – i.e. livestock waste, straw and other plants – to energy. These facilities would be ideal for getting rid of manure, a recurring problem for ranchers, and other biological waste, improving farm-gate income by producing energy that can be used on the farm or sold. But once the wheelers and dealers get involved, once investors who could not care less that farming produces food and does so as well as it can – once these speculators sniff a good deal on the wind and come running, biogas can turn into a blight on the land. This is what is happening in many regions of the Po Valley, particularly where there are large concentrations of intensively reared livestock.

What's happening? Many farmers, left in dire straits by the widespread crisis in the sector, are becoming energy producers and getting out of food production. In effect, they grow maize intensively just to fill up “digesters”: tanks that produce biogas from the anaerobic breakdown of organic matter. Investors help them out, and sometimes they exploit them. On some cattle-rearing farms the farmers are paid to grow corn by those who built the converter tanks: they have become workers in the energy sector, and no longer farmers.

It all began in 2008 when a new green "agricultural" certificate was introduced in order to produce electrical energy from biogas. The production installations were to be “small" electric power plants not exceeding one megawatt. Yet just one megawatt turns out to be a lot. It has stimulated business, since a tariff of 28 euro cents per kilowatt-hour was awarded to those who produce the power, a rate three times higher that the price paid for energy produced "normally".

The subsidy system, in addition to those subsidies paid out by the European Union for maize production, has therefore made building large and expensive (up to €4m) facilities highly profitable, especially as their cost can be amortised over just a few years. In the region of Cremona [North] alone, five licensed facilities were built in 2007; today there are 130. The maize destined for biogas, it is estimated, takes up 25 per cent of the land currently being cultivated. By 2013 there are predicted to be 500 facilities throughout Lombardy.

The environment and agriculture itself are under threat. Some findings (and truisms) are in order.

First: we are giving up growing food to produce energy in its stead.

Second: intensive maize monoculture is harmful to the land because it uses large amounts of chemical fertilizers and consumes an enormous amount of water, which is pumped up from a groundwater table that is sinking lower and becoming polluted. Without plot rotation, soil fertility is degraded and pests spread more easily – and then have to be eliminated by doses of pesticides.

Third: those who produce energy by growing corn can afford to pay much higher rents for land, up to €1,500 per hectare, which creates unfair competition for those who need to rear livestock. It's the same phenomenon that has been created with the solar voltaic parks, which means we are repeating the mistake.

Fourth: the facilities themselves, those that produce one megawatt, are large structures and to build them agricultural land is sacrificed for ever.

Fifth: rumours are already circulating about the birth of a black market for organic waste, such as slaughterhouse offal, which is sold illegally to produce biogas. This waste should never be used as biomass, because the residue of the "digestion" process is then dumped onto the fields as fertiliser, and this waste would not only pollute but also spread disease.

It’s a problem of scale. In itself, the biogas coming from biomass is intrinsically harmless. But if it is produced for speculative purposes and blown out of all proportion, if it intensifies the production of maize for the sole purpose of feeding the biogas facility, if it pushes up land prices, resource depletion and pollution, then we must say no to it. Loud and clear.

Certainly these are issues that must be tabled and debated during the discussions on the new Common Agricultural Policy (CAP) which are underway in Brussels. Sooner or later the subsidies will end. Biogas and its huge installations is a dirty bandage on the wooden leg of our limping agriculture, and it could be the coup de grace. It will be very difficult to go back: the fertile soils are not recoverable, the aquifers are polluted, a healthy agriculture is vanishing, and those who try to practice proper stewardship of the land are forced to give up in the face of ruthless and unsustainable industrial competition.

Industrial agriculture. What an oxymoron.