Green activists in Europe, who have notched up two victories in the last week, are unlikely to win a battle against soybean imports, which protesters in Germany are attempting to ban, US officials said.

Environmental campaigners continued on Tuesday to celebrate a decision by BASF, the German chemicals conglomerate, to abandon development of genetically modified crops for Europe, shifting its divisional headquarters to the US.

The move from the developer of the Amflora potato, one of two GM crops approved in Europe, followed French government confirmation on Friday that it would maintain a ban on sowing the other, a Monsanto corn variety, despite the curbs being ruled illegal by Paris and Strasbourg courts.

However, a third front, which has particular momentum in Germany, against soybean imports looks "impracticable" and "unrealistic", US Department of Agriculture attaches in Berlin said.

"Despite a professional and well-organised anti-soybean campaign", the Green party activists spearheading the movement "face a number of economic and agronomic challenges" to securing production of alternative plant proteins, the attaches said.

'Land grabbing with knives and forks'

Germany's Green party - support for which topped 20% in the wake of Japan's Fukushima nuclear disaster, and which are viewed as a natural coalition partner by the Social Democratic party, the main opposition – has urged a ban on soybean imports on grounds that growing the oilseed encourages deforestation and involves exploitation of small farmers, besides use of biotech seed.

GM varieties account for the vast majority of soybean sowings in major growing, and exporting, countries such as Brazil and the US.

Martin Haeusling, the German Green party member of the European parliament, has decried plant protein imports as "land grabbing with knives and forks", calling for extra taxes for biotech soybean imports, and for Europe to rely on its own supplies of the oilseed or alternative crops.

Pulses including fab beans, field peas and sweet lupins have been proposed as alternatives in animal feed.

'Major disruptions'

However, for livestock farmers to rely on such crops would not just hurt profitability.

"Perhaps the most important obstacle is the scale of production needed to meet protein feed demand in Germany," the attaches said in a report.

"Reaching anything near self-sufficiency would require radical changes in policy, major disruptions to established cropping practices, and shortages of displaced crops."

'Would be impracticable'

Replacing the 4.5m tonnes of soybeans that Germany's livestock consume a year would require, in the case of faba beans, some 7.9m tonnes – requiring 2.5m hectares of crop, or 19% of the country's arable area.

Replacement with sweet lupins would require planting on 37% of German cropping area.

"Pulses currently make up less than 1% of arable land in Germany," the report said.

Even if farmers were willing to give up more profitable alternatives, such as rapeseed and wheat, best agricultural practice requires keeping four years between pulse crops, creating a ceiling of 20% on seedings.

"It would be impracticable for Germany to produce enough plant protein to meet domestic demand."