By the BBC's Catherine Davies in northern Afghanistan

An intensive campaign to fight locust infestations is in full swing across nine provinces in northern Afghanistan.

The Irish non-governmental organisation, Goal, says a super batch of locusts is expected this year and the next few weeks will be crucial in terms of damage limitation.

The plan is to identify the worst affected areas to get logistical support to them and mobilise whole communities - not just farmers - to tackle the problem.

Roads look black

More than 20,000 people are involved in the campaign across the north.

By the end of this month the locusts will be able to fly and cover far greater distances.

Farmers believe this is the worst infestation for at least a decade.

Swarms can be so dense that roads look black.

A single swarm can munch its way through a field in a few hours.

Farmers believe this is the worst infestation for at least a decade.

There's been a lack of resources to fight the locusts, while drought provided good breeding conditions.

Some farmers decided not to plant at all this season. No point in wasting seed, they say.

Low tech approach

The immediate aim is to protect crops. After years of drought there's now finally hope of a harvest.

But without locust control, crops could be lost despite the rain.

Afghans have been displaced already

The approach is low tech; digging trenches to catch and bury the locusts.

To do this requires a massive mobilisation of people. But Goal says it is difficult to organise communities in certain areas because people are on the move.

Communities moved

Displaced because of conflict and drought, they are now returning to their villages.

The hope is that this time next year more people will be back in their homes to tend the land. If crops are lost this year, however, the concern is that villagers will move again.

There is no expectation of eradicating the locust problem now. It is a matter of trying to hold it in check for the time being until a more targeted approach can be introduced.