When the longest river is dry, it's rain that Italy waits for

Giampaolo Basi is in serious trouble on a northern Italian farm near the Adriatic Sea.

When the longest river is dry, it's rain that Italy waits for

Giampaolo Basi is in serious trouble on a northern Italian farm near the Adriatic Sea.

The 32-year old says that salt water is killing plants because they can't withstand such high levels of salt water.

He grabs one of the most sickly-looking plants, and you'll see nothing.

Giampaolo had issues with salt in water before but not like this.

It all has to do with the worst drought in the region for 70 years. This is due to a lack snow and rain since winter, and higher temperatures.

Communities across northern Italy rely on the River Po and its tributaries for their survival.

It runs for 650 km (400 miles) from the Adriatic Sea to the south-western Alps. Satellite images show that riverbeds are becoming more dry each year.

Experts say a weaker river means more salty seawater penetrates further inland.

Professor of Coastal Dynamics at Ferrara University Paolo Ciavola says, "Normally you'll see that the seawater enters into the river mouth for a few kilometres."

"At the moment, the Po Basin Authority's official data shows that there is an ingression up to 30km away from the mouth,"

The freshwater river usually wins when it pushes out to the sea. But, the professor says, "Right now, the river is losing."

You can see that the water used to irrigation is being used by farmers and you can therefore imagine huge economic losses for them.

Locals meet at a boat club cafe near the small town Sermide, in the province Mantua for a drink or a cigarette.

The small boats, however, are now stranded because a large area of the river has been turned into a sandbank.

Here, the Po splits to one side of a small Island.

I can walk to it, my boots dragging along the crackled earth.

Locals inform me that this is unusual, as I look out from the cafe's porch.

Sergio Bettoni, a volunteer there, claims that it's the first time that the little boats have been entirely marooned on the sand which he also claims authorities allowed to build up.

Maria Grazia Lupi Lupi, his wife, said that the view makes her feel desolate.

"I wish the weather would change and slowly it could get back to normal. It's a disaster, not only for us but for all the businesses.

Po's low water level has revealed a sunken World War Two vessel and a German military vehicle.

In 1945, the Allies advanced and the Axis troops were driven north of the river.

Sergio points out the wooden wrecks that poke through the surface, which he claims have been there unrecognised since the war.

This drought exposes the Po's secret history.

You can drive through the agricultural land of Emilio-Romagna and Lombardy, and see the pumps spraying the fields like normal.

The land is often lush and green, so you may not realize anything was wrong.

The river is also healthy, at least in some places, according to laymen.

These are just two of five areas where a state emergency has been declared.

We meet Giuliano Rolfini, 67 years old, about 75km east from Ferrara.

We're at sunset, and we stop to take photos of water being sprayed onto a field of carrots. We are right next to his house, and he is curious about what we're doing.

He says that he has been counting down the days since the last rainy day, when we tell him it is about drought.

"I have lived here since my birth. This is the most terrible year. The future is completely uncertain."

The drought and the fatal avalanche that resulted from the collapse of a glacier at the Dolomites Mountains have highlighted the concerns about climate change.

Giampaolo is looking at his peanut crops and can't give a precise figure but fears that he may lose as much as a quarter of the year's crop.

Other produce is growing and he worries about the future.

"Our concern is the increase in salt inland. This causes soil to become dry. It is affecting more of our land, making cultivation more difficult and less productive.

Rain would be a good way to reduce salt levels, but Giampaolo said that forecasts indicate that there won't be enough in the short-term.

Professor Ciavola warns this type of situation is not uncommon in the future and that Italy, as other countries, will need to adapt.

"Maybe changing the crops or optimizing water use in a better manner. It's not a short-term strategy, but it can be a long-term one.