Millions of dollars are urgently needed to help Lebanon back to its feet after its bombardment by Israel, aid agencies have told international donors.
Aid agencies say Lebanon's rural poor are among the worst-hit
Governments and international organisations are gathering in Sweden hoping to raise $500m (£260m).
Lebanese Prime Minister Fouad Siniora told delegates his country had been "torn to shreds" by the conflict.
Meanwhile UN chief Kofi Annan is due to hold talks in Jordan and Syria to try to cement the ceasefire in Lebanon.
The truce has held for more than two weeks, following a month-long conflict between Israel and Lebanon-based Hezbollah guerrillas.
Israel's bombing of southern Lebanon wreaked huge damage on the Lebanese economy, Oxfam said.
The bombardment coincided with the harvest season and meant fleeing farmers had to abandon crops to rot. Some 170,000 farmers were affected, Oxfam said.
"The destruction of Lebanon's roads, bridges and buildings is evident but beyond the piles of bricks and mortar lies the less visible tragedy of acres of ruined farmland and rotting crops," the charity's executive director Jeremy Hobbs said.
"The donors meeting in Stockholm must respond with new money to help this battered nation get back on its feet."
The Lebanese government estimates that Israeli air strikes caused $3.6bn of damage, and set the country's steady growth back years.
It says 15,000 homes were damaged in the conflict.
In his opening remarks at the donors' conference in Stockholm, Mr Siniora called for help in rebuilding his country.
"Lebanon, which only seven weeks ago was full of hope and promise, has been torn to shreds by destruction, displacement, dispossession, devastation and death," he said.
The Lebanese government has appealed for $75m for temporary housing and $30m to repair major roads and put up bridges.
It has also asked for funds to help clear landmines and unexploded cluster bombs, which are preventing farmers returning to their fields.
On Wednesday the UN's humanitarian chief condemned the "completely immoral" way Israel dropped thousands of cluster bombs on Lebanon even as a resolution appeared imminent.
Israel says its use of the weapons was not illegal.
'Time to step up'
Ministers from more than 40 countries are attending the donors' conference, as well as officials from the UN, the World Bank, the International Monetary Fund, and the Red Cross.
The European Union has already promised 42m euros (£28m) for Lebanon's short-term recovery.
But Swedish foreign ministry spokesman John Zanchi said organisers were hoping for much more.
"We are hoping the international community will step up," he said.
Before the conflict erupted, Lebanon had one of the more promising economies in the Middle East, with the government forecasting strong growth of 6% and paying off its debts.
Now it says output will plummet and it will run a deficit for the first time in several years. Unemployment is up sharply, and industry, agriculture, tourism and fishing were badly damaged.
Continuing his Middle East tour, Mr Annan is due to meet King Abdullah in Jordan before travelling on to Syria, where he is expected to tackle the issue of its support for Hezbollah.
Israel wants UN forces to patrol the Syrian-Lebanese border to stop weapons being smuggled to the militant group, but Syria has said it would consider this a hostile act.