After the driest nine months since its records began, more than a century ago, the county's farmers have had no choice but to abandon more than half their winter wheat harvest, ploughing in the pathetically small plants that should by now be tall, golden and laden with grain.
The drought has blighted Oklahoma, Texas and Colorado as well as Kansas, emptying much of the great US bread basket that helps to feed 100 nations around the world. Even before it struck, global grain stocks were at record lows, after three successive years in which the world has produced less food than it has consumed.
Experts were hoping for bumper crops to restore some measure of security: now they are praying that decent weather worldwide for the rest of the year will avoid disaster. The UN's Food and Agriculture Organisation (FAO) said last week that the world food situation was "extremely precarious", and is organising a special summit in Rome in November to address the crisis.
Dennis Metz stands forlorn in his fields near Oxford, in Sumner County. His wheat, which should by now be waist-high, hardly reaches the tops of his boots. He has already ploughed in nine-tenths of his crop, and expects to have to abandon the rest as well. It will be the first time in 125 years that no crop has been harvested.
Some 250 miles west across the parched plains, near Hardesty, Oklahoma - in the area at the heart of the disaster depicted in John Steinbeck's Grapes of Wrath - Lewis Mayer is also preparing to write off his stunted crop. Less than two-and-a-half inches of rain have fallen in the area over the last six months. The 71-year-old farmer thinks back to when he was 10, during the Dust Bowl years, and says: "As near as I can remember, it just looks similar. Very similar."
And another 100 miles north-west, near Springfield in Colorado, Monty Wessler is facing abandoning 3,000 acres of wheat. "This will probably be the first year I will not cut a bushel in 23 or 24 years," he says.
Kansas has abandoned nearly 30 per cent of the area under wheat - the highest figure for 45 years - ploughing in 3.5 million acres of it. High winds in the south and south-east of the state in early March saved farmers some of the trouble, literally blowing the wheat out of the dusty ground, as they did during the 1930s disaster. Oklahoma has abandoned just over a third of the fields it should by now be harvesting. The state government expects between 5,000 and 10,000 of its 70,000 farmers to go bankrupt before the year is out.
Meanwhile, the Texas Agriculture Commissioner, Rick Perry, says the drought has already cost his state $2.4bn (pounds 1.6bn) in failed crops, and that this could rise to $6.5bn if the dry weather continues. "We are in the grip of a very, very serious drought," he says. "It has the economic potential to be the worst natural disaster to hit Texas in the 20th century."
The US Department of Agriculture (USDA) estimates that a fifth of the land laid down to winter wheat nationwide will not now be harvested, and that the national yield will be down by nearly a third on a normal year, even though some 4 million extra acres were planted with it last autumn. The winter crop makes up two-thirds of the entire American wheat harvest, which is now expected to fall to 56.4 million tonnes, even if the weather is good for the rest of the year. This would be sharply down even on a particularly bad crop last year, falling for the third year in succession to some 20 per cent less than was harvested three years ago.
The USDA is hoping that a bumper maize crop will bail out the nation and the world, but James Greenfield, director of the FAO's commodities and trade division, said: "The global food outlook certainly warrants serious concern. We do not want to scare people, but we do want to warn the world that we are on a very, very tight balance."
On both the FAO's and the USDA's projections, the world should just scrape through this year, with grain crops rising by some 5 to 6 per cent over last year's disastrous world harvest, just about exactly the minimum increase estimated to enable the world to continue feeding itself at the present, inadequate, level. But this assumes that normal weather will prevail world- wide for the rest of the year. Mr Greenfield admits: "Any more bad shocks will really send things through the ceiling."
So far, the omens are mixed. Europe, too, has had a poor start to the year. Too much rain, following a harsh four-year drought, has flooded Spanish fields. And the long, cold, dry spring has hit crops in both Britain and northern France. Sandra Nichols, policy adviser to the National Farmers' Union in East Anglia, Britain's most important grain growing area, says that many crops there are beginning to show signs of being badly affected by the weather.
"We are having the worst of all worlds at the moment," she says. "Normally if it is cool it is also wet, but it has been both cool and dry. In some places the crops are not getting away at all: they are just sitting there, doing nothing."
There has also been severe drought in China, affecting 17 million farmers across a fifth of the country's agricultural land. However, southern Africa, seriously hit by drought last year, is harvesting an excellent crop. South Africa is expected to double its maize harvest, and Zimbabwe should treble its output: both should be able to export grain this year, in Zimbabwe's case after a four-year ban on the trade because of drought. Analysts are also hoping for much better crops in the former Soviet Union.
The problem is that there is no margin of safety. This is because stocks of food have fallen well below the level regarded as the absolute minimum needed to provide the world with a reasonable level of security.
Just nine years ago the world had sufficient grain in store to feed itself for 104 days. But in most of the intervening years it has not produced enough food to meet demand, and so stocks have been drawn down. By the end of this year, at best, there will be enough reserves for 51 days; if there is any further disaster, there will be even less. Stores in the US are heading for their lowest level since the Second World War, while the European grain mountains - as the Independent on Sunday revealed last November - have entirely disappeared.
This precarious state of affairs is sending prices soaring. Wheat, maize and rice prices have all doubled over the last year or so. The European Union, which for so long subsidised exports, is now taxing them to try to keep the grain at home: last month, flour exports were taxed for the first time in two decades, while the tax on wheat exports was raised by more than a quarter.
The big losers are the world's 82 poor food-importing countries. They are already having to find another $3bn this year to feed their peoples at even the present scanty levels. Simultaneously, they are being hit by a sharp decline in food aid, which has dropped to half the level of four years ago. While long-term food aid often does more harm than good, by undercutting local farmers and driving them out of business, emergency aid can make the difference between life and many deaths.
Local emergencies are appearing in such diverse countries as Ethiopia and Tajikistan, North Korea and Afghanistan, Laos and the Sudan. But Africa is much the most vulnerable region, with half of the world's poor, food- importing nations. Over the last two decades the continent's food production per head has fallen by 20 per cent.
The World Disaster Report, to be published by the International Red Cross on Wednesday, will demonstrate that more than three-quarters of a billion people worldwide do not get enough food to live fully productive lives. Feeding them properly - let alone the extra 1.5 billion or so people expected by the year 2015 - depends on growing more food where it is most needed, particularly through encouraging small Third World farmers who, studies show, can double and treble their output when they are given encouragement, access to credit and simple technologies.
Until this happens, the world will go on being unacceptably vulnerable to the vagaries of the weather in its self-styled wheat capital, Sumner County.