0:00:03 > 0:00:06For our farmers, harvest is the busiest,
0:00:06 > 0:00:09most important time of the year.
0:00:11 > 0:00:15It's the culmination of all their hard work.
0:00:22 > 0:00:25I'm Stefan Gates, and I'm completely and utterly,
0:00:25 > 0:00:27obsessively fascinated by food -
0:00:27 > 0:00:30where it comes from, what it tastes like
0:00:30 > 0:00:33and the extraordinary secrets lurking behind it.
0:00:33 > 0:00:37But to grow good food, and to grow enough of it, farmers need to
0:00:37 > 0:00:41intimately understand the science behind the harvest.
0:01:08 > 0:01:10There are almost half a million different
0:01:10 > 0:01:13species of plants on Earth.
0:01:13 > 0:01:17We cultivate nearly 2,000 of them for food.
0:01:20 > 0:01:22These edible plants provide us
0:01:22 > 0:01:25with a dazzling variety of things to eat.
0:01:25 > 0:01:30We harvest cereals and grains to make our bread.
0:01:32 > 0:01:34And fruit and vegetables provide us
0:01:34 > 0:01:37with essential vitamins and minerals.
0:01:39 > 0:01:43Our ability to feed ourselves all depends on how well farmers
0:01:43 > 0:01:46manage the needs of edible plants.
0:01:46 > 0:01:49Take the potato - it feeds a vast proportion of the planet.
0:01:49 > 0:01:52But it still shares the same basic characteristics
0:01:52 > 0:01:54with the rest of the plant world.
0:01:56 > 0:02:00Every plant needs its own particular balance of the same
0:02:00 > 0:02:03key chemicals, so that it can grow.
0:02:04 > 0:02:08And these are absorbed from the soil through the roots.
0:02:09 > 0:02:12By adding fertilisers to the soil, farmers give their crops
0:02:12 > 0:02:14a very specific cocktail of these chemicals,
0:02:14 > 0:02:17and it makes sure they're as healthy as possible.
0:02:17 > 0:02:19Yum-yum!
0:02:21 > 0:02:25Phosphorous is essential for healthy roots and shoots.
0:02:25 > 0:02:29Potassium strengthens stems, the plant's transport system.
0:02:30 > 0:02:34Along with nitrogen, found in nitrates, these nutrients
0:02:34 > 0:02:38help plants to create the energy they need to live and to grow.
0:02:40 > 0:02:44Plants, unlike animals, are able to create their own food
0:02:44 > 0:02:47through the process of photosynthesis.
0:02:49 > 0:02:52This is why they're the first step in the food chain for us
0:02:52 > 0:02:56and almost all other animals, and successful photosynthesis
0:02:56 > 0:02:59is a fundamental part of growing crops for harvest.
0:02:59 > 0:03:03But what does the process actually involve?
0:03:03 > 0:03:08In order to grow, all plants have to pull off the same incredible trick.
0:03:08 > 0:03:15They transform water and carbon dioxide gas into solid matter.
0:03:17 > 0:03:23This amazing growth process is powered by the energy in sunlight.
0:03:23 > 0:03:25Light enters the chlorophyll,
0:03:25 > 0:03:29a green pigment contained within the chloroplasts in the plant's cells.
0:03:31 > 0:03:33Here, it provides the energy that drives
0:03:33 > 0:03:36the reaction between carbon dioxide and water,
0:03:36 > 0:03:38to make glucose.
0:03:40 > 0:03:43This provides the sugars that the plant needs to grow.
0:03:43 > 0:03:49The by-product is oxygen - the oxygen we all rely on to breathe.
0:03:49 > 0:03:52By measuring the speed of photosynthesis,
0:03:52 > 0:03:55we can gauge how healthy a plant is.
0:03:55 > 0:03:58The process is happening right here to this plant,
0:03:58 > 0:04:00but normally it's invisible.
0:04:00 > 0:04:02However, there is a way
0:04:02 > 0:04:05in which we can see photosynthesis actually happening.
0:04:07 > 0:04:10All it takes is a lamp and some aquatic plants.
0:04:10 > 0:04:11If you look underwater,
0:04:11 > 0:04:14photosynthesis is happening right now, and that oxygen
0:04:14 > 0:04:16is being released as these tiny little bubbles.
0:04:19 > 0:04:23The intensity of light affects the speed of photosynthesis.
0:04:24 > 0:04:27Without enough light, the process will stop.
0:04:29 > 0:04:32If I move the light further away...
0:04:34 > 0:04:36..the bubbles slow down.
0:04:36 > 0:04:38If I move the light closer...
0:04:40 > 0:04:41..the bubbles speed up.
0:04:41 > 0:04:43More light means more bubbles,
0:04:43 > 0:04:47which means that photosynthesis is happening faster.
0:04:49 > 0:04:54Faster photosynthesis means that plants can grow more quickly.
0:04:54 > 0:04:57So farmers need plenty of sunshine for their crops to do well -
0:04:57 > 0:05:01and that's why they say they're harvesting sunlight.
0:05:05 > 0:05:08We expect fresh fruit and veg throughout the year.
0:05:10 > 0:05:14So how do farmers grow their crops when there isn't much sunshine,
0:05:14 > 0:05:15like in winter?
0:05:17 > 0:05:20Greenhouses help farmers to grow their crops all year round,
0:05:20 > 0:05:22which means that in the middle of winter,
0:05:22 > 0:05:25and even in the middle of the night, they can grow tomatoes.
0:05:25 > 0:05:27Not in this greenhouse,
0:05:27 > 0:05:29but in a slightly bigger one that we found in Kent.
0:05:41 > 0:05:43This greenhouse is gigantic -
0:05:43 > 0:05:47about the size of ten football pitches.
0:05:48 > 0:05:50It may be February,
0:05:50 > 0:05:54but inside, it's possible to create the ideal conditions for growth.
0:05:57 > 0:06:01The temperature, light and amount of carbon dioxide
0:06:01 > 0:06:04can all be controlled to maximize photosynthesis.
0:06:10 > 0:06:14Water and fertilisers provide all the minerals the plants need.
0:06:21 > 0:06:23Growing crops like this costs money,
0:06:23 > 0:06:27but with almost half a million plants in here, they can harvest
0:06:27 > 0:06:34about 50,000kg of tomatoes every single week, even in winter.
0:06:36 > 0:06:39And this way, they can meet our year-round demand.
0:06:42 > 0:06:45Sometimes, with an understanding of exactly what a plant needs,
0:06:45 > 0:06:49you can artificially create the ideal conditions for farming.
0:06:49 > 0:06:52But farmers can't grow all of their crops inside.
0:06:52 > 0:06:53So how does a plant cope
0:06:53 > 0:06:57when photosynthesis simply isn't happening, like in winter?
0:07:02 > 0:07:06Plants have their own strategies for surviving when it's freezing cold.
0:07:10 > 0:07:12During the warmer months,
0:07:12 > 0:07:16they save some of the glucose created through photosynthesis.
0:07:19 > 0:07:23It's stockpiled in roots, stems and leaves
0:07:23 > 0:07:26as a food store for the cold of winter.
0:07:30 > 0:07:33We use these as food for ourselves,
0:07:33 > 0:07:36and some of them are our most familiar vegetables.
0:07:38 > 0:07:41Carrots are actually the plant's winter food supply,
0:07:41 > 0:07:43stored in its roots.
0:07:43 > 0:07:47Onions are basically energy stored up in swollen leaves.
0:07:47 > 0:07:51And the potato is like a swollen, subterranean stem,
0:07:51 > 0:07:53called a tuber.
0:07:53 > 0:07:55For the plant, it's like an underground larder -
0:07:55 > 0:08:00a stash of food to see it through the cold, dark winter.
0:08:02 > 0:08:05Any extra sugars that the plant doesn't need to use immediately
0:08:05 > 0:08:09are instead used as building blocks to make larger starch molecules.
0:08:10 > 0:08:15Starch is insoluble, meaning it doesn't dissolve in water.
0:08:15 > 0:08:19This makes starch much better than glucose for storing energy.
0:08:21 > 0:08:25If potatoes weren't so starchy, they would draw in lots of water
0:08:25 > 0:08:29from the soil, and all that precious food energy would be lost.
0:08:33 > 0:08:36Every single potato is like a power cell for the plant,
0:08:36 > 0:08:39packed to bursting with starch molecules.
0:08:39 > 0:08:42And that means it's full of energy.
0:08:44 > 0:08:49The potato uses its stored energy to grow a new plant in spring.
0:08:51 > 0:08:53We use it for food.
0:09:02 > 0:09:05I know when you taste a potato, you don't think of the energy,
0:09:05 > 0:09:07but have a little look.
0:09:07 > 0:09:09I'm going to put a couple of teaspoons of starch
0:09:09 > 0:09:13into this bit of piping, and then blow it across a naked flame.
0:09:13 > 0:09:15See what happens.
0:09:22 > 0:09:25What you saw there was the energy being released
0:09:25 > 0:09:28in just 30 or 40 kilocalories of starch.
0:09:33 > 0:09:38The average potato contains around 150 kilocalories,
0:09:38 > 0:09:41so about ten potatoes a day
0:09:41 > 0:09:44would supply almost all the energy you need.
0:09:45 > 0:09:48It's no surprise that lots of our most important foods
0:09:48 > 0:09:51come from plants that are rich in starch.
0:09:53 > 0:09:59As well as potatoes, these include grains like rice, barley and wheat.
0:10:01 > 0:10:03Hidden in the ears of wheat
0:10:03 > 0:10:06are the tiny grains that we use to make flour.
0:10:08 > 0:10:12These are actually the plant's seeds.
0:10:13 > 0:10:16They're packed full of starch and protein -
0:10:16 > 0:10:20all created from the glucose the plant makes during photosynthesis.
0:10:23 > 0:10:27So why do plants need to store energy inside their seeds?
0:10:28 > 0:10:32Seeds are nature's way of ensuring that plants survive
0:10:32 > 0:10:36into the next generation - but what exactly is a seed?
0:10:40 > 0:10:43Seeds come in lots of different shapes and sizes,
0:10:43 > 0:10:49but within every single one of them, new life has already been created.
0:10:49 > 0:10:51This is a broad bean pod.
0:10:51 > 0:10:54If I open it up, you find these.
0:10:54 > 0:10:58These beans are all actually little seeds.
0:10:58 > 0:11:01If I cut open the protective coating...
0:11:03 > 0:11:05..and take a little look inside...
0:11:06 > 0:11:09This little bit up here is the embryo - it contains all
0:11:09 > 0:11:14the genetic information the seed needs to become an adult plant.
0:11:14 > 0:11:17All the rest of the bean is the endosperm -
0:11:17 > 0:11:18it's a package of energy
0:11:18 > 0:11:21to support it on the first stage of its journey.
0:11:24 > 0:11:26Given a very precise combination
0:11:26 > 0:11:29of the right temperature and enough water,
0:11:29 > 0:11:30the seed will germinate
0:11:30 > 0:11:33and the plant starts to push up in search of sunlight.
0:11:35 > 0:11:38Each bean contains about 1 kilocalorie -
0:11:38 > 0:11:41the energy it requires to reach the surface.
0:11:41 > 0:11:43Under optimum conditions,
0:11:43 > 0:11:47it can grow at a speed of 3cm a day.
0:11:50 > 0:11:54So, when farmers sow their crops at the start of the farming year,
0:11:54 > 0:11:58each seed goes into the ground with its own store of energy.
0:12:01 > 0:12:06But from day one, it's also crucial that farmers get things right.
0:12:09 > 0:12:13If they plant their seeds when the ground is too cold
0:12:13 > 0:12:15or too dry, they won't germinate.
0:12:23 > 0:12:25From the minute they sow their seeds,
0:12:25 > 0:12:29farmers must understand exactly what their crops need
0:12:29 > 0:12:31to ensure a good harvest.
0:12:38 > 0:12:41To produce seeds, plants need to reproduce.
0:12:42 > 0:12:45And that's where pollen comes in.
0:12:45 > 0:12:50Each microscopic grain carries the male reproductive cells of a plant.
0:12:50 > 0:12:52For a plant to reproduce,
0:12:52 > 0:12:56its pollen must reach the female parts of another plant.
0:12:56 > 0:12:58The trouble is, plants can't really travel,
0:12:58 > 0:13:01so finding a suitable mate can be pretty tricky.
0:13:01 > 0:13:05And that's why lot of plants rely on animals to act as go-betweens.
0:13:05 > 0:13:09To attract animal pollinators, plants entice them
0:13:09 > 0:13:13with dazzling displays of flowers, rich with nectar and scent.
0:13:14 > 0:13:19Birds, insects, and even mammals feed on the nectar,
0:13:19 > 0:13:23and in return provide an invaluable service.
0:13:25 > 0:13:28Flowers contain both male and female parts.
0:13:28 > 0:13:31If you look at this beautiful lily, you'll see that up here,
0:13:31 > 0:13:34these yellowy-brown things, these are called the anthers.
0:13:34 > 0:13:36They're utterly drenched in pollen.
0:13:38 > 0:13:41The anthers are the male part of the flower.
0:13:44 > 0:13:48They stick out, so that any visiting creatures are sure to get
0:13:48 > 0:13:50a thorough coating of pollen -
0:13:50 > 0:13:54pollen they will then carry to the next plant.
0:13:54 > 0:13:57Hopefully it will drop some of that pollen onto this part here -
0:13:57 > 0:13:59the stigma, which is the female part.
0:13:59 > 0:14:01And when the pollen drops there,
0:14:01 > 0:14:05it travels all the way down to the bottom, to the ovaries.
0:14:07 > 0:14:11Once it reaches an ovary, the pollen fertilizes an egg -
0:14:11 > 0:14:14the flower can now develop seeds.
0:14:14 > 0:14:18And with that, the plant has successfully reproduced.
0:14:21 > 0:14:22After pollination,
0:14:22 > 0:14:27in some plants, the flower will develop into a fruit.
0:14:27 > 0:14:31The fruit will only start growing once the plant has reproduced.
0:14:33 > 0:14:37So the huge variety of fruit that we eat wouldn't exist
0:14:37 > 0:14:40without the help of animal pollinators.
0:14:49 > 0:14:51On some large-scale fruit farms,
0:14:51 > 0:14:57there are so many trees that an army of insects is needed to do the job.
0:15:01 > 0:15:04There just aren't enough bees locally, so at this cherry farm
0:15:04 > 0:15:08in Herefordshire, they import bumblebees by the box-load.
0:15:12 > 0:15:15These bees are specially bred to do this.
0:15:17 > 0:15:21We've relied on bees to pollinate our fruit trees for hundreds
0:15:21 > 0:15:24of years, and they're every bit as important today.
0:15:26 > 0:15:30Without insects like bees, there'd be no fruit.
0:15:31 > 0:15:33And it's not just our fruit trees -
0:15:33 > 0:15:3975% of all the crops we grow rely on animal pollinators.
0:15:44 > 0:15:47Plants create fruits for one very simple reason -
0:15:47 > 0:15:51to spread their seed as far and wide as possible.
0:15:51 > 0:15:54The tasty fruit tempts animals to eat it.
0:15:56 > 0:15:57Mmm.
0:16:00 > 0:16:03The seeds inside the fruit pass through the animal's gut,
0:16:03 > 0:16:07and are deposited far away from the parent plant.
0:16:07 > 0:16:09But creating that fruit requires
0:16:09 > 0:16:12a huge investment of energy for a plant.
0:16:12 > 0:16:15That apple contained over a tablespoon of sugar,
0:16:15 > 0:16:18which the plant had had to painstakingly create
0:16:18 > 0:16:20using photosynthesis.
0:16:20 > 0:16:22So plants won't give up their fruits
0:16:22 > 0:16:26until the seeds inside them are ready.
0:16:26 > 0:16:29And that's why unripe fruit is so unappealing.
0:16:29 > 0:16:32These unripe apples are dry and sour.
0:16:32 > 0:16:34They are packed with carbohydrates,
0:16:34 > 0:16:37but they haven't been broken down into the sweet sugars we can taste.
0:16:39 > 0:16:42Until they ripen, most fruits are green,
0:16:42 > 0:16:45so that they're well-camouflaged within the plant.
0:16:45 > 0:16:47But once they are mature,
0:16:47 > 0:16:51the plant produces a syrupy-smelling gas called ethene.
0:16:51 > 0:16:54This causes the fruit to become sweeter, darker
0:16:54 > 0:16:57and much more appetising.
0:16:57 > 0:17:01For the plant, this is the potential for a future generation.
0:17:01 > 0:17:03But for us, it's a food
0:17:03 > 0:17:07packed full of flavour and essential vitamins.
0:17:11 > 0:17:13Once the fruit is ripe,
0:17:13 > 0:17:17at harvest time, it's a real mission to get it picked before it goes off.
0:17:19 > 0:17:23Cherries are a delicate fruit and need treating with care,
0:17:23 > 0:17:25so it all has to be done by hand.
0:17:29 > 0:17:32Fresh from the trees, they're brought here, to the pack house.
0:17:35 > 0:17:39They're chilled, washed and sorted into different sizes
0:17:39 > 0:17:43before being packed into punnets and shipped off to our supermarkets.
0:17:46 > 0:17:50From tree to table is a very speedy process.
0:17:52 > 0:17:56But strangely enough, the success of the cherry harvest starts
0:17:56 > 0:17:58way back in the depths of winter.
0:18:04 > 0:18:08Snow in January is great news for our fruit farmers.
0:18:13 > 0:18:16It might not look like it, but inside the trees,
0:18:16 > 0:18:19there's actually a lot going on.
0:18:22 > 0:18:25The trees need the cold of winter
0:18:25 > 0:18:29so that they can flower in spring, and then fruit in summer.
0:18:32 > 0:18:36If they don't get enough chilling time, they might not fruit at all.
0:18:39 > 0:18:41And it's not just about cherries.
0:18:41 > 0:18:45All our fruit crops need to go through the cold of winter
0:18:45 > 0:18:47if they're going to produce fruit.
0:18:48 > 0:18:50So what's actually going on?
0:18:52 > 0:18:57Well, it's all to do with the fact that plants really do feel the cold.
0:18:58 > 0:19:02When the trees lose their leaves in winter, they become dormant.
0:19:02 > 0:19:06That's because they are genetically pre-programmed to shut down.
0:19:08 > 0:19:12But what is it that causes the tree to wake up again?
0:19:12 > 0:19:16It's all down to a mysterious process called vernalization.
0:19:16 > 0:19:18Take this apple tree.
0:19:18 > 0:19:22It's only when the plant gets cold for a prolonged period of time
0:19:22 > 0:19:24that another set of genes is activated -
0:19:24 > 0:19:29and this begins the long process of preparing the plant for spring.
0:19:29 > 0:19:35It's a bit like the plant's internal clock is being re-activated.
0:19:38 > 0:19:43The long cold of winter triggers the release of hormones,
0:19:43 > 0:19:48which kick-start the plant into flowering, and eventually to fruit.
0:19:50 > 0:19:55To make an apple, the tree must endure around 700 hours
0:19:55 > 0:19:58of temperatures colder than 7 degrees.
0:19:58 > 0:20:03Without that, it simply won't flower as well when the weather warms up.
0:20:08 > 0:20:12The success of the harvest will always be affected by the weather.
0:20:12 > 0:20:14Urgh.
0:20:14 > 0:20:17But farmers are constantly coming up with more and more clever
0:20:17 > 0:20:21ways of controlling the environment to produce more, and better food.
0:20:21 > 0:20:23Good job too.
0:20:26 > 0:20:28As farming gets ever more high-tech,
0:20:28 > 0:20:32some of our crops lead a really pampered lifestyle.
0:20:33 > 0:20:37Polytunnels were first introduced to British farming 20 years ago.
0:20:38 > 0:20:41They protect our crops from the worst of the weather.
0:20:43 > 0:20:46Inside, it's possible to control the conditions.
0:20:50 > 0:20:53These strawberries aren't grown in soil at all,
0:20:53 > 0:20:56they're actually sitting in ground-up coconut shells.
0:20:58 > 0:21:02They get all the water and food they need through a network of pipes
0:21:04 > 0:21:06The amount of nitrogen, potassium,
0:21:06 > 0:21:10and phosphorus is carefully measured to make the healthiest plants.
0:21:14 > 0:21:17And to grow the very sweetest, plumpest fruit.
0:21:17 > 0:21:21So by controlling the environment that they're grown in,
0:21:21 > 0:21:23our farmers can increase the amount and the quality
0:21:23 > 0:21:25of the fruit and veg that they grow.
0:21:30 > 0:21:33Hmmmmm. That is fantastic.
0:21:36 > 0:21:39But some farmers have taken it one step further,
0:21:39 > 0:21:43and they're experimenting with even wackier techniques.
0:21:45 > 0:21:50Miniature-sized versions of everyday veg are a real
0:21:50 > 0:21:52favourite at fancy restaurants.
0:21:53 > 0:21:56But how do you grow tiny vegetables?
0:21:57 > 0:22:00Basically, it's all about density.
0:22:01 > 0:22:07The plants are squashed together, with nearly 800 in a square metre.
0:22:07 > 0:22:11Provided with the ideal conditions, they take just five weeks to grow.
0:22:13 > 0:22:15And it's not just about the size.
0:22:17 > 0:22:22Researchers have found that growing vegetables under red lights
0:22:22 > 0:22:25speeds up photosynthesis, making them grow faster.
0:22:29 > 0:22:32If red light is combined with blue light,
0:22:32 > 0:22:34it also speeds up root growth.
0:22:35 > 0:22:37And that can alter the taste,
0:22:37 > 0:22:40and even make the vegetables better for you.
0:22:42 > 0:22:45But in actual fact, our farmers have been experimenting
0:22:45 > 0:22:48with how to make better food for thousands and thousands of years.
0:22:48 > 0:22:50And to do that they have to understand
0:22:50 > 0:22:53the process of natural selection, and then speed it up.
0:22:59 > 0:23:02Natural variation in plants is down to chance.
0:23:02 > 0:23:03Everything about them
0:23:03 > 0:23:06is constantly being changed and refined by evolution.
0:23:08 > 0:23:12Sometimes a mutation happens by chance that means a plant
0:23:12 > 0:23:14is more likely to survive.
0:23:14 > 0:23:17If you have a gene that makes you taller than your neighbours,
0:23:17 > 0:23:21you'll get more sunlight, and so you're more likely to thrive.
0:23:25 > 0:23:28Natural selection is a lengthy process.
0:23:28 > 0:23:32But through artificial selection, farmers can speed things up
0:23:32 > 0:23:35by selecting the characteristics we like best.
0:23:41 > 0:23:43Mange tout peas are usually green.
0:23:43 > 0:23:46The plant's genes act like an internal instruction manual,
0:23:46 > 0:23:48telling it to produce a green pod.
0:23:50 > 0:23:52But what if there's a chance mutant?
0:23:52 > 0:23:54A random plant with purple pods,
0:23:54 > 0:23:56and it's the purple colour that I want to keep?
0:23:57 > 0:24:01By cross-pollinating the flowers of the purple pea plants with
0:24:01 > 0:24:06those of other plants, it's possible to help it reproduce.
0:24:06 > 0:24:10So we can artificially spread the genes of the purple pods around.
0:24:11 > 0:24:14This increases the chances of purple offspring.
0:24:16 > 0:24:18It's a painstakingly slow process
0:24:18 > 0:24:22because you have to do this again and again over generations of peas.
0:24:22 > 0:24:25But eventually most of my crop should be purple.
0:24:31 > 0:24:34Farmers have been selecting plants with the characteristics
0:24:34 > 0:24:37we want since farming began,
0:24:37 > 0:24:40making them easier to grow as well as producing
0:24:40 > 0:24:42a better end result.
0:24:44 > 0:24:47Fruit that's sweeter.
0:24:47 > 0:24:50Cereals that produce more grain,
0:24:50 > 0:24:54or vegetables that are less vulnerable to pests and diseases.
0:24:56 > 0:24:58Walk through a field of wheat today
0:24:58 > 0:25:01and the crop stands less than a metre tall.
0:25:02 > 0:25:06That's very different from the shoulder-high wheat that
0:25:06 > 0:25:08farmers grew thousands of years ago.
0:25:09 > 0:25:12And that's because farmers have artificially selected
0:25:12 > 0:25:13for shorter wheat.
0:25:15 > 0:25:18As well as being easier to harvest, it's less likely to be
0:25:18 > 0:25:22damaged by bad weather, and creates less waste from the stalks.
0:25:23 > 0:25:27So experimenting with new techniques to improve our food
0:25:27 > 0:25:29is nothing new.
0:25:29 > 0:25:32But there's one thing that really has changed the way
0:25:32 > 0:25:34we grow our food in the last hundred years,
0:25:34 > 0:25:37and that's the rise of the mega machines.
0:26:03 > 0:26:05There's one machine in particular
0:26:05 > 0:26:08that's completely changed the way we farm.
0:26:09 > 0:26:11The combine harvester.
0:26:16 > 0:26:17The first self-propelled
0:26:17 > 0:26:22combine harvesters were only introduced to Europe in 1952.
0:26:24 > 0:26:28Before that, wheat was harvested in pretty much the same way we'd
0:26:28 > 0:26:30done it for thousands of years - by hand.
0:26:32 > 0:26:35It took a lot of people power to bring in the harvest,
0:26:35 > 0:26:38and the whole community had to pitch in.
0:26:40 > 0:26:44But what once relied on an army can now be done with one machine.
0:26:45 > 0:26:49This combine harvester has an eight-metre knife section
0:26:49 > 0:26:54on the front, which makes around 1,300 cuts per minute.
0:26:54 > 0:26:57It can harvest an area the size of a football pitch
0:26:57 > 0:26:59in less than ten minutes.
0:27:06 > 0:27:11But the real beauty of the combine is that it combines the job
0:27:11 > 0:27:15of cutting and threshing the wheat, and that's how it got its name.
0:27:18 > 0:27:19Inside the machine,
0:27:19 > 0:27:22a set of centrifugal rotors
0:27:22 > 0:27:25separate the grain from the rest of the plant.
0:27:25 > 0:27:27The grain is collected behind the cab,
0:27:27 > 0:27:30and the stems are spewed out the back.
0:27:33 > 0:27:36Processed grain is ready
0:27:36 > 0:27:38within seconds of the crop being cut.
0:27:40 > 0:27:43Because they're so quick, and so efficient, machines like the
0:27:43 > 0:27:47combine harvester make it possible to farm on a much bigger scale.
0:27:52 > 0:27:56The innovation in the way that we farm never stops.
0:27:56 > 0:27:58We'll keep on experimenting,
0:27:58 > 0:28:03keep designing new and more efficient machines,
0:28:03 > 0:28:07and who knows how we'll be growing our food in centuries to come?
0:28:08 > 0:28:11What fascinates me about farming is this extraordinary
0:28:11 > 0:28:14combination of technology, chemistry,
0:28:14 > 0:28:16the magic of photosynthesis,
0:28:16 > 0:28:18and the care and the love the farmer has to show to the crops.
0:28:18 > 0:28:22And there lies the secret behind the food on our plates.
0:28:45 > 0:28:47Subtitles by Red Bee Media Ltd