I am absolutely flabbergasted by  the nonsense the self proclaimed scientists  and PHD diploma graduates spiel about the coined term ' Ghost Circles '. I'm so sorry to offend but these people couldn't boil an egg if they tried, they may have their own abilities in their own world of knowledge but they haven't got a clue when it comes down to understanding plants and soil nutrients.
What is a ghost circle ?
Ghost circles are imprints of previous seasons crop circles which sometimes reappear the following year in different crop. Due to a belief that crop circles are created by paranormal forces the believer  automatically assumes that the paranormals force/energy is responsible for the reappearance of previous seasons crop circle.
Here are some factors for your consideration ( all our research is based on actual findings rather than assumptions - all factors are very important for you to consider if you are a serious researcher who has no vested interest  and seeks the real truth )
Canola / Rape Seed Crop Circles
Very rarely or if at all will you  see a ghost circle appear in next seasons crop if a crop circle was made the previous season ( year before ) in Canola. So if the field is planted with wheat the following season then it is highly unlikely that a ghost circle will appear. If a crop circle was made in wheat and Canola is planted in the same field for the following season then there is a high chance that a ghost circle will appear if no action is taken to prevent it. ( We will explain ! )
Canola crop circles tend to appear in April / May - during these months the Canola plant is maturing and blooming into its striking yellow colour but as yet no seed which can germinate is produced by the plant. The maturity of seed production begins when the plant begins to shed its yellow petals - at this stage crop circle makers tend to avoid making crop circles as the petal less appearance isn't as striking as it would be in blooming Canola. At this stage in growth plant stems become like branches so making crop circles at this stage in maturity would take some determined effort, but as its hard work and not as striking in appearance then circle makers will avoid using this crop and move onto the next which is generally Barley.
During the months of April and May crop circle tourism isn't at its highest so plant crushing footfall isn't as great as it would be in June/July and August. As Canola in April and May has as yet not produced germinating seed so there will be no seed to push back into the soil (which can germinate) by the foot of visiting public. However visitors do still visit old Canola crop circle formations during the seeding process, so plants that have not been snapped but flattened will still continue into maturity and seeding process, so visitors who unconsciously stand on a full head of seed are in fact replanting these seeds to grown again - please remember this factor .
Barley Crop Circles
Ghost Crop Circles can appear in next seasons crop if created in Barley the previous season but there are once again some factors to take into consideration.
Barley crop circles are generally created in young and still green barley but on occasions mature golden coloured barley can be used by the circle makers. If a crop circle is created in young and still green barley then the chances of a ghost circle appearing is slim as young barley has a very good recovery rate after its ordeal of being flattened. Sometimes within 7 days of a crop circle creation the crop circle may appear to have disappeared. If you happen to visit a crop circle in barley ( end of May and beginning of June ) and found that the flattened crop has substantially risen then the chances of a ghost circle are slim as no or very little  trampling of seed back into the soil has occurred. 

However this crop circle was made in matured barley  in a easy to access and popular location and at the height of the tourist season, so the visitor footfall will be much greater. As this circle was made in mature Barley which at this stage will have a zero recovery rate ( it will stay down flattened ) , so the seed of the trampled plant is very likely to be pushed ( replanted ) back into the soil by the feet of the visiting public to grown again. ( this factor is very important which we will conclude in the Wheat section ) .
There is a good chance that this crop circle will produce a ghost circle in 2012 - depending of course if the farmer replants this field and how much nutrient he places in this affected section of the field !?.

Wheat Crop Circles
Crop Circles made in wheat are MOST LIKELY to produce a ghost circle for the following season if the farmer does not replace sufficient nutrient in the effected area.
Wheat crop circles are made at the end of June - in July and August. This part of the season will have the highest rate of crop circle tourism - plant crushing footfall will exceed over a thousand visitors per easy to access crop circles which are within popular locations. Locations such as East Field - South Field - Woodbrough Hill, Silbury Hill and Milk Hill are more likely to develop ghost circles than any other location. Other locations which produce ghost circles would require substantial footfall for a ghost circle to appear - in such cases the reason would be the popularity of a specific crop circle design where it attracts a high tourism demand.
OK - lets get to the nitty gritty and simplicity and explain to you why GHOST CIRCLES APPEAR !
Flattened to the ground crop such a wheat and barley has a head full of seed which will be stepped on when the hoards of infatuated crop circle pilgrims enter the standing walls of surrounding upright wheat. As the seed head is stepped on - the seed pops out of its pod - please consider that we are talking about several thousand seed heads ( kernels  ) that will shed their seed when stepped on  - a pound of wheat seed may contain as much as 10.000 grains ( If not more  ! ).
So you the visiting public are unconsciously replanting this seed by forcing it into the soil with every footstep. So therefore this grain begins the germinating process once again !. Once the crop circle becomes uninteresting as its no longer the current one on crop circle connectors wall and footfall diminishes to a trickle then green shoots begin to appear within the flattened boundary of the crop circle design. ( This may happen before harvest or after harvest, all depends when the crop circle was made ). After harvest the young green shoots in effect have revitalised a harvested crop circle to appear once again and nice and green. This is not a miraculous conception as some would like to believe - this is just the grain going through its germinating and growing process which has been replanted by your foot !!!!
OK What Happens Next ?
The young shoots begin to draw ( suck up ) last of the nutrients from soil where harvested crop has already sucked up existing nutrients - thus making this region of poor soil quality.
So when farmers plough their fields they will either make a mental note or mark the area where a crop circle was made. This area will have to have a double dosage of fertilizer, manure and nutrients which has to ploughed back into the soil. Farmers who bother to treat this area ( at extra cost to them ) with a double dosage or more  are more likely to avoid a ghost circle appearing. Farmers who simply plough their fields and apply equal amount of nutrients throughout the entire field with no extra nutrient applied to where the crop circle was then they are more likely to have a ghost circle in new planted crop in the next season. If the area where a crop circle was made is not treated with double dosage then next seasons crop will have less nutrient for equal growth - so plants with the crop circle boundary will grow slower and not equally as other plants within the field - hence giving that ghost effect.
Snow Ghost Circles
Why does snow melt in the area where a crop circle was made but not outside its boundary ?
Anyone who has some farming knowledge will be putting their hands up with the answer - but of course the crop circle community will persist to inform you that a miracle has indeed happened.
Lets go back a step or two and look at the farmer who has bothered to revitalise his soil with that double nutrient dosage to the affected area but first consider the diagram and text below.

Factors affecting the composting process and acceptable ranges
Factor Acceptable Range Temperature 54 – 60 °C Carbon to Nitrogen ratio (C:N)25:1 – 30:1 Aeration, percent oxygen> 5% Moisture Content50 – 60% Porosity30 - 36 pH6.5 – 7.5
Temperature
Temperature is a very good indicator of the process occurring within the composting material. The temperature increases due to the microbial activity and is noticeable within a few hours of forming a pile as easily degradable compounds are consumed. The temperature usually increases rapidly to 50 - 60°C (122 - 140°F) where it is maintained for several weeks. This is called the active composting stage. Biochemical reaction rates approximately double with each 10°C (50°F) increase in temperature, yet higher temperatures will increase ammonia loss during the composting process. The temperature gradually drops to 40°C (104°F) as the active composting slows down and the curing stage begins. Eventually, the temperature will become that of the surrounding air.

The highest rates of decomposition occur when temperatures are in the range of 43 - 66°C (110 - 150°F). During the active composting stage, the temperature may start to fall because of a lack of oxygen. Turning the material introduces new oxygen and the active composting stage continues. The temperatures can exceed 70°C (158°F) but many microorganisms begin to die, which stops the active composting stage. Cooling the material by turning helps to keep the temperature from reaching these damaging levels. Heat loss occurs primarily because of water evaporation from the material. Heat loss can also occur if the pile is too small or is exposed to cold weather. If the moisture content falls too low it increases the chance of obtaining damaging high temperatures.

The temperature should be maintained at 55°C (131°F) or higher for a minimum of 14 days to destroy the viability of many pathogens and weed seeds. Remember, the edges of the windrow are cool, therefore they must be turned into the centre to kill the weed seeds.

Im sure most of you have seen a compost pile steaming on a cold winters day - so if you see snow melted in an old crop circle then be rest assured that this farmer has bothered to treat his soil with a extra helping of manure and soil nutrients. A higher concentration of manure will create a trickle of constant heat  !!!!!
It has NOTHING TO DO WITH ALIENS I PROMISE YOU !

' There was no muddy footprints in the crop circle but yet it poured down like cats and dogs last night '.
How many times have you heard someone say this ? - quite a few times I guess !.
Lets just place some things into perspective.  When I was a believer that crop circles were the creation by some paranormal entity, we never bothered to look at every tram line for muddy foot prints, with excitement and clouded minds we always looked ahead and raced towards the new circle rather than eyes down onto the ground we walked on - unless you are a serious researcher then you may bother to be more observant.
If you have all intention in looking for every detail then this is what you should do: -
First of all you must be the first person to discover a brand new crop circle formation,  ( so in your mind you may think that no man has as yet stepped in a freshly made circle, apart from you ). Then find the centre of the crop formation ( very likely it will be close to a tram line ) and then check this nearest tram line for footprints all the way to the beginning of the field. Its obviously no point in carrying out this exercise if there was no rain the night before or even over the past few days or even if the ground is rock hard due to lack of rain fall. If the previous night  was indeed damp and wet then there will be footprints ( I guarantee you - there will be footprints - you will find them if you bother or want to ! ). Basically the believer develops a blindness to such things and if they do find foot prints  then they will say that ' someone has beaten them in discovering a circle in question at the time '. I will leave this little dilemma for you to ponder on.
OK - lets assume that you walk into a freshly made crop circle and the night before was pouring with rain - you look at your foot wear and find it caked with mud but yet there is no mud on the crop circle itself. So you instantly make that assumption that the crop circle you have discovered must be a paranormal creation. !! Right ?
Well let me tell you how we overcame getting mud onto a freshly made circle.
We were invited to watch and participate in the making of a crop circle - at the time of planning conditions were dry but an hour or so before entering the field there was a short but sharp shower, this made the soil soft and muddy. Wearing only trainers we knew that we would get them covered with mud before we even started making the crop circle. However one of the team members was a bright spark and watched the weather forecast !, so he came prepared.
We stood there rather puzzled when he begun pulling out of his pockets Sainsburys and Tescos plastic carrier bags.
You should definitely never underestimate the ability and mind of a crop circle maker !. We all did look a bit silly wearing plastic shopping bags over our shoes but you had to admire this guy for the way his mind worked. ( Wearing plastic bags over the shoes kept your shoes mud FREE - not only this it also prevented a tread indention in the mud ! - simple but effective )
When we finally arrived at the chosen spot our plastic bag covered shoes were very muddy.
Two guys kept carrier bags on their shoes - they were  the construction line makers ( the outline of the intended crop circle design )
The rest of us had to take our carrier bags off  - we were the stomppers ! . With mud free shoes we begun flattening wheat as instructed. The clever part is - once you flattened the first initial row of wheat , the flattened wheat instantly acted as a carpet or a barrier between your foot and the damp soil. So in fact as we were walking on flattened wheat we did not get our shoes caked with mud, so therefore we did not cover the crop circle with mud !! as there was little or no contact with the wet soil.
The two guys who were still wearing their carrier bags on their shoes were in theory making a foot wide construction line muddy, but this didn't matter as us the stomppers were instructed to make sure that we did our best to cover the construction line while flattening mud free wheat - so any mud covered wheat stems were hidden beneath the top flattened wheat !.
Once the circle was complete we had to cover our shoes with plastic carrier bags once again, so when we were picked up by the pick up car at least the driver was happy that he wouldn't have to clean his car later that morning !.
Why not ask a researcher, a scientist and top crop circle photographers and see what they tell you..
Its not rocket science folks !

How many times have you heard the term ' Blown Nodes' and understood or have been told by so called scientists that its the work of a paranormal force ?. Well, I'm going to be rather blunt with anyone who has tricked you to believe such nonsense. The ones who have promoted and still continue to do so have not one ounce of knowledge about simple plant behaviour, anatomy and general botany.
Blown nodes occur in young wheat and barley plant stems and matured wheat  ( not so much in mature barley ).
Young and still growing stems intake water at high volume during rain ( OK nothing new and easy to understand). During a prolonged rain fall ( wet summers ) and damp conditions the young stem will be at 'high fluid level' ( if you break a stem you should see fluid ). Consider it as a plastic straw filled with water which is blocked at both ends. If you kink the straw, the fluid within be forced and will find a weakest point and burst open. The same effect happens with a fluid filled plant stem. So when stems are being flattened by a plank they are kinked. The flattening pressure forces fluid upwards and if there is no capacity within the stems to disperse the fluid through the stem then it will burst at the node to release pressure. I'm afraid its as simple as that !
Matured wheat - burst or blown nodes tend to happen more frequently in maturing wheat ( golden in colour ) and especially on hot sunny days and dry summers. How you ever been in a wheat field on a hot sunny day and heard popping sounds ?. The heat of the sun dries the internal stem flesh during maturity process  - the node of the stem becomes hard ( consider it as old dry skin ) and begins to shrivel. As the node is drying and shrinking it will occasionally crack open ( just like dry skin ). So if the node has been full and plump in its growth stage then its more likely to crack in maturing stages as the hardening and shrinking process may not be fully distributed throughout the entire node, so the weakest point release the pressure by simply popping open. 

Sometimes all it takes is doing actual research rather than creating assumptions to aide a belief.

The above image is very important  for anyone who may wish to research crop circles seriously. The crop circle (shown above) at Alton Barnes is man made but look at the image and you will see a bent stem ( such bends were regarded as the work of a paranormal force ) but here we are seeing a bent stem alongside a scraped one, which was found in a man made formation. This bent stem will resume growth and will develop a much stronger base as it attempts to restore its normal growth pattern. So here we have an answer to the many years of doubt and all those images, books and dvds showing the bent stem phenomenon. This is not paranormal science this is simple understanding of plant behaviour - known as BOTANY !. Look at nature around you, look at the house plant in your own home, look at your own plants in your gardens and see how plant stems will twist and turn to face towards the sun. Any plant that is flattened not just by planks but even through adverse weather conditions will activate its own healing process by trying to resume its normal growth pattern the best it can, it wants to rise again to reach the brightest light source - being the sun.  The node of a plant is like a knuckle in your finger, if you break it and don't have it treated through medical assistance then it will heal the best it can but in most cases it will never be straight or function fully again. The nodes in wheat and barley are the plants own self help system. If it wasn't for these nodes then the plant would not have the ability to rise again as the head of the plant would be to heavy for a weak and thin stem to lift and straighten fully again, so the result would be a very poor growth pattern. So the plant selects the nearest node to the head of the plant as this creates less energy and growth effort to lift up the head ( so rather than trying to lift the entire stem it will lift a part of it only ). While this process is in action the node will swell and stretch and create a tough knuckle so the plant can resume growth in a more stable manner.
Canola ( Rape Seed) does not have nodes as its a much tougher branch thickness plant so its defence mechanism is very different so the plant attempts to restore its original growth pattern at the very base closest to the root. So if it was not snapped in the process of flattening it will apply all energy to this point first ( it will attempt to raise the entire stem - hence the base of the plant becomes much tougher and creates the bend ). Young Canola has a very good recovery and will in most cases raise the entire stem by at least 3/4 of the way to being straight again. However in most cases this is the farthest it will reach and never be fully straight again. Canola which is more into a mature stage will also partly raise the head of the plant and if the bend at the base  is still in tact you will find in most cases that the mature Canola will have partly risen the entire body ( stem ) of the plant of the ground.( Thats of course if it hasn't been trampled  by many visitors to crop circles )
Its all a question of carrying out experiments and observations out in the fields rather than in some laboratory where plants have been dried and  can no longer provide a result where it matters the most. It has taken us some time, patience and study in discovering something very simple and it didn't cost $500.000 either. Sorry BLT.

The above image is a screen capture from crop circle connectors web site of a member of WCCSG  holding a bent stem while in the Hannington Crop Circle with a very poor attempt in explaining markings on stems.
When circle makers are flattening plants ( especially Canola ) in the process of creating their desired pattern they will raise the board to approximately quarter of the way up from the root base, hence the head ( flowers ) are generally not affected. As the boards used are generally 1 meter in length, the makers are likely to step on some of the flower heads especially in the walk path but not the entire 1 meter plank length.

Here once again a member of WCCSG is holding up yet another bent stem this time in the Yarnbury ( Keyhole ) crop circle formation in 2010. We have turned the image vertically so we can show you another interesting study in plant behaviour. Look at the root first of all and notice the way its pointing.If you rotate the image horizontally then it would show as if the root is growing sideways so that means the plant would also grow across the ground rather than straight up. So the real explanation to why there is a bend in this particular sample is very straight forward - again its down to understanding some simple botanical plant behaviour. In this instance two plants are planted to close together, so rather than fighting for growing space this plant stem ( as the plant cannot move its root ) at early stage in growth has recognised that that it will be fighting for growing space and light with its neighbour so it decides to grown at a slight angle at first before it resumes a straight growing pattern. Please also look at the bend of the base, you will notice that the plant has developed a hard type skin further up the stem than normal ( a callus ). As this plant recognised that it wasn't going to grow straight like its neighbours so it developed this hard skin as a protection from its soft tissue rubbing against the ground in windy conditions etc..

Here is what WCCSG had to say: Full article can be found by following this LINK
However when the WCCSG team visited it, there were some outstanding features of note, such as odd standing stems amongst flattened crop and swirled nests.
There were also some noted stems that had been clearly bent from the base with no damage to the rest of the plant.
Above text and left image (C) WCCSG 2010

Well what can one say ! ??

Gary King holding up yet another bent stem - this time in 2009.

Image above is from the commissioned crop circle by the BBC for Stephen Frys QI program ( Yatesbury 2010 ). This sample is even more interesting. The root is nice and straight so the growth pattern of this stem looked very normal. When it was snapped during the flattening process part of the plant tissue remained connected, this still allowed the plant to drawn moisture from the ground the best it could, hence the plant stem still attempted to resume a normal growth pattern and still tried to raise itself off the ground, hence the bend. The exposed flesh of the plant developed a hard dry skin so to prevent further moisture loss.

Blown Nodes - Its like trying to find a  NEEDLE IN A HAYSTACK !

If a paranormal force created created crop circles then surely there would be  hundreds of bent nodes rather than one which is hidden like a needle in a haystack. Wake up world !

Perhaps Pfizer should capture some of that crop circle energy and NHS could save a packet by sending their conception patients to stand in a crop circle. As explained below by Lucy Pringle

Lucy is absolutely serious !