Many field landings are made by people who set out on local soaring flights but find themselves needing the services of a generous landowner.
I use the term generous advisedly: when we land in someone's field, not only do we enter uninvited his workplace, but also his home. (How would you feel to find a stranger wandering around in your back garden?) So when the inevitable happens and you arrive in a farmer's field, try to regard it as an opportunity to meet someone new and, maybe, pass on some of your enthusiasm for flying. Above all, leave the landowner knowing in your own mind that, if you needed to, you could land there again next week.
With this in mind, I am strongly of the opinion that ALL glider pilots must make every effort to contact the landowner or his agent BEFORE removing the aircraft and definitely should not take vehicles into the field without agreeing routes with the person responsible for the land. If he is not available then I am sorry but it is a ‘carry out’ and not the variety with a lot of turmeric and pilau rice.
Even if you cannot find or speak to the landowner before removing the glider then the onus is still on you to contact him as soon as possible and be prepared for him to have already heard of your visit and not be best pleased (the jungle telegraph works just as well in the farming community as it does in the gliding world). Remember that analogy of having intruders in your home and react as you would like that person to, in other words to apologize for the intrusion. And make it plain that we do not set out with the intention of deliberately ending up in a field. Explain that we normally try to land at airfields when possible to avoid risk of damage to his crops and our gliders but in this case the need was by way of flight safety.
I cannot give hard and fast rules for dealing with landowners who feel that a landing fee should be paid but I suggest that diplomacy and negotiation should be the order of the day. Obviously you are responsible for any damage done and should settle this as appropriate (a small donation towards a meal out for the landowner and their partner may be much appreciated and possibly avoid the need to involve insurance companies as this always increases costs and hassle to all concerned).

So what, in the UK, should you be choosing to land on? I shall pick out those features of interest to us in selecting good, not so good or bad surfaces for landing on (or, if we get it wrong, crashing into).

Cereals By far and away the majority of cereal crops south of the Scottish borders are winter wheat and winter barley. The crop is sown before the winter sets in, to make a good start growing when spring arrives. A smaller area is sown as the land dries out in February and March.  All of these crops are sown for harvest in July/August and will look from the air as initially brown fields that gradually turn an even green colour with ‘tramlines’ (tractor tracks) visible within the crop at regular intervals across the field. These are useful for two reasons: the spacing between the tramlines – almost universally either 12m or 24m – can help you judge field size. They can also give an indication of the height of the crop; if you can see soil colour in the tramline then it is almost certainly short enough to avoid damaging your glider even with low tailplane types. (Ensure, however, that the wings are kept level with the surface on landing – not necessarily horizontal – as the crop may well be taller than your well-cut grass airfield.) You are also unlikely to do permanent damage to the crop at this stage. If the tramlines appear dark a shadow is being cast across them by the tall crop so it is best avoided if possible both for the sake of your pride and joy and the crop.
At the risk of being wrong almost everywhere I would say that winter crops become unlandable from mid April in the Midlands (earlier by  seven days on the South Coast and later by up to 14 days in the North of England/South of Scotland). Spring sown crops may remain usable for another 4-5 weeks (that is, the end of May in the Midlands).

Oilseed rape is grown in much the same way as a cereal crop but with a number of differences of growth habit, the most marked being the amazing rapidity of growth in the spring from small cabbage  type of size at the beginning of March  to 2m tall within 10 weeks. It can grow at up to 8-10cm/day at its peak rate. Fortunately this crop is equipped with an unmistakable deterrent for glider drivers: in mid-April it turns brilliant yellow and, allegedly, gives everyone hay fever so they do not want to fly anyway. It does however have a dirty trick up its sleeve. After the flowers have fallen off it returns to a green colour, which could catch the unwary glider (literally). The subtle giveaway is that the crop becomes very tangled and mottled in appearance but usually with tramlines still visible – and there are almost always some yellow flowers remaining on immature plants in field margins and gateways.
Oilseed rape is harvested at a very low moisture content of 9 per cent and to facilitate its passage through the combine it is cut and left out to die (we call it swathed) for about 10 days before harvest. This happens usually around early- mid July in the Midlands. This causes confusion every year amongst even the most experienced glider pilots who may mistake swathed Rape for straw rows after harvested barley. The former is a glider eater; the latter is usually OK. Again there is an easy way to tell whether a crop is swathed pre harvest or actually harvested. If you look closely at the row widths swathed crop rows will occupy about two-thirds unit width (i.e. two-thirds crop, one-third space between the row) whereas harvested crop straw rows will typically be the reverse (i.e. one-third straw row, two-thirds gap between the rows).

Peas and beans are grown on reasonably large areas in the UK but to all intents and purposes can be treated as cereal crops for their suitability or otherwise for landing on.

Set Aside is the one where, according to the popular press, I get paid for doing nothing. I wish! Very strict rules are applied to set aside ground and the net result is that some set aside is good for landing and some is most definitely NOT. Land left after late-harvested root crop must be undisturbed until July the following year. It will be like a bomb site until then. Land left set aside after a cereal crop will also be left alone and will most likely be smooth enough for landing, but beware tall weed growth from early summer until it is killed off in early July by cultivation or weed-killer.
 
 

Grass ranges from rough pasture used for grazing to multi-cropped silage fields where up to four harvests are taken per season. Grazed land is fraught with danger for gliders with possible obstructions such as fences (electric being the least visible), water troughs and, last but by no means least, large, mobile, four-legged ones. If by chance you find that some young excitable cattle have beamed into your field between your selecting a stock-free site and climbing out of the glider after landing, stay with the aircraft. Do NOT chase the animals as they then will think this is to be a game of ‘run around the glider and jump on it’. A calm, quiet approach towards the group is far more likely to succeed in persuading them to leave the area and resume grazing quietly. Then use your phone, if you have one, to summon assistance whilst keeping the glider in view in case the animals return to check out the suitability of your total energy probe as a back-scratcher or your shiny paint finish for interesting flavours.
Intensively farmed grassland will follow a reasonably rapid cycle of growth to around 50cm by around the beginning of May and will then be cut and carted away leaving a characteristic yellow/green colour for a short while until new grass growth masks this and the cycle repeats itself. These fields are usually fairly smooth. However, in wet seasons wheelmarks will be left by tractors and these should be avoided like the plague when landing. They will be worst near the entry/exit point in the field so always try to land so as not to run over any unusual marks. Always avoid having a wing hanging over any change in colour/texture as occasionally a part of the field may have not been cut and still have long crop on it.

Maize This crop is grown for harvest in November for animal feed. It is sown in May and the field will be brown until pale green plants emerge in June and grow steadily until September when the crop will be 2m tall.

Root crops are without exception planted in the spring into finely prepared seedbeds to suit the crop type. Potatoes, for example, go into ridges 30cm high and one metre apart. This does tend to shake out the fillings on the ground roll and so is best avoided.
Sugar beet, by contrast, will be sown into a smooth level surface in April with virtually no visible marks until mid-May when pale thin crop rows 50cm apart will be seen. Sugar beet fields are actually quite good from the point of view of landing in, but be aware that the crop is of a high value and you WILL be asked to pay for the damage.
Other root crops widely grown in some parts of the country include carrots and onions. These are grown on raised flat-topped ridges around 30cm high and with wheelways every 2m. Do not land here as you will break your glider and your wallet.

Ploughed fields
Most people know that farming is going through a bit of a tough time at present and a direct result of this is to change the system of preparing land for the next crop after harvest to reduce costs and labour. The modern approach to this is, as soon as possible after the combine has left, to rip up the stubble and leave it to allow weed seeds to germinate and then to follow this up immediately prior to the next crop with a final cultivation to level and then seed the field. This operation will leave the field potentially very rough with clods of soil up to 30cm diameter. So treat all brown fields at harvest time as suspect, a better option is a good stubble field.

Many vehicles are fitted with catalytic converters which when parked heat up sufficiently to ignite stubble/straw or even dry grass so please take care when entering a field for a retrieve. I believe a couple of glider pilots have already found this one out to their cost. (Perhaps that is why most farmers drive around in oil burners).

The ONLY way to be sure about your skill re field selection is as in any flying discipline to remain current so get out to your club and grab an instructor and go look at some fields in the motor glider. I suggest that this should be at least an annual event and more often if you are unsure of your ability to recognize the changes during the season.
 

Adrian Hatton