The first thing to understand is where does all these subsidies go, whether its direct payments to farmers or in manipulating global food prices. The net effect of these subsidies is that they are capitalised into higher agricultural land prices and higher rents.
"In many ways, nature conservation has become just another method of rent extraction by landowners who are trying to hide the fact that modern farmers’ fields are essentially deserts, devoid of wildlife, and the taxpayer must pay ‘rent’ if we want wild animals to occupy ‘their land’." Peter Smith
Rent & high land values are unique in that it stifles our farming efficiency and robs the productive capacity of our farming industry, so for every pound in subsidy nearly all of it does not produce efficient farmers but gets siphoned of in higher rents for tenants and higher land values, virtually non of that helps farming.
This is easily demonstrated when looking to rent land. Agricultural land is offered for rent at two prices. One price where the subsidy is claimed by the landowner and another collected by the tenant. The difference is exactly what that subsidy is minus a tiny amount to cover the hassle of doing the paperwork etc. and some smoothing issues.
“Agricultural subsidies tend to be capitalised into the purchase and the rental price of agricultural land. Because of higher incomes farmers are prepared to bid more to rent in or purchase extra land. But given that the overall supply of land is fixed, farmers will bid against each other up to the point where the entire increase in profitability is dissipated by the higher cost of land. Thus, it is landowners who are the main beneficiaries of farm support policies."
Alan Matthews, CapReform.EU, More on who benefits from farm subsidies, October 14 2007: http://capreform.eu/more-on-who-benefits-from-farm-subsidies/
So overall subsidies does not help real farming - just landowning and those involved in lending money to purchase land (banking).
So what does subsidy do to our land? Subsidies lower the margin at which it is profitable to farm land, therefore more poor quality land is now in agriculture, that means a lot less wildlife, and economically the land now farmed does not produce that much food. An example of this is our bête noire the humble sheep, these woolly maggots that strip our land bare causing global warming, floods to towns and catastrophic loss of wildlife are actually destroying more land than all our arable land put together, yet they only make up one half of one percent of all farming revenue.
"Landlords grow rich in their sleep without working, risking or economizing. The increase in the value of land, arising as it does from the efforts of an entire community, should belong to the community and not to the individual who might hold title."
John Stuart Mill
"The widow is gathering nettles for her children's dinner;'a perfumed Seigneur, delicately lounging in the Oeil de Boeuf hath an alchemy whereby he will extract from her every third nettle—and call it rent. "
"Now what had the landowner done for the community; what enterprise had he shown; what service had he rendered; what capital had he risked in order that he should gain this enormous multiplication of the value of his property! I will tell you in one word what he had done. Can you guess it! Nothing."
This inflation rate would shame any banana republic, but it is a direct result of the hard work of charities, generosity of donors and government grants yet it is utterly wasted by rewarding landowners for doing nothing but own land.
"A Rewilded Britain is a lost dream, just as an affordable home is a lost dream for so many young couples today." Peter Smith