What's the difference between arable and tillable?

Arable

Definition:

(a.) Fit for plowing or tillage; -- hence, often applied to land which has been plowed or tilled.
(n.) Arable land; plow land.

Example Sentences:

(1) Our job now is to get Westminster to understand our unique situation.” The issue for Wales is that only 5% of its agricultural land is arable.
(2) I still believe that the diversion of ever wider tracts of arable land from feeding people to feeding livestock is iniquitous and grotesque.
(3) People mainly depend on food that can be produced on arable land.
(4) In the agricultural sector of the region, the concentration of arable land into large holdings devoted to the production of export crops has resulted in the formation of a large migrant work force and greatly increased use of pesticides.
(5) The development of spraying of sludges and composts will increase the quantity and efficiency of chromium in vegetals, because of various factors: the wastes of many industries: chromium plating plants, tanneries, painting and dyeing industries throw out hexavalent chromium; if the sewage sludges are purified by an irradiation treatment, it will tend to oxidize the whole chromium in hexavalent forms; at last, the presence of sewage sludges in the arable soil favours the assimilation of chromium by inhibiting that of iron (Figure 1).
(6) The report notes that the economic gains from arable land are often overlooked in favour of foreign investment or land grabs.
(7) In The Economy of Cities (1969), Cities and the Wealth of Nations: Principles of Economic Life (1984), Systems of Survival: A Dialogue on the Moral Foundations of Commerce and Politics (1994) and The Nature of Economies (2000), Jacobs proposed that the natural habitat for inventive, ingenious humanity was a teeming city, arguing that livestock had been domesticated and arable farming devised in archaic trading and manufacturing cities.
(8) All of which suggests that the modern central banker has become somewhat analogous with Europe's arable farmers of the 1990s.
(9) • Africa has 60% of the world's total amount of uncultivated arable land.
(10) The plan will place greater priority on protecting arable land, food security, wildlife protection and the "ecological restoration" of areas damaged by construction of roads, rail and other infrastructure.
(11) At the best of times this vast landlocked country – whose estimated 14.7 million people mostly live along a narrow strip of arable land on its southern border – has trouble feeding itself.
(12) Britain's 'angina pectoris' probably arose following the enclosures which changed arable (strip) into animal farming in the middle ages but cases rose only slowly from Heberden's 100 in 1802 to McKenzie's 200 by 1923.
(13) This tendency was intensified by the modern developments of keeping animals in confinements, enlargement of livestock, new kinds of residues like slurry which demanded a change in the management of arable and forage land combined with an increase in the agricultural utilization of residues form the municipal area like sewage sludge and compost made from refuse.
(14) And there are the new agri-environment schemes that encourage landowners to put in new hedges and to leave unploughed "headlands" around the arable fields.
(15) High above rich arable land by the North Sea, three tall wind turbines, blades spinning wildly, have started generating electricity for the national grid with two social purposes: to sell energy and use the income to deliver hundreds of new homes in a scattered rural community while, at the same time, providing additional funds for similar schemes elsewhere in Scotland.
(16) He suggests the use of chemicals on arable fields has probably killed most of the insect prey - "the biomass has simply been removed" - and perhaps had a deleterious effect on the hedgehog's own metabolism.
(17) The population is booming, but every last hectare of prime arable land is already taken!"
(18) They also show the National Farmers Union opposed the change, with the farming body saying it believed solar panels could coexist with agricultural activity such as livestock grazing and even some arable crops.
(19) Arable and vegetable farmers have also made great use of GPS for mapping their crops, he added, and monitoring yield, weed incidence and other vital data, leading to "real rewards".
(20) It is perfectly possible to think, as far as the hedgehog is concerned, the more housing estates built on arable fields the better.