Under the 1923 Act, busier farmers had to rent extra land under an 11-month or seasonal conacre system, as longer arrangements could cause an owner to lose his farm by compulsory purchase by the Land Commission. While there were now some 300,000 Irish landowners compared to several thousand in the late nineteenth-century, the basic term for the use of land had reverted to the norm of the 1860s, with no rights to renew a lease and no incentive to improve rented land. By 1980, some in the state were rented annually under conacre, suggesting a new imbalance between mere ownership and the more active farmers. The cost of agricultural machinery requires larger farm sizes to generate economies of scale.