Agriculture increasingly takes the form of agribusiness which tends, through tax credits for depreciation of buildings and equipment and other forms of tax shelter, to favour the development of large farms and monopolistic control of agriculture by non-farming investors acting on purely financial criteria. The resulting exploitative short-term policies of agribusiness push crop lands to the limits of their yield, with monoculture being a common practice. The most tillable lands are planted season after season with a single crop. The soil is mined of nutrients. Heavy use is made of synthetic petro-based fertilizers in the hope of replenishing the nutrients traditionally sustained by the application of manure, the rotation of crops, and allowing land to lie fallow on occasion. The demand for high yields taxes not only the best lands, but also the marginal lands for which economic justification must be found. This approach increases soil erosion and top soil loss and results in siltation of rivers and estuaries, and lowering of deep-water aquifers due to extensive irrigation. The land gradually becomes sick and sterile through chemical applications and loss of soil structure and soil microflora.
A 1993 report, noting the deterioration of working conditions for Central American plantation labourers, found the average working day consisted of 12-14 hours of labour, with only 20% of the workers being able to rely on steady employment. One multinational plantation employer reported a daily turnover of $7,56 million, whereas it paid its 43,000 workers between $5-$6 per day. Consequently, only 0.57% of the employer's turnover was allocated to the labourers.
Agricultural protectionism in Europe, the United States, and Japan has led to more intensive farming in these regions than is environmentally or economically justified. By inflating prices and per acre revenues, while (in some cases) limiting the acreage that can be planted, agricultural policies induce farmers to use more inputs on each acre planted than they otherwise would. Driven by these incentives, farmers adopt chemical-intensive monocultures that lead to more soil erosion, chemical runoff, loss of biological diversity, and conversion of once-natural ecosystems to cropland than would otherwise take place.