II.

Modern Agriculture

Modern agriculture is characterized by relatively high levels of inputs, often produced off-farm, and high levels of outputs. Standard farm management practice is to divide these inputs into those that vary directly with output (variable inputs) and those that do not (fixed inputs). Fixed inputs include agricultural machinery, and modern agriculture is dependent on the manufacture of machinery for cultivations, harvesting, and other farm operations. Machinery is also needed for draining soils (see Drainage) and, in drier climates, irrigating crops (see Irrigation).

Mechanization has been one of the main characteristics of 20th-century agriculture, easing much of the back-breaking toil of the farmer. Developments in machinery, along with advances in plant breeding and animal breeding, have helped to increase agricultural productivity: it is now possible to produce more output per unit of inputs, fixed and variable. In Western countries, there has also been a trend towards larger, more powerful machinery at the expense of full-time labour. For this type of machinery to be economic, large fields and farms are needed and the substitution of machinery for labour is one reason why farm size has increased in Western countries. The high ratio of machinery to labour inputs in modern agriculture has two further consequences. First, it is intensive in its requirements for energy, and is therefore reliant on stable supplies of fuel; second, it is relatively capital intensive; thus a properly functioning financial system is also a requirement for the success of modern agriculture.

The variable inputs include seeds, fertilizers, and crop protection products (herbicides, pesticides, and fungicides), and feed and veterinary treatments for livestock production. Advances in crop and animal science have led to a much better match between crop and animal needs for variable inputs, resulting in less waste. For example, the timing and level of nitrogen fertilizer applied to crops can be closely matched to the crop’s needs; this means that the farmer can apply less fertilizer, cut his costs of production, and reduce losses of nitrogen to the environment.

Plant breeding and, more recently, genetic modification of crops such as soya and cotton, contribute substantially to farm productivity. Improved understanding of genetics has also placed livestock breeding on a more scientific basis. Despite these improvements, yields for winter wheat, one of the world’s major food crops, have increased by less than in previous decades. Over the period 1984-2004, for example, yields increased from 7.7 to 7.8 tonnes per hectare (19 to 19.3 tonnes per acre) in the United Kingdom and from 2.6 to 2.9 tonnes per hectare (6.4 to 7.2 tonnes per acre) in the United States. In Asia, yield increases have been more pronounced: wheat yields in India have caught up with the United States, increasing from 1.8 to 2.7 tonnes per hectare (4.5 to 6.7 tonnes per acre) over the same period.

Modern agriculture is usually linked to an advanced food processing and marketing sector, although the two can be quite distinct, with most of the activities that transform agricultural products into what people want to eat—the value added—taking place beyond the farm gate. Methods of processing, freezing, chilling, and preserving have changed the nature of the foods that people eat, allowing produce to be stored for long periods of time. Food processing, in developed countries, is now a large-scale industry.

Organic farming methods are becoming more widely practised in developing countries as a reaction to recent food scares generated by bovine spongiform encephalopathy (BSE) and concerns over pesticide residues and the intensive nature of modern farming. In Austria, for example, some 13 per cent of farmland is organic; in the United Kingdom, it is nearer 4 per cent.