Modern Agricultural Tech and the Green Revolution

The Green Revolution was the spread of high-yielding crop varieties, synthetic fertilizers, pesticides, irrigation and mechanization from the 1960s, which greatly increased cereal production in Asia and Latin America, and modern agricultural technology now adds tools such as GPS, drones, sensors, genetic engineering and vertical farming. In brief: new short-stemmed wheat and rice varieties developed by scientists such as Norman Borlaug and at the International Rice Research Institute produced much more grain per hectare when given water and fertilizer. The benefits were large increases in food supply, but the costs included pollution, heavy water use, loss of biodiversity and unequal gains between farmers.

These technologies helped world food production to keep pace with a rapidly growing population, yet they raise questions about sustainability and fairness. This guide explains the Green Revolution and its effects, describes the main modern technologies, compares benefits and costs in a table, works through yield and cost calculations, outlines the history and corrects common mistakes.

What was the Green Revolution?

In the 1940s and 1950s, the American agronomist Norman Borlaug bred wheat varieties in Mexico that were short and stiff, so they did not fall over when loaded with grain, and that responded strongly to fertilizer. Similar work on rice led to the IR8 variety, released by the International Rice Research Institute in the Philippines in 1966. The package that spread to countries such as India, Pakistan, Mexico and the Philippines combined:

• High-yielding varieties (HYVs) of wheat, rice and maize.
• Chemical fertilizers to feed the plants.
• Pesticides and herbicides to control pests and weeds.
• Irrigation, including canals and tube wells, because HYVs need reliable water.
• Mechanization such as tractors and threshers.
• Credit and government support, including guaranteed prices and extension services.

Cereal yields in Asia rose sharply. India, which had faced the risk of famine in the 1960s, became largely self-sufficient in grain by the 1970s, and Borlaug received the Nobel Peace Prize in 1970.

What were its benefits and costs?

Benefits: higher yields per hectare, larger harvests, lower food prices, less need to clear new land and more income for many farmers. It is often credited with helping to feed a rapidly growing population in the second half of the 20th century.

Costs: farmers needed money for seed, fertilizer and irrigation, so wealthier farmers gained more, and some poorer farmers fell into debt or lost land. Heavy use of fertilizer and pesticides polluted soil and water, causing eutrophication and harm to wildlife and health. Irrigation lowered water tables and caused salinization in places such as the Punjab. Planting a few high-yielding varieties reduced crop diversity and increased the risk of disease. Emissions from fertilizer and machinery contribute to greenhouse gases. Many farmers in Sub-Saharan Africa gained less, partly because of different crops, poor infrastructure and limited irrigation.

What modern technologies are used in farming?

• Precision agriculture: GPS-guided tractors, sensors and satellite or drone images measure the needs of each part of a field, so seed, water and fertilizer are applied only where required, which saves money and reduces pollution.
• Genetic engineering (GM crops): crops that carry genes for insect resistance (Bt cotton, Bt maize), herbicide tolerance or enhanced nutrition (such as Golden Rice with beta-carotene). They are widely grown in countries such as the United States, Brazil and India, but are controversial and restricted in parts of Europe.
• Improved breeding: marker-assisted selection and gene editing (such as CRISPR) to develop drought-tolerant, disease-resistant or higher-yielding varieties.
• Controlled-environment farming: greenhouses, hydroponics (growing plants in nutrient solution) and vertical farms in cities, which use little land and water but a lot of energy.
• Efficient irrigation: drip and sprinkler irrigation, which uses less water than flooding.
• Automation and data: robots, automatic milking machines, weather forecasts, mobile phone apps and farm management software.

Benefits and costs compared

Worked example: yield, fertilizer and savings

The figures are hypothetical and illustrate the calculations.

1. Yield increase: traditional wheat yields 1.2 tonnes per hectare, and a HYV with fertilizer yields 3.6 tonnes. The increase is 3.6 − 1.2 = 2.4 tonnes, or 2.4 ÷ 1.2 = 200%, so the yield is three times as high.
2. Output of a region: on 500,000 hectares, the output rises from 500,000 × 1.2 = 600,000 tonnes to 500,000 × 3.6 = 1,800,000 tonnes.
3. Land saved: to produce 1,800,000 tonnes with the old yield would take 1,800,000 ÷ 1.2 = 1,500,000 hectares, so the new varieties spare 1,500,000 − 500,000 = 1,000,000 hectares.
4. Profit of a farmer: with the HYV, the farmer harvests 3.6 tonnes per hectare at 250 per tonne = 900 per hectare. Extra costs for seed, fertilizer and water are 400 per hectare, so the net gain over the traditional 1.2 × 250 = 300 is 900 − 400 − 300 = 200 per hectare. A farmer with 2 hectares gains 400.
5. Precision farming: if sensors allow fertilizer to be cut from 150 kg to 120 kg per hectare, the saving is 30 kg per hectare, or 20%. On 300 hectares, that is 9,000 kg of fertilizer, which at 0.60 per kg is 5,400.
6. Drip irrigation: if flood irrigation needs 1,200 mm and drip irrigation needs 700 mm, drip saves 500 mm, which is 500 ÷ 1,200 = 42% of the water.

What is the history of agricultural technology?

The agricultural revolution in 18th-century Britain introduced seed drills, crop rotation and selective breeding. In the 19th century, steam power and the reaper changed grain harvesting. In 1909, the Haber-Bosch process made it possible to produce ammonia from atmospheric nitrogen on a large scale, which is the basis of modern nitrogen fertilizer. The Green Revolution built on these advances from the 1940s to the 1970s, and the first commercial GM crops appeared in the mid-1990s. Since the 2000s, GPS and digital technologies have made precision agriculture practical, and interest is now growing in approaches that increase yields while reducing environmental impact, sometimes called sustainable intensification.

Which mistakes are common?

Mistake 1: Thinking that the Green Revolution was only about new seeds

The new varieties worked only with fertilizer, irrigation, pesticides and support, so it was a package of inputs and policies.

Mistake 2: Believing that it benefited everyone equally

Farmers with more land and capital gained more. Poorer farmers and regions with little irrigation often benefited less.

Mistake 3: Considering GM crops the same as the Green Revolution

The Green Revolution used conventional breeding. GM crops use genetic engineering and appeared later.

Mistake 4: Assuming that new technology removes environmental limits

Technology can raise yields but brings problems of pollution, water use and dependence on energy that have to be managed.