the same soil for crops year after year When crops grow they pull nutrients especially nitrogen from the soil If humans harvest the crops the nutrients are not returned to the soil for the next crop to use Also some methods of agriculture can cause soil to wash away which makes it increasingly difficult to grow crops One solution to these problems is crop rotation With crop rotation the kind of crop grown in a field is changed each year In some years the field may be left fallow meaning no crops are grown Crop rotation works best when one of the crops is a legume such as beans or clover for animal feed Unlike other crops legumes cooperate with bacteria to capture nitrogen from the air and add it to the soil This nitrogen stays in the soil and feeds the next crops planted in the field Over time people found other ways of enriching the soil including adding nutrients back in the form of a fertilizer such as animal manure Finally farmers learned how to collect and direct water in climates where rainfall was scarce The Agricultural Revolution In the late 1700s and the 1800s in the United Kingdom food production by agriculture greatly increased thanks to a new crop rotation method The method rotated crops in four different fields each year The crops were rye grass barley or oats and turnips a new crop that could be fed to livestock Unlike in previous methods fields were never left fallow so production increased without using up soil nutrients Meanwhile better breeding improved crops and livestock New types of plows made plowing faster and easier And new types of fertilizers added nutrients to the soil The increase in food allowed for a large population increase in the 8
Leaving a field fallow allows nutrients to return to the soil making it better for production the next season United Kingdom These changes in farming were copied across the British Empire and Europe Historians think the agricultural revolution allowed workers to participate in and fuel the Industrial Revolution During the Industrial Revolution which took place from the late 1700s to the early 1800s manufacturing evolved and societies across Europe and the United States became more urban and industrialized Into the 1900s farm production continued to improve More trade and shipping of food increased agricultural profits New machines replaced human workers In 1909 Fritz Haber a German chemist invented a method 9
Case In Point Founders of Organic Agriculture Agriculturist Lord Northbourne 1896 1982 used biodynamic agriculture which focuses on treating soil plants and livestock as one entity with spiritual ethical and ecological approaches This organic farming method was developed in Germany Lord Northbourne was responsible for first using the term organic farming by which he meant that the farm itself was like a living organism English botanist Sir Albert Howard studied farming in India from 1905 to 1931 He is one of the important founders of organic and sustainable farming He learned and improved methods of farming used by small farmers in India Howard also wrote several popular books explaining organic farming methods He wrote about creating healthy soil using compost which uses bacteria and fungi to break down unused plant parts and animal manure into a natural fertilizer Howard’s books influenced another English citizen Lady Eve Balfour She started the Haughley experiment in Suffolk England The experiment compared organic and nonorganic farming methods Balfour believed farmers had become too reliant on artificial fertilizers Her book The Living Soil was published in 1943 and she founded the Soil Association in 1946 The Soil Association still exists and promotes organic farming methods in the United Kingdom and around the world to pull nitrogen from the atmosphere and make artificial fertilizer This method requires large amounts of energy which the manufacturers got from coal and oil 10
The Green Revolution During the twentieth century human populations grew rapidly Some countries around the world were not able to grow enough food and their people faced famine News of these deadly shortfalls spread quickly There were concerns that the human population could grow larger than the planet’s ability to feed us A visit to Mexico in 1940 led US Vice President Elect Henry Wallace to start a research program there to improve agricultural productivity Wallace observed that in Mexico farmers were very poor soil was damaged and crop yields were small compared to those in the United States His research program brought together Mexican and international scientists to create a new corn variety that had greater yields Yield is the amount of a crop that can be harvested from an area of land Higher yields mean more food and more profit The researchers then developed and bred wheat varieties that had far greater yields but only when fields were irrigated and treated with artificial fertilizer This research started what has come to be known as the Green Revolution The Green Revolution 1940s 1970s produced a huge increase in crop yield and production in countries that previously had trouble growing enough food It accomplished this increase with four main changes the creation of new breeds of corn wheat and rice the use of artificial fertilizers the use of pesticides and the combination of the new breeds with both fertilizers and pesticides The Green Revolution has been celebrated as a success because it appeared to prevent widespread famine despite the rapid increase in 11
