<P> Irrigation, crop rotation, and fertilizers were introduced soon after the Neolithic Revolution and developed much further in the past 200 years, starting with the British Agricultural Revolution . </P> <P> Since 1900, agriculture in the developed nations, and to a lesser extent in the developing world, has seen large rises in productivity as human labour has been replaced by mechanization, and assisted by synthetic fertilizers, pesticides, and selective breeding . The Haber - Bosch process allowed the synthesis of ammonium nitrate fertilizer on an industrial scale, greatly increasing crop yields . Modern agriculture has raised social, political, and environmental issues including water pollution, biofuels, genetically modified organisms, tariffs and farm subsidies . In response, organic farming developed in the twentieth century as an alternative to the use of synthetic pesticides . </P> <P> Scholars have developed a number of hypotheses to explain the historical origins of agriculture . Studies of the transition from hunter - gatherer to agricultural societies indicate an antecedent period of intensification and increasing sedentism; examples are the Natufian culture in southwest Asia, and the Early Chinese Neolithic in China . Current models indicate that wild stands that had been harvested previously started to be planted, but were not immediately domesticated . </P> <P> Localised climate change is the favoured explanation for the origins of agriculture in the Levant . When major climate change took place after the last ice age (c. 11,000 BC), much of the earth became subject to long dry seasons . These conditions favoured annual plants which die off in the long dry season, leaving a dormant seed or tuber . An abundance of readily storable wild grains and pulses enabled hunter - gatherers in some areas to form the first settled villages at this time . </P>

Where do scholars agree agriculture most likely emerged in asia