Agriculture

( Article Type: Explanation )

Agriculture is the formalised and structured means by which humankind grows food to feed the growing population. As more people move from rural areas to cities, it has become more necessary to use intensive farming methods to increase crop yields. Early agricultural systems (agro ecosystems) only needed to provide sufficient food to feed the farmer and his or her family. Historical ‘slash-and-burn’ programmes would clear land, grow crops and as soon as yields dropped, the farmer would move on to another area. The farmer would return to the original plot but only after a number of decades, which allowed the fallow land to recover. Increasing populations of people and their animals caused more intensive land use. The fallow periods become shorter and so the need to develop more sophisticated systems arose. These included irrigation, fertilisers, pesticides and herbicides, and, more recently, genetically manipulated crops.

Agriculture modifies the environment and needs to be undertaken with proper consideration for the ecosystem carrying capacity and wider environmental impacts. Agro ecosystems cover more than 25% of global land area but almost 75% of that area has poor soil fertility and approximately 50% has steep slopes, which limit production capacity. About 66% of agricultural land has been degraded in the past 50 years by erosion, salinisation (accumulation of salts in soil which limit plant growth), compaction, nutrient depletion, biological degradation or pollution. About 40% of land has been strongly or very strongly degraded.

With this decline in availability and effectiveness of land to grow food, agro ecosystems will face the challenge over the next 20 years of having to feed an additional 1.7 billion people.