The Significance of Fertilizer

Population and Food Demand

Since the dawn of the industrial revolution in the 19th century, both food production and the world’s population have experienced dramatic increases. The last five years have seen particularly significant benchmarks, with Africa reaching 1 billion people in 2009 and the world population reaching 7 billion in 2011. Looking to the future, FAO (High Level Expert Forum, 2009) and other experts have estimated that the population is likely to surpass 9 billion by 2050, with the majority of the population living in cities.

The question then is whether food production can keep pace with population growth to provide food security for these masses. More effective use of agricultural inputs – improved seeds, crop protection products and chemical and organic fertilizers – can tip the scales in that production goal (Mueller et al, 2012).

Fertilizers Have Fueled Food Production Increase

Mineral fertilizers have irrefutably contributed dramatically to increased cereal production over the last 50 years. These fertilizers have helped save the lives of over 2.4 billion people who otherwise would starve (Wolfe, 2001; Hager, 2008). In 1961 – effectively the dawn of modern fertilizer use – global cereal production stood at 877 megatons (Mt). By 2010, annual cereal production had increased to 2,400 Mt (FAO/IFDC data, 2012).

But this tripling over the past half century was clearly not serendipitous. From 1970 through 2011, global nitrogen, phosphate and potassium (NPK) consumption increased almost proportionally, from 69 Mt to 175 Mt – a strikingly clear correlation between increased production and broader use of NPK fertilizers (FAO/IFDC data, 2012). The greatest evidence for the effectiveness of fertilizer in intensifying food production can be found in South Asia, where fertilizer use on roughly the same area of land over the past 50 years has produced a 165 percent increase in output (FAO/IFDC data, 2012). Examples of excessive fertilizer use in South Asia, however, have resulted in negative environmental impacts. Over the same period, Africa, which is plagued by nutrient-deficient soils and the lack of fertilizer use (averaging only 8 kg per hectare [Abuja Declaration, 2006]), experienced production increases of only 60 percent – and not through crop intensification utilizing modern agro-inputs, but by extending the area of land cultivated while almost irreparably mining the soils of their remaining nutrients (FAO/IFDC data, 2012).

Yet fertilizers alone will not solve the 2050 dilemma. Integrated soil fertility management (ISFM), which combines the use of organic and inorganic soil amendments and resource conservation, must become the production norm in order to conserve our soil and water resources, build soil fertility and improve water quality.

 

Phosphorus

Among the primary nutrients, phosphorus deficiency in the world’s soils stands out as a major constraint to food crop production in low-input systems such as those in the sub-humid and semi-arid regions of sub-Saharan Africa (Lott et al., 2009). Legumes, a key to low-input agriculture because of their capability to produce available nitrogen through biological nitrogen fixation (BFN), are particularly sensitive to phosphorus deficiency (Parish, 1993, IFDC Brief 7, P. 13). Unless phosphorus-based fertilizers are used in these areas, recycling systems will not achieve the minimum soil phosphorus levels required for good yields.

Even with widespread adoption of production techniques such as ISFM, demand for fertilizers will remain high in the coming years, but could also remain out of reach for many. In 2010, according to FAO (FAOSTAT, 2012), global consumption of the primary phosphate fertilizer was 20.0 Mt on a mineral P fertilizer basis. Sattari et al. (2012) estimated mineral P demand by 2050 to range from 14.6 Mt to 28 Mt annually – a range derived based on the anticipated combination of residual soil P, the supplementary use of manure and P recycling efforts. The anticipated global consumption of mineral P fertilizers in 2050 is projected to be 20.8 Mt, almost equal to current consumption rates.

However, the least developed countries, as a group, consume only 1.5 percent of that annual total. This implies a dire need to refocus the use of P by reducing surplus use in some regions, while increasing the production, availability and responsible use of phosphorus to advance global food security in the developing world. 

In the same run-up to 2050, global NPK demand is estimated to be 223.1 Mt in 2030 and 324 Mt in 2050 (Drescher et al., 2011), based on current agricultural practices, in order to meet the massive food production requirements at mid-century. However, that projected fertilizer requirement is likely to continue to be revised downward with the advent of more efficient fertilizer technologies and the widespread adoption of resource-conserving approaches such as ISFM.

(source: IFDC)
 

CITATIONS:

RS1: Population – 9 billion
FAO. (2009).  High Level Expert Forum, “How to Feed the World 2050;" from http://www.fao.org/wsfs/forum2050/wsfs-forum/en/.
RS2: Inputs tip the scale in that production goal.
Mueller, Nathaniel D., Gerber, James S., Johnston, M., Ray, Deepak K., Ramankutty, N., Foley, Jonathan A. (2012). Closing yield gaps through nutrient and water management. Nature, 490, 254–257.
RS3: Alive because of fertilizer – 1/3rd of world population (2.3 billion)
Wolfe, David W. (2001). Tales from the underground: a natural history of subterranean life. Cambridge, Mass: Perseus Pub.
Hager, Thomas (2008). The alchemy of air. New York, NY. Harmony Books.
RS4: World cereal production 1961-2010
FAO data republished as IFDC compilation in Kent and Riegel's Handbook of Industrial Chemistry and Biotechnology, Chapter 24: “Fertilizers and Food Production,” 2012/13.
RS5: World nitrogen, phosphate and potash, and total NPK consumption 1970-2011
FAO data republished as IFDC compilation in Kent and Riegel's Handbook of Industrial Chemistry and Biotechnology Chapter 24: “Fertilizers and Food Production;” 2012/13.
RS6: South Asia cereal production intensification, 1961-2010
FAO data republished as IFDC compilation in Kent and Riegel's Handbook of Industrial Chemistry and Biotechnology, Chapter 24: “Fertilizers and Food Production;” 2012/13.
RS7: Africa averaging only 8 kilograms of fertilizer per hectare
Abuja Declaration; Africa Fertilizer Summit of the African Union Ministers of Agriculture, 2006.
RS8: Sub-Saharan cereal production extensification, 1961-2010
FAO data republished as IFDC compilation in Kent and Riegel's Handbook of Industrial Chemistry and Biotechnology, Chapter 24: “Fertilizers and Food Production;” 2012/13.
RS9: African phosphorus deficiency
Lott, John N.A., Bojarski, Marla, Kolasa, Jurek,  Batten, Graeme D., Campbell, Lindsay C.; Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1 Canada; “A review of the phosphorus content of dry cereal and legume crops of the world,” Int. Journal of Agricultural Resources, Governance and Ecology, 2009. Vol.8, No.5/6, pp. 351 – 370.
RS10: BFN sensitivity to phosphorus deficiency
Parish, Dennis H. (1993). Agricultural Productivity, Sustainability, and Fertilizer Use. Muscle Shoals, Ala: IFDC Paper Series; P-18.
RS11: Global consumption of phosphate fertilizer (P2O5)
Food and Agriculture Organization (FAO) of the United Nations; FAOSTAT database, 2012.
RS12: Demand for phosphate fertilizer, current and in 2020
International Fertilizer Association (IFA). Short-Term Fertilizer Outlook 2011-2012, P. Heffer and M. Prud’homme. 2011.
Sattari, Sheida Z., Bouwman, Alexander F., Giller, Ken F., and van Ittersum, Martin K. (2012). "Residual soil phosphorus as the missing piece in global phosphorus crisis puzzle." Proc. Natl. Acad. Sci., 10.1073/pnas 1113675109
RS13: Total NPK demand in 2030 and demand in 2050
Axel Drescher, RĂ¼diger Glaser, Clemens Richert, Karl-Rainer Nippes; University of Freiburg, Department of Geography, "Demand for key nutrients (NPK) in the year 2050." Data sources (FAO 2010, IFA 2011, T&L 2008). 2011.