Surface N balances and reactive N loss to the environment from global intensive agricultural production systems for the period 1970-2030.
Data for the historical years 1970 and 1995 and the FAO-Agriculture Towards 2030 projection are used to calculate N inputs (N fertilizer, animal manure, biological N fixation and atmospheric deposition) and the N export from the field in harvested crops and grass and grass consumption by grazing animals. In most industrialized countries we see a gradual increase of the overall N recovery of the intensive agricultural production systems over the whole 1970-2030 period. In contrast, low N input systems in many developing countries sustained low crop yields for many years but at the cost of soil fertility by depleting soil nutrient pools. In most developing countries the N recovery will increase in the coming decades by increasing efficiencies of N use in both crop and livestock production systems. The surface balance surplus of N is lost from the agricultural system via different pathways, including NH3 volatilization, denitrification, N(2)O and NO emissions, and nitrate leaching from the root zone. Global NH(3)-N emissions from fertilizer and animal manure application and stored manure increased from 18 to 34 Tg x yr(-1) between 1970 and 1995, and will further increase to 44 Tg x yr(-1) in 2030. Similar developments are seen for N(2)O-N (2.0 Tg x yr(-1) in 1970, 2.7 Tg x yr(-1) in 1995 and 3.5 Tg x yr(-1) in 2030) and NO-N emissions (1.1 Tg x yr(-1) in 1970,1.5 Tg x yr(-1) in 1995 and 2.0 Tg x yr(-1) in 2030).
Bouwman
A F
AF
Netherlands Environmental Assessment Agency, National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA, Bilthoven, The Netherlands. lex.bouwman@rivm.nl
Van Drecht
G
G
van der Hoek
K W
KW
D000383:Agriculture / Q000379:methods*; D000818:Animals; D000829:Animals, Domestic; D018556:Crops, Agricultural; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods; D005544:Forecasting; D006801:Humans; D008372:Manure; D008962:Models, Theoretical; D009566:Nitrates / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D026361:Reactive Nitrogen Species
D008372:Manure; D009566:Nitrates; D026361:Reactive Nitrogen Species; D009584:Nitrogen