Phosphorus: Its future importance in directing horticultural research §§ Virchow D. and J.D.H. Keatinge J.D.H. D. Virchow: Global Horticultural Initiative: c/o ZEF, University of Bonn, Germany; Executive Secretary GlobalHort c/o Center for Development Research (ZEF); University of Bonn; Walter-Flex-Str. 3; D - 53113 Bonn; Germany; E-mail: [email protected] J.D.H. Keatinge: Global Horticultural Initiative: c/o ZEF, University of Bonn, Germany; Director of the Board of Directors and AVRDC – The World Vegetable Center, Shanhua, Tainan, Taiwan; Director General P.O. Box 42, Shanhua, Tainan 74199; Taiwan; E-mail: [email protected] Phosphate is a vital macronutrient for horticultural crop production -- yet its use in intensive vegetable production systems is often abused by either insufficient application resulting in low yields (Grubben et al. 2014) or excessive application resulting in reduced profitability and environmental damage (Yan et al. 2013). The horticultural sector globally needs research now to come to grips with these contrasting positions to justify its P needs for the future, when competition among various agricultural sectors for declining stocks of this mineral resource will increase. Tomatoes are among the top ten agricultural commodities produced globally in terms of economic value (FAOStat 2013), and the combined value of all vegetables, fruits and flowers produced by the horticultural sector exceeds many billions of dollars a year. This alone would justify priority allocations of phosphate to this sector. Yet fruit and vegetables are also vital for human health not only in combating malnutrition but also in significantly reducing deaths from cancer and cardiovascular diseases (Keatinge at al. 2011, Oyebode et al. 2014). As there are now approximately twice the number of malnourished humans compared with people experiencing energy-deficient diets, it makes strategic sense to ensure that horticulture is a priority sector for phosphate allocation. Future phosphate distribution will need to be seen not only in terms of ensuring food security for the planet but also in helping to deliver effective nutritional security with suitably diverse, balanced diets for good human health. Food safety and its implications for P supply to horticulture is a key research topic for the future. The horticultural sector is presently dominant in peri-urban environments in the developing world owing to the short shelf life of fresh fruit and vegetables. As a result, smallholder horticultural production often employs compost, organic fertilizer and irrigation water from urban sources contaminated with either human and animal sewage or heavy metals. Research to solve this key food safety concern is vital if health gains from increased fruit and vegetable consumption are to be realized. FAOStat. 2013. Food and Agriculture Organization of the United Nations, Rome: FAO. Grubben G, Klaver W, Nono-Womdim R, Everaarts A, Fondio L, Nugteren JA, Corrado M. 2014. Vegetables to combat the hidden hunger in Africa. Chron. Hort. 54:24-32. Keatinge JDH, Yang R-Y, Hughes Jd’A, Easdown WJ, Holmer R. 2011. The importance of ensuring both food and nutritional security in the likely future attainment of the millennium development goals. Food Security 3:491501. Oyebode O, Gordon-Dseagu V, Walker A, Mindell JS. 2014. Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of health survey for England data. Yan Z, Liu P, Li Y, Ma L, Alva A, Dou Z, Chen Q, Zhang F. 2013: Phosphorus in China's Intensive Vegetable Production Systems: Overfertilization, Soil Enrichment, and Environmental Implications. J Environ Qual. 2013 Jul; 42:982-9. doi: 10.2134/jeq2012.0463. http://www.ncbi.nlm.nih.gov/pubmed/24216350 SCOPE Newsletter visions for sustainable phosphorus tomorrow contributions received May 2014 Page 109