The influence of trade on the flow of nutrients : a case study between Brazil and the Netherlands

With trade of crops nutrients are being transported from one country to another. This can cause nutrient depletion in the exporting country and nutrient enrichment in the importing country. By looking at a case study about the export of soybeans from Brazil to the Netherlands it can be determined how trade is influencing the nutrient balance in both countries and how this is affecting the environment. Brazil is the second largest soybean producer in the world, producing an average of 74,815,442 tonnes of soybeans each year. Out of these 75 million tonnes almost half is exported. In 2011 an amount of approximately 6,818,402 tonnes of soybeans was necessary for export to the Netherlands. Due to the production of soybeans for export to the Netherlands the soil in Brazil is experiencing a depletion of 51,203 tonnes N/y, an amount equal to 13.6% of the nitrogen demand of the soybean plant. The soil is experiencing a phosphorus enrichment of 30,964 tonnes P/y, an amount which is equal to 34.2% of the phosphorus demand of the soybean plant. Out of the soybean products imported into the Netherlands, a part is re-exported. The remaining soybean products are used domestically, mainly in animal feed. One of the most important destinations is the use of soybeans in the feed for pigs. Out of the 5,657,191 number of pigs kept in the Netherlands half of them are finishing pigs, i.e. pigs that are kept for their meat. As a result of eating soybeans imported from Brazil, finishing pigs in the Netherlands excreted 7,379 tonnes N/y and 1,088 tonnes P/y. Due to agriculture the Dutch soil is experiencing both a nitrogen and a phosphorus enrichment. The nitrogen enrichment is larger with an amount of 50,000 tonnes N/y. The phosphorus enrichment consists of 3,100 tonnes P/y. A part of the enrichment can be traced back to nutrients imported in soybeans from Brazil and excreted by finishing pigs. For nitrogen 1.1% of the surplus can be traced back to Brazil. For phosphorus this amount is equal to 1.8%. Both Brazil and the Netherlands are experiencing negative effects from the export of soybeans from Brazil to the Netherlands and in both countries the environment is affected by the change in nutrient balance. There are six possible measures that can be implemented to reduce the impact of this trade on the environment in both countries. Figure 1 shows an overview of the discussed case study with the measures and there effects. There are four measures which are effective in reducing the influence of trade on the environment. The first two measures do not affect the influence of trade directly, but make the production processes more sustainable. These measures are the replacement of artificial fertiliser use in both Brazil and the Netherlands. In Brazil artificial fertiliser is the main fertiliser source used and in the Netherlands still 38% of the nitrogen fertiliser use and 8% of the phosphorus fertiliser use does still originate from artificial fertiliser. In both countries it is estimated that livestock produces enough nutrients to fulfil the crops demands. Another measure that could be implemented In Brazil to make the production of soybeans more sustainable is the use of an optimum fertiliser amount. The optimum fertiliser amount is equal to the crops demands, minus other fertiliser sources like crop residues and nitrogen fixation. For soybeans the use of nitrogen fertiliser should increase with 230% and the use of phosphorus fertiliser should decrease with 40%. In the Netherlands the production of pork meat can be made more sustainable by changing the diet of finishing pigs or processing their manure in a different way. By changing the diet of finishing pigs the nitrogen excretion could be reduced by 25% and for phosphorus a reduction of 65% could be possible. By processing the manure with reversed osmosis to obtain two end products being either high in nitrogen or high in phosphorus. This would make the application of manure more effective and, as a result, the manure surplus in the Netherlands could decrease. The last two measures focus on changing the trade relationship between Brazil and the Netherlands. The trade relationship could be altered if nutrients were exported from the Netherlands to Brazil or if soybeans could be replaced by a locally produced protein source, so less soybeans would need to be imported. Unfortunately neither measure is effective. Pigs in the Netherlands do not produce enough nutrients in their manure to substitute the fertiliser use on soybeans in Brazil and the only protein sources which could be a suitable replacement are still to innovative. For insects and algae meal to be a suitable replacement for soybeans in pig feed more research needs to be carried out about the digestibility of these protein sources and there production process needs to be optimized. Potatoes and maize, other protein sources, would need an increase in agricultural land or replacement of other crops. All measures described above focus on changing a part of the current production cycles. However there is one solution that could reduce the influence of trade all together: reducing the scale of the pork meat production in the Netherlands. If less pigs would be kept in the Netherlands, less manure would be produced. With a fewer number of pigs, the amount of feed needed would also decrease, leading to a lower demand and import of soybeans. This could lead to a reduction in the soybean production in Brazil. However this could have negative consequences for the Brazilian economy. But for the Netherlands it could have a positive economic effect. Due to a decrease in supply of meat the currently low prices for pork meat could increase.