- Fertilizer uptake by plants is low. Fertilizer use efficiency (FUE) for nitrogen is less than 50 per cent, less than 20 per cent for phosphorus, and less than 10 per cent for sulphur.
- There is potential for “collateral damage,” such as blue baby syndrome and algal blooms.
- There are perceived environmental issues with using petroleum-based synthetic fertilizers.
- Conservation farming techniques.
- Seed coating with fertilizers such as phosphorus.
- Increasing FUE by using polymers and inhibitors.
- The use of solar-powered urea plants in developing nation.
Elsewhere, other suggestions include using different plant
species that make better use of fertilizer inputs, using new
(different) fertilizers (e.g. brewery wastes), or by using more
efficient forms of application, such as fluid fertilizers for phos-phorus. Of course, there are plenty more options, but these are a few suggestions to get us thinking.
An oft-touted assumption is that increased crop yield requires increased (synthetic) fertilizer demand. Of course, if we are removing plant materials from an agronomic situation (i.e., when we harvest), we would logically need to replace those nutrients removed from that ecosystem if we are to expect similar growth in subsequent crops.
But the assumption that those nutrients need to be replaced by using synthetic fertilizers is probably misplaced. Clearly, as the earlier paragraphs have indicated, there is considerable opportunity to improve fertilizer use efficiency rather than just continue to apply higher quantities. And, of course, we can use organic nutrient sources.
In a Guardian article earlier this year, Charlotte Seager states that agricultural production has tripled in the last half-century.3
This increase is, she claims, is “due to innovations in farming technology” – the kind of innovations mentioned previously.
“Smallholder farmers in particular have seen a rise in productivity over the last decade.” (Since Seager is talking about an increase in global agricultural productivity, much of this increase is in developing nations where the baseline output is already very low, so small empirical increases represent large percentage increases.)
Seager offers a number of reasons for this productivity increase, including:
- “Dairy Hubs” which reduce costs for farmers and increase produce value, and have been particularly successful in Bangladesh and Pakistan.
- Fertilizer Deep Placement (FDP) which has increased yields by up to 18 per cent and reduced fertilizer inputs by as much as 30 per cent in smallholder farms in developing nations, particularly Africa.
- High-roof greenhouses, which are being constructed in Eastern Europe and Asia, doubling yields of tomatoes in those countries.
- Software and mobile phone “apps” that are increasing the efficiency of fertilizer use through better placement, better matching applications to crop needs, and through use training and education.
And if you haven’t seen it yet, take 45 minutes to watch “Smarty Plants” on the CBC (part of the David Suzuki “Nature of Things” series). While it’s a bit “out there,” the work of researchers such as James Cahill at the U. of Alberta and his colleagues at UBC might offer many more significant advances in fertilizer use efficiency.
- Biology, Innovation and the Fertilizer Industry: Is the Change Imperative? (2004)
- Bert F. Quin, Quin Environmentals (New Zealand): “Fertilizer Innovations to Increase Efficiency.”
- Seager, Charlotte, “Six Innovations Revolutionizing Farming.” Guardian newspaper, July 8, 2014.