“With the right solution, both the economic and environmental aspects can be sustained”, says Ronald Clemens, ICL Global Marketing & Portfolio Manager CRF. One of the solutions that ICL offers to comply with the Green Deal objectives is the use of enhanced efficiency fertilizers, such as controlled release fertilizers (CRF). “CRF has proven that it can maintain or even increase yields with a lower fertilizer input, while also decreasing nutrient losses to the environment.”
The Green Deal’s impact on yield The European Union’s Green Deal, that includes the Farm2Fork strategy, aims to minimize the environmental footprint in agriculture. Important pillars of the strategy are to reduce fertilizer losses by at least 50%, and reduce overall fertilizer use with at least 20% by 2030. The impact that the implementation of this strategy will have, has recently been investigated. Several studies proved that reducing fertilizer rate by 20%, can result in an overall yield decline in several crops. One of these studies was done by Wageningen University & Research. In the study, conducted on 25 farms across Europe, researchers looked at several scenarios in both annual and perennial crops. Though some crops were affected more than others, the study shows that the implementation of the F2F strategy has a negative impact on overall crop yield and agricultural production with an average production decline of 10-20%. To maintain production levels, extra farmland outside of the EU is to be considered, but will increase costs and severely influence the market. The study focused on the economic impact of the Green Deal rather than the environmental benefits. Clemens: “If farmers want to meet the new regulations, their yield and income will most likely decrease. It also means we can produce less food in general, and we would require more land to maintain the same levels of production. If we look at the environmental aspect, this is obviously not a sustainable solution.”
Enhanced efficiency fertilizers The reduction of yield due to the Green Deal objectives can become problematic, making the search for sustainable, yield-improving solutions more and more essential. Enhanced efficiency fertilizers, such as CRF, have proven to increase nutrient use efficiency, and could be a sustainable solution to reduce N losses as well as to maintain (or increase) yields in all types of crops. Clemens: “New fertilizer technologies make precision farming more and more efficient. Enhanced efficiency fertilizers aim to release the nutrients to match the needs of the crop, and are therefore an essential part of precision farming. But it is not just about the fertilizer. It requires understanding of the soil, the climate, and the crop. For instance, if you use a CRF with a longevity of 5 months in a 4-month cultivation, you are still not very efficient. Your crops will be in the supermarket while the fertilizer is still releasing nutrients in the field. The 4 Rs (Right source, Right rate, Right place, Right time) are crucial for nutrient use efficiency and precision farming.”
Improving nutrient use efficiency Nutrient use efficiency (NUE) is the yield per unit fertilizer input, or in terms of recovery of fertilizer applied. In principle, an improved NUE means that less fertilizer is used resulting in the same or an increased yield. Improving NUE is particularly essential: 1) in light soils with relatively high amounts of leaching, 2) in periods of high rainfall or flooded crops, 3) in crops with high nutrient losses by topdress or many applications, 4) in areas with environmental restrictions, and 5) in crops susceptible to delay in fertilization due to weather conditions, machinery, and labor.
How controlled release fertilizers improve NUE ICL has been testing the NUE of controlled release fertilizers for decades, and even gathered all data from 2015 on into a meta-analysis. This includes an overall summary of research data from many locations combined in order to get a reliable dataset that is used for statistical analysis. The meta-analysis helps in providing trustworthy conclusions on how CRF can reduce fertilizer inputs, improve the nutrient use
efficiency, and which crops see the best improvements with CRF. The meta-analysis includes approximately 70-80 independent field trials, proving the agronomic performance and NUE of CRF in all types of crops. In these studies and field trials, backed up by WUR, NMI, and PISA, the data also shows a significant reduction of nitrogen losses, ammonia volatilization, N2O emission, and an overall reduction on the carbon footprint. Highlights from a few recent trials and experiments are as follows:
Field Trials in Potato ICL recently published the results of two field trials in potato with controlled release fertilizers. The independent trials were set out in Germany and in the UK. In these trials, the CRF Agromaster was compared to conventional fertilizers and the nutrient use efficiency was measured. Both trials showed that Agromaster improved the nutrient use efficiency: when the same amount of N was applied, the yield increased. When less N was applied, the yield remained the same. Clemens: “ICL extensively tests and trials its products through field trials, experiments, and long-term studies. We need extensive datasets to be able to give reliable recommendations on lowering fertilizer rates, while being certain that yields are maintained and environmental standards accomplished. The more field data we have, the easier it is to draw the right conclusions. We have a strong Agronomy team in Europe to support this.”
The more field data we have, the easier it is to draw the right conclusions.
Controlled release fertilizers versus conventional N The German trial was conducted at IASP in Berge (close to Berlin) with the objective to compare the efficiency of a single application of Agromaster, as CRF, replacing standard fertilization with conventional N, as CAN, that is applied twice during the crop cycle. IASP is a research organization with specific knowledge in nutrition/ fertilization in the agricultural sector. The trial was executed in a ware potato variety on typical sandy soil, which is sensitive to Nitrogen leaching.
Conclusion of the German potato trial Using only one application of Agromaster versus two applications of CAN, as was the growers’ practice, increased the yield of tubers higher than 55 mm by 25%. The overall marketable yield (>35mm) increased by 6.6%. The use of Agromaster improved the nutrient use efficiency, and provided a positive return of investment (ROI) of an additional 146 euro/ha.
Controlled release fertilizers versus ammonia nitrate The UK trial was conducted by Eurofins UK, and held the objective ‘to compare the efficiency of Agromaster, as controlled release nitrogen-based fertilizer, vs ammonium nitrate, in one application, in seed potato production’. The trial was executed in the East Riding of Yorkshire on a clay-loam soil with a high pH level. The trial was executed in a seed potato variety which showed a particular positive effect on the controlled release availability of nitrogen during the crop cycle.
Conclusion of the UK trial As explained, the UK trial compared one application of Agromaster to one application of ammonium nitrate. The use of Agromaster resulted in a total yield increase of 10%, thus improving the nutrient use efficiency. Agromaster also provided a positive return on investment of an additional 736 pounds/ha.
Decreasing nutrient losses with CRF Besides the economic aspect of maintaining or increasing yields, controlled release fertilizers also have an environmental benefit. In a recent independent study, executed by NMI, nutrient losses in controlled release fertilizers were measured. The study was a pot experiment with red beet (Beta vulgaris vulgaris) and aimed to measure leaching, NH3 volatilization, and N2O emissions after applying a CRF. A loamy sandy soil was used with a pH level above 7. Clemens: “We conducted many studies that focused on one type of nutrient loss. But this is the first time we combined measurements of leaching, volatilization and N2O emissions in one study. It is a complicated experiment, but NMI is specialized in these types of set ups. It is complicated in technical sense to capture and measure all N losses in a system where plants have to grow under practical circumstances.
The experiment included 4 treatments using the following fertilizers: • Zero N (control) • Urea | 1 x N (46-0-0 | full N rate > as base fertilizer) • Urea | 2 x N (46-0-0 | split N rate > 50% as base + 50% top dress) • Agrocote Max (CRF) | 1 x N (44-0-0 | full N rate > as base fertilizer)
The leachate is collected in a plastic plate below the pot. To achieve this the pot was placed on 3 small cubes in plate to ensure free drainage.
Volatilization of NH3 was measured following an enclosure method (Yang et al., 2018) by placing an acid trap 10 cm above the soil surface.
Static flux chambers (12.2 cm radius and 23.8 cm height) were placed on top of the pots. The chambers had two openings which were connected with the gas analyzer creating in this way a closed loop.
Key conclusions The NMI experiment showed that using a CRF reduced leaching of N with 59% compared to conventional urea. While applied at the same time and same rate, CRF reduced the NH3 volatilization with 70% compared to conventional urea. The N2O losses were significantly higher for conventional urea in the first 30-40 days. Overall, CRF reduced the N2O emission with 15%. When using conventional urea, 40-50% of N applied is lost to the environment. CRF limits these losses to only 13-15% of the total N applied. The N uptake increased and in general the experiment showed a 60% increase of NUE. Clemens: “These results confirm our thoughts that with CRF we are able to improve nutrient use efficiency by reducing fertilizer rates, and at the same time lower nutrient losses, without farmers losing their yields.”
These results confirm our thoughts that with CRF we are able to improve nutrient use efficiency by reducing fertilizer rates, and at the same time lower nutrient losses, without farmers losing their yields.
EU’s Green Deal objectives will most likely result in a decrease of yield and income for farmers based on existing fertilization systems. To maintain yield with less fertilizer use, farmers need to look for innovative solutions. One of those solutions is the use of enhanced efficiency fertilizers that will increase nutrient use efficiency, meaning that less fertilizer is used while yield remains the same or even increases. Decades of research and trials have proven that controlled release fertilizers (CRF) increase nutrient use efficiency, and are very suitable in a precision farming strategy. From the environmental point of view, the use of CRF has proven to reduce leaching, volatilization, and N2O emissions, compared to conventional fertilizers.
In short, these are the proven statistics of the use of CRF (usually 1 application) in comparison to conventional fertilizers (usually 2 applications):• CRF reduces N leaching by 56 – 63%• CRF reduces NH3 volatilization by 56 – 70%• CRF reduces N2O emissions by 15%• CRF increases yield by 26%• CRF increases nutrient use efficiency by 60% ●
ICL has recently published the results from two field trials in potato with CRFs.
