Chapter 4.33
4.33 -Split Application of Synthetic Fertilizer
Ammal Raza, University of Guelph, Canada
Suggested citation for this chapter.
Raza,M. (2022) Split Application of Synthetic Fertilizer . In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Introduction to the Split Application of Synthetic Fertilizer
Agriculture faces the challenge of meeting nutrition and fiber demands in a sustainable, ethical, and economical manner (Nutrient Stewardship, 2021). To meet this demand, farmers are in urgent need of solutions that use resources efficiently. About 13% of Sub Saharan Africa is covered in sandy soil, making it difficult for the soil to retain its nutrients, given the limited organic matter, which reduces crop growth (Chinabut, 2005). It is also important to note that smallholder farmers cannot afford necessary inputs such as fertilizer and seeds, therefore using their supplies efficiently is critical (Minde et al., 2008). If farmers administer the full fertilizer dose at once, it causes leaching. Leaching is not only inefficient and harmful for the crop but also bad for the environment, as it poses the risk of running off into lakes and rivers (Brune et al., 2017). One potential solution to this problem is splitting the fertilizer application into multiple, smaller doses (Nutrient Stewardship, 2021) which is the topic of this chapter.
How Can The Split Application Of Synthetic Fertilizer Be Used In Agriculture For Maximum Efficiency?
Instead of inputting the fertilizer all at once before plant growth, split application in doses ensures that the plant can efficiently uptake all the nutrients (Nutrient Stewardship, 2021). This technique also gives farmers the ability to match peak crop demand for fertilizer which tends to be later in the growing season (e.g. when grain is produced) (Kabir et al., 2021).
The split application of synthetic fertilizer increases nutrient use efficiency, while decreasing nutrient loss. Specifically, this technique can decrease fertilizer use by 20-30% of the total rate recommended, while yielding the same results (Trenkel, 2010). It also mitigates the risk of leaching, as the dose of fertilizer administered adhere to just the right amount the plant needs, and therefore, it stays in the soil instead of running off into nearby lakes and rivers which could cause water contamination and eutrophication (Lie, et al., 2021). It is vital for farmers to study the growth cycle of the target crop to pinpoint its nutrient demand profile to determine the best time to administer the fertilizer doses.
Figure 1. Estimations of potential N losses that occur when N fertilizer is applied in a single application vs split applications. Credit: Waskom, Cardon, and Crookston
What Are The Benefits Of Using Split Applications Of Synthetic Fertilizer?
The split application approach is more environmentally sustainable, as studies show that it helps lower greenhouse gas emissions that are commonly associated with the production and application of fertilizer. There was a study conducted in Northeast China on rainfed maize fields, which showed that the split application method lowered “cumulative N2O emissions by 51.8%” in comparison to the single application approach (Dong et al., 2021). This method also reduces the likelihood of overfertilization, which significantly improves crop quality.
Another study showed that when the split application method was properly executed, there was improved crop size, flavor, nutritional value, and appearance (Hopkins, 2015). There was a study conducted in the Vhembe district municipality of Limpopo province in South Africa, where 84 farmers were randomly sampled to participate in a survey that showed that 75% of the farmers could not afford the quantity of fertilizer necessary for their crops when applied as a single dose (Odhiambo & Magandini, 2008). As mentioned in an earlier section, the split application method used 20-30% less fertilizer while yielding desirable outcomes (Nutrient Stewardship, 2021). This makes the method more accessible and cost-efficient for smallholder farmers.
How Can the Split application of Synthetic Fertilizer be Adopted by Smallholder Farmers?
It is important for farmers to be educated on the process before attempting to implement it as their main fertilization practice. Farmers should try to consult with local or regional extension officers so they can identify the best management practices (BMP’s) (Nutrient Stewardship, 2021). Here are some general estimates as to when administersplit application doses for maize, wheat, and rice:
1.Maize: For the split fertilizer application for maize, the first dose should be at the sowing stage, and the second during the V12 stage of the growth cycle (Figure 2). During the V12(+) stage, the crop is in need of all major primary nutrients (including phosphorus, nitrogen, and potassium). This is the stage where the number of kernels and the plant’s ear size are determined, and therefore, the second dose should be administered at this stage (Tonneson, 2020).
Figure 2. Corn/ Maize vegetative growth stages. Credit: Tonneson, 2020.
2. Wheat: Listed in Figure 3 is the recommended split N application for winter wheat. Administering the first dose during the first split application window helps with tillering.
Figure 3. Split application windows for winter wheat. Credit: Follings, 2022.
3. Rice: The split nitrogen application for rice should be as follows; ⅓ of the dose of nitrogen, and full doses of phosphorus and potassium should be applied prior to the last puddling (associated with the start of the growing season). Apply the second dose three weeks after that, and the final dose of nitrogen three weeks after the second dose (Shrestha, et al., 2022).
Figure 4. Growth stages for rice. Credit: Sheng, 2022
Critical Analysis
Split fertilizer application does come with potential increased labor and equipment costs, as administering multiple doses requires more time and increased use of machinery due to multiple trips into the field (Taylor, 2024). There are also practical weather constraints, as the fertilizer cannot be administered when it is wet due to mud (Kelly, 2017). Indeed, a study conducted in Eastern D.R. Congo showed that a single application of fertilizer was more profitable than split applications (Zamukulu et al., 2024). However, if labour or machinery is available, the numerous benefits listed above may often outweigh these challenges.
Practical Links & Resources to get Started
https://www.youtube.com/watch?v=KhEmnHn89fc This video gives information on the split application of nitrogen for corn, and gives a few sidedress tips on how to get started.
https://thebreakthrough.org/issues/food-agriculture-environment/to-increase-yields-african-farmers-must-have-better-access-to-synthetic-fertilizer The article above analyzes the results African farmers could gain by investing in synthetic fertilizer.
http://www.knowledgebank.irri.org/training/fact-sheets/nutrient-management/nitrogen-split-applications This site assists farmers on how to develop a splitting pattern.
https://ageconsearch.umn.edu/record/33985/?v=pdf This article gives an in-depth analysis on how to adopt new agricultural practices.
https://www.youtube.com/watch?v=3F50SQHuKAk The video above is an introduction on how/why farmers should adopt the split application approach for a better environment, and potentially increasing profit.
References
1.Brune, D., Killpack, S. C., & Buchholz, D. (2017, September 27). Nitrogen in the Environment: Leaching | MU Extension. MU Extension. https://extension.missouri.edu/publications/wq262
2.Chinabut, N. (2005) Management of tropical sandy soils for sustainable agriculture. Food & Agricultural Organization of the United Nations. https://www.fao.org/3/ag125e/AG125E08.htm
3.Liu et al. (2021) Controlled-release and slow-release fertilizers as nutrient management tools. (September 2, 2021). Publication HS1255/HS1255, University of Florida. https://edis.ifas.ufl.edu/publication/HS1255
4.Deng, T., Wang, J. H., Gao, Z., Shen, S., Liang, X. G., Zhao, X., Chen, X. M., Wu, G., Wang, X., & Zhou, S. L. (2023). Late Split-Application with Reduced Nitrogen Fertilizer Increases Yield by Mediating Source-Sink Relations during the Grain Filling Stage in Summer Maize. Plants 12(3), 625. https://doi.org/10.3390/plants12030625
5.Follings, J. (2022, March 21). Should I split and apply nitrogen in winter wheat? – Field Crop News. Field Crop News. https://fieldcropnews.com/2022/03/should-i-split-apply-nitrogen-in-winter-wheat/ Kabir, T., Laporte, A. D., Nasielski, J., & Weersink, A. (2021). Adjusting Nitrogen Rates with Split Applications: Modelled Effects on N Losses and Profits Across Weather Scenarios. European J Agronomy 129, 126328. https://www.sciencedirect.com/science/article/pii/S116103012100099X
6.Minde, I., Pedzisa, T., & Dimes, J. (2008). Improving access and utilization of fertilizers by smallholder farmers in the Limpopo province of South Africa. Monograph. International Crops Research Institute for the Semi-Arid Tropics. https://oar.icrisat.org/425/
7.Nutrient Stewardship (2021) Split Fertilizer Application Helps Optimize Nutrient Management. (2021, September 2). Retrieved March 23, 2024, from https://nutrientstewardship.org/implementation/split-fertilizer-application-helps-optimize-nutrient-management/.
8.Odhiambo, J. J., & Magandini, V. N. (2008). An assessment of the use of mineral and organic fertilizers by smallholder farmers in Vhembe district, Limpopo province, South Africa. African Journal of Agricultural Research, 3(5), 357-362
9.Organic Alberta (2019) Organic Week: Let's Talk about Synthetic Fertilizer. (2019, September 19). https://organicalberta.org/article/synthetic-fertilizer/
10.Ramachandran, V., Shah, S., and Smith, A. (2023, February 13). African Farmers Need Access to Synthetic Fertilizer Now. The Breakthrough Institute. https://thebreakthrough.org/issues/food-agriculture-environment/to-increase-yields-african-farmers-must-have-better-access-to-synthetic-fertilizer
11.Shrestha, J., Karki, T.K., and Hossain, M.A. (2022). Application of Nitrogenous Fertilizer in Rice Production: A Review. J. Nepal. Agric. Res. Council 8, 16-26. https://www.neliti.com/publications/431533/application-of-nitrogenous-fertilizer-in-rice-production-a-review
12.Taylor, J. A. (2024, March 5). Precision Agriculture. Retrieved April 7, 2024, from https://www.sciencedirect.com/topics/earth-and-planetary-sciences/precision-agriculture
13.Tonneson, L. (2020, May 18). Insights into corn's vegetative growth stages. Farm Progress. https://www.farmprogress.com/corn/insights-into-corn-s-vegetative-growth-stages
14.Trenkel, M.E. (2010) Slow-and Controlled-Release and Stabilized Fertilizers An Option for Enhancing Nutrient Use Efficiency in Agriculture. International Fertilizer Industry Association (IFA), Paris. Scientific Research Publishing. https://www.scirp.org/reference/ReferencesPapers?ReferenceID=1846413
15.University of California Agriculture & Natural Resources. (n.d.). Healthy Lawns—Fertilizers vs. soil amendments. UC IPM. https://ipm.ucanr.edu/TOOLS/TURF/SITEPREP/amenfert.html
16.Zamukulu, P. M., & Bagula, E. M. (2024). Assessment of the nitrogen fertilizer split-application on maize grain yield and profitability on Nitisols of South-Kivu, Eastern D.R. Congo. CABI Agriculture and Bioscience 5, 222. https://cabiagbio.biomedcentral.com/articles/10.1186/s43170-024-00224-3