Author: Natalia Gomez – Farming Specialist, Farming Services

As the potato season begins, you may be asking yourself how to improve production and increase productivity. At the same time, with nitrogen (N) fertiliser being a major input (depending on variety), you are also wondering how to get the best efficiency from your N applications.

Nitrogen Use Efficiency (NUE) has become a top priority in potato growing because of impact on return on investment, quality and yield. Your crop requires substantial amounts of N, but because it is a highly mobile nutrient and vulnerable to leaching, a significant portion of what you apply can be lost before it ever reaches the plant. Not only does this mean wasted investment and potential effect on yield, but those losses can also harm the environment. That is why it is essential to have a strategy that applies N at the right time, rate and in the right place, exactly when and where your potatoes need it to match the crop growth cycle.

In this context, eNpower (Ammonium Stabiliser) emerges as an innovative solution, giving you compelling reasons to incorporate it into your farming practices. It helps you improve N efficiency, boost crop performance, and contribute to more sustainable farming and environmental protection.

Nitrogen cycle: Understanding loss pathways in potato production
Deciding on the right amount of N fertiliser is a key decision for growers, affecting the success of each crop in terms of not just yield, but quality parameters such as size, shape, and specific gravity. Balancing tuber yield and size (depending on the end market) requires smart N management. Too much N, incorrect timing or the wrong product choice can harm tuber quality, waste money, and affect the environment. Identifying the correct rate for N fertiliser is tricky as soil N levels are different in every field coupled with specific potato varieties having different N requirements. 

While various sources contribute to the presence of N and availability, the soil mobility of this element combined with crop nutrient demand, introduces a very distinct challenge for growers. This is typically an issue where large amounts of N are applied at or prior to planting and applied to lighter soils that are prone to leaching or heavier soils prone to water logging, where denitrification can be an issue. 

The problem is, N can be lost from the potato root zone once in the nitrate form. Ammonium nitrogen is relatively stable however through the nitrification process, nitrate nitrogen is produced.  This occurs for urea and ammonium (NH4+) based fertilisers such as MAP or DAP. Nitrate moves in the soil solution so can move out of the plant root zone, into water bodies, or diffusing into the atmosphere as nitrous oxide (N₂O), a potent greenhouse gas (GHG).   

When N is lost from the system there is a direct cost of the value of nitrogen plus the opportunity cost of lost production. This presents a double challenge, as it not only impacts the growers’ budgets but also poses a threat to both the yield and quality of the crop when the nutrient is unavailable precisely when the crop needs it. 

These N loss pathways compound the challenge (Figure 1): 

  • Leaching: Negatively charged nitrate ions are subjected to leaching through the soil profile, leading to a redistribution or complete removal of nitrate in the root zone.  
  • Denitrification: the conversion of nitrate to nitrous oxide, or di-nitrogen gas under anaerobic and warm soil conditions.  
  • Volatilisation: the loss of ammonia gas.

Figure 1: Activity of EFF’s on the nitrogen cycle. Source: Incitec Pivot Fertilisers, 2025

Maximising nitrogen efficiency and solving loss pathways with eNpower 
eNpower is a spray on technology, that is applied to urea and ammonium fertilisers by Incitec Pivot Fertilisers, which can improve N use efficiencies by reducing denitrification and leaching losses in certain conditions.  Through protecting fertiliser N applications, losses can be reduced. Traditionally, high rates of N are applied early in crop development, leaving N prone to losses before plants can recover it. Typically, between planting and early tuber development. By using eNpower, the applied N at or prior to planting remains largely available to the crop as demand increases, typically around tuber initiation and rapid vegetative growth stages. This allows for equivalent, if not improved, yields and a better bottom line while minimising the loss of N to the environment.

This eNpower formulation is compatible with many different IPF (Incitec Pivot Fertilisers) N products like DAP, MAP, Gran Am, Urea, NPKS Compound, Easy N and custom blends. Please check with your regional IPF representative for a full list of compatibilities.

In many regions, up to 60% of applied N fertilisation in potato crops takes place before the crop demand starts to ramp up (usually as vegetative top growth increases), depending on a grower’s individual operational management, variety and soil type.

eNpower helps protect the applied Nitrogen at planting during early crop establishment phase when crop demand is low (Figure 2). As the effect of eNpower declines over time (mainly due to increased soil temperature and moisture), the nitrification process continues, as does the increase of plant nitrogen demand.  

Figure 2: N rate accumulation in potatoes. Source: Incitec Pivot Fertilisers

eNpower is a suitable product to assist with mitigating N losses, maintaining more in the system for plant recovery.  By utilising eNpower, we seek to ‘smooth out’ the nitrogen availability through the growing season to align supply more to the peak demand and critical growth periods of the potato plants (Figure 3)

Figure 3: Comparing the N uptake pattern in potatoes: eNpower vs. conventional N supply. Source: Incitec Pivot Fertilisers

Empowering Sustainability: eNpower’s dual role in enhancing potatoes and reducing Greenhouse Gas Emissions
Nitrous oxide (N2O) emissions are a critical global concern. N2O is a potent GHG and there is a need to develop innovative solutions that can improve crop characteristics and reduce N2O emissions within the Australian potato industry. 

eNpower not only helps improve crop characteristics but also actively reduces N2O emissions. This dual benefit holds significance for potato growers in Australia, who play a vital role in the country’s agriculture sector. 

By choosing eNpower, potato growers in Australia can help optimise their crop yields and quality while actively mitigating the environmental impact of potato farming. This integrated approach signifies a progressive step toward a more sustainable and responsible future for the Australian potato industry. It aligns with the industry’s commitment to environmental stewardship and contributes to Australia’s broader goals of sustainable agriculture and reduced GHG emissions.

eNpower’s N management success
This demonstration was conducted at Newlyn, Victoria in season 23/24 using the potato variety Innovator. The objective was to compare the grower’s standard fertiliser program (9:15:14, MAP/MOP based) with and without eNpower applied to the blend MAP component. The fertiliser was banded at sowing at a rate of 1600kg/ha .

Potatoes we harvested from randomised 3 x 3 metre strips in both the treated (+eNpower) and untreated sections to determine yield and saleable characteristics.  Tthe eNpower treatment produced an additional 8 t/ha compared to the standard block, an increase of almost 12% (Graph 1). In addition, the eNpower treatment also visually resulted in improved tuber uniformity and shape.  Samples were weighed and then graded to length – <90mm length, 60-90mm length and <60mm length. The eNpower treated section produced more marketable tubers with an 8.2% increase in the >90mm category (by weight) and a 21% increase in the 60-90mm category (by weight) versus the untreated section.

Figure 4: Harvested potatoes produced from demonstration site. Source: Incitec Pivot Fertilisers.

Graph 1: Est. Yield T/Ha using random 3m strip samples (x3) Standard fertiliser program versus eNpower program. Source: Incitec Pivot Fertilisers.

The use of eNpower demonstrated economic value based on improved yield and graded potato characteristics.

Summary 
eNpower is a proven solution for mitigating N losses in potatoes and ensuring its retention during crucial growth periods.
It helps improve N efficiency, boosting crop performance, and contributing to more sustainable farming and environmental protection.
eNpower not only improves crop characteristics but also actively reduces N2O emissions.

Further information
For more information on fertiliser programs for potato crops, feel free to contact IPF’s Farming Specialist, Natalia Gomez at natalia.gomez@incitecpivot.com.au or +61 427 232 982. 

References
Rosen, C. J., & Eliason, R. (2005). Nutrient management for commercial fruit & vegetable crops in Minnesota (BU-05886). University of Minnesota Extension Service. http://hdl.handle.net/11299/51272