Ask an Agronomist: How Can Smart Fertigation Solve Water Quality Challenges?
Learn how water use can be optimized and hard water challenges mitigated through fertilizer management programs that improve crop production profitably
Every drop counts when it comes to agricultural water usage. With increased focus on soil health, water conservation, and nutrient innovation, making the most of our resources has become increasingly important. We asked ICL’s agronomist some quick questions about hard water challenges and new opportunities for optimizing water use and crop production profitably. Here’s the dirt.
Jason Haegele, North American Agronomy Lead
Jason Haegele leads ICL’s research collaborations with universities and third-party research contractors in North America to demonstrate the efficacy of ICL products on a broad range of row crops and specialty crops. He is a graduate of the University of Illinois and Iowa State University and has a broad range of experience in applied research and field sales support for plant nutrition, adjuvant, crop protection, and biological products.
Which factors influence irrigation water quality and why is water quality a challenge?
Access to adequate quantities of water is critically important for agricultural production in many parts of the world, but water quality can often be an equally challenging concern. Factors like water pH, salinity, and bicarbonate levels interact to influence water quality and create unique challenges for irrigation system function and nutrient availability. Also, because soils in irrigated regions often have already existing characteristics of high pH and salt accumulation, poor water quality only exacerbates a challenging environment for nutrient management and crop production.
How can clogging or damage to fertigation systems be safely reduced?
Over time, impurities in irrigation water like bicarbonates react with calcium or other positively charged elements, precipitate, and impair flow through important system components like drip emitters. Additionally, because high pH irrigation water may be associated with elevated levels of calcium, the addition of phosphate containing sources of fertilizer are not recommended due to the formation of calcium phosphates, which also cause precipitation and damage or reduce the effectiveness of irrigation components. In drip irrigation or other types of micro-irrigation systems, injecting some form of acid, like sulfuric acid, into the irrigation water is a common practice to reduce the formation of harmful precipitates and to promote greater availability of certain nutrients like phosphorus and most micronutrients. As an alternative to sulfuric acid and other acidification options for irrigation systems, ICL’s Nova PeKacid (0-60-20) provides a convenient and effective strategy for acidifying irrigation water while also supplying phosphorus and potassium.
Does water quality also affect nutrient uptake?
Poor water quality is not only problematic for irrigation systems, but also negatively impacts nutrient uptake for the crop and return-on-investment for nutrient applications. For example, when calcium reacts with bicarbonates present in irrigation water, calcium on soil exchange sites is reduced over time, potentially leading to poor soil structure or other nutrient imbalances. This leads to applications of calcium through gypsum to address soil structure concerns or use of other calcium containing fertilizer products for crops like fruit and vegetables in which calcium directly impacts produce quality. As another example, most micronutrients including zinc are more available for crop uptake as pH decreases. As a result, elevated pH in either irrigation water or soil does not promote micronutrient availability and plant tissue deficiencies may be more common.
How are growers profitably addressing these challenges?
Nova PeKacid (0-60-20) is a patented product exclusive to ICL. This fertilizer is unique in that it is a dry, crystalline form of phosphoric acid that also includes potassium. A 1-percent solution of PeKacid results in a solution pH of approximately 2.2 and is very effective at maintaining a precipitate-free irrigation system, while also supplying P and K. These characteristics of Nova PeKacid promote ease of use and improved irrigation system function, greater nutrient availability, compatibility with calcium products also applied through irrigation, and ultimately, increased crop productivity.
Where do acidifying fertilizers like PeKacid or Agrolution pHLow fit into a fertility program?
In addition to replacing an acid source like sulfuric acid, Nova PeKacid application may reduce or eliminate other sources of soluble or liquid phosphorus like 10-34-0 applied through irrigation. If a N-P-K fertilizer is desired for use in fertigation or other methods like starter fertilizer or side-dress applications, ICL’s Agrolution pHLow family of products provide another option which also contains the PeKacid technology and the same acidification benefits. For example, a product like Agrolution pHLow 11-45-11 with 2% zinc provides an analysis that is especially suited for starter fertilizer use or other early season applications in which enhanced availability of phosphorus and zinc is desirable. Other options in the Agrolution pHLow family provide flexibility in designing a nutrient application approach tailored to the crop, growth stage, and most appropriate nutrient balance. In conclusion, with Nova PeKacid and Agrolution pHLow products, ICL has the solutions to help address important agronomic challenges related to the interactions of water quality and nutrient sources used in agriculture.