Jan. 8, 2021

Northern Water Examining Ways Crops Can Reduce Consumptive Water Use

Despite the region’s tightening water supplies, Northern Colorado’s future can include both cities and thriving farms. Agricultural research conducted by Northern Water is examining one method to potentially make that a reality. 

Northern Water has spent several years collaborating with the U.S. Department of Agriculture and Colorado State University at the Limited Irrigation Research Farm near Greeley, examining deficit-irrigation methods that may allow farmers to grow grain corn with less water while also maintaining historic return flows.  

Northern Water’s South Platte Projects Manager Jon Altenhofen said the ultimate goal is to eventually implement these practices on more fields served by a given ditch company, and then have farmers lease their saved consumptive water use to cities and other water providers. In addition to maximizing efficiency, these leases would create an additional revenue stream for farmers, enhancing the long-term viability of local farms and helping keep those operations in production.   

Altenhofen’s specific goal in his research efforts is to produce 80 percent of normal grain corn yields on just 50 percent of the typical consumptive water use. That equates to a 60 percent increase in production per inch of consumptive water use. He said he’s achieved these numbers on some of his smaller plots and is now looking to produce those results across larger fields.  

In his efforts to achieve those goals, Altenhofen experiments with various drought-tolerant grain corn varieties, plant populations, distances between plant rows, timing of irrigation and levels of water-stress at different stages of plant growth, among other variables. As part of his research, he does extensive monitoring of soil moisture, evapotranspiration, the resulting reductions in consumptive water use from his deficit-irrigation practices, and water flows on and off of his fields, along with other factors.  

Altenhofen performs his research under furrow, or flood, irrigation, as that method has proven to be the most effective in maintaining return flows that are required when considering an alternative use for all or a portion of their associated water rights. Altenhofen refers to his program as “augmented deficit irrigation.” Without maintaining historic return flows, no transfers or leases would be allowed under Colorado water laws. Furthermore, about 50 percent of irrigated acres within Northern Water’s boundaries are under furrow irrigation. 

LIRF is owned by CSU, while the USDA leases acres to conduct research. Northern Water began its experiments at the farm in 2010. In addition to his own deficit-irrigation efforts, Altenhofen also collaborates with CSU and USDA staff on their various projects out at LIRF, and vice versa, in what he and CSU and USDA staff describe as a “very collaborative” atmosphere.