Potato growers are focusing on crop quality during the season ahead, even as agriculture’s water-use efficiency comes under increasing scrutiny. Winter is the time to conduct irrigation “pre-flight” checks, says Mike Williams, CEO of California-based crop nutrition specialist OMEX Agrifluids.
“Irrigation decisions should always be based on firm evidence,” says Williams. “By making sure your log contains all the data—soil moisture levels, water composition, soil samples—you’ll have a firm basis for your irrigation calculations. Others will rely on sensors and weather data analysis to guide their irrigation strategy. Either way, with appropriate preparation, you’re setting yourself up to achieve a quality crop and optimum water consumption.”
But whether old-school or tech early adopter, Williams says one thing a lot of growers overlook is the soil’s ability to allow water to properly penetrate and reach the crop’s roots.
“If your soil’s water penetration is compromised,” he says, “the crop can find itself under-irrigated despite the irrigation calculations being correct.”
Excess magnesium or sodium within the soil can cause individual clay particles to clump together. This blocks the soil pores, preventing free movement of water through the soil profile. Displacing the magnesium can restore water penetration.
Williams says it’s somewhat frustrating to see water penetration issues going undetected so often, because it’s a relatively simple issue to address. “It’s as easy as adding calcium to the irrigation water supply,” he says.
“Gypsum is an option and it’s inexpensive,” Williams continues. “However, if you’re using drip irrigation, gypsum presents a major disadvantage. If you have even small traces of bicarbonate in your irrigation water, there’s a risk that it will end up blocking your system with lime deposits.”
To avoid this, Williams suggests growers turn to solutions containing calcium nitrate. OMEX has developed its own calcium nitrate formulation, Cell Power SLYCE Ca8%, which also contains humic acid.
“Humic acid increases the capacity of the soil’s colloidal structure,” says Williams. “By creating a more friable soil structure, it increases water-holding capacity and aeration.
“Short-chained sugars are an additional component in SLYCE. As well as maximizing the soluble calcium, these can help to stabilize aggregates in surface soil and improve water infiltration.”
In addition to improving water penetration within the soil profile, products like SLYCE also increase available fertility, especially when applied after granular fertilizers.