Poor irrigation water plagues the agricultural industry. As water access becomes scarce, farmers look to shallower wells and less than ideal water quality sources for their irrigation needs. Often times, these water sources are high in sodium, sulfates, nitrates and other salts. Over application of these minerals can be antagonistic to the soil environment and thus require remediation before use.

The accumulation of salts, due to irrigation water or input choice, alters the balance of minerals in the “cloud” surrounding the soil colloid (see soil compaction/dormant program). Ultimately, the continual dosing of salts into the soil environment disperses the soil colloids and creates compaction, which in turn collapses the soil’s pore space. Compaction reduces the water holding capacity of the soil, limits biological activity, and any buffering capacity to high sodium, chlorides, sulfates, and/or nitrates in the soil is depleted. The soil’s small aerobic zone becomes toxic.

Plant growth in these environments is often stunted, with a high demand for external inputs of potassium. These crops typically experience an early onset of necrosis with chlorotic leaf margins. In the Midwest, we often find areas where the dispersed soil colloids erode and accumulate in the low-lying parts of the fields. The soil in these areas has a white crust in the spring and is often dominated with foxtail and kochia, if any crop at all. These areas are merely a symptom of an unhealthy soil environment.

While the soil conditioning/dormant program works to remediate the compaction on these fields and start the healing process, if the underlying cause is not corrected, the problem will continually resurface. Along with instilling a soil conditioning/dormant program to alleviate the excess salts, open up the soil and allow for water and roots to penetrate deeper into the aerobic zone, poor irrigation water and/or sodic parent materials requires continual maintenance with available calcium.

In the arid west where agricultural production relies heavily on irrigation water, correcting the cause requires micro-dosing available calcium multiple times a year. Along with a soil conditioning/dormant program, micro-dosing available calcium counteracts the antagonist effects of the impurities in the irrigation water. It is a necessary input to keep production possible. If avoided, it is only a matter of time before the field input costs outweigh the profit and the soil no longer can support a crop.