Drought resilience: Managing nutrition to reduce crop water requirements

Advancing Eco Agriculture (AEA) collaborates with growers to develop tailored crop programs that integrate biological nutrition products with regenerative farming techniques. John Kempf founded the company and hosts regular webinars on the AEA YouTube channel on various topics relating to biological and regenerative farming.

In this webinar, John Kempf provides insights into managing crop nutrition to reduce water requirements and improve drought resilience.

Kempf first outlines crop water requirements and how soil composition can affect this. In general, a dryland crop requires around one inch of water each week, and each percentage point of organic matter should represent roughly a week's supply of reserve water.

He then outlines how nutrition influences water use and specific tools and techniques to reduce water usage. He explains how the absorption of nitrate greatly increases water requirements for nitrate metabolism and hydration, as well as weakening cell membranes causing permeability and water loss. Reducing nitrate absorption can reduce a crop's daily water use by 30%+.

When plants absorb nutrient ions from the soil solution, they require additional water to metabolise and absorb these nutrients. Conversely, plants can gain nutrients by absorbing bacteria and fungal cells through the endophyte process. The endophyte process requires no additional water and has limited metabolisation, and is therefore a far more water efficient method of nutrient absorption.

For improving crop drought resilience Kempf recommends using bacterial and fungal endophytes, which can provide nutrients to plants in the absence of free soil water. To provide bacterial endophytes to a crop, Kempf suggests inoculating when seeding and ensuring high-quality seed parents. He also discusses fungal endophytes, which can be found in fungally-dominated compost and compost teas and used as a seed inoculant or applied after planting.

Kempf provides other recommendations for managing nutrition, including the use of fertilisers. He recommends avoiding high salt index fertilisers, like urea or potassium chloride, which directly impact root water absorption. He recommends that if these inputs are required, Advancing Eco Agriculture's product, HumaCarb, can be used to buffer the effects.

Kempf also explains that electrolyte balance is essential for plants, particularly potassium, sodium, and chloride, which are readily absorbed from the soil. An electrolyte imbalance can lead to a weak watery plant, requiring more water to maintain proper hydration. But when used correctly, electrolytes can be very beneficial to improving drought resilience. When electrolytes are applied, sap testing analysis must be used to determine if electrolytes are balanced.

If you are interested in learning more context-specific information for your crops and soils, contact the Advancing Eco Agriculture team at [email protected].