Water, the Forgotten Nutrient?

May 22, 2025

By Dr. John Yost

I have a riddle for you. If you have too much, or too little, you worry about it constantly but if you have the right amount you don’t think about it.

The answer is water.

We understand that water is the single most important nutrient to sustain life, yet most of the time we take it for granted. After all, have you ever been standing in front of the kitchen sink, watching your neighbor get a rain shower that you wish would move a half mile to the north to help your crops out? Our crops in the field don’t care about the quality of the water, as long as they get it. For our livestock, water availability and quality are crucial to their health and performance.

There are several factors that determine how much water cattle will need to consume. A cow’s body is estimated to be comprised of 58% to 81% water. If she is lactating, her milk is about 87% water. The volume of free water that needs to be available per head is dependent on several factors. Their mature body weight, the amount of dry matter consumed, ambient temperature and relative humidity, production level, the temperature and quality of the water all affect their consumption. In general, it is estimated that beef cattle require one gallon of water per 100 pounds of body weight. The estimation can double for lactating cows, and as environmental temperatures reach 90 degrees for all production classes, to allow 2 gallons of water per 100 pounds of body weight (Oklahoma St. Univ. Extension Publication e-974).

As you consider supplying your herd’s water needs, you need to factor in their housing environment and behavior. Spring forages can be 80% moisture, and supply about 0.5 gallons of water for every pound of forage dry matter consumed. As forages mature their moisture content drops significantly, and more free water will need to be made available. Cattle are estimated to drink 2 to 5 times each day, for 1 to 4 minutes at each visit, consuming about 2 gallons of water per minute.

Source : osu.edu

Video: Turning Plant Defense Into a Management Strategy

Turning Plant Defense Into a Management Strategy

Understanding how a plant responds to stress is one thing.

Using that knowledge to make better management decisions is another.

Systemic acquired resistance, or SAR, is the plant's more direct defense response. When stress or infection occurs, the plant begins signaling throughout its system and preparing defensive compounds.

But if we know that response exists, can we help prepare the plant before the stress arrives?

The answer starts with understanding what triggers the response and what the plant needs to carry it out.

The Trigger and the Fuel

Salicylic acid plays an important role in triggering the SAR pathway.

Think of it as turning the truck on.

The engine may be running, but it still needs fuel to do the work.

In this case, manganese plays an important role in supporting the enzyme systems involved in the plant's defensive response.

This makes manganese status an important part of the conversation. Whether a producer is using tissue testing, sap analysis, or simply scouting for visible deficiency symptoms, the goal is to make sure the plant has adequate manganese available.

Manganese is required in relatively small amounts, but that does not make its role small.

If the plant receives a signal to defend itself but lacks the nutrition needed to support that response, it may struggle to carry out the process efficiently.

The trigger matters.

The fuel matters too.

Prepare Before the Stress Arrives

The best time to think about stress management is before the plant is overwhelmed.

Once a crop is already struggling, management can quickly turn into a game of catch-up.

This is similar to nitrogen management. Once a plant becomes severely deficient, correcting the problem does not necessarily erase the time and yield potential already lost.

Plant defense can work the same way.

Low-rate, targeted approaches designed to support the SAR pathway may fit best ahead of an expected stress event rather than after significant damage has already occurred.

That requires producers to think about predictable stress.

We may not know exactly what the weather will do tomorrow, but we generally know summer heat is coming. We know certain field conditions increase disease pressure. We know a herbicide application can temporarily stress a crop as the plant processes the chemistry.

Even a properly timed and labeled herbicide application can create a temporary response in the plant.

That does not mean the herbicide is bad.

Weeds can create significantly more yield loss than the temporary stress caused by controlling them.

The question is not whether we should eliminate every stressor.

The question is whether we can better prepare the plant to manage necessary and predictable stress.

Not All Stress Is Bad

Stress is a normal part of plant growth.

A perfectly stress-free environment does not exist in the field.

In fact, some stress is necessary for normal plant development. A plant responds to wind, temperature, moisture, sunlight, and countless other environmental signals throughout the season.

The environment is stress.

The plant's job is to manage it.

Problems begin when the stress load becomes greater than the plant's ability to respond.

Extreme heat, drought, high salt concentrations, disease pressure, and even certain management practices can add to that load.

This is where understanding SAR becomes useful.

Instead of waiting until the plant is visibly struggling, producers can begin identifying periods when stress is likely and make management decisions around those windows.

ISR Starts With the Soil

While SAR is a more direct defense response, induced systemic resistance, or ISR, brings the conversation back to soil health.

The longevity of a farm is closely connected to the health of its soil.

Carbon plays a major role because it supports biological life within the soil. Bacteria, fungi, and other organisms interact with plant roots and influence how the plant grows, accesses nutrients, and prepares for stress.

This is why soil health cannot be reduced to one product or one application.

It is a system.

Keeping living plants in the field longer can support biological activity. Cover crops may fit some operations. Better water management can improve soil conditions.