Grain Sorghum in Cotton Rotations: How to Protect Soil, Water, and Profit

Executive summary (TL;DR)

Grain sorghum in cotton rotations protects soil structure, saves water, and spreads risk across two crops instead of one.
Sorghum’s drought tolerance lets you “rest” fields and still harvest a crop, setting cotton up for better stands, vigor, and fiber quality the following year.
Run the math: in many dryland and limited‑irrigation systems, a smart cotton–sorghum rotation beats continuous cotton on risk‑adjusted profit.

Grain Sorghum in Cotton Rotations: How to Protect Soil, Water, and Profit

If you farm in a place where the wind never stops and the rain never quite shows up on time, you already know this truth: the rotation is your real insurance policy. Grain sorghum has been quietly doing that job for cotton producers for decades. It doesn’t always grab headlines like corn or soybeans, but on the High Plains and in other semi‑arid regions, it’s often the crop that keeps the lights on.

This isn’t a seed salesman pitch. It’s a look at why grain sorghum still earns its spot in cotton rotations—and how to make that rotation actually work for your soil, water, and bottom line, instead of just being something you do out of habit.

Why sorghum belongs in a cotton rotation

Cotton is a fantastic cash crop but a demanding neighbor. It’s sensitive to early‑season stress, picky about planting conditions, and unforgiving when water comes at the wrong time. Sorghum, by contrast, is the tough kid in the corner. It handles heat, handles drought, and usually leaves something in the tank for the next crop.

Three big reasons it belongs in the mix:

Resilience. Sorghum can hang on in summers that would flat‑out wreck dryland cotton.
Water efficiency. It generally uses less water per unit of grain produced than corn in hot, dry climates.
Rotation value. It changes root patterns, residue, and pest cycles in ways that benefit cotton the following year.

If you think of your farm as a portfolio, switching a field from continuous cotton to a cotton–sorghum rotation is a lot like diversifying out of a single stock into a pair of related, but not perfectly correlated, positions.

Soil health: residue, roots, and wind protection

Sorghum simply covers the ground better than cotton in most dryland systems.

Residue cover. Sorghum leaves a heavier residue blanket than cotton stalks. That residue:
- Shields the soil from direct sun and wind.
- Slows evaporation between rains or irrigations.
- Reduces erosion when your worst spring windstorm shows up on freshly tilled ground.
Root structure. Sorghum’s fibrous roots help:
- Improve soil structure and aggregation.
- Open up pores and channels that later cotton roots can follow.
- Increase organic matter over time when roots and residue break down.
Microbial activity. Different crops “feed” the soil microbial community in different ways. Rotating away from a cotton‑only system introduces diversity at the microscopic level too, which often shows up later as better tilth and infiltration.

Over a handful of years, the difference physically under your boots—on fields where sorghum has been in the mix versus those stuck in continuous cotton—can be noticeable.

Water: why sorghum helps you stretch every inch

In water‑limited systems, the right rotation is a water‑management tool.

Here’s how grain sorghum helps:

Lower peak water demand. Sorghum’s critical water window is shorter and, in some regions, comes a bit earlier than cotton’s most sensitive period. That timing difference lets you spread your irrigation or stored soil moisture demand over a longer calendar, instead of asking every acre to peak at once.
Better water capture. Thanks to heavier residue and stronger soil structure, sorghum stubble often:
- Improves infiltration during off‑season rains.
- Captures snow or off‑season moisture that would otherwise blow away or run off.
- Leaves more water stored in the profile going into cotton year.
Dryland strategy. Even if yields bounce around, a sorghum‑first, cotton‑second approach in marginal dryland fields can:
- Keep your fallow periods shorter.
- Reduce the number of “complete failures” compared to continuous cotton.
- Give you more shots on goal in ugly weather years.

When you zoom out, the rotation’s job is not just to grow crops; it’s to fill and protect the soil moisture bank account your cotton depends on.

Profit: looking beyond single‑year gross revenue

Cotton usually pencils a higher top‑end gross than sorghum in a good year. The mistake is stopping the analysis there.

Think in two‑year blocks instead:

Scenario A: Continuous cotton
- High upside in the rare perfect year.
- High downside risk: stand failures, replant costs, low yields, quality discounts.
Scenario B: Sorghum → Cotton rotation
- Sorghum year may have a lower ceiling but is often more “bulletproof.”
- Cotton follows on improved soil structure and often a better moisture profile, raising the floor and sometimes lifting the average.

When you average the two years together—factoring in replant costs, chemical passes, and quality discounts—the rotation can rival or beat continuous cotton on risk‑adjusted profit per acre, especially on sandier soils, slopes, or water‑short circles.

Your banker and your stress level both care more about consistency than one home‑run year followed by two strikeouts.

Weed and pest management benefits

Sorghum isn’t a magic bullet, but it absolutely changes your pest and weed math.

Different chemistry options. Alternating between cotton and sorghum:
- Lets you rotate herbicide modes of action.
- Gives extra tools for problem grasses or broadleaves that are tough in cotton.
- Reduces some of the pressure that leads to resistance blow‑ups.
Insect and disease cycles. Many cotton pests prefer cotton. Breaking that host cycle with sorghum:
- Helps lower pest pressure going into the next cotton crop.
- Gives you one more card to play in integrated pest management.

As always, the details are local. But at a systems level, having another crop to rotate herbicides and pests around is an advantage, not a headache.

Where sorghum–cotton rotations shine

They tend to pay best in:

Semi‑arid, wind‑prone regions where residue and water capture matter most.
Fields with marginal irrigation—where you can’t fully water cotton every year anyway.
Soils vulnerable to erosion or structural decline under aggressive tillage.
Operations that want to spread workload, so not every field needs planting, spraying, and harvest attention on the exact same dates.

In other words, exactly the kind of situations where growers start saying, “I can’t just brute‑force this with more water and horsepower anymore.”

Practical rotation patterns

A few simple patterns that many growers use as a starting point:

1:1 rotation – Sorghum one year, cotton the next
- Straightforward.
- Easy to remember which field is in which crop.
- Good fit for dryland or limited irrigation.
2:1 rotation – Two years of sorghum, one year of cotton
- More conservative on water and soil.
- Cotton gets the best conditions after extra residue and rest.
- Makes sense on fragile soils or where cotton risk is highest.
Split‑circle strategies under pivots
- Half circle in cotton, half in sorghum in a given year.
- Rotate halves each year.
- Spreads marketing and workload while keeping the system flexible.

The “right” pattern depends on your land, wells, and risk tolerance. The key is to treat the rotation as part of your water and risk management plan, not just a seed decision.

Marketing considerations for a sorghum–cotton operation

Adding sorghum changes your marketing rhythm—but that can be a feature, not a bug.

Different seasonal price patterns. Sorghum often follows corn in the futures curve but can have export‑driven basis pops that don’t line up perfectly with cotton. That gives you more chances during the year to lock in profitable spreads.
Storage and logistics. Grain uses different storage and hauling than lint. That’s extra complexity, but:
- It can let you use bins or local elevators that would otherwise sit idle.
- It spreads trucking and cash‑flow timing over more months.
Risk diversification. Cotton and sorghum rarely have identical price and yield stories in the same year. Diversifying across both:
- Smooths your revenue swings.
- Gives you more marketing levers (HTAs, basis contracts, forward contracts) spread across commodities.

The same marketing discipline you apply to cotton—cost of production, realistic yield assumptions, staged sales—ports nicely over to sorghum.

Getting started without over‑committing

If you’re mostly in cotton today and sorghum feels like a step backward, start small:

Pick your most erosion‑prone or water‑stressed field.
Drop a sorghum–cotton rotation on just that field for a few seasons.
Track:
- Total inputs and yields.
- Stand quality, plant health, and ease of management.
- Your actual profit per acre over a two‑ or three‑year window.

If the numbers are clear—and often they are—you can add more acres to the rotation over time without flipping your entire operation at once.

Questions to ask before you add sorghum

Do I have reliable grain markets or elevators within a workable haul?
How does sorghum fit into my labor and machinery (planter setup, header types, storage)?
Which fields are giving me the most headaches in continuous cotton—and would benefit most from a break?
What’s my realistic water situation over the next 5–10 years?

If your honest answers lean toward “we’re tight on water” and “some fields are burning us in bad years,” then giving sorghum a seat at the table is worth more than just a coffee‑shop conversation.

Grain sorghum won’t replace cotton as the main crop on a cotton farm. But in the right rotation, it quietly does three jobs: protects your soil, stretches your water, and smooths out your profit curve. That’s the kind of partner most cotton operations could use more of.

Grain Sorghum in Cotton Rotations: How to Protect Soil, Water, and Profit