Windrow Meaning: How It Forms and What It Costs

A windrow is a long, narrow row of cut hay, straw or crop residue laid up in a field so it can dry in sun and wind before baling, chopping, grazing or collection. It names both the row and the job of making it, and the same word is used for a long pile of compost. At cutting, forage holds 75 to 80% moisture; hay must fall to 14 to 18% before baling (University of Wisconsin Extension).

The row is not just a tidy pile. Its width, density and timing decide how fast the crop dries and how much leaf you lose on the way to the baler. This page gives the definition first, then what only our page has: a loss-by-operation chart from a university circular, 2025 custom rates for mowing, windrowing and raking, a hay price chart from USDA, and a calculator that turns your raking loss into dollars.

Windrow meaning: the row and the job

As a noun, a windrow is the row itself, for example “a windrow of alfalfa”. As a verb, windrowing is the work of mowing a standing crop and putting it into that shape. Air moving through and over the row carries moisture away from the cut stems and leaves.

Windrowing is a separate step from baling. It only arranges the crop for drying. A different pass then removes it from the field: a baler, a forage harvester, a combine that picks up the row, or cattle in the case of windrow grazing. If someone asks “what is windrowing” and “what is a windrow”, the answer is process in the first case and product in the second.

Two machine setups make a windrow. A windrower, also sold as a swather, cuts the crop and lays it in a row in one pass. Or a mower-conditioner cuts and drops a wide swath, and a rake or merger gathers that swath into a narrower row later. Both end with a continuous ridge of cut material, but the timing and the drying rate differ a lot, as the next sections show.

In everyday talk people also write “wind row” or “winrow”. They mean the same thing. In some regions a windrow is also called a swath, but the two words are used differently in forage research, so the next section separates them.

How a windrow is formed, step by step

The steps below show the common path for hay. Details change with crop, climate and equipment, so treat it as an outline and follow your own equipment manual.

Infographic

Windrow in 5 steps

1. 1CutMow or swath the crop; leave a wide swath so it dries fast.
2. 2ConditionBreak or scuff the stems so water can leave.
3. 3DryWait until moisture falls to the raking band for your crop.
4. 4Rake or mergeGather swaths into a row sized for the baler or harvester.
5. 5RemoveBale, chop or graze the row at the right moisture.

The figure that matters most is the moisture content at each step. Wisconsin Extension gives the starting point (75 to 80% at cutting) and the target (14 to 18% for hay, lower for large bales).

Swath or windrow: why width changes drying time

In forage work, a swath is the cut crop laid wide behind the mower, and a windrow is the narrower row made by raking or merging swaths together. University of Wisconsin Extension calls a wide swath the single most important factor for fast early drying. Its recommendation is to lay the cut crop over at least 70% of the cut area (UW Extension, field drying forage).

The reason is biology. Right after cutting, leaf pores stay open in daylight and the plant keeps breathing. Wide spreading exposes more leaf to the sun, so the crop loses its first 15% of moisture fast, and that early speed saves starches and sugars. Conditioning does not change this first phase. It helps later, when moisture leaves through the stem.

The Arlington, Wisconsin trial is the clearest number. Alfalfa put into a wide swath reached 65% moisture in about 8 hours and could be chopped for haylage the same day. The same forage put into a narrow windrow was not ready until the next day, and for hay the drying took about one more day (Focus on Forage, UW Extension, 2013 update). Note this is one research station, with alfalfa, so it is not a rule for every field.

Many growers have drifted to narrower rows as mowers got bigger while the conditioner stayed the same size, according to the same Wisconsin sheet. In measurements at Wisconsin Farm Technology Days in 2002, the ratio of windrow width to cut width was the most important factor in how wet the alfalfa still was 5.5 hours after mowing. Grass needs extra care: laid in a narrow row at cutting, it settles together, dries very slowly and is hard to loosen later.

Note that many windrowers and swathers can also lay a wide swath instead of a narrow row; check the machine setting before you assume the row width.

So the practical split is simple. For quick drying, keep the crop wide. Gather it into a windrow only when it is dry enough to rake without breaking the leaves, or just before chopping.

When to rake: moisture, timing and leaf loss

Raking turns wet material up to the sun and air, but it also knocks off leaves. Alfalfa leaves carry much of the feed value, so raking too dry costs quality and yield. Wisconsin Extension advises merging or raking when forage is at 40 to 60% moisture, a point often reached 12 to 24 hours after mowing in good drying weather. For haylage, it suggests merging swaths just before chopping, about 5 to 7 hours after mowing.

Not every extension service gives the same range. A New Mexico State University circular puts the best raking window for alfalfa at 35 to 40% moisture. The two ranges differ and neither source says why, so use them as a starting band and check moisture with a meter or a moisture test before you rake a whole field.

Raking too wet has a cost as well. The New Mexico circular says wet raking twists plant material, which can lengthen drying. If rain is forecast, weigh any gain from raking early against the rain losses shown in the chart below.

Cutting time, conditioning and drying aids

Weather and crop stage set the pace of drying before any rake touches the row. The New Mexico State circular says solar radiation is the most important weather factor for alfalfa, ahead of temperature, humidity, soil moisture and wind. It also says younger tissue dries faster than older stems, and that narrow, dense swaths delay drying. That matches the Wisconsin advice to spread the crop wide.

Time of day matters too. In wet periods, cutting early in the morning gives the crop a full day of drying and cuts the time it is exposed to coming weather. The same circular notes newer research showing that late-afternoon cutting leaves more sugar in the plant, because the plant stores sugars by day and uses them at night. The authors say a producer has to weigh that gain against the damage from a delay of about 12 hours before baling.

Mechanical conditioning scuffs or crushes stems so water can leave. NMSU reports it can raise the drying rate of alfalfa by up to 80% (Rotz and others, 1987), at a dry matter cost of up to 4% in the conditioning step. There is a trade-off in wet weather: rain damage can be up to four times higher in crimped hay than in uncrimped hay, so the benefit depends on getting the hay up before it rains.

Chemical drying aids, which are potassium or sodium carbonate solutions sprayed at cutting, can double the drying rate under warm, dry conditions, according to the same circular. They add no benefit in wet weather, need a tank on the machine and are not very effective on cool-season grasses. Check the product label and local rules before using any additive.

Tedding also needs good timing. NMSU says tedding should be done shortly after swathing, or it can do more harm than good. Swath inversion, which turns the swath over to expose the damp underside, had lower losses than tedding or raking in its table (average 1% against 3% and 5%).

Rain, storage and the rest of the loss chain

Rain is the largest loss in the chart in the next section, and it is not equal in every case. In the NMSU table, 0.2 inch of rain averaged 5% dry matter loss (range 3 to 7%), 1 inch averaged 17% (7 to 27%) and 2 inches averaged 30% (12 to 50%). The circular adds that rain does less quality damage to hay that is still wet than to hay that is nearly dry, and that a long, light rain does more damage than a short, heavy one with the same total.

Losses do not stop at the windrow. The same table lists round baling at an average of 6% (range 3 to 9%), and storage inside at an average of 5% (3 to 9%) against 15% (6 to 30%) for hay stored outside. So a careful windrow can be undone by a bale left in the weather, and a hay plan should follow the crop from mowing to feeding. These percentages are for alfalfa and come from earlier research summarised in the circular, so use them to compare steps and not to forecast one field.

How much hay is lost between mowing and baling

A New Mexico State University circular collects dry matter losses for alfalfa harvest from earlier research by Rotz and Muck. It gives an average and a range for each operation. These are alfalfa figures, so grass hay and straw will differ (NMSU Circular 668).

Chart

Average dry matter lost at each harvest step

% of dry matter, alfalfa, average value for each step

Raking shows the widest spread: from 1% of dry matter lost to 20%, with an average of 5%. That range is the case for managing moisture. The same operation on the same crop can cost almost nothing or a fifth of the harvest, depending on how dry the leaves are when the rake runs. Rain is the other large item. One inch of rain on cut alfalfa averages 17% dry matter lost, and two inches averages 30%.

The same circular notes that mowing and conditioning losses are small, and that swath inversion (turning the swath over without raking) loses less than tedding or raking. A tedder lifts and re-spreads the crop to speed drying. Wisconsin Extension warns that tedding grass is best done about 24 hours after cutting, once the crop has started to dry.

Chart

Range of loss for the same step

% of dry matter, alfalfa, range reported in the table

Windrower or mower plus rake: how to choose

There are two ways to get to a windrow, and the choice is partly about money and partly about weather. A windrower puts down a row in one pass, so fewer trips cross the field. A mower-conditioner plus rake gives you the wide swath that dries fastest, then a second pass makes the row when the moisture is right. The Wisconsin evidence favours a wide swath for drying speed; the case for a windrower is fewer passes, which is not something these sources measure.

The table lists what hiring each step cost in Wisconsin in 2025. It is a survey of hired work, so use it to compare steps, not to price a job. Sums of averages from different groups of respondents are only a guide.

Source: UW Extension Farm Management, Custom Rates for 2025 Wisconsin Farm Operations (fuel included).

A simple reading: mow-and-condition plus one raking pass adds up to about US$28 per acre at the survey averages, and mow-and-condition plus a windrowing pass adds up to about US$30. The gap is small next to a raking loss. On 40 acres at 2 tons per acre and US$160 per ton, each extra 1% of dry matter lost is worth about US$128, or US$3.20 per acre. A pass at the survey averages of about US$10 to US$13 per acre pays for itself only if it saves roughly 3 to 4 percentage points of dry matter.

If you own equipment, the question changes to hours and acres. The small fleet that serves 40 acres may cost more per acre than the hired rate. Count machine hours, fuel, repairs and your own time, and compare them with a local quote. Keep the comparison to one season of your own records.

Windrowing costs: custom rates and hay prices

If you hire the work, the 2025 Wisconsin custom rate survey gives a recent local price list. It had 135 respondents, the rates include fuel, and each line has a different number of answers. Windrowing hay averaged US$13.40 per acre (range US$10 to US$17, 10 responses). Raking averaged US$11.77, tedding US$9.83, and mowing with conditioning US$16.48 (UW Extension Farm Management, 2025 custom rates). These are survey averages for Wisconsin, not quotes. Rates vary by state and by operator, so ask a local custom hire service for a current price.

Chart

Custom rates for hay field work in Wisconsin, 2025

US$ per acre, survey average, fuel included, 135 respondents in total

Whether a loss matters depends on what the hay is worth. USDA’s National Agricultural Statistics Service reports the US average price of baled hay at US$208 per ton in 2023, US$166 in 2024 and US$160 in 2025 (the 2025 figure is preliminary). The Wisconsin average was US$160, US$144 and US$119 (USDA NASS, Crop Values 2025 Summary, February 2026). Lower prices make a lost ton cheaper. NASS also lists alfalfa hay on its own line: US$170 per ton for the United States and US$129 for Wisconsin in 2025 (preliminary). Use the price for your own hay type and market in the calculator.

Chart

Price per ton of baled hay, 2023 to 2025

US$ per ton, United States and Wisconsin; 2025 is preliminary

Calculator: what does raking loss cost you?

Use the tool below with your own acres, yield and price. It turns a raking loss percentage into tons and dollars, and shows the loss at which the lost hay is worth more than a hired raking pass.

Here is what the default numbers show. A 40-acre field at 2 tons per acre holds 80 tons. At US$160 per ton, the crop is worth US$12,800. A 5% raking loss takes 4 tons, or US$640. At 20%, the top of the NMSU range, it takes 16 tons, or US$2,560. At 1%, the bottom of the range, it takes less than a ton, about US$128. At a raking rate of US$12 per acre, hiring the pass costs US$480, so a loss above 3.75% costs more than the pass itself in this example.

Change the price to your own. A premium hay market, or a dairy that needs high-protein alfalfa, values leaves above the USDA state average. Remember what the calculator leaves out: lower feed quality, rain risk from slow drying and the time cost of a second pass.

Try the numbers for your own farm below.

Windrow grazing: leaving the row for cattle

Windrow grazing, also called swath grazing, means cutting a forage crop, leaving it in rows, and letting cattle graze the rows in the field instead of baling and hauling. Montana State University Extension says the costs of swathing, baling, stacking, storing and feeding baled hay can fall by as much as 60 to 75% this way. Its cost list shows baling at US$8 to US$10 per acre, hauling and stacking US$8 to US$10, and feeding US$5 to US$10, with fence and labour adding back less than US$2 per acre (MSU Extension, swath and windrow grazing). The page cites projects from the 1990s and gives no date for these dollar figures, so read them as relative sizes, not as current prices.

The University of Nebraska-Lincoln NebGuide G1616 adds animal results. In two High Plains studies, weaned calves and bred heifers grazing windrows did as well as, or better than, cattle fed baled hay cut from the same place. Crude protein in windrowed and baled meadow forage stayed similar, 10.6%, from September to February, while standing forage fell to 5.7% (UNL NebGuide G1616, Windrow Grazing).

The row is built differently for grazing than for drying. Montana State advises rows no more than 4 feet wide, high and dense, made by raking two or more together while the forage is still moist. Nebraska suggests swathing in early fall when nights are cool, and raking right after the swather so the rows rope together. Both warn about waste. Montana State cites a Nebraska study where fences moved only every 10 to 14 days and waste was as high as 26%; in other studies that gave cattle one day’s feed at a time, waste was below 5%.

Two cautions apply. Annual forages such as sorghum-type crops can carry nitrate or prussic acid, so Nebraska says to test before grazing. And deep snow, ice crust or wildlife can make rows hard to use, so keep a backup feed plan. This is livestock feeding advice from two extension services; check local guidance and ask a nutritionist or veterinarian before you change a winter feeding plan.

▶ The benefits and costs of mixing crops and livestock on one farm. · 2:55

Windrows beyond hay: grain, canola and compost

Windrowing is not only for hay. Prairie canola growers swath the crop and let it cure in the row before combining. The Canola Council of Canada tells growers to start checking fields about 10 days after flowering ends and to swath when about 60% of seeds on the main stem show some colour change (Canola Council of Canada, Canola Watch). Some small grains are also cut and cured in a row before a combine picks them up; the Wisconsin survey lists a separate custom combining rate for small grains from the swath.

Compost makers use windrows for a different goal: to let air in and keep heat in. Cornell’s composting fact sheet says that if a windrow is too large, oxygen cannot reach the centre, and if it is too small it will not heat up. Autumn leaves are usually piled about 8 feet tall and 16 feet wide, and a mix of grass clippings and leaves nearer 5 feet high and 10 feet wide (Cornell Cooperative Extension, Building Windrows). FAO gives a wider farm range: from 90 cm high for dense manure to 360 cm for light leaves, and 3 to 6 m wide. It adds that easily broken-down mixes may need daily turning at first and weekly turning later (FAO, composting windrow method).

Common windrow mistakes and how to spot them

• Rows that are too narrow after mowing. Narrow, dense rows slow drying. Check the conditioner setting and the width of the row against the cut width. Wisconsin found one machine leaving a row at 48% of cut width that stayed wet at 70% moisture after 5.5 hours.
• Raking by the clock. Time since mowing is a guide, not a measurement. Wisconsin says 40 to 60% moisture is often reached 12 to 24 hours after mowing, so in your field it can come earlier or later.
• Tedding at the wrong moment. NMSU warns that tedding late can do more harm than good.
• Ignoring wheel tracks. A wide swath means a tractor wheel may drive over some of it. Wisconsin found this causes less loss than making a narrow row, and suggests driving one wheel between swaths and one near the thinner middle.
• Leaving the row to the weather. Rain on nearly dry hay does more quality damage than rain on wetter hay (NMSU), so a forecast should change the plan before you cut.
• Grazing rows that are too wide. Montana State says rows made too big encourage animals to bed down on them and waste forage.

When a problem shows up in a part of the field, such as slow drying in one low block, map it. A note on the field edge, a photo or a satellite map helps you plan the same block earlier or later next cutting.

Seven windrow habits and where each one comes from

These habits come from the sources above. Each says where its support comes from, so you can see which are measured results and which are advice.

1. Lay the crop wide first. Cover at least 70% of the cut area right after mowing (UW Extension).
2. Adjust the conditioner. Wisconsin Extension says properly set conditioners show light bruising on 1 to 5% of leaves, and roller types suit alfalfa because they cut leaf loss.
3. Check moisture before you rake. Aim for the 40 to 60% band (UW) or 35 to 40% (NMSU) and pick the range that fits your crop.
4. Match the row to the machine. Size the windrow to the baler pickup or chopper header you use. This is a practical rule from machine makers, not a measured figure.
5. Use a tedder with care. Tedding grass about 24 hours after cutting is Wisconsin advice. NMSU lists alfalfa tedding losses of 2 to 8% of dry matter (average 3%) and says to ted shortly after swathing.
6. Watch rain, not the calendar. One inch of rain on cut alfalfa averaged 17% loss in the NMSU table, far more than any raking step.
7. Keep rows off wet low spots. Water and cold air collect in hollows, so a row through one dries later. This is field experience, not a number from a trial.

Row spacing is a different thing from planting spacing. Inter-row spacing is the gap between rows of a standing crop, set at planting. Windrow spacing is set after cutting, by the machine that makes the row.

Planning a windrow job with satellite maps

A satellite image cannot show how dry a windrow is, but it can show where a field greens up unevenly, where weak patches sit, and how large each block is, before the mower starts. Sentinel-2 images fields at 10 m resolution with a revisit of about 5 days at the equator for the pair of satellites (ESA Copernicus SentiWiki, Sentinel-2 mission). Farmonaut Satellite + AI Farm Monitoring System uses imagery like this to give field-level vegetation maps you can open from the web or mobile app, so you can compare blocks before you cut.

▶ How satellite vegetation maps show crop condition across a large farm. · 4:09

Weather and the cutting window

Rain turns a good windrow into a loss, so haymakers watch the forecast closely. The NMSU numbers show why: one inch of rain on cut alfalfa averaged a 17% dry matter loss. Pick a cutting window with a run of dry days, and cut a block you can rake and bale before the next front arrives.

Cloud makes optical satellites less useful in a wet spell. Radar satellites see through cloud, so they can still show change on the ground when optical images are blocked. The short video below explains how radar imagery works.

▶ How radar satellite images see through cloud. · 2:37

How we checked the numbers

The original page quoted a 1967 USDA labour survey, machinery price lists, a “30 to 40% moisture” figure attributed to Wisconsin Extension and a baler-fill number. We could not match them to a source we opened, and the moisture figure disagrees with Wisconsin’s published 40 to 60%, so we removed them. Every figure above comes from a page we opened: UW Extension, NMSU, USDA NASS, Montana State, University of Nebraska-Lincoln, Cornell, FAO, the Canola Council of Canada and ESA. Dollar figures are survey averages or reported prices with their year, not quotes. Always follow product labels and local rules for any crop-protection or fertilizer pass over a windrow, and get professional advice on financial decisions.

FAQ

What is a windrow?

A windrow is a long, narrow row of cut hay, straw or crop residue left in a field to dry before baling, chopping or grazing. It can also mean a long pile of compost that is turned for air.

What is windrowing?

Windrowing is the job of cutting a crop and laying it in a row, or raking a wide swath into a row. It only positions the crop for curing; a baler, harvester or livestock removes it later.

What is the difference between a swath and a windrow?

A swath is cut crop laid wide behind the mower. A windrow is the narrower row made when swaths are raked or merged. Wisconsin Extension says a wide swath dries faster early on, so rows are made later.

How much hay do I lose when I rake?

The NMSU table shows raking losses of 1 to 20% of dry matter for alfalfa, with an average of 5%. The loss depends mostly on how dry the leaves are, so check moisture before you rake.

What does it cost to hire windrowing?

The 2025 Wisconsin custom rate survey averaged US$13.40 per acre for windrowing hay, with a range of US$10 to US$17. Rates differ by region and operator, so ask a local provider.

Is windrow spacing the same as inter-row spacing?

No. Inter-row spacing is the distance between rows of a standing crop, set at planting. Windrow spacing is set after cutting, when the crop is raked into rows.

Related pages on our site: crop traceability, fleet and machinery management, carbon footprint tracking, crop loan and insurance, large-scale farm management and weather API documentation.