Bean straw is the residue most row-crop farmers used to leave in the field — and that a lot of cattlemen now bale for cheap roughage and bedding. But before you bale it or buy it, two questions decide whether it's a smart move: what fertility are you hauling off the field, and what's a bale actually worth? Producers who've forage-tested their own bean straw have put real numbers on both, and there's a storage twist that quietly changes the math.
Quick answer: Bean straw is a low-protein roughage and bedding material — handy and cheap, but heavy and dusty. Tested bales ran about 0.14% P and 0.88% K (dry matter), which is roughly 6.4 lb P₂O₅ and 21 lb K₂O per ton, or about $6.71 in replaceable nutrients in a 1,400 lb 5×6 bale. Nitrogen basically doesn't count — it takes more N to break the straw down than the straw holds, so removing it actually frees N for the next crop. The catch: leave bales lying out and over 50% of the nutrients leach away after they get rained on, so the fertility you "sold" was already gone. Bale promptly and store it off the ground.
What you're hauling off: the P and K math
The question every row-crop farmer asks before baling bean straw is exactly this one:
"How much p and k am I taking off when baling it?"
— original poster, NE Illinois · AgTalk thread 1179143
The cleanest answer came from a producer who actually weighed and forage-tested his own bales and ran the dollars:
"Last bean straw bales I tested were .14%P and .88%K based on DM which works out to 6.41lb P205 and 21.21lb K20 per ton on 20% moisture bales. Given .24/lb Urea, 0.37/lb DAP, and 0.23/lb Potash it works out to $6.71 in nutrients for a 1400 5x6 bean straw bale."
— MiradaAcres, SC MN · AgTalk thread 1179143
So in fertility-replacement terms, a big bean-straw bale carries on the order of $6 to $7 of P and K off the field at those prices. That's the number to weigh against what the straw is worth to you as feed or bedding — and against what you'd pay to replace the nutrients.
The nitrogen surprise: removing straw can help next year
It's tempting to add nitrogen to the "removed" column, but for bean straw it works the other way. The straw is so carbon-heavy that soil microbes have to borrow nitrogen to rot it down — so taking the straw off leaves more N available to your next crop, not less:
"N does not count since it takes more N to breakdown the straw than the straw contains so removing the straw makes more N available for the next crop."
— MiradaAcres, SC MN · AgTalk thread 1179143
The other practical takeaway from the thread: don't guess your own numbers — weigh and test. As one producer put it, "you can weight some and then forage test them and the test will tell you. Don't forget about N." (Crete, Badger State). Residue nutrient levels vary with yield, weather, and how much leaf is in the bale.
The storage twist that erases the value
Here's the part that changes the decision: the fertility you're "selling" off the field is mostly gone by the time weathered bales sit out. Nutrients leach back into the ground — and a good soaking takes most of it:
"One thing to add is the longer they lay nutrients will leach out into the soil so the nutrient removal drops. If they get rained on and dry out over 50% of the nutrients will was out."
— MiradaAcres, SC MN · AgTalk thread 1179143
That cuts two ways. If you're the landowner worried about hauling off fertility, weathered bales took less than the test suggests. If you're the one feeding or selling the straw, a bale that's been rained on and bleached is worth less as feed and has shed half its nutrient value — so bale it promptly and keep it off wet ground. The same storage rules that protect hay protect straw; see how to store round bale hay and round bale storage base prep.
Using bean straw: feed and bedding realities
Bean straw is a low-protein, high-fiber roughage — useful to stretch a ration or as bedding, but not a feed you build a wintering program around without supplement. Two handling notes producers consistently raise: bean-straw bales are dense and heavy even when dry, so they tax your loader and stack weight; and like all residue, the cleaner and less weathered they are, the better cattle accept them. If you're feeding it, watch intake and pair it with adequate protein and energy; if you're bedding with it, it's hard to beat on cost.
| Factor | Bean straw reality |
|---|---|
| Nutrient value off field | ~$6–7 P+K per 1,400 lb bale (tested ~0.14% P, 0.88% K) |
| Nitrogen | Effectively zero removed; taking straw can free N for next crop |
| Storage loss | Over 50% of nutrients leach out once rained on |
| As feed | Low-protein roughage; supplement; watch intake |
| As bedding | Cheap and effective; bales are heavy/dense |
Where XES fits
Whether you bale bean straw for feed, bedding, or sale, the value is in the bale you keep tight and off the ground — a weathered bale loses both feed quality and nutrient value. Dense residue bales also push hard against the net as they expand, so they want adequate wraps to hold shape. XES Extreme net wrap is DLG-tested (Report #7439) for strength and full-width coverage, and UV-rated 12 months (tested to ISO 4892-2) for bales stored outside. See how many net wraps per bale, or compare sizes on the net wrap product page.
The bottom line
Bean straw is cheap roughage and excellent bedding, and it carries only about $6–7 of replaceable P and K per big bale off the field — with nitrogen working in your favor, since removing straw frees N for next year. But that fertility evaporates fast: once bales weather and get rained on, more than half the nutrients leach back into the ground, taking feed quality with them. Test your own bales rather than guessing, bale promptly, and store off wet ground so the straw is still worth something when you use it.
Frequently asked questions
How much P and K is in bean straw?
Tested bales have run about 0.14% phosphorus and 0.88% potassium on a dry-matter basis, which works out to roughly 6.4 lb of P₂O₅ and 21 lb of K₂O per ton. Levels vary with yield, weather, and leaf content, so weighing and forage-testing your own bales is the only way to know your numbers.
What is a bale of bean straw worth?
In fertility-replacement terms, about $6 to $7 of P and K in a 1,400 lb 5×6 bale at recent fertilizer prices. Its feed and bedding value is separate and depends on quality and local demand. Weathered, rained-on bales are worth less on both counts.
Does baling bean straw hurt the next crop?
Less than you might think. You remove some phosphorus and potassium, but nitrogen effectively does not count — the straw is so carbon-heavy that breaking it down ties up more N than it contains, so removing it can leave more nitrogen available for the next crop.
Do bean straw bales lose value sitting outside?
Yes, substantially. Once bales lie out and get rained on, over half the nutrients leach back into the soil, and feed quality drops as the straw bleaches and weathers. Bale promptly and store the bales off wet ground to keep the value.
Is bean straw good cattle feed?
It is a low-protein, high-fiber roughage — useful to stretch a ration or for bedding, but not a stand-alone feed. If you feed it, pair it with adequate protein and energy and watch intake. The cleaner and less weathered the bale, the better cattle accept it.
This guide is maintained by the XES Netting team — a bale net-wrap manufacturer. Every farmer quote in this post is verbatim with a thread link, so you can read the originals. Nutrient values and prices are producer-tested figures from specific bales; test your own straw and confirm current fertilizer prices for your numbers.
Related guides
Featured photo: Mike Starkey Soybean Harvest by USDAgov, in the public domain, via Wikimedia Commons.
