The field you cut ten times
Harvest a wheat field and that planting is finished. Harvest an alfalfa field and it starts over — and in the desert it starts over again, and again.
Think about a field of wheat or rice at harvest time: the crop is taken, that planting is over, and the field has to be sown again before there is another one. Alfalfa is not harvested like that, and USDA’s own leaflet on the plant explains why in one short line: “New growth occurs from buds in the crown.” The crown is the woody knot where the stems meet the root. Cut the stems above it and the buds down there start the plant over. Under the crown is the other half of the machine: “The plant has a tap root which may penetrate deep into the soil.” That root stays put through every cut. USDA’s guidance is to cut again “at ¼ bloom stage or after a 5 to 6 week recovery period,” and it describes the crop itself as one that “is harvested as hay which is processed or fed directly to livestock.” So an alfalfa field is less like a crop that is grown and gathered, and more like a plant that is kept — and interrupted, over and over.
Basis: USDA NRCS, Plant Fact Sheet, “Alfalfa (Medicago sativa L.),” USDA NRCS National Plant Materials Center, sections Uses, Description and Management. Quotations unchanged.
How many times you can interrupt it depends on where the field is. The University of Arizona ran alfalfa trials for nearly thirty years and described the country around them like this: fields “typical of agricultural areas of the low elevation deserts of Arizona where 8 to 10 harvests of alfalfa are common each year, and stands typically remain productive for 3 to 4 years.” Eight to ten times, off the same planting, in one year. The same report also records how those fields were watered: “All fields were laser-leveled and alfalfa was irrigated using the border-strip method.” Laser-levelled means the ground is graded flat enough that water walks evenly across it instead of pooling at one end; border-strip means the field is divided into long strips and flooded, strip by strip.
Basis: University of Arizona Cooperative Extension, az1928 (March 2022), “Arizona Cooperative Alfalfa Forage Yield Trials (1993-2020)” (Michael J. Ottman, Jeffrey W. White and Steven E. Smith), Background section. Quotations unchanged. The report describes the university’s own trial fields and the farming region around them, not every alfalfa field in the state.
This is why “which state grows the most” and “which state grows the most per acre” are two different questions with two different answers. USDA prints both tables for alfalfa in the same year. In the per-acre table Arizona prints the highest figure of any state USDA counted. In the acreage table beside it, Arizona is nowhere near the top — the state with the most alfalfa acres is South Dakota, and Arizona sits in the middle of the list. Neither table is more honest than the other. They are answers to different questions, and if you only ever look at totals, the whole desert half of this story is invisible.
Basis: Both statements are machine-checked against committed USDA NASS fixtures on every build of this site (2025 annual crop survey): Arizona has the highest printed alfalfa yield per acre, South Dakota the most alfalfa acres harvested, and Arizona ranks 19th of the 41 printed states in acres. Registered in pipeline/curated/claims.json as alfalfa_yield_arizona_top, alfalfa_acres_south_dakota_top and alfalfa_acres_arizona_rank19. The quiz shows the numbers.
So why does the top of that table read like a list of the driest places in the country? The pieces are tempting: hot bright days, a growing season that barely stops, and irrigation that arrives when the farmer decides rather than when the weather decides. Put them together and you get more cuttings from the same ground, and more cuttings is more hay. That chain sounds obvious, and it may well be right — but no source consulted for this note actually states it, so it is written here as a guess. What is documented is the pieces: that 8 to 10 harvests a year are common in Arizona’s low deserts, that those fields are irrigated, and that USDA’s general guidance is to allow a ¼ bloom stage or a 5 to 6 week recovery before cutting again. There is also a much bigger question underneath, which this note is not equipped to answer: where that irrigation water comes from, and what else it could have been used for.
※ A hypothesis is an idea that isn't proven yet.
📊 Sources for the rankings mentioned in this note (links to the original data and retrieval dates) are on each quiz page below.