43:null 44:["$","title",null,{"children":"Where bioenergy crops pencil out on the High Plains | Karthik Ramaswamy | Observable"}] 4a:T54a,

Profit-gap version · Ramaswamy et al. 2026

Where bioenergy crops pencil out on the High Plains

How far dryland sorghum or switchgrass trails the most profitable crop, in dollars per acre, across 180 High Plains Aquifer counties. Teal counties are where the crop is already as profitable as any alternative.

From Ramaswamy, Uludere Aragon & Lark (2026), Agricultural Water Management 334, 110675. Read the paper →

4b:T6d64,// Bioenergy crops on the High Plains (profit-gap version): the whole map page in one cell. // Data: Supplements S3, S6, S8 and S10 of Ramaswamy et al. (2026), attached as hpa_county_results.csv. // County shapes: us-atlas@3 (US Census Bureau), loaded from jsDelivr. display(await (async () => { // High Plains bioenergy-crop map. Needs Plot, d3 and topojson in scope // (all three are built into Observable notebooks). // Light palette, checked for color-vision separation: the teal "$0" class // stays distinct from every orange step for deutan, protan and tritan readers. const HPA_COLORS = { surface: "#fbfbf9", // map background and legend panel outside: "#eceae4", // counties outside the 180 modeled counties outsideStroke: "#fbfbf9", ink: "#1f2321", // outlines, labels muted: "#666a66", // state names, secondary text c0: "#0f7f8c", // $0/acre: already economically competitive c1: "#fde6d6", // $1-100 c2: "#f2a06a", // $101-200 c3: "#d9622a", // $201-300 c4: "#963a10", // over $300 nf: "#d4d3cc", // modeled, but this crop isn't feasible there marker: "#ffffff" }; const HPA_CLASSES = [ {id: "c0", label: "$0 — as profitable as the best crop"}, {id: "c1", label: "−$1 to −$100"}, {id: "c2", label: "−$101 to −$200"}, {id: "c3", label: "−$201 to −$300"}, {id: "c4", label: "Below −$300"}, {id: "nf", label: "Not feasible for this crop"} ]; const HPA_CROPS = {ds: "Dryland sorghum", sg: "Switchgrass"}; const HPA_LABEL_LEFT = new Set(["48069"]); // Castro County, TX // Labels sit just outside the modeled counties so they don't cover data. const HPA_STATE_LABELS = [ {name: "SOUTH DAKOTA", lon: -100.4, lat: 44.55}, {name: "WYOMING", lon: -106.1, lat: 43.55}, {name: "NEBRASKA", lon: -96.85, lat: 41.15}, {name: "COLORADO", lon: -105.4, lat: 39.15}, {name: "KANSAS", lon: -96.25, lat: 38.35}, {name: "OKLAHOMA", lon: -97.2, lat: 35.75}, {name: "NEW MEXICO", lon: -105.3, lat: 35.3}, {name: "TEXAS", lon: -98.4, lat: 32.3} ]; function hpaClass(row, key) { if (!row) return null; const cost = row[`cost_${key}`]; if (row[`feasible_${key}`] !== 1 || cost == null || Number.isNaN(cost)) return "nf"; if (cost === 0) return "c0"; if (cost <= 100) return "c1"; if (cost <= 200) return "c2"; if (cost <= 300) return "c3"; return "c4"; } function hpaTipText(row, crop, year) { const key = `${crop}_${year}`; const cost = row[`cost_${key}`]; const cls = hpaClass(row, key); const costLine = cls === "nf" ? "Not feasible here in the model" : cls === "c0" ? "$0/acre — as profitable as the best crop" : `−$${d3.format(",.0f")(cost)}/acre vs. the most profitable crop`; const lines = [ `${row.county} County, ${row.state}`, `${HPA_CROPS[crop]}, model year ${year}, profit gap: ${costLine}`, `Modeled irrigated area: ${d3.format(",")(row.irrigated_acres)} acres`, `Crop in years 1 → 16 → 30: ${row.crop_year1} → ${row.crop_year16} → ${row.crop_year30}` ]; if (row.dryland_transition_year) lines.push(`Shifts to dryland in year ${row.dryland_transition_year}`); if (row.irrigated_sorghum_year) lines.push(`Switches to irrigated sorghum in year ${row.irrigated_sorghum_year}`); return lines.join("\n"); } // Turns raw CSV rows (all strings) into typed rows, keeping FIPS as text. function hpaParse(rows) { const num = (v) => (v === "" || v == null ? null : +v); return rows.map((r) => { const o = {...r}; for (const k of Object.keys(r)) { if (/^(cost|feasible|competitive)_/.test(k)) o[k] = num(r[k]); } o.irrigated_acres = +r.irrigated_acres; o.dryland_transition_year = num(r.dryland_transition_year); o.irrigated_sorghum_year = num(r.irrigated_sorghum_year); return o; }); } function hpaMap({ data, topo, crop = "ds", year = 1, showIrrigatedSorghum = true, width = 900, colors = HPA_COLORS, legend = true, fontFamily = "system-ui, sans-serif" }) { const key = `${crop}_${year}`; const byFips = new Map(data.map((d) => [d.fips, d])); const counties = topojson.feature(topo, topo.objects.counties).features; const states = topojson.feature(topo, topo.objects.states); const study = topojson.feature(topo, topo.objects.study); const stateLines = topojson.mesh(topo, topo.objects.states, (a, b) => a !== b); const modeled = counties .filter((f) => byFips.has(f.id)) .map((f) => ({...f, row: byFips.get(f.id), cls: hpaClass(byFips.get(f.id), key)})); const others = counties.filter((f) => !byFips.has(f.id)); const competitive = modeled.filter((f) => f.cls === "c0"); const irrigated = showIrrigatedSorghum ? modeled.filter((f) => f.row.irrigated_sorghum_year != null) : []; // Frame on the modeled area with room for the state labels. const frame = { type: "MultiPoint", coordinates: [[-106.9, 31.3], [-95.6, 31.3], [-95.6, 44.7], [-106.9, 44.7], [-101.2, 44.9]] }; const fillFor = (f) => colors[f.cls]; const svg = Plot.plot({ width, projection: {type: "conic-equal-area", parallels: [33.5, 42.5], rotate: [101.2, 0], domain: frame}, style: {fontFamily, fontSize: "12px", color: colors.ink, background: colors.surface, overflow: "visible"}, marks: [ Plot.geo(states, {fill: colors.outside, clip: "frame"}), Plot.geo(others, {stroke: colors.outsideStroke, strokeWidth: 0.5, clip: "frame"}), Plot.geo(modeled, {fill: fillFor, stroke: colors.surface, strokeWidth: 0.6}), // Second channel for the key class: an ink outline, so it holds up in print and CVD. Plot.geo(competitive, {stroke: colors.ink, strokeWidth: 1.1}), Plot.geo(stateLines, {stroke: colors.muted, strokeWidth: 0.9, strokeOpacity: 0.7, clip: "frame"}), Plot.geo(study, {stroke: colors.ink, strokeWidth: 1.6}), Plot.text(HPA_STATE_LABELS, { x: "lon", y: "lat", text: "name", fill: colors.muted, fontSize: 10.5, fontWeight: 600, stroke: colors.surface, strokeWidth: 3, paintOrder: "stroke" }), Plot.dot(irrigated, Plot.centroid({r: 4.5, fill: colors.marker, stroke: colors.ink, strokeWidth: 1.6})), // Castro (TX) sits beside Swisher, so its label goes to the left. ...[ [irrigated.filter((f) => !HPA_LABEL_LEFT.has(f.id)), 7, "start"], [irrigated.filter((f) => HPA_LABEL_LEFT.has(f.id)), -7, "end"] ].map(([feats, dx, textAnchor]) => Plot.text(feats, Plot.centroid({ text: (f) => `Yr ${f.row.irrigated_sorghum_year}`, dx, textAnchor, fontSize: 10.5, fontWeight: 700, fill: colors.ink, stroke: colors.surface, strokeWidth: 3, paintOrder: "stroke" }))), Plot.tip(modeled, Plot.pointer(Plot.centroid({title: (f) => hpaTipText(f.row, crop, year)}))) ] }); if (legend && width >= 640) hpaDrawLegend(svg, {crop, year, colors, showIrrigatedSorghum, fontFamily}); return svg; } // Profit-gap legend: a stepped bar from $0 (teal) to below -$300 (darkest orange), // plus keys for "not feasible" and the irrigated-sorghum dots. Draws into a d3 . function hpaGapLegend(g, {colors, showIrrigatedSorghum, fontFamily}) { const segW = 54, barH = 12, x0 = 46, top = 28; g.attr("font-family", fontFamily).attr("text-anchor", "start"); g.append("text").attr("x", 0).attr("y", 12).attr("font-size", 11.5).attr("font-weight", 700) .attr("fill", colors.ink).text("Profit gap vs. the most profitable crop ($/acre)"); // $0 block, set apart from the ramp because it is its own category. g.append("rect").attr("x", 0).attr("y", top).attr("width", 36).attr("height", barH) .attr("fill", colors.c0).attr("stroke", colors.ink).attr("stroke-width", 1.1); ["c1", "c2", "c3", "c4"].forEach((id, i) => { g.append("rect").attr("x", x0 + i * segW).attr("y", top).attr("width", segW).attr("height", barH) .attr("fill", colors[id]).attr("stroke", colors.surface).attr("stroke-width", 1); }); g.append("rect").attr("x", x0).attr("y", top).attr("width", 4 * segW).attr("height", barH) .attr("fill", "none").attr("stroke", colors.muted).attr("stroke-opacity", 0.5).attr("stroke-width", 0.5); const tick = (x, label, anchor = "middle") => { g.append("line").attr("x1", x).attr("x2", x).attr("y1", top + barH).attr("y2", top + barH + 4) .attr("stroke", colors.muted); g.append("text").attr("x", x).attr("y", top + barH + 15).attr("font-size", 10.5).attr("fill", colors.ink) .attr("text-anchor", anchor).style("font-variant-numeric", "tabular-nums").text(label); }; g.append("text").attr("x", 18).attr("y", top + barH + 15).attr("font-size", 10.5).attr("font-weight", 700) .attr("fill", colors.ink).attr("text-anchor", "middle").text("$0"); tick(x0 + segW, "−100"); tick(x0 + 2 * segW, "−200"); tick(x0 + 3 * segW, "−300"); g.append("text").attr("x", 18).attr("y", top + barH + 28).attr("font-size", 10).attr("fill", colors.muted) .attr("text-anchor", "middle").text("competitive"); g.append("text").attr("x", x0 + 4 * segW).attr("y", top + barH + 28).attr("font-size", 10).attr("fill", colors.muted) .attr("text-anchor", "end").text("further behind →"); const y2 = top + barH + 46; g.append("rect").attr("x", 0).attr("y", y2 - 9).attr("width", 18).attr("height", 12).attr("rx", 2) .attr("fill", colors.nf).attr("stroke", colors.muted).attr("stroke-width", 0.5).attr("stroke-opacity", 0.5); g.append("text").attr("x", 24).attr("y", y2 + 1).attr("font-size", 11).attr("fill", colors.ink).text("Not feasible"); if (showIrrigatedSorghum) { g.append("circle").attr("cx", 117).attr("cy", y2 - 3).attr("r", 4.5) .attr("fill", colors.marker).attr("stroke", colors.ink).attr("stroke-width", 1.6); g.append("text").attr("x", 127).attr("y", y2 + 1).attr("font-size", 11).attr("fill", colors.ink) .text("Switch to irrigated sorghum (yr)"); } return {width: x0 + 4 * segW + 50, height: y2 + 8}; } // Overlays the legend inside the map SVG (bottom-left, over New Mexico), so a downloaded PNG/SVG carries it. function hpaDrawLegend(svg, {crop, year, colors, showIrrigatedSorghum, fontFamily}) { const H = +svg.getAttribute("height"); const boxW = 312, boxH = 104; const g = d3.select(svg).append("g").attr("transform", `translate(6,${H - boxH - 6})`); g.append("rect").attr("width", boxW).attr("height", boxH).attr("rx", 4) .attr("fill", colors.surface).attr("fill-opacity", 0.94) .attr("stroke", colors.muted).attr("stroke-opacity", 0.35); hpaGapLegend(g.append("g").attr("transform", "translate(12,12)"), {colors, showIrrigatedSorghum, fontFamily}); return svg; } // Standalone legend SVG, shown under the map (an overlay would cover Texas counties on wide screens). function hpaLegendSVG({colors, showIrrigatedSorghum, fontFamily}) { const svg = d3.create("svg").attr("width", 320).attr("height", 96).attr("viewBox", "-2 0 320 96") .style("max-width", "100%").style("height", "auto").style("overflow", "visible"); hpaGapLegend(svg.append("g"), {colors, showIrrigatedSorghum, fontFamily}); return svg.node(); } // Builds the map geometry from the public us-atlas counties file: // counties in the eight High Plains states, nearby state outlines, // and one merged outline of the modeled counties. function hpaTopology(us, data) { const studyIds = new Set(data.map((d) => d.fips)); const highPlains = new Set(["08", "20", "31", "35", "40", "46", "48", "56"]); const nearby = new Set([...highPlains, "30", "38", "27", "19", "29", "05", "22", "04", "49", "16", "17", "55"]); const counties = { type: "GeometryCollection", geometries: us.objects.counties.geometries.filter((g) => highPlains.has(g.id.slice(0, 2))) }; const states = { type: "GeometryCollection", geometries: us.objects.states.geometries.filter((g) => nearby.has(g.id)) }; const study = topojson.mergeArcs(us, counties.geometries.filter((g) => studyIds.has(g.id))); return {...us, objects: {counties, states, study}}; } const hpaData = hpaParse(await FileAttachment("hpa_county_results.csv").csv()); const us = await fetch("https://cdn.jsdelivr.net/npm/us-atlas@3/counties-10m.json").then((r) => r.json()); const hpaTopo = hpaTopology(us, hpaData); const root = document.createElement("div"); root.className = "hpa-app"; root.innerHTML = `

Crop

Model year

Show switches to irrigated sorghum

This view

Key findings

Declining groundwater shifts what's grown. Over 30 years, the model suggests about 23% of today's irrigated corn area on the High Plains Aquifer could move to dryland farming.
Dryland sorghum already competes in parts of the north. In Year 1 it matches or beats the most profitable alternative in 19 counties: 9 in Kansas, 5 in Nebraska and 5 in Wyoming.
Further south it still trails. In 10 Texas Panhandle counties, dryland sorghum is feasible but earns $266–$428 per acre less than the best crop in Year 1. No Oklahoma county is competitive.
Switchgrass suits the western edge. It is competitive in Year 1 in 15 counties: 10 in Colorado, 3 in New Mexico and 2 in Kansas.
A larger bioenergy feedstock base. Non-irrigated sorghum production could roughly triple, from 0.20 to 0.77 million tonnes a year.
Competitive is not a forecast. A $0 profit gap doesn't measure how much more profitable a crop is, or predict an immediate switch. Real decisions depend on markets, policy, infrastructure and each farm.

Counties by state

County table for this view

`; const $ = (r) => root.querySelector(`[data-r="${r}"]`); const cssColors = { surface: "var(--surface)", outside: "var(--outside)", outsideStroke: "var(--outside-stroke)", ink: "var(--ink)", muted: "var(--muted)", c0: "var(--c0)", c1: "var(--c1)", c2: "var(--c2)", c3: "var(--c3)", c4: "var(--c4)", nf: "var(--nf)", marker: "var(--marker)" }; const fontFamily = '"Public Sans", "Segoe UI", system-ui, sans-serif'; const state = {crop: "ds", year: 1, irr: true}; const mapEl = $("map"); const fmt = d3.format(",.0f"); let lastWidth = 0; function bindSeg(r, key, parse) { const el = $(r); el.addEventListener("click", (e) => { const b = e.target.closest("button"); if (!b) return; state[key] = parse(b.dataset.v); el.querySelectorAll("button").forEach((x) => x.setAttribute("aria-pressed", String(x === b))); update(); }); } bindSeg("crop", "crop", (v) => v); bindSeg("year", "year", (v) => +v); $("irr").addEventListener("change", (e) => { state.irr = e.target.checked; update(); }); function drawMap() { const width = Math.max(300, Math.floor(mapEl.clientWidth || 600)); lastWidth = width; const svg = hpaMap({ data: hpaData, topo: hpaTopo, crop: state.crop, year: state.year, showIrrigatedSorghum: state.irr, width, colors: cssColors, legend: false, fontFamily }); mapEl.replaceChildren(svg); const lh = $("legend"); lh.hidden = false; if (!lh.hidden) { lh.replaceChildren(hpaLegendSVG({colors: cssColors, showIrrigatedSorghum: state.irr, fontFamily})); } } function updatePanel() { const key = `${state.crop}_${state.year}`; const cropName = HPA_CROPS[state.crop]; const rows = hpaData.map((d) => ({...d, cls: hpaClass(d, key), cost: d[`cost_${key}`]})); const comp = rows.filter((d) => d.cls === "c0"); const costlier = rows.filter((d) => d.cls && d.cls !== "c0" && d.cls !== "nf"); const nf = rows.filter((d) => d.cls === "nf"); $("n").textContent = comp.length; $("nlabel").textContent = `counties where ${cropName.toLowerCase()} is economically competitive in model year ${state.year}`; const byState = d3.rollups(comp, (v) => v.length, (d) => d.state).sort((a, b) => b[1] - a[1]); $("chips").innerHTML = byState.map(([s, n]) => `${s} ${n}`).join(""); const ext = d3.extent(costlier, (d) => d.cost); $("stats").innerHTML = `

Behind the best crop${costlier.length}

Profit gap range${costlier.length ? `−$${fmt(ext[0])} to −$${fmt(ext[1])}/ac` : "—"}

Not feasible for ${cropName.toLowerCase()}${nf.length}

Modeled counties${rows.length}

`; $("caption").textContent = `${cropName}, model year ${state.year}. Profit gap in $/acre: profit of the crop shown minus profit of the most profitable crop in each county. ` + `Black outline marks the 180 modeled counties.` + (state.irr ? " Dots mark counties where the model switches from irrigated corn to irrigated sorghum, labeled with the model year." : ""); const byStateAll = d3.rollups(rows, (v) => ({ comp: v.filter((d) => d.cls === "c0").length, cost: v.filter((d) => d.cls && d.cls !== "c0" && d.cls !== "nf").length, nf: v.filter((d) => d.cls === "nf").length, n: v.length }), (d) => d.state).sort((a, b) => b[1].comp - a[1].comp || b[1].cost - a[1].cost || a[0].localeCompare(b[0])); $("statetitle").textContent = `Counties by state: ${cropName.toLowerCase()}, model year ${state.year}`; $("statetable").innerHTML = `StateCompetitive ($0)Behind best cropNot feasibleModeled counties` + byStateAll.map(([s, o]) => `${s}${o.comp}${o.cost}${o.nf}${o.n}`).join("") + `All states${comp.length}${costlier.length}${nf.length}${rows.length}`; const sorted = rows.slice().sort((a, b) => (a.cost == null) - (b.cost == null) || (a.cost ?? 0) - (b.cost ?? 0) || a.state.localeCompare(b.state)); $("table").innerHTML = `CountyStateProfit gap ($/ac)StatusDryland fromIrr. sorghum fromCrop yr 1 → 16 → 30` + sorted.map((d) => `${d.county}${d.state}` + `${d.cls === "nf" ? "—" : d.cost === 0 ? "$0" : "−$" + fmt(d.cost)}` + `${d.cls === "c0" ? "Competitive" : d.cls === "nf" ? "Not feasible" : "Behind"}` + `${d.dryland_transition_year ?? "—"}${d.irrigated_sorghum_year ?? "—"}` + `${d.crop_year1} → ${d.crop_year16} → ${d.crop_year30}`).join("") + ``; } function update() { drawMap(); updatePanel(); } update(); let t; new ResizeObserver(() => { clearTimeout(t); t = setTimeout(() => { if (mapEl.clientWidth && Math.abs(mapEl.clientWidth - lastWidth) > 4) drawMap(); }, 120); }).observe(mapEl); return root; })()); 4c:[{"id":"8d11cab2090a83138c6e7f7751fd836bf12ffee8fb2354ba8af4cef98b89db819982de38f3b1ab88feab085f05c8abf1620dd25d8c7ac436ec9e8c6d5e4e20b7","href":"https://static.observableusercontent.com/files/8d11cab2090a83138c6e7f7751fd836bf12ffee8fb2354ba8af4cef98b89db819982de38f3b1ab88feab085f05c8abf1620dd25d8c7ac436ec9e8c6d5e4e20b7","name":"hpa_county_results.csv","type":"text/csv","lastModified":1792508275651,"size":33026}] 48:{"id":"040de40ad54ae634","slug":"bioenergy-hp_fork","title":"Where bioenergy crops pencil out on the High Plains","thumbnail":"0512758c5a1a47862acf215ae52dcf238a2b2db9fe5c09307b08bda687c23d5e","access_level":"public","create_time":"$D2026-10-20T17:22:28.272Z","update_time":"$D2026-10-20T17:24:55.610Z","view_time":null,"first_public_time":"$D2026-10-20T17:49:48.876Z","has_unpublished_edits":null,"fork":{"id":"27b8fb47037f3f8a","slug":"bioenergy_on_hp","title":"Where bioenergy crops pencil out on the High Plains","owner":{"id":"9736ccf33b4dd1b8","login":"karthikramaswamy","name":"Karthik Ramaswamy"}},"stars":0,"starred":false,"owner":{"type":"team","id":"9736ccf33b4dd1b8","login":"karthikramaswamy","name":"Karthik Ramaswamy","avatar_url":null,"tier":"free_2026","bio":"","following":false},"version":57,"publish_version":57,"role":null,"authored":false,"authors":[{"type":"individual","id":"f4b5ce6952ea85e3","login":"karthikramaswamy","name":"Karthik Ramaswamy","avatar_url":null,"tier":null,"bio":"","following":false}],"members":[{"type":"team","id":"9736ccf33b4dd1b8","login":"karthikramaswamy","name":"Karthik Ramaswamy","avatar_url":null,"tier":"free_2026","role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"titling":"auto","title":"Where bioenergy crops pencil out on the High Plains","cells":[{"id":1,"value":"$4a","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"$4b","pinned":false,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W4c","stdlib":"2"}} 49:"$48:body"