Irrigation and Fertilization

The irrigator walks each pivot tower, drop, and gasket and inspects buried mainline risers for frost heave and rodent damage. Note any pinhole leaks, sheared sprinkler heads, or eroded soil at riser bases — small leaks at 60 PSI become unwetted strips by V8.

Pull and clean the suction screen, change pump oil, inspect the impeller for cavitation pitting, and verify shaft seal integrity. For deep-well pumps, check column-pipe alignment and amperage draw against last season's baseline.

Verify GPM at the rated boom pressure. A drifting flow meter is a common reason fertigation rates miss target — the injector ratio is set off the meter, not the prescription. Compare today's reading to the manufacturer pump curve at the current dynamic head.

Run a clean-water test on the diaphragm injector at three rates and confirm the check valve and anti-siphon device hold. The check valve is the regulatory requirement that keeps fertilizer from back-flowing into the well — failures are findings on a state ag inspection.

Sample to a 6-8 inch depth on 2.5-acre grid (or by EC zone if zoned), 12-15 cores per composite. Pull a separate 0-24 inch deep core where corn-on-corn carryover N is in question. Bag, label by zone, and log GPS points in the FMS.

Servi-Tech, Ward Labs, A&L, or the state-affiliated lab — request the standard fertility panel plus organic matter, CEC, and base saturation. Specify the recommendation set the CCA uses (Tri-State, MRTN, or state extension) so output is comparable year over year.

Well water nitrate counts toward the season's N budget — 10 ppm NO3-N at 12 inches of irrigation delivers ~27 lb N/ac. Check EC and bicarbonate too if the field shows scaling on emitters. FSMA Produce Safety Rule covered farms also need the agricultural-water microbial test on the schedule the rule requires.

Walk through each zone's deficiency call against this year's yield goal, prior-crop credits (soybean N credit, manure history), and irrigation-water nitrate. Decide whether the field needs a variable-rate prescription or a flat rate is acceptable.

Generate the Rx in Climate FieldView, Operations Center, or SMS — N, P, and K layers per zone, with the controller-compatible shapefile. Hold the rate on field edges that border the organic neighbor and trim around grassed waterways.

Confirm the NMP reflects current setbacks from streams, tile inlets, wells, and property lines under your state's standard (often NRCS 590). Rebuild the application map if any setback changed since last season.

For fields that received fall manure, subtract the plant-available N credit from this spring's commercial N rate. Over-applying when manure is already in the bank is the most common NMP non-compliance the state inspector flags on a CAFO walkthrough.

Run pan-test at target speed and confirm spread pattern is even across the boom. Bulk density on urea vs. MAP vs. potash differs — recalibrate with the actual product loaded, not yesterday's setting.

Wind 3-10 mph, no inversion, knife depth set to keep NH3 in the soil. Verify the safety water tank is full and the operator has gloves, goggles, and the emergency-response card in the cab. Anhydrous burn is the single most common ag medical incident at this stage.

Load the prescription, verify rate-controller GPS lock, and apply. Trim end-gun shutoff so the tractor turns wide at field edges. Watch the as-applied map in real time — a row-unit dropping rate is a sensor problem, not a planter problem.

Field, date, product, EPA / fertilizer registration, rate, total applied, applicator, weather (wind speed and direction, temperature, humidity), equipment. File within the state's reporting window — federal recordkeeping is two years; many states require three to five.

Pull reference ET from the state mesonet and adjust by crop coefficient for current growth stage. Cross-check against the in-field capacitance probes at 6, 18, and 36 inches — if the 36-inch sensor is reading near field capacity, hold off and let the crop pull from depth.

Verify the check valve, anti-siphon, and low-pressure shutoff are functional before the injector starts. Inject UAN at the late-side timing window; pivot speed and injector rate together determine lb N / acre. Run clean water for at least one full revolution after the last injection to flush the lateral.

Walk the boundary at end-gun arc. Drift of fertigated N onto a certified-organic field is a buffer violation for them and a neighbor-relations problem for you. Document the shutoff arc on the pivot map.

Walk a representative pattern across each pivot. Yellow V on lower leaves is N; interveinal chlorosis on upper leaves is sulfur or zinc; purpling at V5-V6 is P. Geo-tag any symptom areas in the scouting app for follow-up.

Collect the ear leaf at tasseling (R1) — 15-20 leaves per zone of concern. Submit for a full nutrient panel so the rescue decision (foliar vs. additional fertigation pass) is data-backed, not eyeball.

Upload as-applied maps and signed logs to the FMS (Operations Center, FieldView, or Granular). Confirm each field's record is complete before the state ag department's reporting deadline — incomplete records are the first thing flagged on a routine audit.

Match retail invoices and as-applied totals against certified acres on the FSA-578. Any discrepancy needs to be resolved before crop-insurance APH submission and before EQIP cost-share invoicing — both pull from the same record set.