By Scout Nelson
For the 2025 crop year, south-central Nebraska’s Little Blue Natural Resources District introduced its first groundwater allocation, limiting each certified irrigated acre in Hydrogeologic Unit 1 to 65 acre-inches over five years. Alongside this, new high-capacity wells and irrigation expansions are on hold to preserve long-term aquifer health.
To help farmers prepare, a 2024 field study at UNL’s South-Central Agricultural Laboratory near Clay Center tested two irrigation scheduling methods—Watermark sensors and a commercial satellite-based tool. Corn was planted on May 12 using DEKALB DKC61-40RIB, with five irrigation treatments applied across replicated plots.
Watermark-based treatments used soil tension levels of 60 and 80 centibars to trigger irrigation, while the commercial tool provided full and 70% recommendations, plus a satellite-only model. Irrigation began in August due to adequate June and July rainfall.
Applied water ranged from 4.4 inches (WM-2, deficit) to 8.8 inches (WM-1, full). Yields across treatments were similar, though WM-2, using 50% less water, produced just 6% less yield than WM-1.
“These results suggest strong potential for deficit irrigation when timed properly,” the report noted. The findings highlight that minimal early-season irrigation, combined with targeted late-season watering, can maintain yields with reduced water use.
Yield averages matched regional producer data, with irrigated plots yielding 236.5 to 287.0 bushels per acre, while dryland corn reached 180 bu/ac—showing a yield boost of up to 74 bu/ac from irrigation.
The study confirms that in silt loam soil, smart irrigation decisions can help Nebraska farmers meet water limits while sustaining productivity in a changing climate.
Photo Credit:istock-i-stockr
Categories: Nebraska, Crops, Corn, Weather