Benefits of Preplant Row Crop Irrigation

Unusually dry winter and spring conditions can severely limit the availability of soil moisture in the planting zone. If dry fields do not receive rainfall soon after planting, irrigation may be needed to promote germination and stand establishment.

Center pivot irrigation systems are available for preplant irrigation across a large geographic area including the High Plains region of Texas, western Kansas, and eastern Colorado through much of the western Corn Belt. This region experiences a wide range of annual precipitation, seasonal precipitation distribution, and groundwater well capacities, all of which influence the need for and availability of preplant irrigation.

Preplant irrigation is common in areas of the High Plains, where declining well capacities may limit growers’ ability to provide adequate water during peak use times in crop development. In areas where irrigation capacity is moderate to high, preplant irrigation is typically not necessary. However, preplant irrigation may be beneficial in these regions when unusually dry soil conditions exist at planting.

Benefits of Preplant Row Crop Irrigation Following a Dry Winter/Spring with Moderate to High In-Season Irrigation Capacity

In fields with overhead irrigation systems, moderate- to high-capacity wells, and adequate winter/spring precipitation, irrigation is generally not needed prior to planting. However, if extremely dry soil conditions carry over from winter into the planting season, the lack of soil moisture in the seedbed may not be conducive to achieving uniform germination and stand establishment. In those cases, preplant irrigation can be beneficial in several ways.

Softening Hard Soil Prior to Strip-Tillage or Other Tillage

Softening the soil with preplant irrigation can help to prevent clods and may help the tillage equipment perform better than it would in extremely dry conditions.

Improving Soil Conditions for Planting Row Crops

Planter operators are likely to have more difficulty maintaining proper downforce in hard soil than soft soil, which could result in uneven planting depth, emergence, and stand establishment. Planting into overly dry soil can also cause cavities where seed-to-soil contact is reduced, especially in no-till fields.¹ Preplant watering may provide a seedbed that is more uniformly moist for the planter to work in, which can help avoid these problems. However, the soil should be allowed to dry properly before planting to avoid sidewall compaction issues, which can be exacerbated by planting too shallowly or by applying too much downforce on the press wheels. Regardless of irrigation, the soil should fracture easily for good seed-to-soil contact.

Incorporating Fertilizer or Herbicides

Preplant irrigation can help to incorporate fertilizer and avoid volatilization, especially with urea-based products. If the soil is dry, preplant irrigation can also help reduce the risk of root burn from anhydrous ammonia or starter fertilizers. Overhead irrigation can help incorporate pre-emergence herbicides that might otherwise be subject to reduced effectiveness if left on a dry soil surface.¹ Follow all instructions on the herbicide product label regarding moisture and all other requirements.

Providing Moisture After the Termination of a Cover Crop

Preplant irrigation can help provide more uniform soil moisture conditions following the termination of a cover crop.

Preplant Row Crop Irrigation in Limited Irrigation Capacity Situations

Many growers—especially those in the High Plains region of the US, as mentioned above—may choose to use center pivots for preplant irrigation, either because of a lack of winter and spring precipitation, or because many irrigation wells are declining in their capacity to provide adequate water during times of peak water use later in the summer.

Impact of Preplant Irrigation on Crop Emergence

A study published in 2020 examined the effects of four levels of preplant irrigation on the emergence and grain yield of corn. Irrigation water was applied at the rates of 15, 25, 45, and 60 mm (about 0.60, 1.00, 1.75, and 2.3 inches, respectively). The 45 mm (1.75 inches) preplant irrigation rate produced the highest average grain yield and emergence rate over the two years of the study.²

Corn Yield Response to Preplant Irrigation

A study conducted by Kansas State University from 2006 to 2009 tried to determine the profitability of preplant irrigation in low-capacity groundwater situations at different plant densities. The researchers applied about 3.0 inches of preseason irrigation water and system capacity was set at 0.10, 0.15, and 0.20 inches of water applied per day. Their results indicated that preplant irrigation increased grain yield by an average of 16 bu/acre. In addition, grain yield was 28% higher when irrigation capacity was increased from 0.10 to 0.20 inches per day. Seeding rates of about 28,000 seeds per acre were more profitable than lower seeding rates even at the lower irrigation levels. In their findings, preplant watering was profitable at all irrigation capacity levels. Profits declined as delivery capacity increased, leading them to conclude that preseason watering may not be warranted if irrigation systems can provide more than 0.20 inches of water per day.³

Another study found similar results. The 2017 study attempted to determine which combination of preseason irrigation amount and irrigation system capacity would optimize yield potential and water productivity. The researchers found 10 to 17% higher yields when 3 to 4 inches of preplant irrigation water was applied compared to no preseason watering. However, the benefit of preplant irrigation was only realized if the yield potential was less than 150 bu/acre.⁴

Researchers in Texas reported that preplant irrigation is often essential for high yields in most years in the High Plains, but preseason amounts more than 4 inches of applied water are not warranted.⁵

Although there is generally a yield advantage with preplant irrigation, growers should be aware that evaporative losses were found to be higher than from in-season watering.

Sources

¹Brhel, J., Melvin, S., Jhala, A., Iqbal, J., and La Menza, N.C. 2025. Considerations for planting into dry conditions. Cropwatch. University of Nebraska Extension. https://cropwatch.unl.edu/2022/considerations-planting-dry-conditions/
²Mo, Y., Li, G., Wang, D., et al. 2020. Planting and preemergence irrigation procedures to enhance germination of subsurface drip irrigated corn. Agricultural Water Management. 242: 106412. https://www.sciencedirect.com/science/article/abs/pii/S037837742030322X
³Schlegel, A.J., Stone, L.R., Dumler, T.J., and Lamm, F.R. 2012. Managing diminished irrigation capacity with preseason irrigation and plant density for corn production. Transactions of the ASABE. 55(2): 525-531.https://elibrary.asabe.org/abstract.asp??JID=3&AID=41394&CID=t2012&v=55&i=2&T=1
⁴Kisekka, I., Schlegel, A., Ma, L., Gowda, P.H., and Prasad, P.V.V. 2017. Optimizing preplant irrigation for maize under limited water in the High Plains. Agricultural Water Management. 187: 154–163. https://www.sciencedirect.com/science/article/pii/S0378377417301038?via%3Dihub
⁵Jordan, W. R. and Sweeten, J. M. 1987. Irrigation water management for the Texas High Plains: A research summary. https://twdl-ir.tdl.org/items/426262d6-60a6-4c4f-9953-ceb1832e44ad
Web sources verified 04/13/26. 1121_836750