In the Pod: Soybean Updates

Bruce Sundeen: 00:00

You're listening to In The Pod, soybean updates, a weekly trek into the latest soybean information from NDSU Extension. Today, we're digging into irrigation management for soybeans. According to Laxmi Prasad, NDSU Extension water engineer, a little water at the right time can go a long way. Laxmi, why is water management important for soybeans in North Dakota?

Laxmi Prasad: 00:25

That's a great place to start. In North Dakota, there are about 70,000 acres of irrigated soybeans. Even though most production depends on rainfall, soybean yields are closely tied to water availability, and they respond well to irrigation, especially during critical growth stages. Irrigation management helps ensure that soil moisture is optimized when the crop needs it most, reducing the risk of stress during dry spells and improving overall productivity as where irrigation management helps.

Bruce Sundeen: 01:01

When should a producer start irrigating soybeans?

Laxmi Prasad: 01:04

Great question. In most years, irrigation from mid July through August will have the greatest effect on yield. Mainly, soybeans are sensitive to water stress during flowering and pot fill stages that are like r one to r five. Depending on planting date, the reproductive stages fall between mid to late July. If your topsoil is drying out and your plants are looking wilted, don't wait. That's your cue to start irrigating.

Bruce Sundeen: 01:35

In North Dakota, how much water do soybeans typically need in a growing season?

Laxmi Prasad: 01:40

That's a broad range. It mainly depends on local weather and variety. Soybeans need around 17 to 28 inches of water for the whole season. Depending on the year, rainfall might supply it. But if you are supplementing with irrigation, focus on reproductive or critical growth stages.

Bruce Sundeen: 02:00

So how do soil characteristics affect irrigation?

Laxmi Prasad: 02:04

The greater the water holding capacity of soil, the less frequent the irrigation applications should be. Soil texture mainly determines the amount available water in the root zone. Other factors like organic matter and soil compaction can also affect them. The North Dakota soybean production guide has information on soil water holding capacities for different soil textures, but a more field specific information can be obtained from the NRCS web soil survey.

Bruce Sundeen: 02:34

Laxmi, what's the best way to plan irrigation? How much to apply and when?

Laxmi Prasad: 02:39

The best strategy is to mix up with soil moisture monitoring, irrigation scheduling, and tracking crop growth stages. NDSU Extension has several publicly available irrigation scheduling tools to help farmers make those decisions based on their local weather and field conditions. During the growing season, soybean water use estimates can also be obtained from North Dakota Agricultural Weather Network website by selecting the station closest to their field.

Bruce Sundeen: 03:10

Thanks, Laxmi. Our guest has been Laxmi Prasad, NDSU Extension water engineer. You're listening to In The Pod, soybean updates, a weekly trek into the latest soybean information from NDSU Extension supported by the North Dakota Soybean Council.