November 21, 2006

 

Soy inoculants still inconsistent for yield

 

 

Despite improvements over the years, soy inoculants still might be inconsistent in delivering higher yields in Iowa, according to university and on-farm research.

 

The conclusion was based on trials conducted by Iowa State University soy specialist, Palle Pedersen and the Iowa Soybean Association (ISA).

 

While in the 2005 trial, none of the tested inoculants showed much of a yield increase over the non-inoculated plots, the trials conducted in the previous year had only one inoculant at one location out of 12 conducted at 2 locations recording a significant yield increase over the non-inoculated soy.

 

According to field research operations manager, trials this year would have a more rifle approach by targeting farm ground high in pH and low in phosphorus unlike a shotgun approach applied in previous trials. They hope to use bacteria and fungus as their products.

 

The researchers seem hopeful about the results with fungus as it yielded an average increase earlier. Another researcher noted his results showed an average boost of 1 bu./acre by using soy inoculants, a figure well enough to cover the cost of inoculants.

 

However, the results might be lower in Iowa, warned Conley, a soy specialist.

 

Generally, soy inoculants delivered a more consistent yield response with a low quantity of organic matter in the soil and Iowa's soil was known to have higher amounts of organic matter than that on the eastern corn-belt.

 

Despite the results, there might be a place for soy inoculants.

 

Pedersen recommends inoculants be used if the field has been out of soy production three to five years as inoculants were cheap insurance. Other conditions that might warrant using inoculants in soy include non-plantation of soy ever in the field, the soil pH to be below 6.0 and a high sand content in the soil.

 

Further, he suggests testing the worth of inoculating soy by splitting the field in half or putting some four to five-row wide test strips and repeating them between non-inoculated strips.

 

Also, since all inoculants were not created equal, farmers should research different products, he added.

 

Conley believed soy inoculants might deliver more-consistent yield results in the future as the inoculant industry like many others, was going through consolidation, which might improve the performance of the product.

 

Also, in the future, inoculants might come treated on the seed and have a polymer what would allow farmers a 30-day window to plant.

 

One soy inoculant company recently announced its product would allow a 90-planting window.