Posted 26 June 2014. PMN Crop News.
Delayed Soybean Planting Considerations
Source: Penn State University Press Release. agsci.psu.edu
University Park, Pennsylvania (June 18, 2014)--Soil considerations: With tilled soil, planting into wetter conditions may lead to compaction and more damaging soil crusting. These fields if planted will need to be monitored to determine if the surface has become compacted enough to inhibit the seedling to pop through to sunlight. In the past I have run a cultipacker over top of crusted soybeans with no ill affect accept for an immediate jump in the emerged plants. This season my soybeans were tilled and I noted crusting but fortunately additional rains came and the beans pushed through.
In no till fields, that are still wet, crusting generally doesn’t present a major problem. Growers might consider; however, a shallow planting in these situations taking care that residue hairpinning doesn’t rob the seed of soil contact.
Maturities: There’s been talk about moving to a shorter maturity. Past experience in this area would say ‘stay the course’. Our double crop beans planted with full maturity over the last several years have matured with no ill problems in the fall. This simple table best illustrates the impact of planting date.
Row width and population: This is where we can improve the position of the soybeans in later plantings. Narrow rows are better. Research at Landisville has shown the detrimental affect of wide rows planted late so narrow the rows is certainly any easy change to increase yields perhaps by 5% or more.
Population increases with later planting is also another easy adjustment that has sound science behind it. We have shown increases in stand from 150 to 200,000ppa in double crop scenarios so I would advise treating this later plant time as a double crop situation and increase populations accordingly as June progresses into July. Higher populations and narrower rows have the affect of creating taller plants as they compete for sunlight and other plant growth requirements resulting in yield bumps with late planted soybeans.
Seed treatment and inoculation: Inoculation is still recommended regardless of planting date and remember inoculation is not seed treatment! Soybeans should emerge rapidly at this point with elevated soil temperatures and moisture so the natural reaction might be to eliminate them. In fields with a history of bean leaf beetle and/or soybean aphids the insecticide portion might prove useful. Similarly, wetter fields or fields with history of phytophtora may benefit on the fungicidal side.