Soybean has a large nitrogen (N) requirement. Indeed, soybean requires about four times more N per bushel produced than corn. On average, soybean needs to absorb 4.8 lbs of N per bushel produced. Hence, a soybean crop that produces 50 bu/ac (similar to current Nebraska average) will need to absorb 240 lbs N per acre.
Planting date studies conducted on UNL's East Campus showed yield decreases of 1/4 bu/ac (2003) and 5/8 bu/ac (2004) for each day after May 1 that soybean were planted.
The benefits of planting soybean near May 1 are well documented. Now, what are the next steps growers can take to further expand on these benefits? Are different maturity groups warranted? What groups are typically being used in irrigated and rainfed environments in Nebraska?
Figure 1. Planting into cold soil (below 50°F) when cold conditions are expected for the next 48 hours can lead to germination problems and seedlings not emerging or not emerging well. 1a. Corn seedling that started leafing out below ground and now has twisted leaves which will delay or negate normal plant development.. Figures 1b-c. Unemerged seedlings attempting to leaf out belowground. None of the seedlings shown should be counted as a productive plant.
With stormy conditions back in the picture, many growers may be concerned about planting corn into cold, wet soils? By checking weather forecasts and soil temperature at planting (in the field and online) and the cold tolerance of seed, growers can identify 48-hour windows of opportunity for planting.
Crop modelers wrap up their forecasts of rainfed and irrigated corn yields across the Corn Belt for 2017, noting above-average yields for about 80% of the irrigated sites and more than 60% of the rainfed sites. Irrigated yields ranged from 11%-17% over long-term averages at those sites and rainfed yields at those sites were 13%-40% above average. View data for all the sites.
Forecasts for end-of-season corn yields improved across much of the Corn Belt since the early August forecast. View crop stage and yield forecasts as well as weather data. In Nebraska predictions are for near to above average corn yields for most sites, except northeast and northwest sites.
Corn yield forecasts for Nebraska sites indicate near-average to above average yields for most irrigated sites. There was much more yield variability for rainfed locations where three of the sites were forecast with a 50%-100% chance of below-normal yields and three were forecast for normal yields, while one was near average.
Corn growth stages are estimated for 41 sites in 10 states and yields are estimated for select irrigated and rainfed sites, based on the Hybrid-Maize model and input from specialists and educators across a 10-state area as of July 18, 2017. The authors note that these early season yield forecasts vary widely, particularly for rainfed fields, and may change considerably by end of season.
This article discusses data and data collection for the Yield Forecasting Center forecasts of crop phenology and yield for 2017, including a map of the site locations and specific data on crop management and soil types for each site.
