Hi, this is Chuck Burr, your University of Nebraska Lincoln Extension Educator serving Phelps and Gosper Counties and the surrounding area. The calendar says we are getting close to the spring planting season, but the weather sure doesn’t. Starter fertilizer can help spur growth and yield in cooler soils, including no-till soils. Soil temperature commonly is lower with no-till than with tilled soils due to more ground cover and often higher soil water content. Cooler soil temperatures slow plant root development and the release of plant nutrients from soil organic matter. A greater response to starter fertilizer is expected under reduced tillage, compared with tilled conditions.
In recent research conducted in Nebraska, starter fertilizer use commonly resulted in increased grain yield. The yield increased an average of 13.5 bushels per acre for no-till irrigated corn on medium texture soils when the soil test level was less that 15 parts per million.
Starter fertilizer application did not result in increased no-till dryland corn in eight trials conducted in eastern Nebraska, but the soil test was above 15 parts per million for seven of these trials. Placing the starter fertilizer over the row, in the furrow and to the side and below the seed was equally effective.
Starter fertilizer placed near the seed has a salt effect that can damage germination and early plant development. The starter fertilizer rate that can be applied safely depends on the fertilizer’s salt content, or salt index value. The salt index value is based on the soil texture and the distance between the fertilizer and the seed.
When soil moisture at planting is adequate and rainfall occurs soon after planting, problems associated with salt damage will be minimal or will not occur. Problems from salt damage, such as reduced germination and emergence, can be anticipated when soil moisture becomes limited.
The moisture may become limited when fertilizer was placed too close to the seed and no rainfall occurs for two to three weeks after planting. Salt concentration is greater when there is less soil water, such as with sandy soil or with low soil water at and following planting, creating greater risk of salt damage to the germinating seed and early root growth.
In general, application of too much nitrogen, potash and sulfur close to the seed will reduce stand and delay corn, grain sorghum and soybean emergence.
