| |
NORTH CENTRAL:
February 1, 2012 — In this series, we examine how plant nutrition helps get the most from the ever-increasing investment in a bag of seed.
Many farmers are observing improved corn yields with new genetics, and these yields are often coming with no changes in N management. Higher yielding corn does require more nitrogen, but does this additional N need to come from fertilizer? Three possibilities exist. In this Quick Tip, we examine the possibility that the soil may be supplying the extra N needed.
Believe it or not, the soil acts like it has a memory. The quantities of nutrients it supplies today depend on the nutrient management practices of the past. Except for coarse, sandy soils, historically higher N rates allow the soil to provide more N to a corn crop. The scientific literature indicates that years producing good corn yields are also years conducive to greater release of N from the soil. So if past N rates have been adequate or above, it is likely that the soil is supplying at least part of the additional N needed by a higher yielding corn crop. While this is good news, we also need to be thinking about the future. If the additional N needs of higher yielding crops are being met by soil supplies, what is the sustainability of those reserves? This is an active area of research, but some studies have shown that soils with a history of lower N rates are not able to supply as much N to corn, creating a greater dependence on the N coming from fertilizer.
--
Dr. Scott Murrell, IPNI
NORTHERN GREAT PLAINS:
February 1, 2012 – Take a Look at Increasing Your Plant Densities
While attending agronomic meetings this past fall I have been impressed at the reported benefits from moving towards higher planting rates, and the resulting increased plant stand densities. Generally speaking there are some achievable benefits from increasing plant stand densities. Benefits include: more crop competition to weeds and less weed growth; less late tillers on cereal crops and less branching off main stems in broadleaf crops that result in earlier and more even maturity; improved crop grain quality due to the more even maturity, and in many cases improved yields. This is a management practice that is relatively easy to implement and can result in benefits. One item of advice is to check with other farmers and local agronomists in your area and discuss practical increased planting rates for the crop varieties and hybrids grown in your area.
--
Dr. Tom Jensen, IPNI
SOUTHERN & CENTRAL GREAT PLAINS:
February 1, 2012 – Starter bands
Starters benefit corn in cool, moist soils. Nitrogen and P work together to boost the vigor of the young seedling, and K and S can be important in some soils. In calcareous soils (high pH) starters can also improve the root environment by temporarily lowering pH. Ammonium forms of N and mono-ammonium phosphate are particularly good acidifiers. The small band of soil with lowered pH can supply more manganese, zinc, iron and P while the seedling is still young.
--
Dr. Mike Stewart, IPNI
WEST:
February 1, 2012 – Do organic amendments make agriculture more environmentally friendly? A common misperception is that organic amendments are the best source of plant nutrients and the more organic matter that is added, the better the soil will be. There are several problems with this notion. A heavily amended soil releases large amounts of nutrients. If the nutrients are not taken up by plants or microbes, they can be lost from the soil. Water movement can be restricted between the amended soil and the native soil. Organic amendments can provide significant benefits to soil, but don’t overdo a good thing.
--
Dr. Rob Mikkelsen, IPNI
SOUTHEAST:
February 1, 2012 – Starter Fertilizer in Cold Soils
Starter fertilizer placed near the seed provides an abundant supply of P and K for crop uptake early in the growing season. Applying plant nutrients in the “Right Place” is especially important when crops are planted into cold soils. Cold soil temperatures slow down the movement of P and K, which can affect root growth, nutrient uptake, and ultimately yield. Typically, when soil tests indicate high P or K levels, a response to starter fertilizer is not expected. However, there are university data that show early spring-seeded crops, like potato, respond favorably to starter fertilizers when planted into cold soils even when soil test levels are high.
--
Dr. Steve Phillips , IPNI
|
|
