FieldTalk

1. Planting Population – target 28,000-34,000 seeds/ac (rate influenced on numerous factors – climate, soil type & productivity, resources available, planting date, hybrid characteristics, chu region, end use, economics)

        1 bag = 80,000 kernels/bag > 32,000 seeds/ac = 2.5 bags/acre; 34,000 ac/bag = 2.35 ac/bag

2. Plant corn using a planter > consistent seed placement & consistent seed depth

3. Depth – target planting depth is 1.5 – 2.5”; plant into 0.5” of moisture 

1. Target this depth to achieve good seed-to-soil contact and good development on the nodal root system (critical for structural support and nutrient and water uptake)
2. Goal: even planting depth > even emergence
3. Too shallow is worse than too deep

Too Shallow: < 1.5"	Too Deep: > 2.5”
Poor development of nodal root system Early season lodging Poor plant health mid-late season	Delayed/ no emergence Leafing out underground

4. Soil Temperature – 10 ℃ at planting depth with a 48 hr warming trend

1. Corn does not germinate below 10 ℃; corn seed is very temperature sensitive
2. Wait for warm soils to avoid imbibitional chilling (within 24 hrs of planting) & cold injury
   1. Imbibitional chilling occurs when there is a drastic change in the water temperature during imbibition. The critical time for this to occur is within 24 hours of planting.
   2. Cold Injury is when there is a change in the soil temperature after the seed has imbibed water. Cold injury is typically less severe than imbibitional chilling.
3. Cool soils + cool weather > better to leave the seed in the bag

5. Seed Bed Preparation – plant into a firm seed bed with residue well managed

1. Poor residue management/ no-till fields can result in hair-pinning of the emerging seedling
2. Want seedbed to be firm because seed-to-soil contact is increased and for good nodal root development
3. Excess tillage can result in crusting & compaction
4. Avoid planting and tilling wet soils

6. Planter Speed – most planters run at 4-5 mph at the fastest

1. As speed increases, spacing within the row and depth uniformity is reduced
2. Speed is dictated by planters metering abilities

7. Emergence – Optimal emergence conditions: 10 - 16 days; Unfavorable emergence conditions: up to 21 days.

1. Even emergence is critical; yield loss from uneven emergence can range from 5-10%

CORN FERTILITY TIPS

Nitrogen (N)

• Critical to profitability > corn has a very high response to N
• Application
  • Pre-plant – broadcast & incorporate
    • Side band – 4 inches from seed row High salt index products – ammonium nitrate, urea, potash
  • Fertigation (through the irrigation pivot)
• Grazing – consider the N left from manure and urine
• General Recommendation Rates
  • 1 lb actual N/ target bu of grain
    • 150 bu = 150 lbs actual N
  • 8-10 lbs of N/ target ton
    • 21 ton = 189 lbs actual N
• 63% of plant N is taken up by pollination; 37% of N is taken up during grain fill
  • 50% of N supply used between V8 and VT

Phosphorus (P)

• Early season development & growth of root system
  • Cold soils have a very slow release of plant available P > Include P in starter fertilizer
• Important after tasseling – continually taken up during grain fill > long season supply is critical
• Starter P response can vary year-to-year based on:
  • soil moisture, temperature, crop vigour, hybrid
• Include in the seed row or close to the seed – immobile nutrient
• Depending on soil levels: 10 – 40 lbs P2O5
• Band phosphorus
  • Side banded
  • Spring, fall or at planting
• Rotation – not recommended to plant corn after canola

Potassium (K)

• Associated with movement of water, nutrients, and carbohydrates within the plant and stalk strength
• Rapid K uptake between V6 and VT/R1 timing
• Application: banding is more efficient than broadcast
• Watch the salinity of the fertilizer

Sulfur (S)

• Available S vs elemental S
• N:S ratio – 10-12:1
• Know what the crop needs and apply for that season