The important point to remember is not how early the seed should be in the ground, but what can be done to get it out of the ground as soon as possible, so that the plant is growing healthy.

SOIL TEMPERATURE

The most critical factor is soil temperature. Soil temperature drives all metabolic processes and although many of the other factors such as moisture, aeration, nutrition and depth are also important, they do not begin to influence the seed until it’s warm enough to start all the biochemical processes of seed germination: >4°C to 6°C is preferred for cereal and oilseeds.

SOIL MOISTURE

Soil moisture affects how quickly water penetrates the seed. Seeds require a percentage of moisture by their weight before germination takes place. Having adequate moisture in terms of stored soil water and early spring precipitation plays a large role in successful and rapid germination, at the correct temperature. Dependent on soil type: e.g. >25-30% VWC.

FERTILIZER RATES

The amount of water available for germination is affected by the type, amount and placement of fertilizer. Fertilizers placed very close to or with the seed will reduce the amount of moisture available for seed germination because these fertilizers end up using some of the available moisture to dissolve the fertilizer and bring it into solution.

DEPTH OF PLACEMENT

Seeding depth is the next factor that’s important in rapid and even germination. Soil moisture, soil temperature, soil type, trash cover, and others, all affect seed depth each year. Depth will vary based on soil temperature and moisture – shallow with cold, wet soils. Deeper with dry and warm soils. Generally, 3.5 to 7.5 cm.

SPRING SPRAYING

Pre-seeding spraying is very important. Weeds that emerge before the crop, will out-compete the crop for moisture, nutrients and sunlight. Just a small number of weeds, a few per square foot, emerging before or with the crop can be much more damaging to yield potential than a larger number of weeds developing later.

Factors Affecting the Early Versus Late Approach

Seeding in Western Canada can range from April through May and sometimes into early June, if flooding occurs. In Europe, seeding and sowing can range from March to late June and are highly dependent on climatic conditions from country to country, crop to crop.

What is too early or too late for crop development and ultimately yield?

Fundamentally, seeding into warm soils ensures the best start for the crop. Proper germination and crop emergence is an important step for reaching the crop’s yield potential.