What difference does it make to plant wheat at 5cm or 2cm depth?

Question

I have just finished practical where had to plant wheat at 10cm, 5cm, and 2cm depth. The plant coming out of the 10cm pot was obviously handicapped, but I struggle to find a difference between the 5cm and 2cm. But there has to be some kind of difference, otherwise we would probably not have been given this assignment. Help please?....

Answer 1

I reviewed some of the other answers you received and did not see one yet that was satisfactory.  Here's the scoop:  the coleoptile (the little pointy tube that heads for the soil surface) is inherently limited in length it can grow by both genetics and by the fact that there is only so much energy stored in the seed.  Thus, if you plant a wheat seed (or any seed)  to deep, it can exhaust its energy reserves before it reaches the surface, and begins to photosynthesize as the leaves start to emerge.  Not only can you exhaust the seed reserve, but you can inhibit early growth and development as the plant struggles to replace the depleted energy reserves.

Answer 2

If moisture is adequate, 2 cm and 5 cm depths will produce indistinguishable results.

If soil is dry to the 5 cm depth, wheat in the 2 cm depth may not germinate at all. At 10 cm germination is likely to be much more consistent even if emergence is delayed.

When seed is placed 10 cm down, in a drought season, it may be the only wheat emerging.

What we see as a problem is that  shallow wheat that does germinate may still not get its roots deep enough, soon enough to permit it to survive the drought. We have not developed a seeder that will slice the soil to  15 cm while dropping seed just as deep as it needs go for germination.

(Deep slicing lets roots penetrate quickly.

Next, if seed is dropped in 10 cm deep, the soil can be tilled shallow, to reduce the amount of water loss resulting from capillary action in closely packed soil. This can be done next day, even 3-4 days later.

Seed dropped deeper may be slightly more frost resistant, but wheat is always moderately frost resistant.

Answer 3

I'm just a Yank, but isn't 10 cm around 4 inches?  If you have to plant that deep to get to moisture, you have problems.  The problem with deep planting is if you get any kind of hard rain, on high clay soils especially, the soil will crust over and you'll never get anything to come up.  The seed has only so much energy stored in it and even if the soil isn't crusted, the seed sometimes runs out of energy before getting to the surface.  

In Missouri, if it's very dry (like it was last fall), you're better off planting shallow and wait for a rain than to plant hub deep, get a big pounding rain and have the soil set up like concrete.  If you're planting in wet soil, getting a rain afterwards is a sure fire way to get a very poor to no stand.

Answer 4

when it is planted so shallow, its basically (   dusted in) , it is  used as a last resort when the soil is too dry. You are basically hoping a small rain will cover it deeper ( runnoff from the furrows) to germinate it and start growing. 5cm is ok if you have moisture and soils which hold moisture at shallow depths. Remember the hotter the soil, the shorter the sprout the plant makes, planting in cooler weather is best, but this is all hard red winter wheat guidelines. Planting too deep will usually get you a stand but tillering ability is difficult because the crown of the plant is too deep. The shallow planted wheat if it gets just enough moisture to sprout and grow but, then gets dry again is highly prone to winterkill.

Answer 5

the deeper the seed the longer to germinate.