Questions to look at:

1) Why would plowing be a problem?

2) What does plowing have to do with us anyway??

3) Dragging a chair on mud, is that ok?

4) Digging in a sandbox, is that ok?

5) Can I remove rocks and twigs from a lawn?

6) Can I weeding?

7) Can I fertilise soil?

8) Can I place a bean in a jar of water?

9) Can I walk on soft soil and make a foot print?

10) Can I push a baby carriage on soil?

Now we begin going through the 39 types of work they did in the mishkan, which was like the temporary temple whilst they travelled through the desert.

In the mishkan they had the miraculous "lechem hapanim", which stayed fresh for an entire week!

The 1st 11 melachas will go through the steps of producing the bread, the 1st of which is plowing.

The basic premise of plowing is the preparation of soil for the purpose of making it more suitable for seeding or planting. Plowing loosens the soil, so any activity which loosens soil is included even if planting wasn't his intention. 

So many ways we are involved in this even when we are not gardeners as we shall see.

Remember the tiniest hole is sufficient to accommodate a very small seed.

So going back to each question:

3) Not ok to drag a chair on earth as the chair legs scrape and loosen the soil whilst it's being dragged.

4) Digging in a sandbox is ok as it's too loose to form a hole. However if it was wet then could be an issue. (Reason sandbox not muktza is its automatically set aside for play.)

5) Removing rocks and the like not ok as it's making the land surface more cultivable.

6) Weeding not ok as it improves the soil potential.

7) Fertilising soil not ok as it enriches the soil so improving it for seeding or planting.

8) Placing a bean in a jar of water to sprout not ok.

9) Walking on soft soil is ok even if will cause a footprint because the walking only compresses the soil beneath the foot.

Loosening the soil is the problem, not compressing it. Compacting soil doesn't improve it for planting.

10) Pushing baby carriage on soil is also ok even if get a wheel mark as again it merely compresses it.