Is a useful method of asexual reproduction for propagating hard-to-root plants.
grafting
layering
cuttings
budding

grafting

Explanation:

Grafting is a method used for the creation of grafts, which are instruments used in a type of asexual reproduction for the propagation of difficult root plants. This method is done by plant specialists (such as botanists or agronomists) and consists of the union of two different species. The process takes place between a part of a plant called a graft (or rider) that is inserted into another part of another plant (or another individual of the same species), which may be the root system or the stem known as a rootstock (or horse)

compost can be added to topsoil as a:

pesticide

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.