Calculate in teragrams the difference in the supply of phosphorus to the soil from the two stores shown in Figure 1.

Show your working.

Answer ______________ Tg

Using all the information, evaluate the effectiveness of using mycorrhizae to increase crop production under conditions of water shortage and no water shortage.

The tomato seeds were planted into sterilised soil.

Suggest two reasons why the soil was sterilised.

1

2

The soil used in this investigation had the recommended concentration of fertiliser.

Suggest two reasons why the soil contained the recommended concentration of fertiliser.

1

2