Question

how can we conserve land

Answer 1

Planting trees stops soil erosion. 
do not deposit garbage in flowing water or waste land. Either dig and make a garbage gober gas plant or put fire to the garbage from houses. 
Send garbage to the garbage waste taking government Trucks which safely deletes the wastes or put the garbage in provided places on roads where the govt. vehicles come to take it. Give manures to the plants and wells and pools and rivers to protect the ecosystem friendly animals. Watering plants, and trees, planting more trees helps to make a eco friendly ecosystem.

Answer 2

Conserving land means to be able to maintain the fertility, strength, moisture, minerals, greenery and usefulness of land.   Land means all residential, agricultural, industrial, coastal, forestry, desert  lands.

We need to take different actions for different types of lands, in order to stop them from deteriorating.

1.  For agricultural lands, we need to prevent flooding of them, salinization due to waterlogging or other reasons and excess use of pollution etc.

2.  We need to maintain the area of forests and if possible increase number of trees in communities, waste lands, beaches and around industries.  Growing trees, grass and bushes reduce soil erosion.

3.  We need to educate all the landowners regarding the importance of natural land resources and how to retain the lands.

4.  Contour ploughing

5.  By terracing methods.

6.  Stop cutting trees without proper planning of replantations.

7.  Construction of dams and canals.  Water storages including rainwater harvesting for preventing rain water escaping the land on which rain falls.

8.  Planting trees around the borders of deserts will prevent hot winds and sand storms, which spoil lands near deserts.

9.  The responsibility of National Natural Resources Department and forestry department to see the better use of lands.  Now most of the lands of the country are digitized, mapped.  There are satellites to study and monitor.   So better protection and care should be possible.