Proper digging and filling of pits in which saplings have to be planted is one of the critical determinants of growth and productivity of fruit and other trees.
Generally, pits for plantation are kept ready before the end of May. Exposure to the sun’s rays kills pests in the soil. The earlier the pits are dug, the better.
After layout of trees is finalised, pit-digging is done as follows:
- A wooden stick is pegged into the ground where a pit is to be dug. The peg is used as the centre to mark out a square of required dimensions. For mango saplings, the dimensions are 1m x 1m x1m. For cashew, it is 0.6m x 0.6m x 0.6m and for MPTS it is 0.3m x 0.3m x 0.3m.
- Digging is done according to the dimensions.
- Dug up top soil is collected in a heap on the upper slope of the pit. In the event of pre-monsoon rains, the fertile soil flows back into the pit with the rainwater.
- A stick is pegged on this heap of soil as a mark of identification.
- Gravel and stones dug from the pit are piled separately.
- The second layer of soil that is dug out is heaped outside the pit on the opposite side of the first layer.
- While digging, care is taken to maintain the length and breadth of the pit from the top to the bottom of the pit.
Pit-filling is undertaken towards the end of May, after the pits have been baked in the sun.
Biomass waste is collected in advance, to be filled in the pits; it makes excellent compost. Linden powder, neem cake, vermicompost/farmyard manure and bone meal are also used while filling up pits. (See planting material quality standards).
Pit filling is done as follows:
- Linden powder is sprinkled on the four sides of the pit to destroy termites in the soil. A layer of biomass is put into the pit.
- The first layer of soil that had been dug out is added. If this soil is of poor quality, fertile soil from the bank of a river or stream is collected and added to the pit.
- Linden powder is sprinkled again followed by a layer of dried biomass. This layer should be 20 to 25cm high (about one arm’s length).
- A mixture of farmyard manure/vermicompost, Linden powder and soil is made and added into the pit.
- Another mixture of Linden powder, bonemeal and soil is prepared and added into the pit followed by a mixture of neem cake and soil.
- After filling up the pit in this manner, a wooden stick is pegged in the centre of the pit. This marks the spot for planting the sapling.
- A heap of soil around 15cm high is made around the peg. This soil will settle in the pit with the rains.