Orchard Management

EXERCISE 8

EXERCISE 8: USE OF ORGANIC MULCHES IN FRUIT ORCHARDS

Mulching is the practice of spreading of organic or inorganic material on the soil to avoid the tree trunk, to conserve soil moisture and create condition more favourable for growth.

Material: Organic mulches: Hey (Plate 8.1), straw, leaves pine needle, bark chips, saw dust, cotton burs, wooden pieces, rice husk, bran, onion and garlic scales.

Plate 8.1. Grass mulching in peach plantation

Aim

1. To conserve soil moisture
2. To check weed growth.
3. Organic mulch add enough organic matter to the soil after decomposition
4. Increase soil infiltration and control soil erosion
5. Mulch lower the soil temperature in summer and increase it in winter

Procedure: During the spring, remove weeds from the tree basins with light hoeing. Spread material such as hey, straw, pineapple, leaves etc. on the top of the soil in the tree basins. The thickness of the mulch is usually between 10-15cm. The material should be applied at least 15cm away from the tree trunk.

Calculation of volume of mulch: If the grower wants to apply 10cm thick mulch in the basins of 3 m diameter, the volume of the mulch to be applied can be calculated as follows:

Diameter of basin = 3m
Radius of basin = 1.5m
Area of the basin = pr2
= 22/7x1.5m2
= 22/7x 2.25 =7.07m2

The thickness of mulch is =10cm or 0.1m
The volume of the mulch per tree will be 7.07x0.1 =0.707 =0.71 cubic meter.

Precaution

1. Do not apply mulch too close to the tree trunk, as may cause collar rot problem due to excessive humidity and harbour insect pests.
2. Remove mulch just at the onset of monsoon as rain to avoid water logging.
3. Mulching material should be spread only after the removal of the weeds.
4. Black polyethylene mulch should be used only in cold climates.
5. Use seedless grass only as mulch, as it may cause weed problem.
6. Dry mulch invite fire hazard in dry climates.

Observation to be taken

1. Record soil moisture contents and soil temperature of 15days internal from 30cm soil depth.
2. Count the number of weeds if any and record their dry weight.
3. Record soil organic matter contents of the end of season.