6.3.5 Irish Potato – Compost/Manure Technique

Irish Potato is the world’s 4th largest crop after maize, wheat and rice. Potatoes have a high starch component of 17% making them a staple food source for many people. Although they have some Vitamin B6 and C, their nutritional value relative to other vegetables is very low.

Irish potato grows in temperature ranges of 7-30°C but with optimal ranges between 15-25°C. In Southern African summer rainfall regions, it is recommended to plant in August through to January. They are classified as a cool season crop as once temperatures go above 27°C tuber formation stops.

Layout

Potatoes are planted at 30cm between plants and 75cm between rows on the flat or on permanent raised beds.

Lay Strings for Furrow

Place a top string or measuring rope from one 75cm permanent peg to its adjoining peg on the opposite side. Make sure the rope is taut and straight by lifting and dropping it.

Remove God’s Blanket

Move God’s Blanket 30cm downslope of the string to expose the soil.

Soil Fracturing

If your soils are compacted give your potatoes a good chance of success by fracturing each 75cm line to 30cm deep but due to the 15cm deep furrows this may not be necessary.

Furrows

Prepare furrows 15cm deep, every 75cm row line, being careful not to throw the soil too far downslope.

Correcting Acidic Soils

To correct acidic soils and allow for readily available plant nutrients evenly sprinkle 1 tablespoon of woodash/bonemeal or 1 teaspoon of lime, every 60cm on the planting lines.

Manure/Low Volume Compost Inputs

Evenly spread 500ml of compost or manure per meter then cover with at least 3cm of soil to attain the 10cm planting depth.

Planting Seed Potatoes

Potatoes are grown from small disease free tubers or from tuber cuttings with 2 or 3 eyes or growth points on each cutting. Place seed potatoes at 30cm intervals in the row and cover level.

God’s Blanket

No hilling up is necessary for good tuber formation but a good blanket is. Leave a 5cm gap on top of the furrow to allow for germination. After germination place a very thick blanket between 5-10cm thick, to prevent potato tuber greening and also to encourage shallow tuber formation.

Harvest

The thicker the blanket the easier it is to harvest the potatoes and the less soil disturbance there will be. Use a fork to gently lift the potatoes, which will be found just below the surface because of the moisture conservation from God’s Blanket.