To kick-start the seed potatoes spread them in a single layer in crates and keep them under semi-light conditions until they start to sprout. Prepare trenches 20 cm deep and fill those 10 cm high with compost. Place the potatoes in these trenches and cover them with compost and topsoil.
When the plants are about 15 cm tall start “earthing them up” by bringing the soil back against the stems or even top dressing them with compost, so that only the top leaves remain visible. As the plants grow keep repeating this until the potatoes grow on ridges. This will encourage new growth of side roots that will continue to produce potatoes and thereby increase your yield drastically.
Water regularly if you grow your potatoes outside the rainy season. Potatoes need about 500mm of water during their growth cycle. Water stress will lead to reduced yield. Especially during the early growth phase the soil should be kept moist constantly to a depth of 15 cm. After the plants start flowering irrigation needs to be reduced to once or twice per week.
Potato is a crop with a high Potassium (K) need, with 140kg/acre, most of it during the tuber bulking stage. Nitrogen is taken up by potatoes at a rate of 97kg/acre and needed mainly during the early growth stages. Phosphorus (P) on the other hand is only needed at 12kg/acre. Potassium is usually a nutrient that can be supplied by the soil, but that can only be determined by a soil test. Wood ash and sheep manure are organic sources for Potassium. Good Potassium supply will also improve storage quality of potatoes.