Belt feed planters space the potatoes less accurately but they can be used at high speed. Intended for unchitted seed, spacing in the row will be improved if the seed is carefully graded for size.
Two-, four-, six-, eight- and twelve-row belt-feed potato planters usually have a hydraulically tipped seed hopper, and some are equipped with a control unit in the tractor cab to regulates tuber spacing and monitor planter performance. The hopper is gradually tipped as the potatoes are deposited on to a wide belt or belts which transfer them on to a series of small belts used to convey the tubers to soil immediately behind furrow openers. The potatoes are covered with ridging bodies or with concave disc which can be adjusted to leave a wide or narrow ridge.
Figure 18.14 The cup feed mechanism on a four-row potato planter with a 2.5 tonne capacity hopper. The belts have a double row of cups which allow high speed planting with an output of up to 10 hectares in a normal day. (Kverneland)
Figure 18.15 A cup-feed machine planting two staggered double rows of potatoes six inches apart in pre-formed beds. (Grimme)
Figure 18.16 This cup-feed planter makes narrow furrows for two separate rows of potatoes which are covered before the rear shaping board forms two even-shaped ridges.
Figure 18.15a Planting four, five or six rows of potatoes in 1.8-2.0 m wide beds instead of individual rows improves soil moisture retention and gives more regular shape and size of potatoes for specialist markets.
Figure 18.17 A two-row trailed belt-feed potato planter working on the flat. As the 1250 kg hopper empties, it is tipped in stages by a pair of hydraulic rams to maintain the flow of potatoes to the feed belts.