Sustaining soil fertility in support of intensification of Sweetpotato cropping systems

Abstract

Sweetpotato is the most important food and cash crop in the Highlands of Papua New Guinea (PNG). However, low tuber yield due to declining soil fertility, unsustainable cultivation practices as well as yield-limiting virus infestations are\ua0 increasing problems threatening food security. Sustainable, farmer-adoptable soil fertility management strategies are needed to satisfy the increasing demand for sweetpotato. This is now of particular importance with the projected rapid adoption of high yielding, virus free (Pathogen Tested, PT) sweetpotato varieties. Over the past 4 years several on-stationand on-farm trials showed that substantial yield increases of over 40% are possible from a combination of using PT material and applying fertiliser, either in mineral or organic form