Soil and Land Management

Sustaining soil fertility in support of intensification of sweetpotato cropping systems

Project code
AUD 2,999,970
Research program manager
Dr James Quilty
Project leader
Neal Menzies, University of Queensland
FEB 2016
APR 2023
Project status
Legally committed/Active
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This project is providing farmers with a range of nutrient supply options to underpin the sustainable intensification of the PNG Highland sweetpotato cropping system. 

Papua New Guinea’s (PNG) population has more than doubled in the last 30 years, with the highest growth rates in the Highland provinces. Chronic malnutrition is rife. 

The country has limited land available to expand agricultural production, which means that existing food production systems will need to intensify to feed the rapidly growing population. 

Sweetpotato is both a staple food and a cash crop in the PNG Highlands, with most producers engaged in subsistence farming. Studies show that farmers in the region are growing sweetpotato with a shorter fallow period and more rotations with legume crops, and using shorter cropping periods compared with 10 years ago. The sustainable intensification of the sweetpotato cropping system will be essential in increasing food security and improving the livelihoods and incomes of all rural highland communities. This project seeks to address this need.

Expected project outcomes

  • Improved food security and sovereignty as well as higher household incomes of rural communities in the PNG Highlands thanks to increased and sustained production of sweetpotato.
  • Greater dietary diversity and improved nutrition, especially among women and children, due to increased use of legume rotation crops.
  • Increased nutrient inputs through crop rotations, hedgerow management, and the use of commercial fertilisers for the projected adoption of high-yielding varieties by semi-commercial farmers.
  • Improved quality and reliability of the PNG national plant and soil analytical service, and greater capacity of junior scientist/technician to manage the improved service after the project is completed. 
Key partners
National Agricultural Research Institute
fact sheet placeholder image
Fact sheet SMCN/2012/105