PAPUA NEW GUINEA
NATIONAL AGRICULTURAL RESEARCH INSTITUTE
An Evaluation of Soil Fertility
Constraints in the Highlands
of Papua New Guinea
TTTTTTTTT TTTTTTTT TT. 22
DDDDDDDD 2008
THE INSTITUTE
The National Agricultural Research Institute (NARI) was established by an Act of National
Parliament of Papua New Guinea (PNG) in July 1996 as a publicly funded, statutory research
organisation, to conduct applied and development oriented research on food crops, alternative food
and cash crops, livestock and resource management issues. Besides applied and adaptive research,
NARI is responsible for providing authoritative technical, analytical and diagnostic services and
up-to-date information to the entire agriculture sector in PNG. The major targets are the smallholder semi-commercial farmers in the country.
The mission of NARI is to promote innovative agricultural development in Papua New Guinea
through scientific research, knowledge creation and information exchange.
An Evaluation of Soil Fertility
Constraints in the Highlands of
Papua New Guinea
Compiled by Bailey, J.S,1 Ramakrishna, A.1 and Krichhof, G.2
Technical Bulletin No. 22
December 2008
1
National Agricultural Research Institute, Highlands Programme, Aiyura, Eastern Highlands Province, PNG
2
The University of Queensland, School of Land and Food Sciences, Brisbane, Queensland, 4072, Australia.
ii
Correct Citation: Bailey, J.S., Ramakrishna, A. and Kirchhof, G. 2008. An Evaluation of Soil Fertility
Constraints in the Highlands of Papua New Guinea. Technical Bulletin No.22. National Agricultural
Research Institute, Lae, Papua New Guinea.
The views expressed in this information bulletin are those of the compilers and do not necessarily constitute or coincide with the opinions of the National Agricultural Research Institute.
ISBN: 9980-932-72-4
Copyright © 2008 National Agricultural Research Institute (NARI). All rights reserved.
The Director General
National Agricultural Research Institute
Sir Alkan Tololo Research Centre
NARI Head Office
Kana Aburu Haus
P O Box 4415
LAE 411
Morobe Province
Papua New Guinea
Ph: (675) 475 1444/475 1445
Fax: (675) 475 1450
E-mail: [email protected]
Website: www.nari.org.pg
iii
Table of Contents
Page
Summary........................................................................................................1
1. Introduction.............................................................................................................................2
1.1 Soil fertility problems in the highlands of PNG.....................................................................2
1.2 Identifying the causes of soil infertility using DRIS methodology...........................................3
2. Aims and Objectives of the Study..........................................................................................4
2.1 Aims..................................................................................................... ............................4
2.2 Objectives.........................................................................................................................4
3. The Data Base........................................................................................................................4
3.1 Data collection and selection..............................................................................................4
3.2 Soil classification and clay mineralogy .................................................................................6
3.3 Potential problems with the data..........................................................................................7
4. Methodology...........................................................................................................................7
4.1 Soil and plant analysis........................................................................................................7
4.2 DRIS methodology.............................................................................................................8
4.3 Regression analysis and statistical procedures.......................................................................9
4.4 Analyses of variance (ANOVA) and the Tukey test..............................................................9
5. Results and Discussion..........................................................................................................9
5.1 Development of a DRIS model for sweet potato..................................................................9
5.2 The effects of garden and soil on tuber yield and soil attributes...........................................13
5.3 The effects of garden and soil type on leaf DRIS indices....................................................14
5.4 A negative correlation between soil CEC and soil organic C...............................................18
5.5 Relationships between leaf -P and soil-P in volcanic and non-volcanic soils.........................21
6.General Discussion ..............................................................................................................23
7. Conclusions...........................................................................................................................25
8. Innovative Startegies for Combating Soil infertility............................................................25
8.1 Conservation of nutrient-rich ash from burnt vegetation......................................................26
8.2 Use of compost and green manure as an alternative to ‘slash and burn’..............................26
8.3 Improving short-term fallow using NPK accumulator species.............................................26
8.4 Delayed-fertilised fallow....................................................................................................27
8.5 Liming to increase soil CEC and reduce P fixation .............................................................28
Bibliography..............................................................................................................................30
Acknowledgements..................................................................................................................34
iv
Other Technical Bulletins
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
Description of Selected Sweet Potato Varieties for Lowland Conditions: Selection as of
December 1998.
Towards an Integrated Cabbage Pest Management Strategy for the Wet Lowlands of Papua
New Guinea.
Improved Taro Varieties with Resistance to Taro Leaf Blight for Papua New Guinea Farmers.
Conservation of Domestic Animal Genetic Resources in Papua New Guinea.
Potential for a Pepper Industry in Papua New Guinea.
Evaluation of Sweet Potato Varieties in Eight Pacific Island Countries and the Philippines:
Results and Recommendations as of April 1993.
Strategies for Agriculture and Rural Development in Papua New Guinea.
Sweet Potato Variety Evaluation in PNG: Achievements and Methods.
Yam Germplasm Collection in PNG.
Pig Nutrition Research in PNG in the 1970s and Early 1980s.
Evaluation of Rice Varieties for Upland Rainfed Production in the Lowlands of Papua New
Guinea.
Plant Genetic Resources Strategy for Papua New Guinea.
Soil and Plant Sample Collection, Preparation and Interpretation of Chemical Analysis.
Participatory Rural Appraisal & Planning (PRAP) in Seko and Deyamos Local Level
Government, Kabwum District, Morobe Province.
Ownership and Management of Sheep and Goats in Three Highlands Provinces of Papua
New Guinea.
Peri-urban Agriculture Programme, Hillside Farming Survey.
Physico-chemical and eating qualities of selected rice varieties in Papua New Guinea.
Survey of Current Feeding Practices and Attitudes to Broiler Chicken Production.
Impact and Management of Oribius Weevils in Papua New Guinea
Confirmation of Genetic Gains for 12 Taro (Colocasia esculenta (L) Schott) Lines for Taro
Leaf Blight Resistance, Yield and Eating Quality.
Think Global before going Global: Understanding Consumer Preference of Fresh Produce in
Papua New Guinea
Copies can be obtained from:
The Publications Section
Sir Alkan Tololo Research Centre
National Agricultural Research Institute
Kana Aburu Haus
P.O. Box 4415
LAE 411,
Morobe Province
Papua New Guinea
Phone: (675) 475 1444/475 1445
Facsimile: (675) 475 1450
Email: [email protected]
Website: www.nari.org.pg