Opinion: Pacific marks World Soil Day

Soil samples tested in a lab in Samoa. Picture: SUPPLIED

Soil is an invaluable resource for any country because it provides ecosystem services critical for life and the medium for supporting food production, either directly or indirectly.

World Soil Day on December 5 provides us the opportunity to recognise the challenges faced by Pacific farmers and the programs implemented by SPC’s Land Resources Division (LRD) in our member countries and territories. Soil management is a key LRD service.

We aim to strengthen soil partnerships through the Pacific soil partnership platform by working with Ministries of Agriculture in Pacifi c Island Countries and Territories and linking the Pacifi c to the global community via the global soil partnership framework.

In Pacific Island countries, traditional gardening systems have intensifi ed over the years, resulting in the depletion of the soil nutrients vital for sustainable crop production. At the extreme end of this continuum is continuous cultivation of the same piece of land, causing nutrient loss through crop harvesting, soil erosion and loss of organic matter.

Increases in crop pests and diseases are often associated with the loss of soil fertility. An example of contemporary soil nutrient decline can be found in the sugarcane systems of Fiji, where researchers have documented substantial topsoil fertility decline over 30 years caused by inadequate soil conservation and poor nutrient management practices.

This problem is not confined to cane production, but occurs more broadly across farming systems in the Pacific, especially through intensification and crop exporting. For the Fiji island of Taveuni, it is estimated that since 1990, when taro production intensifi cation began, about 150,000 tonnes of taro have been exported.

This export has resulted in a net export of nutrients from the soil system that has led to nutrient decline. In other parts of the Pacific, land degradation, nutrient imbalances, decline in soil biological function and very high rates of erosion threaten the viability of current agricultural systems and reduced future management options.

Large yield gaps still persist, and soil fertility decline has not been reversed in island agricultural systems. Though sustainable soil management is a prerequisite for long-term success in agriculture, it is often not practiced, which leads to soil mining and yield decline on leased land, especially in Fiji.

Achieving food security, healthy ecosystems and climate change mitigation requires understanding the value and impact of soil restoration efforts.

On Taveuni, farmers have become aware of the importance of nutrient inputs for taro production because of the research and extension activities supported by the Australian Centre for International Agricultural Research (ACIAR).

Soils project addressing soil management and lack of soil knowledge in Pacific Island countries SPC is a partner in the ACIAR-funded project “Soil management in Pacifi c Islands: investigating nutrient cycling and development of the soils portal”. The project works to enhance soil knowledge and provide a reliable foundation for sustainable intensifi cation of agricultural systems.

The project is led by the Commonwealth Scientific and Industrial Organisation (CSIRO) with international partner Manaaki Whenua Landcare Research of New Zealand. Pacific Islands in-country partners are the Ministries of Agriculture in Fiji, Samoa, Tonga, Kiribati and Tuvalu.

SPC organised capacity building for farmers and agricultural officers in participating countries Soil management initiative project partners have trained in-country staff in Fiji, Samoa, Tonga, Kiribati and Tuvalu in various methods of collecting soil and plant sampling, data management and interpretation and development of farming system fertiliser recommendations.

For Fiji, LRD, in collaboration with the Fiji Ministry of Agriculture, organised trainings on soil health in April 2021 for farmers at Nawaisomo and Dakuibeqa on Beqa island. About 50 farmers attended the trainings that focused on the following topics: soil physical, chemical and biological components, management for healthy soil, sustainable fertiliser application using the 4R approach, and crop production in Fiji.

Farmers also practiced soil sampling, which is important for collecting good soil samples to accurately determine the levels of nutrients in the soil. The majority of the farmers made clear that the training was an eye-opener on soil.

They learned the importance of protecting soil and using organic materials and manure to maintain fertility. Some also reported they have learned how to apply mineral fertilisers sustainably.

A second training in April 2021 planned for agricultural extension offi cers and farmers on Taveuni on sustainable soil management was postponed for early 2022 due to COVID-19 travel restrictions in Fiji.

In October 2021, SPC and the University of the South Pacific (USP) School of Agriculture, Geography, Environment, Science and Ocean collaboratively organised a Doctor Soil Field Day at the USP Samoa Campus.

The aim was to provide training for agricultural offices and soil technicians on soil sampling, testing of the samples using the Palintest kit and interpretation of analysis results.

Twelve agricultural officers and soil technicians from the Scientific Research Organisation of Samoa, Ministry of Agriculture and Fisheries and USP attended, with certificates awarded to the participants. Participants reported that the training was useful and would help them in their work, especially when providing technical advice to farmers in Samoa.

As we join the world in marking World Soil Day, the SPC LRD team hopes these projects and our other soil work will draw attention to one of the most underrated, yet vital, parts of our land ecosystems.

We are thankful there is a day dedicated to the importance of healthy, sustainable soil management, and we aim to continue celebrating it to ensure Pacific soils thrive for generations.

 DR ELLEN IRAMU is the resident soil scientist with Land Resources Division. The views expressed are those of the author’s and do not reflect the views of this newspaper.

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