Tea is Sri Lanka’s primary export and main source of foreign exchange. Photo / 123rf
The Sri Lankan Government’s policy on organic farming is an example; the result was catastrophic.
Domestic rice production fell 20% in the first six months, food prices surged upwards (by 50% in some cases) and the tea crop was devastated.
Tea is Sri Lanka’s primary export and main source of foreign exchange.
(In terrible timing, Covid destroyed tourism, which was Sri Lanka’s other main source of foreign income.)
The abrupt transition to organic production systems contributed significantly to a decline in agricultural production and worsened Sri Lanka’s wider economic crisis.
Although the economy has recovered, the World Bank reports that in 2026, “socio-economic indicators have continued to worsen: poverty is double its 2019 levels, malnutrition and stunting have increased, and the labour market recovery remains incomplete”.
Despite this example, statements continue to be made that New Zealand (and the world) should transition to agroecological practices (such as regenerative and organic approaches), which would entail phasing out both the use of fossil fuels for agricultural processes and the use of synthetic nitrogen fertilisers.
Doing so would not be consistent with the aim of enabling food to be safe, accessible and affordable.
For New Zealand, which is mostly under pasture rather than cropping, the results would not be as immediately catastrophic as in Sri Lanka.
There would, however, be an effect – scientists have already done the research.
When superphosphate fertiliser was removed in trials on sheep and beef country, the production decreased.
A decade after the experiments had finished, the production had not picked up – it was 70-80% of the conventionally farmed areas, possibly reflecting the change in pasture species caused by the withholding of superphosphate.
In contrast to superphosphate, the effects of nitrogen are rapid.
The presence of dark-green urine patches on pasture indicates that the grass is deficient and will respond to applied nitrogen.
Synthetic nitrogen acts rapidly. Organic sources of nitrogen act more slowly.
They are available in New Zealand (such as barn bedding from housed animals, compost and fish “fertiliser”), but nitrogen and general nutrient content are not always known, and nutrient availability tends to rely on rainfall and temperature.
Just like synthetic forms of nitrogen, and contrary to some beliefs, organic sources of nitrogen can be leached .
Misunderstandings also occur when data are extrapolated from one area to another.
The suggestion that New Zealand should use “much less” synthetic nitrogen is based on a figure from cropping land, which occupies a very small area in New Zealand.
Arable crops are produced on only 180,000 hectares of New Zealand’s area (26.8 million hectares).
Further, the figure of 150kg/ha nitrogen loss appears to be calculated as the difference between the nitrogen applied to crops as fertiliser by farmers, and the amount harvested by farmers in the crop itself.
No account is taken of the nitrogen that has enabled the increase in soil organic matter apparent on the Canterbury Plains.
A figure for nitrogen loss from agricultural (rather than cropping) land is provided by the OECD , calculated as the difference between the total quantity of nitrogen entering an agricultural system (mainly as fertilisers and livestock manure) and the quantity of nitrogen leaving the system (mainly via uptake by crops and grassland).
The OECD reports that New Zealand’s loss (not including the storage in building up organic matter) was 57kg/ha N in 2023 (and in 2024 was 60kg/ha, as it was in 2022 63.4), in comparison with 83 for the UK and 133 for the Netherlands.
No farmer wants applied nitrogen to escape, but food production is a leaky system.
When food production per kilogram of product is considered, organic production systems have greater impact in several areas (including nitrogen loss) than conventional systems.
And organic food is more expensive than food produced from conventional production systems, in part because yields per hectare are lower.
Policies implemented without adequate consideration of agronomic realities risk serious unintended consequences.
Sri Lanka ignored the advice from many agricultural scientists , and the ramifications continue for society.
– Dr Jacqueline Rowarth, Adjunct Professor Lincoln University, is a farmer-elected director of DairyNZ and Ravensdown.
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