Dr Gordon Rajendram, a leading New Zealand soil scientist and consultant for sustainable farming, explains that even slight overuse of fertiliser can result in nutrient imbalances, water pollution, and long-term soil damage. “Even if over-fertilisation isn’t a crisis now, farmers must focus on efficiency and sustainability. Applying only what is necessary protects the land and the environment,” he says.

Fertilisers contain key nutrients like nitrogen (N), phosphorus (P), and potassium (K), which are vital for plant growth. However, if these nutrients exceed crop requirements, they can leach into groundwater or wash into nearby water bodies. Nitrogen, in particular, poses a risk as it transforms into nitrates, which can contaminate both groundwater and surface water. High nitrate concentrations not only threaten aquatic ecosystems but can also make drinking water unsafe, particularly in rural areas dependent on groundwater sources.

Dr Rajendram stresses that “soil testing is key in modern agriculture; applying excess fertiliser may seem beneficial initially, but it can lead to nutrient imbalances and soil acidification, which ultimately harms crop yields.” When excess nutrients disrupt soil pH, beneficial microorganisms that help plants absorb nutrients and resist diseases are negatively impacted. This degradation compromises soil structure and reduces its ability to retain moisture, making crops more vulnerable to drought.

In addition to environmental risks, excessive fertiliser use results in a reliance on chemical inputs, increasing farming costs. Over time, continuous over-fertilisation can lead to an accumulation of salts in the soil, which harms plant roots and reduces crop resilience. This dependency threatens both farm productivity and profitability.

To mitigate these risks, Dr Rajendram advises using precision farming techniques. “Farmers can improve both yield and sustainability by adopting best practices, such as soil nutrient testing and targeted fertiliser application,” he recommends. Technologies like GPS-guided fertiliser application allow for targeted delivery, ensuring crops receive what they need without excess.

By prioritising balanced nutrient management, Dr Rajendram believes that farmers can achieve optimal yields while protecting the health of their soil and the environment. Implementing these practices ensures that fertilisers contribute positively to crop productivity while safeguarding the long-term viability of the land.

For more information, please contact:

Contact Dr Gordon Rajendram

021 466077

rajendram@xtra.co.nz

www.gordonrajendramsoilscientist.co.nz

Contact Media PA

phillip@mediapa.co.nz

027 458 7724

www.mediapa.co.nz