Archive: March 2025

Soil is the foundation of productive farming, yet it is often treated as an afterthought rather than a long-term investment. According to soil scientist Dr Gordon Rajendram, a sustainable soil management plan ensures land remains fertile, minimises environmental impact, and enhances pasture and crop yields year after year. By following a structured approach, farmers can build resilience into their soil and protect their farming future.

1. Start with Comprehensive Soil and Pasture Testing

A sustainable soil plan begins with understanding the current state of your soil. Regular soil and pasture testing provide essential data on pH levels, nutrient availability, organic matter content, and potential deficiencies. Without this baseline information, farmers risk applying fertilisers inefficiently or missing critical imbalances. Testing should be conducted at least annually, preferably before major planting or fertilisation.

2. Balance Soil pH for Optimal Nutrient Uptake

Soil pH directly impacts nutrient availability. If the pH is too low or high, key nutrients become less accessible. Research by Condron et al. (2000) emphasises the importance of managing pH for improved soil quality, especially in organic farming systems. Regular testing and pH adjustment (e.g., applying lime) are essential for ensuring plants can access the nutrients they need.

3. Improve Soil Structure and Organic Matter

Healthy soil structure promotes water retention, drainage, and root development. Regularly incorporating organic matter—such as compost, manure, or cover crops—enhances microbial activity, improves soil aeration, and builds long-term fertility.

4. Implement Strategic Fertilisation

Rather than applying fertilisers blindly, use soil test data to create a targeted nutrient plan. This not only prevents overuse (which can lead to leaching and environmental damage) but also ensures crops and pastures receive exactly what they need for optimal growth. Consider slow-release or bioavailable fertilisers for sustained benefits.

5. Rotate Crops and Manage Pastures Effectively

Crop and pasture rotation reduces disease and nutrient depletion. Research by Horne et al. (2016) shows that rotating crops and pastures improves soil structure, enhances biodiversity, and increases resilience to pests. Proper rotation ensures better nutrient cycling and promotes long-term soil health.

6. Monitor and Adjust

Soil health is dynamic and requires ongoing attention. Regular testing, observation, and adaptive management ensure your sustainability plan evolves with changing conditions and farm needs.

By following these steps, farmers can protect their soil, maximise productivity, and ensure their land remains fertile for future generations. Dr Gordon Rajendram emphasises that investing in soil health today leads to better yields, lower costs, and a more sustainable agricultural future.

References:
Condron, L. M., Cameron, K. C., Di, H. J., Clough, T. J., Forbes, E. A., & McLaren, R. G. (2000). A comparison of soil and environmental quality under organic and conventional farming systems in New Zealand. New Zealand Journal of Agricultural Research, 43(4), 443-466. https://doi.org/10.1080/00288233.2000.9513442

Horne, D. J., Johnson, P. R., & Horne, M. A. (2016). Effects of crop and pasture rotations on soil quality and productivity. New Zealand Journal of Agricultural Research, 59(4), 451-462. https://doi.org/10.1080/01140671.2016.1229345

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

Dr Gordon Rajendram’s scientific work has been used in farming tools such as Overseer quietly helping farmers make smarter farming decisions. More recently he’s moved from research to consulting so farmers can now benefit directly from his expertise.

“My job is to bring science to the farm. For example I quantify how much pasture is actually growing when fertiliser is put on,” says Dr Gordon whose 22-year tenure at AgResearch’s Ruakura Research Centre established him as one of New Zealand’s leading soil scientists.

With New Zealand’s GDP heavily dependent on agricultural output, he says that understanding soil composition and optimising its fertility has never been more crucial. As fertiliser costs continue to rise, soil and pasture testing are essential for farmers looking to maximise their fertiliser efficiency. According to Dr. Gordon the best approach is through comprehensive soil and pasture/herbage testing.
“Applying too little fertiliser can be just as wasteful as using too much. Soil testing enables farmers to optimise nutrient use while minimising leaching and runoff into waterways. My approach to agricultural consultancy is rooted in balancing sustainability with productivity.”

He says historically farmers and scientists have been operating in separate bubbles and in the middle is what he terms “sales talk”. The shift from research to consultancy represents a direct bridge between scientific knowledge and practical farming.
“Soil testing empowers farmers to make well-informed, data-driven decisions, leading to healthier land, stronger livestock and improved profitability,” says Dr. Gordon.

His research has significantly influenced New Zealand’s agricultural sector, particularly through his development of field-calibrated soil tests for nitrogen and sulphur and leaching of nutrients from pastoral soils. The sulphur test and nutrient leaching work have been incorporated into the Overseer nutrient model. These contributions earned him nominations for awards including Scientist of the Year in 2008 and Science Entrepreneur of the Year in 2010. His research into Soil Nitrogen and Field Calibration led to the development of a field-calibrated pastoral soil N test for New Zealand in 2008, which was subsequently acquired by Ballance Agri-nutrients as part of an $18 million funding deal with MSI and AgResearch. Initially called ‘N Guru’ and later renamed ‘Pasture planner’, this tool exemplifies how scientific research can be translated into practical farming applications.

With more than 70 publications and six patents to his name, most achieved during his time at MAF and AgResearch, Gordon’s expertise spans analytical testing development, applied research, and consulting to farmers and fertiliser companies.

As a member of both the New Zealand Society of Soil Science and New Zealand Grasslands Society, he continues to contribute to the sector’s knowledge base through regular publications and consulting work.

Despite reduced government funding for research in recent years, Dr Gordon maintains his commitment to advancing agricultural science through practical application. His services include consultancy on fertiliser use, nitrate N leaching solutions, nutrient management planning, product development, educational seminars and workshops, research and analysis, environmental impact assessments and regulatory compliance guidance. Dr Gordon’s website (gordonrajendramsoilscientist.co.nz) is dedicated to helping farmers maximise soil potential by providing expert knowledge to enhance efficiency, sustainability, and profitability. His initial visit to the farm is free of charge.

Contact Dr Gordon Rajendram today!

021 466 077

rajendram@xtra.co.nz

gordonrajendramsoilscientist.co.nz