Workshop Manual (Feb 2025) – Summary

Purpose & Scope: McLeod’s manual is explicitly written for farmers and consultants worldwide to learn and apply the Albrecht model of balanced soil fertility. Its aim is to bridge complex soil science with practical farming: demonstrating how balanced nutrition – matching fertilizer to soil needs – can restore and sustain soil while maintaining high yields. The manual emphasises that by addressing all limiting nutrients and restoring ideal base saturation ratios, growers can increase crop, fruit, pasture and animal production AND regenerate soil at the same time. In sum, it treats soil as a living system where “restoration, sustainability and productivity go hand in hand” under the Albrecht approach.

Background – Dr. W. A. Albrecht & Bryan McLeod: Dr William A. Albrecht (University of Missouri soil department head, 43 years) is presented as the founder of modern soil fertility in the USA. Albrecht famously taught that “soil [is] a living organism” and must be fertilised only to match each soil’s specific requirements, addressing every limiting element so nutrients “can work together” without antagonism. Bryan L. McLeod is introduced as a New Zealand-raised agronomist (Massey Univ. ’62) with 40+ years’ experience applying the Albrecht model globally. He established the first Albrecht lab outside the US (APAL, Adelaide, 2000) and later a lab in China. McLeod has worked on soils in NZ, Australia, China, Japan and beyond, solving nutrient imbalances by teaching Albrecht principles. In his own words, he regards himself as a “messenger” for Albrecht’s ideas.

Key Concepts of the Albrecht Model

• Base Saturation Percentages: The model focuses on the cation exchange balance of soil. All exchangeable Ca, Mg, K, Na (and H) occupy clay/organic colloid sites summing to 100% saturation. Albrecht defined ideal base saturation ratios (on most soils) at roughly Ca ~60–70%, Mg ~10–12%, K ~3–5%, Na ~0.5–3%, H ~12%. In this view, maintaining these proportions means all nutrient cations “work together without any antagonism”. (Pragmatically, McLeod notes that light sandy soils often need slightly higher Mg/K and lower Ca than heavy soils.)
• Cation Balance & Soil Health: A “good cation balance” – i.e. nutrient cations near their ideal percentages – yields a sustainable soil. McLeod explains that when Ca and cation ratios are near ideal, soil structure, microorganism activity, water use efficiency, root growth, and crop/pasture quality are all optimized. Importantly, balanced ratios automatically bring soil pH into the optimum 6.0–6.5 range. Conversely, imbalances cause structural and health problems. For example, low Ca saturation often leads to hard soil pans, poor aggregation, low microbial activity and plant uptake issues. The manual illustrates (with graphs) how correcting Ca/Mg ratios with lime and appropriate fertiliser rapidly transformed WA soils from a blocky, imbalanced state to ideal structure.
• Holistic Balance: McLeod stresses that nutrient balance (not just absolute levels) determines soil function. He notes Albrecht’s insight that the sum of all base saturations (including H) must be 100%, and any “wide variation” from the ideal will still allow plants to grow, but only when the targeted proportions are restored do quality and yield improvements manifest. In essence, the Albrecht model provides a “picture in time” of soil fertility: by analyzing base saturation and CEC, one can predict and prevent crop/animal issues before they occur.

Applications in China, Australia, Japan & New Zealand

McLeod documents case studies worldwide demonstrating the model’s flexibility:

• China (rice, vegetables, peanuts): McLeod began work in China in 1998, collaborating with the HAAS research Center in Hunan. Soil samples sent to the USA showed severely imbalanced Albrecht base saturations. By simply rebalancing soils (often adding Ca/Mg and micronutrients) according to Albrecht recommendations, yields surged. For instance, his first Changsha vegetable trial achieved ~20% higher yield and 20% higher nutritional quality versus local practice. In peanut trials (2004–05), adopting the Albrecht-based soil program doubled farmer yields – and when combined with targeted foliar feeding, yields tripled. Rice trials in Hunan also showed ~10–13% yield gains simply by correcting nutrient ratios. McLeod observes that even a 10% national improvement in China’s yields/quality via this model would dramatically boost food production.
• Australia (and NZ): McLeod spent decades consulting across Australia (especially WA) and NZ. He helped establish the Perry Ag Lab (APAL) in Adelaide and later advised many farms. State-level trials in Western Australia (Dept. of Ag. with McLeod & Barnett) applied the Albrecht recommendations to coarse, “hard-setting” grey clays. Even within one year, treated plots showed significant increases in soil organic matter and plant stand. Overall crop yields rose above control by ~0.3–0.5 t/ha (wheat, peas) after rebalancing Ca/Mg and adding needed nutrients. McLeod also notes practical lessons: in very low-CEC WA sands, adding lime can suppress Mn and reduce yield, demonstrating the need for site-specific balance. In New Zealand, McLeod’s home, he applied the model on dairy pastures and crops, identifying common nutrient gaps (e.g. boron, copper in ryegrass) and improving animal health.
• Japan: From 2010–2020 McLeod was invited by a Japanese agribusiness to solve nutrient imbalances. By introducing basic Albrecht principles (balanced fertiliser programs tuned to soil tests), he reports “solving many soil/plant issues” and improving productivity. This included adjusting calcium and magnesium in soils to address hidden deficiencies (e.g. excess K in orchards suppressing Ca uptake).

These examples illustrate that the Albrecht approach can be adapted globally: McLeod remarks that “one can take the Albrecht model to any area or country… without any prior knowledge and achieve significant results in both yield and quality”.

Relevance to Organic, Conventional & Regenerative Systems

McLeod emphasizes that all growers benefit from Albrecht-style soil balancing. The manual explicitly addresses organic, conventional and regenerative farmers alike:

• Organic/Regenerative: These growers need strong soil biology. McLeod advises that understanding soil mineral balance is the foundation for creating “an ideal soil environment… in which to achieve and maintain good soil biology”. In other words, even if one uses only organic amendments, the underlying mineral ratios still govern microbial activity and nutrient cycling.
• Conventional: For high-input farms, the concern is waste and imbalances. The manual cautions conventional producers to maintain biological health and “only address one’s soil limiting factors so as to not apply high amounts of unnecessary fertilisers”. The goal is to avoid the common trap of over-applying NPK and ignoring micronutrients, since every overuse of one nutrient can create deficiencies of others. By treating all limiting nutrients (macro and micro), farmers can often reduce fertilizer bills and increase efficiency.

The takeaway is that balanced nutrition is system-agnostic. Whether ploughing chemicals or practicing composting, knowing your soil’s needs ensures productivity and conservation. McLeod notes he has partnered with “many high-producing organic farms” achieving superior quality and yields by Albrecht-informed programs.

Soil Chemistry, Biology & Structure: An Interdependent System

A central theme is soil as a living system. The manual repeatedly links chemistry, biology and physical structure:

• It states plainly that all three phases are interdependent: a change in soil chemistry (mineral balance) will affect soil structure and microbial life, and vice versa. For example, adding calcium (a “structural” cation) can flocculate clays and improve porosity; conversely, waterlogged or compacted soils can alter nutrient availability.
• McLeod underscores that “soil has a basic nutritional requirement of its own for optimum management and sustainability”. In practice, soil chemistry (mineral content) determines structure – e.g. calcium is called the “prince of elements” because it stabilizes aggregates. Without sufficient minerals, soils will crust, drain poorly, and host fewer microbes. Thus, he argues, fertility management is really structuring management: “calcium is not only important for plants, but it also enhances the structural stability of soils”.
• Similarly, good structure (porosity, moisture retention) enables robust biology. The manual notes that all soil “elements are part of the chemistry” controlling microbial diversity. Imbalanced chemistry (say high N with low Ca) can reduce earthworms and beneficial fungi, leading to thatch buildup and disease.

In short, the manual frames fertility as a three-legged stool: chemistry (nutrients), structure (physical pore space/aggregation), and biology (microbes/plants). It warns that neglecting one leg undermines the others. This holistic view reinforces the Albrecht mantra: feed the soil (its chemistry), not just the crop, and the rest will follow.

Nutrient Interactions, Excesses & Deficiency Patterns

McLeod emphasizes that nutrients interact antagonistically. A key lesson is: “a soil nutrient excess will always result in a deficiency of another element”. The manual includes an “Excesses to Know” chart showing, for example:

• Excess nitrogen often leads to potassium deficiency in plants.
• Excess phosphorus can induce K, zinc, calcium or iron deficiencies.
• Excess potassium can suppress magnesium uptake.
• Excess sodium can trigger K or Ca deficiency in tissues.
  .

These interactions mean that one cannot interpret a plant’s low level of, say, magnesium without checking if another element is in surplus. McLeod illustrates cases from his work: e.g. in Japan he saw excess K in asparagus plots suppressing boron uptake; in NZ dairy pastures excess K caused low Mg in grass; in Australia excess Ca from heavy liming created Mn deficiency in crops.

The manual repeatedly cautions growers to monitor both deficiencies and excesses. In practice, this means using soil/base saturation data to spot any element “over ideal levels” (e.g. >20% Mg, >8% K, etc as flagged in the chart) and adjusting fertilizers accordingly. The overarching principle: in Albrecht terms, even an “excess” nutrient is really an imbalanced ratio that must be corrected.

Diagnostic Tools: Soil and Plant Analysis

McLeod provides practical guidance on testing:

• Soil Testing: He stresses obtaining a full soil analysis (preferably by an Albrecht/Perry-style lab) that reports base saturation, cation exchange capacity (CEC) and nutrient levels. The soil report is used to identify every limiting factor – not just N, P, K, but also Ca, Mg, trace elements and potential excesses. The manual encourages farmers to compare their soil’s base saturations against the Albrecht ideals and to calculate lime/fertiliser needs based on those ratios. (E.g. instead of liming solely to raise pH, the strategy is to apply lime or dolomite only to correct a calcium or magnesium shortfall.) The “real value” of soil analysis, McLeod insists, comes from using it as a diagnostic roadmap. He states that a good soil test should be used to address all limiting factors in the fertilizer program.
• Plant (Tissue) Testing: The manual distinguishes soil vs tissue tests clearly. It cautions that a leaf analysis is a reflection of the soil’s current balance, not a substitute for a soil test. McLeod writes that different crops will accumulate nutrients to different degrees, so leaf levels must be interpreted relative to soil context. For example, he notes that high soil Mg can suppress K uptake – so grass might show a “potassium deficiency” on a leaf test even if the soil has ample K. Therefore, fertiliser decisions (especially lime or bulk P/K) should be based on soil analysis, while plant tests guide foliar or supplementary applications.
• Integrated Interpretation: McLeod repeatedly advises using both tests in tandem. He says never to use a leaf test “to totally formulate a soil fertilizer program”. Instead, leaf analysis is best for diagnosing acute plant symptoms or planning foliar sprays (e.g. when a soil nutrient excess is causing a deficiency, a foliar can correct the plant’s immediate need). The manual even includes side-by-side summaries: “SOIL ANALYSIS shows available soil elements and balances/imbalances. LEAF ANALYSIS shows plant uptake levels resulting from those soil balances”. In practice, McLeod recommends getting a good soil report first, using it to set fertilizer rates, then using leaf samples (e.g. from pasture or fruit tissue) to fine-tune micronutrient foliar programs as needed.

Overall, the diagnostic section teaches readers to look for symptoms in the data: low base saturation of Ca or low soil boron, for example, or excessive soil P. When unusual patterns appear on tissue tests (e.g. high plant N with low Mg), the manual refers back to the soil chart to identify likely causes. McLeod’s goal is to make this process clear and actionable: farmers are walked through reading a soil report’s base saturation % and using it to make recommendations (with worksheets and examples throughout).

In summary, the workshop manual distils four decades of experience into a farmer-friendly guide. It uses clear language and examples to show that balanced soil nutrition (per Albrecht) is both scientifically sound and practically attainable. By framing soil fertility in terms of “right ratios” and corrective strategies, McLeod makes a complex topic approachable. The many case studies and bullet-pointed checklists encourage growers and advisors to methodically test, interpret, and rebalance soils – a process that, the manual argues, pays off in healthier soils and higher-quality yields.

Top of Form

Bottom of Form