Lesson 1Soil organic matter: functions, mineralisation rates, and management implicationsExamines soil organic matter as a store of nutrients, water, and biological activity. Covers mineralisation rates, environmental factors, and management practices that build or preserve organic matter in intensive systems.
Organic matter contributions to CEC and waterNitrogen and sulfur mineralization processesTemperature and moisture effects on releaseResidue management and cover crop impactsTillage intensity and long-term SOM trendsLesson 2Common fertiliser sources, nutrient forms, and conversion to elemental N, P2O5, K2O (e.g., urea, ammonium nitrate, MAP, DAP, potash, sulfate, chelates)Reviews common fertiliser materials used in maize production, including nitrogen, phosphorus, potassium, sulphur, and chelated micronutrients. Stresses nutrient forms, analysis, and converting product rates to elemental nutrients.
Typical N, P, K, and S fertilizer productsAmmonium, nitrate, and urea behavior in soilConverting analysis to lb nutrient per acreMAP, DAP, and potash handling and placementChelated micronutrients and compatibility issuesLesson 3Maize macronutrient uptake patterns and timing (N, P, K) by growth stageDescribes how maize uptake of nitrogen, phosphorus, and potassium varies by growth stage. Links uptake curves to top-dressing timing, starter fertiliser value, and strategies to cut losses while meeting peak crop demand.
Early-season nutrient needs and starter useRapid uptake during V6 to tasseling stagesLate-season nutrient demand and remobilizationAligning N timing with crop demand curvesSynchronizing P and K supply with root growthLesson 4Secondary nutrients and micronutrients relevant to maize (S, Mg, Zn, B, Mn): roles and critical sufficiency rangesDetails the roles of sulphur, magnesium, zinc, boron, and manganese in maize physiology. Reviews deficiency symptoms, soil and tissue critical levels, and when supplemental applications are warranted in intensive production systems.
Physiological roles of S, Mg, Zn, B, and MnSoil and tissue critical levels for each nutrientVisual deficiency symptoms by growth stageSoil and foliar sources for secondary nutrientsWhen micronutrient fertilization pays in cornLesson 5Interpreting soil test reports: units (Bray/P, Mehlich-3, Olsen), extractant differences, and common lab recommendationsCovers how to read soil test reports, focusing on units, extraction methods, and calibration. Learners compare Bray, Mehlich-3, and Olsen P tests and translate lab results into clear, field-ready fertiliser decisions.
Common soil test units and conversionsBray, Mehlich-3, and Olsen P comparisonsInterpreting P and K calibration categoriesUnderstanding lab fertilizer recommendationsSampling depth, timing, and lab quality controlLesson 6Recommended soil test ranges for high-yield maize for pH, organic matter, Bray/Mehlich-3 P, exchangeable K, and micronutrientsSummarises recommended soil test ranges for high-yield maize, including pH, organic matter, phosphorus, potassium, and key micronutrients. Links categories to expected yield response and refines fertiliser strategies.
Optimal pH and organic matter benchmarksBray and Mehlich-3 P target categoriesExchangeable K ranges by soil CEC classMicronutrient guideline levels for cornAdjusting targets for yield and rotationLesson 7Typical high-yield targets and corresponding nutrient removal rates (tonnes/ha to kg nutrient/ha conversions)Links typical maize yield goals to nutrient removal in grain and stover. Teaches tonne-to-kilogram conversions, removal coefficients, and how to use them to design replacement and build-up fertiliser programmes.
Nutrient content of corn grain and stoverBushel-to-pound nutrient removal factorsEstimating field-level nutrient exportsBalancing removal with fertilizer inputsPlanning build-up versus maintenance ratesLesson 8Soil texture, structure, and water-holding capacity: implications for nutrient retention and leaching riskExplores how soil texture and structure affect water storage, aeration, and root growth in fields. Links these properties to nutrient retention, leaching risk, and management practices that protect yield and water quality.
Classifying Midwest soil textures in the fieldStructure types and their impact on root growthAvailable water capacity and measurement methodsTexture effects on cation exchange and leachingTillage and compaction impacts on structureLesson 9Soil pH effects on nutrient availability and liming guidelinesExplains how soil pH controls nutrient availability, aluminium toxicity, and microbial activity. Provides liming guidelines for soils, including lime quality, rates, and placement to achieve target pH for maize rotations.
pH effects on macro and micronutrient solubilityAluminum and manganese toxicity thresholdsTarget pH ranges for corn and rotationsCalculating lime rates from buffer pH testsLime sources, fineness, and application timing
