Cultivating Flora

Why Do Some Ohio Soils Hold Nutrients Poorly And How Fertilizer Strategy Helps

Ohio farms include a wide range of soils: from deep, productive loess-derived silt loams in the west-central portion of the state to sandy outwash and gravelly tills along glacial margins and river terraces. Some of these soils tend to “leak” nutrients–nitrogen, potassium, phosphorus and various micronutrients–more readily than others. Understanding the physical, chemical and biological reasons for poor nutrient retention, and matching fertilizer and soil-management strategies to those causes, is the most reliable way to improve nutrient use efficiency, crop yields and environmental outcomes.

Why soil nutrient retention varies: the main drivers

Soil nutrient retention is governed by a mix of properties that influence how nutrients are stored, transformed and moved. In Ohio, the most important factors that cause poor nutrient holding capacity are texture and structure, organic matter levels, cation exchange capacity (CEC), soil pH and chemistry, drainage and climate, and management history.

Texture and structure: sand, silt and clay

Soil texture is one of the single biggest controls on nutrient retention. Sandy soils have large pores and low surface area, so they do not retain water or charged nutrient ions well. Cations–ammonium (NH4+), potassium (K+), calcium (Ca2+), magnesium (Mg2+)–adsorb to negatively charged clay and organic matter surfaces. In sands, there is little clay and little organic matter, so the cation exchange capacity is low and nutrients move with water.
Silt loams and clay loams have more surface area and higher CEC, but the type of clay matters. Some clay minerals (like montmorillonite) have high charge and greater nutrient-holding capacity; others (like kaolinite) hold less. In Ohio, glacial tills and alluvial soils vary in clay types and amounts, so two fields a few miles apart can behave very differently.

Organic matter and biology

Soil organic matter provides negative charge sites for cation adsorption, hosts nutrients in organic forms, improves soil structure and supports microorganisms that cycle nutrients. Low organic matter soils–common in intensively tilled or recently cleared fields–have reduced nutrient-holding capacity and faster leaching of nitrate and other mobile nutrients. Biological processes also control mineralization and immobilization rates; fields with low microbial activity may release nutrients more slowly or unpredictably.

Cation exchange capacity (CEC)

CEC is a measured property that summarizes the soil’s ability to hold cationic nutrients. Low-CEC soils (commonly sandy or low organic matter soils) require different management: more frequent, smaller fertilizer applications; banding to place nutrients where roots are concentrated; and inputs that increase organic matter and surface charge over time.

pH, phosphorus fixation and micronutrient availability

Soil pH influences nutrient solubility and fixation. In acidic soils (pH below 6.0) phosphorus can be strongly fixed by iron and aluminum oxides and become unavailable to plants even when total P levels are high. In calcareous spots or soils with high pH, micronutrients such as iron, manganese and zinc become less available. Both extremes create situations where nutrient is present but not plant-available, effectively reducing the soil’s “holding” function from the crop’s perspective.

Drainage, leaching and climate

Well-drained sandy soils or heavily tile-drained fields can lose nitrate quickly after heavy spring rainfall. Excessive drainage increases leaching risk, especially for nitrate and soluble potassium. Conversely, poorly drained soils can become anoxic, changing nitrogen chemistry (denitrification) and causing loss as N2 or N2O gases.

Management history and disturbance

Continuous intensive tillage, removal of crop residues, lack of cover crops, and repeated monoculture reduce organic matter and disrupt soil structure. Over time, this increases the risk of nutrient loss. Repeated broadcast applications of soluble fertilizers without incorporation or timing consideration also amplify leaching and runoff losses.

How fertilizer strategy helps: principles and tactics

A fertilizer program that recognizes the soil constraints can substantially reduce losses and increase plant uptake. The principles are simple: match source, rate, timing and placement to the crop need and the soil’s ability to retain nutrients. The tactics listed below are the practical ways to do that in Ohio conditions.

Start with good information: soil testing and mapping

Reliable soil tests identify nutrient levels, pH, CEC and often phosphorus buffering or other indices that influence fertilizer recommendations. For variable fields, consider grid sampling or management zones so you can apply fertilizer rates where they are needed rather than uniformly. Use consistent sampling depth (commonly 0-6 or 0-8 inches for most agronomic crops) and sample at the same time of year for comparability.

Timing and split applications

Split applications reduce the window of time when a nutrient is in the soil but not yet absorbed by the plant. For example:

Split phosphorus is less common because P is relatively immobile once placed, but timing can matter for early-season P uptake–starter or banded P near the seed helps in cool, wet soils when root growth is slow.

Placement: banding, starter, and incorporation

Placement changes how quickly a nutrient is exposed to fixation or leaching. Banding phosphate or potassium places nutrients in concentrated zones where roots will forage and reduces contact with P-fixing iron/aluminum oxides that dominate in some Ohio soils. Starter fertilizer at planting provides a localized P and N supply for young seedlings without broadcasting large amounts that might be fixed or lost.
Broadcast applications can be effective when followed by incorporation or when soil conditions favor limited losses, but for low-CEC or acidic soils, banding or subsurface application is often superior.

Product choice: conventional vs enhanced-efficiency fertilizers

Enhanced-efficiency fertilizers–coated urea (slow-release), nitrogen stabilizers (nitrification inhibitors, urease inhibitors), ammonium sulfate vs urea, stabilized ammonium nitrate blends–can reduce losses in vulnerable soils. They do not replace good timing and placement but expand the options for keeping nutrients available when crops need them.
For phosphorus and potassium, choosing forms that reduce fixation or are formulated for banding is key. Liquid starters or monoammonium phosphate (MAP) in banded application are common choices for early-season phosphorus delivery.

pH management and lime

Correcting soil pH in acidic soils is a high-return activity because it improves nutrient availability, increases microbial activity, and reduces P fixation in many cases. Lime recommendations should be based on buffer pH tests or state-extension guidance. In Ohio, many soils benefit from periodic liming to maintain pH in the optimal range for corn-soybean systems (typically pH 6.2-6.8, depending on crop and soil).

Building soil organic matter and biology

Long-term improvement of nutrient retention comes from building organic matter: reduced tillage, cover cropping, manure or compost additions, and diverse rotations. Every 1% increase in soil organic matter can measurably increase CEC and water holding capacity, particularly in coarser-textured soils. Cover crops also capture residual nitrate and return it slowly to the system when they decompose.

Micronutrient strategy

Soils that test low in micronutrients should be managed proactively. Zinc and iron deficiencies are common in high pH patches; boron issues appear in some sandy soils or in crops with high boron demand. Foliar sprays can correct acute deficiencies quickly, while soil-applied chelated forms, banding, or adjusted pH provide longer-term correction.

Practical, actionable recommendations for Ohio growers

Below are concrete steps to translate the principles above into field-ready practice. These are general guidelines; local Extension recommendations and soil tests should guide precise rates and products.

Monitoring, adaptation and record-keeping

No single strategy fits every field or year. Keep accurate field records of soil tests, fertilizer products and timings, weather events (heavy rains, drought), yields and tissue tests. Use those records to refine variable-rate prescriptions, to identify fields where organic matter-building pays off most quickly, and to track improvements in nutrient use efficiency (pounds of nutrient applied per bushel produced).
Consider starting small: trial a split-N program, banded P, or a cover crop on a representative field and compare results to the previous practice. Analyze not just yield but also input costs, plant health, and evidence of nutrient loss (nitrate in tile outlets, visual deficiency symptoms).

Seasonal timeline example for Ohio row crops

  1. Fall: sample soils after harvest; apply manure where logistic and environmental considerations allow; seed winter cover crops to capture residual nitrate.
  2. Winter to early spring: review soil test recommendations and adjust lime plans if needed; finalize spring fertilizer product and placement decisions.
  3. Pre-plant/planting: apply starter banded P and a small N starter if desired; incorporate broadcast P/K if incorporated tillage is planned.
  4. Early season: scout for deficiencies; perform tissue tests if growth is poor despite adequate soil test levels.
  5. V4-V6 (corn): sidedress N or apply in-season N based on crop staging, expected weather and soil test history; use inhibitors on vulnerable fields.
  6. Post-harvest: evaluate manure nutrient contributions, analyze yield maps vs. fertilizer applications, and plan adjustments for the next season.

Conclusion: integrate soil knowledge with fertilizer tactics

Some Ohio soils hold nutrients poorly because of low clay or organic matter, low CEC, inappropriate pH, or aggressive drainage and weather patterns. A fertilizer strategy that aligns product choice, timing, placement and rate with those soil realities will improve nutrient uptake, crop performance and environmental stewardship. Start with good soil testing and mapping, implement split timing and targeted placement when soils are sandy or low-CEC, correct pH issues with lime, and invest in organic matter and biological health for durable gains in nutrient retention. Practical experimentation at field scale, combined with careful record-keeping, will fine-tune the approach for each unique Ohio field.