Soil Quality Assessment Report

1. Executive Summary

This assessment evaluates soil health across five agricultural parcels (440 acres total) in the Meadowbrook district to support crop rotation planning and nutrient management decisions. Soil samples were collected at 2.5-acre intervals and analyzed for physical, chemical, and biological indicators.

Key Findings:

• Organic matter content ranges from 2.8-4.1%, slightly below regional targets
• Phosphorus levels are adequate to high across all parcels
• Soil compaction detected in 30% of sampling points, concentrated in Parcels 16-17
• Microbial biomass indicators suggest moderate biological activity

Primary Recommendations: Implement cover cropping on Parcels 16-17 to address compaction and organic matter; reduce phosphorus applications on Parcel 15; continue current rotation on Parcels 14 and 18.

2. Methodology

2.1 Sample Collection

Soil cores (0-12 inch depth) were collected from 176 georeferenced points using a hydraulic probe. Samples were composited by management zone, resulting in 42 analytical samples. Collection occurred under dry conditions following USDA-NRCS field sampling protocols.

2.2 Laboratory Analysis

Samples were analyzed at the University Extension Soils Laboratory using standard methods:

• Texture: Hydrometer method (ASTM D422)
• pH and EC: 1:1 soil:water extract
• Organic matter: Loss-on-ignition at 360°C
• Nutrients: Mehlich-3 extraction (P, K, Ca, Mg, Zn)
• Bulk density: Core method at selected sites
• Microbial biomass carbon: Chloroform fumigation-extraction

3. Results

3.1 Soil Physical Properties

Bulk density exceeding 1.45 g/cm³ in silt loam soils (Parcels 16-17) indicates compaction that may restrict root growth and water infiltration. These parcels were under continuous corn 2023-2025, likely contributing to compaction.

3.2 Soil Chemical Properties

Phosphorus levels on Parcel 15 (62 ppm) exceed agronomic optimums and approach environmental thresholds. Continued high-rate P fertilization is not recommended. Parcels 16-17 show lower P, likely due to crop removal without replacement.

3.3 Biological Indicators

Microbial biomass carbon ranged from 240-410 µg C/g soil. Highest values were observed in Parcel 15 (crop rotation including cover crops) and lowest in Parcels 16-17 (continuous corn, minimal residue). These differences align with management history and organic matter content.

4. Management Recommendations

Parcel 14

Status: Good overall condition. Continue current corn-soybean rotation. Consider modest organic matter improvement through residue retention.

Parcel 15

Status: High phosphorus levels. Action: Suspend phosphorus fertilizer applications for 2-3 years; monitor with annual soil testing. Excellent biological activity — maintain cover crop rotation.

Parcels 16-17

Status: Compaction and low organic matter from continuous corn. Action: Implement fall-seeded cover crop (cereal rye or oat/radish mix) to reduce compaction and add biomass. Consider deep-rooted crop (alfalfa, sorghum-sudangrass) in rotation. Delay field operations until soil moisture permits to prevent further compaction.

Parcel 18

Status: Balanced condition. Maintain current practices.

5. Conclusion

Meadowbrook district soils are generally productive with localized management needs. Priority actions are compaction remediation (Parcels 16-17) and phosphorus reduction (Parcel 15). Continued monitoring every 3-4 years will track progress and inform adaptive management.