Transforming Our Garden with Wood Chips: 2-Year Soil Test Results

Table of Contents:

1. Introduction
2. The Experiment: Wood Chips vs No Wood Chips
3. Initial Concerns: Nitrogen Depletion
4. Results of the Soil Test
   • Nitrogen Levels
   • Other Macronutrients and Organic Matter
5. Benefits of Wood Chips
   • Weed Control
   • Moisture Retention and Nutrient Release
   • Organic Matter and Soil Health
6. The Role of Compost and Chicken Manure
7. Comparing Wood Chip Method to Traditional Tilling
8. The Impact on Crop Rotation
9. Soil Results from High Tunnel
10. pH Levels and Adjustments
11. Conclusion

The Experiment: Wood Chips vs No Wood Chips

Over two years ago, half of our vegetable garden was covered with wood chips, while the other half remained without any wood chips. This experiment aimed to compare the effects of wood chips on soil quality, nutrient availability, and crop growth. Both sides of the garden were treated the same, without the addition of compost, amendments, or tilling. Now, with the soil test results in HAND, we can finally analyze the impact of wood chips on the garden.

Initial Concerns: Nitrogen Depletion

One of the primary concerns associated with using wood chips as mulch is the potential depletion of nitrogen in the soil. The fear was that the decomposition process of wood chips would Consume significant amounts of nitrogen, leaving inadequate levels for plant growth. However, research suggested that as long as wood chips were left on the surface without being incorporated into the soil, the nitrogen depletion would be minimal.

Results of the Soil Test

The soil test results revealed interesting findings for both the wood chip and no wood chip sections of the garden. In the wood chip section, the nitrogen level was significantly low, measuring only 11 ppm, which falls within the higher end of the low range. On the contrary, the no wood chip section showed nitrogen levels on the high end of the medium range, with a measurement of 24 ppm. Other macronutrients and organic matter levels were excellent in both sections.

Nitrogen Levels

The low nitrogen levels in the wood chip section confirmed the initial concerns about potential nitrogen depletion. To address this, the addition of nitrogen-rich amendments, such as composted chicken manure and compost, were recommended. The no wood chip section, however, did not require any nitrogen amendments due to its already high nitrogen levels.

Other Macronutrients and Organic Matter

Apart from nitrogen, the levels of other macronutrients (phosphorus, potassium, calcium, magnesium, boron, and sulfur) and organic matter were excellent in both sections of the garden. Organic matter plays a vital role in moisture retention, nutrient release, and overall soil health, while macronutrients are essential for plant growth and development.

Benefits of Wood Chips

Despite the lower nitrogen levels observed in the wood chip section, there are several noteworthy benefits that come with using wood chips as mulch in the garden.

Weed Control

Wood chips excel at suppressing weed growth, providing a natural barrier that prevents weeds from emerging. This eliminates the need for excessive weeding, saving time and effort during the gardening season.

Moisture Retention and Nutrient Release

Wood chips contribute to moisture retention in the soil, reducing the need for frequent watering. Additionally, as the wood chips break down over time, they release nutrients back into the soil, ensuring a steady supply of essential elements for plant growth.

Organic Matter and Soil Health

The presence of wood chips increases the organic matter content in the soil. Organic matter improves soil structure, aeration, and Water-holding capacity. As it decomposes, it also enhances nutrient availability and fosters a healthy soil environment for beneficial microorganisms.

The Role of Compost and Chicken Manure

Compost and chicken manure are valuable amendments that can help address low nitrogen levels. Adding composted chicken manure and compost to the soil replenishes the nitrogen content, providing plants with an adequate nutrient supply. It is important to distribute these amendments evenly throughout the garden to ensure uniform nutrient availability.

Comparing Wood Chip Method to Traditional Tilling

The experiment also highlighted the differences between the wood chip method and traditional tilling. In the wood chip section, where tilling was avoided, the nitrogen levels were noticeably lower. However, tilling in the no wood chip section seemed to contribute to higher nitrogen levels, possibly due to the incorporation of green material into the soil through regular tilling practices.

The Impact on Crop Rotation

Crop rotation plays a crucial role in maintaining soil health and preventing nutrient imbalances. The results of the experiment indicated that the wood chip section required additional nitrogen amendments for optimal crop growth. This finding highlights the importance of monitoring nutrient levels and adjusting crop rotation plans accordingly to ensure a balanced nutrient supply.

Soil Results from High Tunnel

The experiment also encompassed a soil test conducted on the high tunnel, where wood chips were used as mulch for growing tomatoes. Surprisingly, despite only one year of wood chip application, nitrogen levels remained high, indicating that the wood chips did not significantly impact nitrogen availability. Other macronutrients and organic matter levels in the high tunnel soil were also excellent.

pH Levels and Adjustments

pH levels were examined in both the wood chip and no wood chip sections of the garden. The wood chip section showed a slightly alkaline pH of 7.08, while the no wood chip section exhibited an even higher alkaline pH of 7.19. Adjustments for optimal pH levels may be necessary, such as the addition of elemental sulfur to decrease alkalinity or lime to Raise acidity levels.

Conclusion

The two-year experiment comparing the effects of wood chips on soil quality provided valuable insights. While the wood chip section displayed lower nitrogen levels, the numerous benefits of wood chips, including weed control, moisture retention, and organic matter enrichment, outweighed this drawback. By incorporating nitrogen-rich amendments and adjusting crop rotation accordingly, the wood chip method can effectively sustain healthy and productive gardens.