Soil erosion is a significant issue worldwide. Climate change is a major driver of erosion through sustained droughts and heavier rainfall. It’s crucial to find solutions to soil loss that are sustainable and effective. There is much research demonstrating the usefulness of mulching for this purpose. In this article, we will explore some of the findings.
Key takeaways 
- Soil erosion threatens food security, especially in poorer parts of the world.
- Rain can wash away soil dried out by extended droughts.
- Climate change accelerates erosion through severe weather patterns.
- Mulching protects soil from rain and traps sediment.
- One study found mulching decreased soil loss relative to a control.
- A mulch of any type and density was beneficial to varying degrees.
- Another study found mulch effectively supplemented native soil conservation practices in Tanzania.
Soil erosion
Soil erosion is a significant issue for the fertility of farmland. It is one of the most severe threats to food security in vulnerable parts of the world. Erosion is usually caused by wind blowing sediment away or rain removing residue through runoff. Sediment loss leads to the loss of nutrients. Nutrient loss prevents soil from supporting crops. Eroded land is also subject to worse flooding and creates an unlivable environment.
The onset of climate change is increasing the rate of erosion. Unpredictable weather patterns lead to a higher frequency of extreme weather events. Extended drought periods dry out the soil. Periods of rain and flash flooding will then carry the earth away. As erosion rates accelerate, the negative impact will compound. Finding a method to protect arable land efficiently and cost-effectively is critical.
Mulching
Mulching has demonstrated a lot of potential as a preventative measure against erosion. Creating a mechanical layer of organic material cushions the impact of raindrops. This layer lessens damage to the soil. The mulch allows water to infiltrate the soil and traps the sediment to prevent loss through runoff. Mulch also keeps soil temperature low which prevents evaporation and retains moisture.
Research findings
Study #1
Research into the impact of mulch on erosion control shows positive results. Field studies on the island of Rodrigues (an autonomous island of the Republic of Mauritius) provide exciting insights. The island is erosion-prone and vulnerable to climate change.
The trial applied varying amounts of three mulch types (banana, coconut and vetiver grass). The unmulched control plot’s soil loss was the equivalent of 8.5 tonnes per hectare per year (tha-1yr-1). Plots with banana mulch at 10 tha-1 lost 5.9 tha-1yr-1. Plots with coconut mulch at 40 tha-1 only lost 3.55 tha-1yr-1. While some mulch types were more effective, any application was beneficial. The more mulch applied, the less erosion. The table below shows the percentage of soil loss across all mulch types and mulching rates.
Study #2
Another study conducted in Tanzania looked at the effectiveness of different mulch types in preventing erosion when added to miraba. Miraba is an indigenous soil and water conservation method using grass strips to enclose crop fields. Two mulch covers were tested. Each mulch was made of a flowering plant, Tithonia and Tughutu. The researchers conducted tests in Majulai village and Migambo village in northeast Tanzania.
The findings demonstrate the significant benefit of mulch to erosion control practices. The below graph shows the results:
The researchers found that adding mulch to the traditional miraba practice decreased soil loss dramatically. Adding Tithonia mulch decreased loss by 55% in Majulai village and 50% in Migambo village. Adding Tughutu decreased loss by 56% and 50%, respectively. The study attributed the slight difference between the villages to the steeper slopes in the Majulai village area.
Work with us
Climate change will have an increasing impact. As weather events become more severe and unpredictable, soil erosion will become a greater threat. Implementing simple and cost-effective methods to preserve fertile soil is critical. Mulching provides significant advantages that will mitigate soil loss.
East Coast Mulching is an experienced operator with a wealth of local expertise. If you want to see what forestry mulching can do for your property, contact us today for a free quote.
