Having good quality soil is the foundation for enjoying growing healthy and productive plants. This is even more relevant if we want to have a garden, since the quality of the soil is directly related to the quantity and quality of the harvest. However, soils can present limitations that make cultivation difficult, and in these cases, applying improvement techniques is fundamental.
Determining the type of soil we have is the first step. There are simple observations and tests that allow us to identify whether our soil is fertile or needs intervention. Below, you'll discover how to evaluate and modify the soil quality of your garden or orchard, integrating key physical, biological, and chemical criteria for sustainable management.
Essential factors that define soil quality
- Texture: It determines the proportion of sand, silt and clay, influencing water and nutrient retention.
- Structure: It refers to how soil particles are grouped together, affecting aeration and drainage.
- Organic material: Decomposing plant and animal remains that improve fertility and biological activity.
- pH: It defines acidity or alkalinity and determines the availability of nutrients.
- Biological activity: Presence of microorganisms, worms and other organisms that decompose organic matter and create beneficial structures.
How to know if your soil is poor or fertile?
Characteristics of a poor soil:
- It tends to compact and makes water drainage difficult.
- It erodes easily, losing the fertile surface layer.
- In extreme drought it may develop deep cracks.
- Predominantly lands clayey and calcareous (light brown) with little organic matter.
Characteristics of a fertile or good soil:
- Tone dark brown or black, reflecting an abundance of organic matter.
- It is kept slightly moist, with good water and nutrient retention.
- When you pick up a handful, some of the soil sticks to your hands.
- Presence of worms or other living organisms.
Practical identification of soil types
| Soil Type | Key features |
|---|---|
| Sandy | Good drainage, low water and nutrient retention. |
| Clayey | High water retention, tendency to waterlogging and compaction. |
| Silty | Balance between retention and drainage, fertile but susceptible to compaction. |
| franc | Ideal mixture of sand, silt, and clay; excellent for agriculture. |
| Limestone | High alkalinity and low availability of some nutrients. |
| Saline | Salt accumulation affects nutrient absorption and causes stress to plants. |
Indicators and tests to assess soil quality
- Dark color: Indicates high organic matter content.
- Fresh and earthy smell: Reflects healthy soil.
- Structure: Formation of stable, non-caking aggregates.
- Presence of worms: The greater the quantity, the better the biological activity.
- Basic tests: It is advisable to measure the pH with kits and check the texture by kneading a small amount of moistened soil.
A simple test is to dig down 15-20 cm, collect the soil, and count the worms. A count of more than 70 worms/m² indicates good biological health.
Effective methods to improve soil quality
A proper diagnosis allows for the application of sustainable strategies to transform poor soil into fertile and balanced ground:
- Incorporate organic matter: Compost, manure, plant remains or worm humus increase fertility, biodiversity and water retention capacity.
- Crop rotation: Alternating species (especially legumes and cereals) helps prevent nutrient depletion and improves structure.
- Avoid compaction: Do not work the soil when it is wet or use heavy machinery excessively.
- Use of green roofs: Planting soil cover species protects against erosion, fixes nitrogen and maintains structure.
- Erosion control: Improve fertility through terraces, plant barriers or direct sowing (avoiding intensive tillage).
- Mix the fertilizer correctly: It can be done by four main methods: spreading on the surface, mixing with the top layer, replacing part of the soil with compost or filling planting holes with fresh mix.
- Efficient irrigation management: Use drip or pulse irrigation depending on the soil type and avoid waterlogging and nutrient leaching.
Sustainable agricultural practices and monitoring
- Conservation Agriculture: Minimum tillage and permanent cover to reduce erosion and improve structure.
- Agroforestry: Introduction of trees and shrubs to promote fertility and biodiversity.
- Integrated pest management: Promote biological control and use chemicals only when absolutely necessary.
- Analysis and registration: Conduct periodic analyses (pH, nutrients, texture, salinity) and keep a diary of practices and climate to detect changes and adapt strategies.
Role of organic matter and life in the soil
Organic matter is the pillar of a fertile soilIts inclusion improves structure, increases nutrient and water retention, balances pH, promotes beneficial microorganisms, and helps mitigate erosion.
- The presence of earthworms and a rich soil fauna allows nutrients to be released gradually and roots to find open paths to grow.
- In dry regions, it is key to replenish organic matter frequently due to its rapid decomposition.
Responsible and sustainable management of soil quality is an essential investment to ensure healthy crops, biodiversity, and environmental protection. By integrating practices such as incorporating organic matter, crop rotation, the use of mulches, and periodic monitoring, we can transform deficient soils into living, fertile, and productive soils, ensuring long-term agricultural success and ecosystem health.
