The performance of biochar application in water conservation, salt distribution, water infiltration

Biochar is a carbon-rich material produced through the pyrolysis of organic matter in low-oxygen conditions. Its application to sandy soils significantly impacts their chemical properties, improving fertility, nutrient dynamics, and overall soil health. Here are the detailed effects of biochar on the chemical properties of sandy soil:

1. Increased Cation Exchange Capacity (CEC):

Sandy soils typically have low CEC, meaning they cannot retain nutrients effectively. Biochar has a high surface area and is rich in functional groups, which increase the soil's ability to hold and exchange essential nutrients like calcium (Ca²⁺), magnesium (Mg²⁺), potassium (K⁺), and ammonium (NH₄⁺). This prevents nutrients from being washed away by water, making them more available to plants.

2. Improved Nutrient Retention:

The porous structure of biochar acts as a sponge, adsorbing nutrients and water. This reduces nutrient leaching—a common issue in sandy soils due to their large particle size and low organic matter content. As a result, biochar helps maintain soil fertility over time.

3. pH Regulation:

Sandy soils are often acidic, which can limit the availability of certain nutrients. Biochar typically has an alkaline nature, which helps neutralize soil acidity and create a more favorable environment for nutrient uptake and microbial activity. This is especially beneficial for crops sensitive to low ph.

4. Enhanced Soil Organic Carbon (SOC):

Biochar is a stable form of carbon that remains in the soil for long periods. Its addition increases the soil's organic carbon content, which improves nutrient cycling and long-term soil fertility. Biochar also interacts with native organic matter, further enhancing soil chemistry.

5. Improved Microbial Activity:

The chemical composition of biochar supports the growth of beneficial soil microorganisms by providing a habitat and releasing small amounts of nutrients. These microbes play a critical role in nutrient mineralization and improving soil structure.

6. Reduction of Toxic Elements:

Biochar can adsorb toxic elements like heavy metals (e.g., lead, cadmium) and limit their availability in the soil. This property protects plants from toxicity and enhances overall soil health.

7. Greater Efficiency of Fertilizers:

By retaining nutrients and reducing leaching, biochar increases the efficiency of applied fertilizers. This reduces the need for frequent fertilizer applications, making agricultural practices more sustainable.

In conclusion, biochar addresses many of the chemical limitations of sandy soils by improving nutrient retention, increasing pH and CEC, and enhancing soil organic matter. These changes make sandy soils more productive and sustainable for agriculture and plant growth.

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Le biochar joue un rôle majeur dans le maintien d'un niveau de la CEC, ce qui milite favorablement dans l'absorption des elements minéreaux par les cultures. Aussi, il permet le maintien de l'humidité du sol. Bref il garantie un maintien et ou une augmentation de la fertilité du sol

Wood, agricultural waste, or manure are examples of organic resources that can be pyrolyzed to create biochar, a highly porous, carbon-rich substance. It can greatly enhance the chemical characteristics of sandy soils. This is how biochar helps: 1. Improving Cation Exchange Capacity (CEC): The low CEC of sandy soils restricts their capacity to hold onto nutrients. The soil's ability to retain and exchange vital elements like calcium (Ca²⁺), magnesium (Mg²⁺), potassium (K⁺), and ammonium (NH₄⁺) is improved by the high surface area and functional groups of biochar. 2. Increasing pH and Liming Effect: Many crops cannot grow in sandy soils because of their low pH, which makes them acidic. Because biochar is alkaline, it can increase the pH of soil, lowering the toxicity of aluminum and making nutrients like phosphorus more available to plants.

3. Improving Nutrient Retention and Availability:

Biochar acts as a reservoir for nutrients, reducing leaching losses, which are common in sandy soils.

It binds to nitrate (NO₃⁻) and other nutrients, making them available to plants over time while minimizing environmental pollution.

4. Boosting Organic Carbon Content:

Sandy soils are typically low in organic matter.

Adding biochar increases the organic carbon content, which is crucial for maintaining soil fertility and supporting microbial activity.

5. Reducing Soil Contaminants:

Biochar can adsorb heavy metals and other contaminants in sandy soils, reducing their bioavailability and potential toxicity to plants.

6. Enhancing Water Holding Capacity:

Although primarily a physical property, this indirectly affects chemical interactions.

By retaining more water, biochar can improve the dissolution and mobility of nutrients in sandy soils.

7. Stimulating Microbial Activity:

Biochar provides habitats for beneficial microorganisms, which can enhance nutrient cycling and improve soil health.

Practical Implications:

Improved nutrient use efficiency can lead to lower fertilizer requirements.

Enhanced soil fertility contributes to higher crop yields and sustainability.

In summary, biochar significantly ameliorates the inherent chemical limitations of sandy soils, making them more productive and resilient to environmental stressors.

Though,biochar can alter the texture of sandy soil for better water retention,but it's hydrophobicity could be a major factor limiting its functions in enhancing soil water retention.As biochar provides only trace nutrients from source material but not N,P,K,thus,its use along with fertilizer is desired. Plz go through these articles. 1. Role of biochar in improving sandy soil......

Water,2021,13(4),407. 2.Biochar improves the nutrients cycle.....

Env.Evidence2024.

Biochar can be used in a large number of applications, ranging from heat and power production to soil amendment. The properties depend on the feedstock and the process conditions. Selection of suitable conditions to produce a char with the desired properties therefore requires knowledge of dependencies and influencing factors, both quantitatively and qualitatively. Processes include both torrefaction and slow pyrolysis at high temperatures. Narrow temperature range between 200 and 400 °C causes the most significant changes and is therefore very sensible to influences and possibly difficult to control.

Biochar, (solid product of biomass pyrolysis) has been produced and utilized for several thousand years and is best known as charcoal (when produced from woody biomass). The applications are very diverse - from heat and power production, flue gas cleaning, metallurgical applications, use in agriculture and animal husbandry, building material, to medical use. It has gained increasing popularity in the last years as a replacement for fossil carbon carriers in several of these applications to reduce carbon.

Although scientific studies are primarily concerned with investigating underlying mechanisms and meta-analyses, industrial research and development aim to achieve optimized products with the highest possible efficiencies. Often Biochar products are developed for specific applications based on the scientific results from the higher increases in yield, root growth, SOC, nutrient efficiency and GHG emission reductions.

Hope this will be useful apart from vast references available in the literature.