Retaining crop residues in the field after harvesting plays a critical role in sustainable agriculture by fostering several key benefits:

1. Enhanced Soil Health:

• Erosion Control: Residues act as a protective barrier, absorbing the impact of raindrops and wind, significantly reducing soil erosion. This helps preserve valuable topsoil, crucial for long-term fertility and productivity.
• Improved Water Management: Residues help retain moisture in the soil by reducing evaporation and promoting infiltration. This is particularly important in arid regions and during periods of drought.
• Increased Organic Matter: Over time, decomposing residues add organic matter to the soil, enhancing its structure, fertility, and water-holding capacity. This improved soil health fosters better plant growth and reduces the need for external inputs like fertilizers and amendments.

2. Environmental Benefits:

• Reduced Carbon Footprint: Retaining residues promotes carbon sequestration in the soil, mitigating climate change by storing atmospheric carbon.
• Habitat for Beneficial Organisms: Residues provide habitat for earthworms, beneficial insects, and microbes, promoting biodiversity and fostering a healthy soil ecosystem.

3. Economic Advantages:

• Reduced Tillage Costs: Leaving residues on the field allows for reduced or no-till farming practices, lowering fuel consumption and labor costs associated with traditional tillage methods.
• Improved Fertilizer Use Efficiency: Enhanced soil organic matter from residue decomposition improves nutrient retention, reducing fertilizer runoff and leaching, which can contaminate water sources.

Sustainable Residue Management:

While retaining residues offers numerous benefits, it's crucial to practice sustainable residue management for optimal outcomes. This involves considering factors like:

• Crop type and residue characteristics: Different crops produce varying amounts and types of residues, influencing decomposition rates and nutrient content.
• Climate and soil conditions: Rainfall, temperature, and soil type affect decomposition rates and moisture management needs.
• Long-term crop rotation plan: Diversifying crops with varying residue characteristics can help maintain soil health and nutrient balance.

By adopting practices like no-till farming, cover cropping, and proper residue management, farmers can contribute significantly to sustainable agricultural practices, ensuring long-term soil health, environmental protection, and agricultural productivity.

Significant in Doing the opposite of residue removal. Residue removal leads to soil mining; taking away nutrients that were extracted from the soils by the plant residues. It also leads to organic matter removal and the many benefits of organic matter: soil structure, texture, microbial activity, soil moisture retention, soil pH buffering, nutrient release;humus, humic acids, mineralization.

Retention of residues is a climate-smart practice; provides for carbon sequestration.

Dr Murtadha Shukur and Joseph Kipkorir Cheruiyot thank you for your contribution to the discussion

Retention of crop residues after harvesting is considered to be an effective antierosion measure. Crop residues can improve soil structure, increase organic matter content in the soil, reduce evaporation, and help fix CO2 in the soil. The return of crop residues into the soil is a common way to preserve soil OM, boost ecological activities, physical properties, and recycling of nutrients, especially N. With the adoption of conservation agriculture-based technologies these residues can be used for improving soil health, increasing crop productivity, reducing pollution and enhancing sustainability and resilience of agriculture. Crop residue is an effective material that can minimize the erosion of soil by wind and water. Residues reduce the forces of wind and water that would otherwise act upon loose particles at the soil surface. Residues also provide thermal protection to plants from winter temperature extremes.Crop residue returning can increase the content of organic carbon, nitrogen, available phosphorus, and potassium in soils. In addition, crop residue application into soil can prevent the loss of nutrients and improve essential nutrient availability.Crop residue retention plays a vital role in replenishing nutrient stock in soil. It is an essential aspect of sustainable crop production due to its beneficial effect on soil fertility status and organic matter content. Crop residue management through conservation agriculture can improve soil productivity and crop production by maintaining SOM levels. Two significant advantages of surface-residue management are increased OM near the soil surface and enhanced nutrient cycling and retention. Crop residue management practices include reduced tillage or conservation tillage, such as no-till, ridge-till, and mulch- till, as well as the use of cover crops and other conservation practices that provide sufficient residue cover to significant- ly reduce the erosive effects of wind and water.