Rethinking High-Input Agriculture: A Sustainable Approach to Almond and Walnut Cultivation

Introduction

The global agricultural landscape has long been dominated by the high-input, high-output model—a system that prioritizes maximum yields through intensive resource use. Originating in California and spreading across developed nations, this model has significantly boosted production in many regions, including Europe. However, there are many forms of plantations, from dryland to deficit irrigation systems, where resources like water are scarce. Today, rising input costs and falling commodity prices are exerting economic pressure on this model. Moreover, increasing awareness of sustainability issues—such as water scarcity, biodiversity loss, and environmental degradation due to pesticides and fertilizers—calls for a reevaluation of our agricultural practices. Rather than discrediting the high-input model, it's time to adapt and consider alternatives that offer not just economic returns but also environmental and social benefits. This blog post focuses on the critical issue of water usage in almond and walnut cultivation. Drawing from global studies and our experience at Joseph's Dream in the Guarda district, we propose a more sustainable and economically viable approach that aligns with current market and social dynamics.

The Water Challenge in Almond and Walnut Cultivation

The High-Input Model and Its Limitations

Almonds and walnuts are traditionally grown in Mediterranean climates, where water is often not available in the quantities or at the times we desire. In California, both almonds and walnuts typically consume 12,000 to 14,000 cubic meters (m³) of water per hectare annually to achieve yields averaging 3,000 kilograms (kg) per hectare for almonds and 5,000 kg per hectare for walnuts. This intensive water use, coupled with high operational costs and inputs like fertilizers and pesticides, has raised environmental concerns and economic vulnerabilities, especially in regions facing water scarcity.

The Iberian Peninsula Scenario

On the Iberian Peninsula attempts to replicate the Californian model have often fallen short. Even the largest and best-managed farms rarely average yields above 2,200 kg per hectare for almonds. For walnuts, while the high-input model targets 5,000 kg per hectare, actual yields are closer to 3500kg. Water usage in these regions typically hovers around 6,000 m³ per hectare, closely aligning with local evapotranspiration rates. Operational expenditures (OPEX) for maintaining the high-input model on the Iberian Peninsula range between €4,500 and €7,000 per hectare, adding to the economic strain.

A Sustainable Alternative: Lower Input, Efficient Output

Leveraging Lower Evapotranspiration Rates

The Guarda district in Portugal offers unique climatic advantages for almond and walnut cultivation:

• Lower Evapotranspiration (ETo): The region has an average ETo that is approximately 25% lower than southern regions like Évora, Portugal.

ETo Comparison:

Month	ETo in Guarda (mm/day)	ETo in Évora (mm/day)
June	5.0	6.5
July	6.0	7.5
August	5.5	7.0

*Source: Instituto Português do Mar e da Atmosfera (IPMA)

The crop coefficient (Kc) values recommended by the Spanish Ministry of Agriculture, Fisheries, and Food (MAPA) (https://www.mapa.gob.es/es/), are 30% lower for Almonds and 15% lower for walnuts than the values from UC Davis. Applying this to our region while factoring in early rains we reach:

• Full Irrigation Rate for Almonds in Guarda: Approximately 4000 m³ per hectare per season.

• Full Irrigation Rate for Walnuts in Guarda: Approximately 4500 m³ per hectare per season.

Practical Application in the Guarda District

Water Management Strategies

• Deficit Irrigation: Applying between 2,000 and 3,000 m³ per hectare keeps us between 50% and 70% of the crop's evapotranspiration needs.

• Rainfall Utilization: Leveraging the 800 mm of annual rainfall, especially with continued precipitation in late spring and early fall, reduces overall irrigation.

• Precise irrigation management: Using precise soil and atmospheric monitoring allows us to get the most out of each drop of water.

Yield Expectations

Studies done across the world have constantly shown increased water use efficiency under reduced irrigation systems. Other benefits go beyond the scope of this post, like reduced leaching and crop adaptation. The results commonly show that moderate deficit irrigation, applying 50% to 70% of ETc (ETo multiplied by crop coefficient), reduces yields between 20% and 40%. Taking into consideration other factors in our Low-Input Farming System (LIFS) and compensating for our organic practices, yields of 1500kg in Almonds and 3000kg in Walnuts are reasonable.

Economic and Environmental Benefits of lower water usage

• Lower Operational Costs: Accepting lower yields leads to a 50% reduction in OPEX, reducing expenses like fertilizers and phytosanitary products significantly.

• Organic Premiums: Transitioning to organic farming is easier when we are already targeting lower yields and inputs. The premiums enhance revenues by 25% on average, enhancing profitability.

• Land Costs and Valuation: Buying land outside of the established irrigation schemes allows for discounts of up to 80% on acquisition. Investing in decentralized infrastructure like dams, boreholes, and solar results in more resilience and increases the value of the assets above the actual cost to install them.

• Positive Externalities: Decreased inputs, local sourcing of fertilizer, and other organic regenerative practices enhance biodiversity and soil health, contributing to long-term sustainability. 

• Alignment with EU policy: To promote rural development, many countries including the European Union are providing investment grants and annual subsidies for these underdeveloped regions.

• Social Responsibility: Investing in areas that become viable with this model and have been overlooked, increases the local economy while supporting rural communities through sustainable land use and reduced environmental impact.

The Joseph's Dream Vision

By thinking outside the box and taking the opportunities that have not yet been fully priced by the market, we believe we can provide a decent economic return with lower risks. As we scale, we can drive the change everyone is talking about in a practical ground fashion. We are collaborating with various organizations across the Iberian Peninsula to set up a trial farm where the knowledge we are acquiring can be documented and transmitted. As we become Europe's largest organic regenerative project, we will demonstrate the viability of this model at scale. Our efforts focus on combining sustainability with modern science, creating a resilient food system that benefits all people and the planet.

Conclusion

The high-input, high-output model has its merits but is increasingly unsustainable in the face of environmental challenges and economic pressures. We create a different economic reality by embracing a lower-input model, especially in areas with more rainfall and lower evaporation. Leveraging this climatic advantage while incorporating efficient water use and regenerative practices, we can achieve respectable yields of almonds and walnuts while restoring our environment.

Nature provides us with a basic yield based on our climate, soil, and rainfall. We believe that bringing science and sustainable extra resources, allows us to create the optimal balance between costs, inputs, and outcomes. Going to one extreme or another can work for a period but doesn’t offer optimal results.

It's time to broaden our agricultural paradigms, prioritize sustainability, and redefine success beyond mere yield metrics. At Joseph's Dream, we're excited to be at the forefront of this transformative movement, cultivating crops and a better future for agriculture.

References

1. GARC International Journal of Engineering and Technology. (2020). Volume 11, Issue 3, Article 3.2.

2. https://www.sjvtandv.com/blog/u9hr7o6dtyudtx0wfjkiv0i90q1jo3

3. Doll, D., and K. Shackel. (2015). Drought management for California almonds. ANR Publication 8515 10

4. Cohen, M., Valancogne, C., Dayau, S., Ameglio, T., Cruiziat, P., & Archer, P. (Year). Yield and physiological responses of walnut trees in semi-arid conditions: Application to irrigation scheduling

5. Instituto Português do Mar e da Atmosfera (IPMA). Climatic data for the Guarda district and Évora. Available at: https://www.ipma.pt

6. Ministerio de Agricultura, Pesca y Alimentación (MAPA), Spain. Crop coefficient (Kc) values for almonds and walnuts. Available at: https://www.mapa.gob.es