Archaeology & Sustainability

Cheatsheet Content

### Introduction This cheatsheet explores how ancient agricultural techniques, rediscovered through archaeology, offer sustainable solutions to modern environmental challenges like climate change and desertification. These traditional methods can often be more resilient and suitable for developing countries than modern, fossil-fuel-dependent technologies. The key idea is that we already have the "technology" (ancient methods) to manage our environment sustainably, improve food production, and support rural economies worldwide. ### Wetlands: Ancient Solutions for Wet Landscapes Traditionally, wetlands were seen as obstacles to agriculture and drained. However, ancient cultures developed sophisticated ways to farm in wet environments. #### Raised Field Agriculture - **Example:** Lake Titicaca basin (Peru/Bolivia) and the Valley of Mexico (Aztec *chinampas*). - **Method:** Creating artificial islands or raised beds surrounded by canals. - **Benefits:** - Continuous cropping with natural fertilizer (canal material, nitrogen-fixing algae). - Higher yields than modern methods (e.g., 10 metric tonnes of potatoes per hectare vs. 1-4 tonnes). - Soil texture allows water to be drawn up by capillary action, preventing waterlogging and drying out. - Can supply significant portions of urban food needs (e.g., *chinampas* could supply a quarter of Mexico City's vegetables). - **Modern Relevance:** Reinstating these systems has been successful where economic and political support exists, proving their viability for sustainable agriculture. ### Desert Agriculture: Water Harvesting in Arid Lands Deserts can be productive with sympathetic management, especially through ancient water-harvesting systems. #### Negev Desert Systems - **Historical Evidence:** English explorers in the 1800s described ancient settlements, stone walls, cisterns, and check dams indicating past fertility. - **Archaeological Findings:** Comprehensive mapping in 1948 revealed extensive systems of stone mounds, walls, and terraces linked by artificial canals leading to wadis (river canyons) and farms. - **How it Works:** - Fine silt soils form a crust when it rains, causing water to run off. - Stones were raked into piles to encourage water to flow into channels. - Channels direct water to fields and cisterns. - **Run-off Efficiency:** Stone removal increases water run-off by nearly 250%. - **Rainfall Amplification:** Actual rainfall of 100mm/year could result in 300-500mm/year reaching cultivated areas. - **Benefits:** - Terraces control erosion and harvest rainwater. - Experimental run-off farms had good harvests even during extreme droughts, using less water than local irrigated farms. - Prevents salinization (a common problem with modern irrigation). - Produced unusually sweet fruit and potent medicinal plants. - **Challenges & Modern Adaptations:** - Difficulty with tractors on terraced fields; Bedouin use camels. - Unpredictability of rains. - Modern applications are spreading to other Middle Eastern and North African countries. ### Cisterns: Ancient Water Storage Underground cisterns were crucial for desert life and water management. - **Purpose:** Collect and store run-off water from harvesting systems. - **Historical Context:** Date back to the Chalcolithic (before 3000 BC), found across the Middle East, India, and North Africa. - **Decline:** Many modern cisterns are filled with sediment, as water supply became centralized and piped from large reservoirs. - **Consequence:** In Jordan, 92% of annual rainfall now evaporates. - **Modern Viability:** Reinstating rainwater-harvesting systems could save 10-15% of lost water (6.6 billion cubic meters). ### Qanats: Underground Water Channels Qanats are ancient underground canal systems for water distribution. - **Definition:** Underground canals that bring water from hills to agricultural plains. - **Benefits:** Extend habitable land and protect water from evaporation in deserts. - **Distribution:** Widespread across Asia and North Africa (e.g., Iran, Oman, China, Pakistan). - **Decline:** Replaced by deep wells with power pumps, leading to aquifer depletion and lower water tables. - **Reinstatement Efforts (e.g., Oman):** - **Goal:** Revitalize rural economies and reduce food imports. - **Improvements:** - Empty into storage tanks to reduce waste. - Solar-powered pumps for regular water delivery. - Enables farmers to grow cash crops with consistent water supply. - **Safety & Efficiency:** Can operate without child labor; lining channels with tiles or concrete improves safety and prevents leakage. - **Climate Change Relevance:** Reinstating these systems is crucial as desertification and arid regions expand. ### Soil Erosion: Terracing for Land Reclamation Agricultural terraces are a long-established method to combat soil erosion and land degradation. - **Example:** Yemen's extensive agricultural terraces, once considered a "wonder of the world," were abandoned due to political instability and modernization. - **Consequences of Abandonment:** Increased water flow caused erosion in valleys, buried agricultural land with silt, and depleted water tables. - **Reversal:** Terraces are being rebuilt, saving soil on hillsides and preventing sedimentation in valleys. - **Global Impact:** An estimated 24 billion tons of soil are lost to erosion annually. - **Benefits of Terracing:** - Conserves soil and water. - Prevents erosion on steep hillsides, unlike modern clear-cutting forestry. - Protects water quality and reduces flood risk. ### Intercropping: Diverse Planting for Sustainable Yields Intercropping, or planting multiple species together, is a form of intensive, sustainable agriculture practiced worldwide. - **"Three Sisters" (Americas):** Maize, beans, and squash. - Maize provides stalks for beans. - Beans fix nitrogen in the soil. - Squash leaves cover the ground, reducing erosion, conserving moisture, and deterring weeds. - **Complex Chinese Systems:** - Crop rotation, flood control, irrigation, and manuring for over 2000 years. - **Integrated Paddy-Dike System (Pearl River Delta):** - Rice paddies double as fish ponds (grass carp eat weeds). - Other fish eat grass carp excrement. - Nitrogen-rich mud from paddies used to fertilize raised fields for mulberry trees. - Mulberry leaves feed silkworms; silkworm waste and leaves feed fish. - **Philosophy:** Emphasis on balance, sustainability, and working *with* nature. - **Benefits:** - Improves soil fertility (nitrogen fixation). - Reduces erosion and conserves water. - Reduces pest and weed growth. - Increases biodiversity. - More resilient to environmental extremes; different crop strains can withstand varying conditions. ### Conclusion: The Future is in the Past Sustainable agriculture is not a "luxury" but a necessity, and ancient techniques offer proven, effective solutions. - **Evidence of Success:** Sustainable methods have doubled and even tripled food production in regions where modern technology is unavailable. - **Global Benefits:** Regenerates exhausted soil, improves biodiversity, enhances farmers' health, and supports rural economies. - **Call to Action:** We already possess the knowledge and "technology" from the past to live sustainably and address global challenges like hunger, poverty, and environmental degradation. The future of sustainable living is already happening by integrating these ancient solutions with modern insights.