5.2B Agriculture systems Notes

Agricultural Systems Vary Across the World Due to Soil and Climate Differences

1. Agricultural systems differ because soil characteristics and climate conditions vary widely across the world and impose physical limits on crop choices and livestock practices.
2. Soil fertility, texture, structure, drainage, depth, and mineral content determine which crops can be grown successfully and how much yield can be produced.
3. Climatic factors such as temperature, rainfall patterns, humidity levels, and frost frequency restrict the types of crops and livestock that can survive in each region.
4. Farmers must adapt their agricultural practices to local physical conditions, which results in different systems such as terrace farming, irrigation schemes, dryland pastoralism, and intensive crop production.

Influence of Soil Differences on Agricultural Systems

1. Highly fertile soils support intensive cropping systems, whereas poor or shallow soils are more suitable for pastoralism or low-input agriculture.
2. Tropical rainforest soils (Oxisols/Latosols) are nutrient-poor due to heavy leaching and therefore require shifting cultivation or fertilization when used for agriculture.
3. Temperate grassland soils (Mollisols/Chernozems) contain high levels of organic matter, allowing extensive cereal production such as wheat, barley, and maize.
4. Volcanic soils (Andosols) are extremely fertile, making them suitable for crops such as coffee, bananas, and potatoes in regions like Indonesia and Japan.
5. Mountain soils are often thin, stony, and prone to erosion, limiting farmers to grazing or terrace farming.
6. Alluvial soils near rivers provide high fertility and reliable moisture, supporting rice cultivation in monsoon regions.

Influence of Climate Differences on Agricultural Systems

1. Climate determines the length of the growing season, which restricts the number of crops that can be harvested annually.
2. Tropical climates support multiple cropping cycles per year, whereas cold climates may only allow one short season.
3. Regions with high temperatures and abundant rainfall support plantation crops such as sugar cane, bananas, and cocoa.
4. Dry regions with low rainfall often rely on pastoralism, drought-resistant crops, and irrigation systems.
5. Extreme climates (e.g., deserts, tundra) limit agriculture to highly adapted farming systems or require technological intervention.

Agricultural Variation by Biome

Tropical Rainforests

1. Soil: Nutrient-poor oxisols, highly weathered, acidic, low in minerals.
2. Climate: Hot and humid with high rainfall, leading to rapid nutrient cycling but also leaching.
3. Crops: Bananas, cocoa, coffee, cassava.
4. Challenges: Deforestation, poor soil retention, dependence on shifting cultivation.

Temperate Grasslands

1. Soil: Rich in organic matter, deep, fertile mollisols.
2. Climate: Moderate temperatures, distinct seasons, adequate rainfall.
3. Crops: Wheat, corn, barley, soybeans.
4. Challenges: Soil erosion from intensive farming, monoculture risks.

Deserts

1. Soil: Sandy, saline, low organic matter, poor water retention.
2. Climate: Extreme temperatures, very low rainfall.
3. Crops: Date palms, drought-resistant crops (millet, sorghum).
4. Challenges: Water scarcity, dependence on irrigation.

Mediterranean

1. Soil: Thin, rocky, prone to erosion but moderately fertile.
2. Climate: Hot, dry summers and mild, wet winters.
3. Crops: Grapes, olives, citrus fruits, almonds.
4. Challenges: Water shortages, soil degradation, wildfires.

Tundra

1. Soil: Permafrost, very low fertility, poor drainage.
2. Climate: Cold temperatures, short growing seasons.
3. Crops: Limited agriculture, small-scale greenhouse farming.
4. Challenges: Climate change, thawing permafrost.

Diversity in Agricultural Systems and Their Sustainability

1. These decisions have sustainability implications, affecting food security, environmental degradation, and economic stability.
2. Agricultural systems can be classified based on outputs, purpose, and inputs.

Outputs from the Farm System

1. Arable Farming: Focuses on crops (e.g., rice, wheat, maize).
2. Pastoral/Livestock Farming: Involves raising animals (e.g., cattle, sheep, poultry).
3. Mixed Farming: A combination of crop cultivation and livestock (common in Europe).
4. Monoculture: Cultivation of a single crop species (e.g., palm oil plantations in Indonesia).
5. Diverse/Polyculture: Growing multiple crops together (e.g., traditional farming in the Amazon).

Purpose of Farming

1. Commercial Farming: Large-scale production for profit
2. Subsistence Farming: Small-scale farming for family consumption
3. Sedentary Farming: Fixed location agriculture
4. Nomadic Farming: Moving livestock in search of grazing land

Types of Inputs in the Farm System

1. Intensive Farming: High input of labor, fertilizers, and technology per unit land
2. Extensive Farming: Low input per unit land, relying on natural conditions
3. Irrigated Farming: Requires artificial water supply
4. Rain-fed Farming: Relies on natural rainfall
5. Soil-based Farming: Uses traditional soil methods
6. Hydroponic Farming: Grows crops without soil, using nutrient solutions
7. Organic Farming: Avoids synthetic chemicals, focusing on natural fertilizers and biodiversity
8. Inorganic Farming: Uses chemical fertilizers, pesticides, and GMOs for higher yields

Factors Influencing Farmer Decision-Making

1. Physical factors (soil fertility, climate, water availability, slope) strongly influence what is possible on a given piece of land.
2. Economic factors such as input costs, market prices, access to technology, and transport infrastructure influence profitability.
3. Social and cultural traditions shape which crops are grown and which farming skills are passed down through generations.
4. Environmental factors including biodiversity, sustainability goals, and regulations influence long-term planning.
5. Government policies such as subsidies, land rights, and trade incentives determine what farmers prioritize.

Nomadic Pastoralism

1. Involves moving livestock seasonally in search of pasture and water.
2. Common in semi-arid and arid regions, such as the Sahel (Africa), Mongolia, and Central Asia.
3. Supports livelihoods of millions, particularly indigenous and rural communities.

Sustainability Challenges

1. Desertification: Overgrazing leads to soil erosion and land degradation.
2. Land Conflicts: Competition over grazing land with farmers and urban expansion.
3. Climate Change: Unpredictable rainfall patterns affect pasture availability.
4. Government Restrictions: Many governments enforce fixed settlements, limiting mobility.

Slash-and-Burn Agriculture (Shifting Cultivation)

1. Farmers clear forest land, burn vegetation, and use the ashes as fertilizer.
2. After a few years, the land loses fertility, and farmers move to a new plot.
3. Historically sustainable in low-density tropical regions (Amazon, Indonesia, Central Africa).

Sustainability Challenges

1. Deforestation: High population pressures prevent the land from regenerating.
2. Soil Degradation: Repeated clearing depletes nutrients, reducing fertility.
3. Carbon Emissions: Burning releases CO₂, contributing to climate change.
4. Government Bans: Many countries have outlawed slash-and-burn due to environmental concerns.

The Green Revolution

1. The Green Revolution occurred between the 1950s and 1970s, transforming global agriculture.
2. High-Yielding Varieties (HYVs) of wheat, rice, and maize were introduced, dramatically increasing yields.
3. Large-scale irrigation networks were expanded, including canals, tubewells, and dams.
4. Synthetic fertilizers, pesticides, and herbicides became widely used, allowing more intensive farming.
5. Mechanization such as tractors and harvesters increased efficiency and reduced labor needs.

Positive Impacts of the Green Revolution

1. Global cereal production increased significantly, preventing predicted famines in Asia and Latin America.
2. Countries like India became food self-sufficient due to increased production.
3. Higher incomes for many farmers improved living standards.
4. Agricultural research and technology sectors expanded, supporting long-term development.

Negative Environmental Impacts

1. Excessive fertilizer use caused eutrophication and water pollution, harming aquatic ecosystems.
2. Pesticide overuse reduced biodiversity, killing beneficial insects and contaminating soils.
3. Irrigation increased soil salinization, reducing long-term productivity.
4. Monocultures reduced genetic diversity, increasing vulnerability to pests and disease.
5. Groundwater depletion worsened in intensively irrigated regions such as the Punjab.

Social and Economic Challenges

1. Smallholders often could not afford fertilizers, HYV seeds, and mechanization, increasing inequality.
2. High input costs led to farmer indebtedness, contributing to rural poverty in some regions.
3. Rural–urban migration increased as mechanization reduced labor needs.
4. Dietary diversity decreased because HYVs prioritized cereal yields over diverse local crops.