Iowa Agriculture Runs on 110 Billion Pounds of Manure, at a Cost to Its Water – Inside Climate News

 

Report on Agricultural Manure Management in Iowa and its Implications for Sustainable Development Goals

Executive Summary

This report examines the practices of manure management within Iowa’s intensive agricultural sector, a leading producer of pork and corn in the United States. While livestock manure serves as a cost-effective fertilizer that can enhance soil health, its overapplication, driven by economic pressures and the consolidation of farming operations, has led to significant environmental and public health crises. This situation presents a direct conflict with several United Nations Sustainable Development Goals (SDGs), particularly those concerning clean water, public health, and responsible production. The state’s current voluntary approach to mitigation has proven insufficient, resulting in worsening water quality and highlighting a critical need for integrated policy solutions that balance agricultural productivity with environmental stewardship.

Agricultural Production and Nutrient Cycling in Iowa

Iowa’s agricultural system is characterized by high-volume production of both crops and livestock, creating a massive nutrient cycle centered on manure. The management of this cycle is pivotal to achieving goals related to food security and sustainable land use.

The Scale of Production and Manure Generation

• Iowa is a top agricultural producer, home to 25 million hogs and 46 million chickens, which generate approximately 110 billion pounds of manure annually.
• This volume of animal waste is 25 times that produced by the state’s human population.
• Concentrated Animal Feeding Operations (CAFOs) have grown in scale, consolidating the livestock industry and concentrating manure production in localized areas. This trend impacts progress towards SDG 12 (Responsible Consumption and Production) by creating waste management challenges that traditional, smaller-scale integrated farming systems did not face.

Manure as a Resource for SDG 2 (Zero Hunger) and SDG 15 (Life on Land)

Manure is a valuable byproduct utilized as a primary fertilizer, supporting the high crop yields necessary for food security. Its use aligns with certain sustainability principles:

1. Nutrient Source: Manure provides essential nitrogen, phosphorus, and micronutrients, reducing reliance on synthetic fertilizers and supporting SDG 2 by ensuring productive agriculture.
2. Soil Health: The organic matter in manure improves soil structure and microbial diversity, contributing to the targets of SDG 15 by combating land degradation and promoting healthy terrestrial ecosystems.
3. Circular Economy: Proponents argue that using manure creates a closed-loop system, recycling nutrients within the local agricultural economy.

Conflict with Sustainable Development: Water, Health, and Ecosystems

The current system of manure application in Iowa creates significant negative externalities that directly undermine key SDGs. The “leaky” nature of this nutrient cycle results in widespread pollution with severe consequences.

Violation of SDG 6 (Clean Water and Sanitation)

Nutrient runoff from over-fertilized fields is the primary driver of Iowa’s water quality crisis.

• Widespread Impairment: Half of all tested waterway segments in Iowa fail to meet quality standards, primarily due to nitrate and phosphorus pollution from agricultural sources.
• Drinking Water Contamination: Municipalities like Des Moines incur significant costs (up to $10,000 per day) to operate nitrate removal facilities, a direct challenge to ensuring access to safe drinking water for all.
• Ineffective Mitigation: The state’s voluntary Nutrient Reduction Strategy, implemented in 2014, has failed to stem the flow of pollutants; nutrient loads leaving the state have doubled over the past decade.

Impacts on SDG 3 (Good Health and Well-being) and SDG 14 (Life Below Water)

The consequences of water pollution extend beyond sanitation, affecting human health and marine environments.

• Public Health Risks: Long-term exposure to nitrates in drinking water is linked to various cancers and birth defects. Iowa is the only U.S. state with rising cancer rates, a critical concern for SDG 3.
• Marine Dead Zones: Iowa is a major contributor of the nutrient pollution that fuels the hypoxic “dead zone” in the Gulf of Mexico, severely damaging marine ecosystems and fisheries, in direct opposition to the goals of SDG 14.

Systemic Barriers to Sustainable Manure Management

Achieving a balance between agricultural productivity and environmental protection is hindered by economic, scientific, and institutional challenges.

Challenges in Application and Measurement

• Inexact Science: The nutrient content of manure is variable, making precise application difficult. Farmers often over-apply manure to ensure sufficient nitrogen for crops, leading to excess phosphorus runoff.
• Timing Constraints: Spreading manure in the fall, post-harvest, is common practice but increases the risk of nutrient leaching before the next planting season.

Institutional Weakness and SDG 16 (Peace, Justice and Strong Institutions)

A lack of robust governance and regulatory oversight perpetuates the cycle of pollution.

• Regulatory Hesitancy: The state government has resisted implementing mandatory regulations on farmers, favoring voluntary measures that have proven ineffective.
• Reduced Funding for Science: The state legislature has cut funding for critical water quality monitoring infrastructure, undermining the data-driven approaches needed to manage the crisis and demonstrating a weakness in institutional commitment to environmental protection as outlined in SDG 16.

Pathways Toward Integrated and Sustainable Solutions

While challenges are significant, opportunities exist to better align Iowa’s agricultural practices with the SDGs through regenerative agriculture and improved management techniques.

Advancing SDG 12 and SDG 15 through Regenerative Practices

A minority of farmers are adopting practices that reduce nutrient loss and improve soil health.

• Cover Crops: Planting cover crops can absorb excess nutrients from fall manure applications, holding them in the soil until the spring. This practice directly supports SDG 15 by preventing soil erosion and nutrient loss.
• No-Till Farming: Reducing tillage improves soil structure and its capacity to retain nutrients and water.
• Diversified Crop Rotations: Moving beyond a two-crop system can enhance soil fertility and reduce the overall need for fertilizer inputs.

These practices exemplify a shift towards more responsible production patterns (SDG 12) by internalizing environmental costs and creating a more resilient and less “leaky” agricultural system.

SDGs Addressed in the Article

• SDG 2: Zero Hunger
• SDG 3: Good Health and Well-being
• SDG 6: Clean Water and Sanitation
• SDG 8: Decent Work and Economic Growth
• SDG 12: Responsible Consumption and Production
• SDG 14: Life Below Water
• SDG 15: Life on Land

Identified SDG Targets

1. SDG 2: Zero Hunger

   • Target 2.4: By 2030, ensure sustainable food production systems and implement resilient agricultural practices that increase productivity and production, that help maintain ecosystems, that strengthen capacity for adaptation to climate change, extreme weather, drought, flooding and other disasters and that progressively improve land and soil quality.
     
     Explanation: The article discusses Iowa’s role as a leading producer of pork and corn. It highlights both unsustainable practices (overapplication of manure leading to pollution) and resilient agricultural practices. For example, Landon Plagge’s farm uses “cover crops, a three-crop rotation and no-till practices” to enrich soil health and reduce dependence on fertilizers, directly aligning with the goal of improving land and soil quality within a food production system.

2. SDG 3: Good Health and Well-being

   • Target 3.9: By 2030, substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination.
     
     Explanation: The article directly links water pollution in Iowa to negative health outcomes. It states, “Studies link long-term exposure to nitrate in drinking water, even at low levels, to various cancers as well as birth defects.” It also notes that Iowa is “the only state in the nation with rising cancer rates,” suggesting a direct connection between the environmental issues discussed and public health.

3. SDG 6: Clean Water and Sanitation

   • Target 6.3: By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials…
     
     Explanation: The central theme of the article is the degradation of water quality due to agricultural pollution. It describes how “Nitrate and phosphorus from excess manure leach into waterways,” creating a “long-running clean-water crisis.” The failure of the state’s “Nutrient Reduction Strategy” to stem the flow of pollutants further underscores the relevance of this target.
   • Target 6.6: By 2020, protect and restore water-related ecosystems…
     
     Explanation: The article provides evidence of the degradation of water-related ecosystems. It mentions that “722 waterway segments in the state… do not meet water quality standards” and that many impairments are due to “phosphorus-fueled algae and bacteria blooms,” which harm wildlife and the overall health of the aquatic environment.

4. SDG 12: Responsible Consumption and Production

   • Target 12.2: By 2030, achieve the sustainable management and efficient use of natural resources.
     
     Explanation: The article discusses manure as a natural resource for fertilizer. However, it highlights inefficient use, stating that “economic pressure faced by farmers, time constraints… and the difficulty of knowing its exact nutrient contents all lead to overapplication in the fields.” This inefficient management results in a “leaky cycle” rather than a sustainable one.
   • Target 12.4: By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle… and significantly reduce their release to air, water and soil…
     
     Explanation: The article focuses on the management of livestock manure, a significant waste product from Iowa’s 10,000-head hog facilities and other concentrated animal feeding operations. The mismanagement of this waste, leading to its release into waterways as nitrate and phosphorus pollution, directly relates to this target.

5. SDG 14: Life Below Water

   • Target 14.1: By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including… nutrient pollution.
     
     Explanation: The article explicitly connects the land-based activities in Iowa to marine pollution. It states that Iowa “is one of the leading contributors to nitrate and phosphorus buildup in the Gulf of Mexico, creating a low-oxygen marine ‘dead zone’ each summer.” This is a direct example of nutrient pollution from a land-based source impacting a marine ecosystem.

6. SDG 15: Life on Land

   • Target 15.3: By 2030, combat desertification, restore degraded land and soil… and strive to achieve a land degradation-neutral world.
     
     Explanation: The article discusses the quality of agricultural land and soil. Practices like using manure, cover crops, and no-till farming are mentioned as ways to “build soil microbial diversity and improve soil structure.” Conversely, the overapplication of fertilizers and soil erosion contribute to land degradation, making this target highly relevant.

Indicators for Measuring Progress

1. For Target 6.3 (Improve water quality)

   • Indicator: Concentration of pollutants in water.
     
     Explanation: The article mentions “dangerously high levels of nitrate in drinking water sources” and the presence of “Nitrate and phosphorus from excess manure” in waterways. Monitoring these concentration levels is a direct way to measure progress.
   • Indicator: Cost of water treatment.
     
     Explanation: The article provides a specific financial metric: “Des Moines Water Works spends about $10,000 a day operating its nitrate removal facility.” A reduction in this daily cost would indicate an improvement in the quality of the source water.

2. For Target 6.6 (Protect water-related ecosystems)

   • Indicator: Proportion of water bodies with good ambient water quality.
     
     Explanation: The article cites Iowa’s “Impaired Waters List,” stating that “722 waterway segments in the state, half of all those tested, do not meet water quality standards.” The number and proportion of impaired water bodies is a direct indicator.
   • Indicator: Frequency and extent of algal blooms.
     
     Explanation: The article mentions that many water impairments are “due to phosphorus-fueled algae and bacteria blooms.” Tracking the occurrence of these blooms would serve as an indicator of ecosystem health.

3. For Target 3.9 (Reduce illnesses from pollution)

   • Indicator: Incidence of diseases attributable to pollution.
     
     Explanation: The article implies this indicator by noting that Iowa is the “only state in the nation with rising cancer rates” after linking nitrate in water to “various cancers.” Tracking these cancer rates could be used as an indicator of the long-term health impacts of water pollution.

4. For Target 14.1 (Reduce marine nutrient pollution)

   • Indicator: Size of marine “dead zones.”
     
     Explanation: The article explicitly mentions that nutrient runoff from Iowa contributes to “creating a low-oxygen marine ‘dead zone’ each summer” in the Gulf of Mexico. The size of this zone is a key indicator of the impact of land-based nutrient pollution.

5. For Target 2.4 / 15.3 (Sustainable agriculture and soil health)

   • Indicator: Proportion of agricultural area under productive and sustainable agriculture.
     
     Explanation: The article provides a metric for a specific sustainable practice: “Only about 5 to 10 percent of [Iowa’s] acres are planted with cover crops.” An increase in this percentage would indicate progress towards more sustainable agricultural systems.

SDGs, Targets, and Indicators Analysis

SDGs	Targets	Indicators Mentioned or Implied in the Article
SDG 2: Zero Hunger	2.4: Ensure sustainable food production systems and implement resilient agricultural practices… that progressively improve land and soil quality.	Proportion of agricultural land using sustainable practices (e.g., “Only about 5 to 10 percent of [Iowa’s] acres are planted with cover crops”).
SDG 3: Good Health and Well-being	3.9: Substantially reduce the number of deaths and illnesses from… water… pollution.	Incidence of water-related diseases (e.g., “rising cancer rates” in Iowa, linked to nitrate exposure).
SDG 6: Clean Water and Sanitation	6.3: Improve water quality by reducing pollution. 6.6: Protect and restore water-related ecosystems.	– Concentration of pollutants (“dangerously high levels of nitrate”). – Cost of water treatment (“$10,000 a day operating its nitrate removal facility”). – Number of impaired water bodies (“722 waterway segments… do not meet water quality standards”). – Occurrence of algal blooms (“phosphorus-fueled algae and bacteria blooms”).
SDG 12: Responsible Consumption and Production	12.2: Achieve the sustainable management and efficient use of natural resources. 12.4: Achieve the environmentally sound management of… all wastes.	– Volume of waste generated (“110 billion pounds of manure each year”). – Evidence of inefficient resource use (“overapplication in the fields,” “leaky cycle”).
SDG 14: Life Below Water	14.1: Prevent and significantly reduce marine pollution… in particular from land-based activities, including… nutrient pollution.	Impact on marine ecosystems (contributing to a “low-oxygen marine ‘dead zone’ each summer”).
SDG 15: Life on Land	15.3: Combat desertification, restore degraded land and soil.	Adoption of soil health practices (use of cover crops, no-till practices to improve soil structure).

Source: insideclimatenews.org