Managing Livestock Manure to Enhance Water Quality and Social Benefits Dr. Jeffery Lorimor Iowa State University Ames, IA USA

Income from Livestock  In Romania – –Rural population is 46% of total –Overall Ag GDP is 18.5% of total –Of 14.8 million hectares, 63% is arable –Meat and egg production has declined approximately 40% since 1990 except for milk, even though adequate feed is available L. Lordache, senior researcher, World Economy Institute

Animal Contributions  Animals play multiple roles by providing –Draft power –High quality protein  (meat, milk, eggs) –Cash income/income diversification –Ability to graze non-cropped ground –Animal waste products  Nutrients  Gas for heating and cooking IFPRI 2020 Brief no. 61

Livestock Benefit the Poor More  Livestock benefit the poor by alleviating micronutrient deficiencies and by directly alleviating poverty.  The rural poor tend to get a higher share of their income from livestock than better- off rural people

Environmental Effects  The environmental concerns of increasing livestock production are –Higher concentrations of animals –Water quality deterioration –Air quality deterioration

Two Environmental Threats  Two primary threats to water quality may exist from animal production –Direct discharge of collected wastes –Over application of manure nutrients  Good management can minimize or eliminate both threats

Direct Discharge Elimination  Primary concern for direct discharge from manure to surface waters –Acute toxicity  Oxygen demand (COD/BOD)…kills aquatic life  Ammonia NH 3 -N …kills aquatic life –Chronic effects  Phosphorus …excess algae growth

Direct Discharge Elimination  Primary concern for discharge to ground waters –Acute toxicity  Microorganismse coli, streptococcus, etc. –Might result from poor well construction  Nitrate…Blue baby disease –Might result from too much nitrogen applied to the land

Direct Discharge Elimination  Solid manure less risky than liquid manure –Direct discharges are less likely since the manure does not flow –Adequate space between the manure and the water source is the primary means of protection

Direct Discharge Elimination  Most states in the US require separation distances between livestock production/ manure storage facilities and water resources –Iowa, for example, for liquid manure from animal buildings and manure storages requires meters separation

Direct Discharge Elimination  Solid manure stacks –Build stacks on impermeable floors/soil –Protect against rainfall with roofs or covers to avoid seepage –Keep stacks away from streams, rivers, and lakes

Avoid Over Application of Manure  Crops need nutrients to produce well  Nutrients can come from manure, legumes (N), or from purchased fertilizer  We know what the crops need  We know what the animals “produce” in manure

Clarification NOTE: animals do not produce nutrients. They use nutrients. We say they “produce” because non-grazing animals accumulate nutrients from feed taken from a large area into manure that accumulates in a small area.

Basic Objective  To avoid water quality problems we need to redistribute the animal manure back onto approximately the same area that the animal feed was produced on.  Research data tells us that properly distributed manure nutrients do not cause water quality deterioration

Properly Managed Manure Will Reduce Nitrates in Shallow Groundwater

Nitrates in Tileflow Poultry Manure Plots

Nitrogen Concentrations

Typical Nutrients Used by Crops  We know the nutrient needs of the crops –Corn needs kg of N-P-K –Wheat needs kg of N-P-K

Yearly Nutrients “Produced”

Animals per Hectare to Provide Nitrogen needed CornWheatSoybeans Swine bedded (16) Beef bedded 22 0 (6) Poultry (600)

Protecting Water If we do not apply more nutrients than the crops need, we will protect water quality. This applies to both purchased fertilizer and to animal manure. This applies to both purchased fertilizer and to animal manure. To protect water quality…do not over apply nutrients

Other Issues  Good manage must include other issues –Soil erosion…manure can increase of decrease soil erosion, depending on how it is managed –Losses…nitrogen losses can occur if manure is not covered with soil soon after being applied to the field –Seepage…seepage from storage piles can be an issue if left uncontrolled

Summary  Animals can play a vital role in the well being of a country  One of the many contributions animals can make is to concentrate nutrients from feed into manure for use as crop fertilizer  Good manure management is the key to changing a potential pollutant into a valuable natural resource

Summary  The current world bank project near Calarasi is an excellent example of a project that can result in improved manure management and improved water quality.  I commend you for your efforts

Annual Nutrient Amounts  Solid (bedded) beef manure – lb/hd/yr ( kg/hd/yr)  Poultry – lb/100 birds/yr ( kg/100 birds/yr) ( kg/100 birds/yr)

Compost  Proper compost requires four things: –Carbon –Nitrogen –Oxygen –Moisture

Composting Principles

Temperature ºF Heating Temperature plateau Substrate depletion Time Mesophilic (degradation) Psychrophilic (maturation) Thermophilic (conversion)

Composting Principles Efficient composting requires  A balanced source of energy and nutrients Typically with a C:N ratio between 20:1and 40:1  Sufficient moisture Typically between 40% and 60%  Sufficient oxygen Typically 5% or greater  A pH range between 6 and 8

Composting Principles Moist, high- nitrogen primary ingredient Bulking agent with large firm particles Dry, high- carbon amendment

Composting Principles Composting methods  Passive composting pile  Windrow  Passively aerated windrow  Aerated static pile  In-vessel

Composting Principles — In-Vessel Bin

Composting Principles -- Windrows