 Hello. I'm Chris Augustine. I'm a nutrient management specialist at the Carrington Research Extension Center. My contact information is at the bottom of this slide. Recently, compost has become a popular manure nutrient management tool. There are many benefits with composting. Some of those include order reduction, volume reduction, improved handling properties, improved soil properties, and the killing of pathogens in weed seeds. This presentation will cover the basics of composting animal minors. So what is compost? Composting is a controlled biological process that converts organic wastes like manure, carcasses, and plant materials into a humus-like material suitable for fertilizer. Composts are organic residue mixtures that have been mixed, piled, and moistened to undergo thermophilic decomposition. This is also known as high-heat decomposition. The decomposition occurs until the organic materials have been substantially altered or decomposed. What we are basically doing is that by composting, we're speeding up the decomposition process. Here is a picture of three wind-road compost piles at the Carrington Research Extension Center. The piles are a mixture of feedlot manure and bedding. This was piled on May 8. The piles are roughly 4 feet high and 10 feet wide. There are three piles in this picture. The west pile, or the one on the left, is hidden behind the middle pile. These are the same piles. However, this picture was taken August 4. As you can see, the west pile can now be seen, and the pile volume has been greatly reduced. Most composting volume reduction studies indicate that it is common to reduce the volume by as much as two-thirds. It is the reduction of volume that reduces hauling costs that make composting an economic advantage when compared to hauling raw manure. Also note that there are no weeds growing on the pile, and the pile of manure resembles black topsoil. The high temperatures in the pile sterilize weed seeds and kill pathogens. Here is a pile of manure. There are weeds growing on it. Piling the manure and letting it set is not enough. True, piling the manure does reduce manure volume, but manure needs to be turned. Turin stimulates the microbes that raise temperatures and does the composting. Turin fungi in the compost are indigenous to the pile. They will start composting almost immediately. It is our job as compost managers to make the pile habitable for the decomposing microbes. To do that, we need a carbon-to-nitrogen ratio or CN ratio to range from 20 to 40. That is 20 parts of carbon for every part of nitrogen, and 40 parts of carbon for every part of nitrogen. There is poor space between the chunks of manure and other materials in the compost pile. The poor space needs to have approximately 40 to 65 percent water and 60 to 35 percent air. By managing the CN ratio, water and air properly, the compost pile should heat in a day or two after the initial piling. The CN ratio should range from 20 to 1 to 40 to 1. If the CN ratio is too low, meaning there is excessive nitrogen, nitrogen can be lost due to ammonia volatilization. The pile may smell like ammonia and temperatures can exceed 150 degrees Fahrenheit and kill beneficial microbes. Adding a carbon source like straw or wood chips can help remediate this. If the CN ratio is too high, meaning there is excessive carbon, the pile may not heat or compost slowly. Adding more manure can alleviate this issue. Here are some book values of common composting materials. As a rule of thumb, if the CN ratio is under 40 to 1, the material is a nitrogen source, such as cattle manure and cattle carcasses. If the CN ratio is over 40 to 1, the material is a carbon source, like sawdust and wheat straw. NDSU Extension Publication, Composting Animal Miners, a guide to the process and management of animal manure compost, NM-1478, shows how to determine CN ratios. If you are composting cattle manure and wheat straw, you will need approximately 90% manure and 10% wheat straw. 40 to 65% of the pore space needs to have water. Summer rainfall and moisture in the composting materials can serve as a water source. However, during long dry periods, water may need to be added. Here, water is being added to the pile by manual application from a pickup pulling a sprayer nurse tank. The pile was turned shortly after the water application, so water could be mixed in. Some compost turners do have water applicator attachments and water the pile while turning. Testing for adequate moisture can be easily done. This test is known as the wet rag test. To perform this test, take a handful of compost. It should feel like a rung out rag, damp to the touch, but not dripping water. If the compost doesn't feel moist, then water needs to be added. If the compost is dripping water, the pile should be turned to increase evaporation or add a dry composting material. Microbes doing the composting require oxygen to breathe. 60 to 35% of the pore space needs to have air. This is known as aerobic conditions. If there isn't sufficient oxygen, anaerobic decomposition occurs. Anaerobic refers to lacking oxygen. Anaerobic conditions produce little heat, compost slowly, and is odiferous. A common smell is rotten eggs. This is a sign that hydrogen sulfide is being produced. Monitoring pile temperatures is a way to monitor oxygen. Turning the pile is a way to introduce oxygen into the system and homogenize the compost. This is a front-mount compost turner. It can scrape pens clean and windrow at the same time. The Dickinson Research Extension Center, Wells County SCD, Stutzman County SCD, and Lemor County SCD have this type of turner. The SCDs offer custom composting services. This is the Carrington Research Extension Center's windrow turner. The compost is pre-piled and the tractor drives on the side of the pile as it pulls the implement. It is very important that the tractor pulling any turner has a creeper gear. The first turn is a very slow process, but becomes easier with every turn as the manure and other materials decompose. Monitoring temperatures is an important part of composting. A temperature probe of 18 to 24 inches works fine. They can be found on the internet or hardware stores and cost roughly $30. When checking the temperature, several locations in a pile should be checked and averaged out. This gives you an idea of the entire pile's temperature. The pile should be checked every three to five days. Checking temperature gives you an indication of pile turning frequency and if weed seeds or pathogens will die. It takes about 131 degrees Fahrenheit for a few days to kill most pathogens. Many weed seeds will sterilize at this temperature too. However, some weeds require higher temperatures to sterilize, while buckwheat requires about 145 degrees for a few days to become sterile. To compost efficiently, the pile should be turned when temperatures drop below 110 degrees. It is okay to turn the pile if the temperature is assumed ambient temperature for long duration. Once the pile is turned, the pile should heat back up after a day or two. The photo of this thermometer was taken on May 9th. The manure embedding was piled on May 8th, so it took less than a day for the temperature to rise from the ambient air temperature to 130 degrees. This graph shows the dates correlated with pile temperatures. Piling, turning, and watering practices are indicated by the yellow arrows. The y-axis displays the temperature, and the x-axis shows the date. The compost was first piled on May 8th, and thermophilic conditions remained until May 27. High temperatures were maintained for nearly three weeks. The pile was turned on May 30th, and the temperatures rose almost immediately. This time, the pile didn't heat as much and the high temperature duration was shorter. The pile was again turned on June 13th and required water. The pile didn't heat as much as the second turn, but did maintain the high temperatures for a longer time. The pile was turned for a third time on July 3rd, and the temperature barely rose. This indicates that the pile is almost done composting. On July 25th, the pile was turned one last time. The temperature rose slightly and slowly. This indicates that the pile is essentially composted, and the majority of the manure and bedding are decomposed. The pile should be allowed to sit a month or so to assume air temperature. This is known as curing. Curing is done once the temperatures don't rise. The compost can then be applied on a field. Applying immature compost on a field can cause crop issues. Compost can improve many soil properties. Improved properties include lower soil bulk density, increased soil water holding capacity, and increase the cation exchange capacity of the soil. Cation exchange capacity allows the soil to release positively charged plant nutrients slowly throughout the growing season and prevents those nutrients from being lost. Not only does compost improve many soil characteristics, but it is also a fertilizer. Here are the averages from 10 compost nutrient tests. These values come from the NDSU soil testing lab. The average was 16.6 pounds of nitrogen per ton of compost, 13 pounds of phosphorus per ton, and 14.3 pounds of potassium per ton. These values do have a wide range. Total nitrogen ranged from 8 to 36 pounds per ton of compost and phosphorus ranged from 5 to almost 21 pounds per ton. Values like this can be used to plan ahead, but sampling the compost and testing it for nutrients are important, so nutrients aren't over or under applied. It is important to soil test and follow soil test trends when determining compost applications. In many instances, compost should be used as a phosphorus source and be supplemented with a conventional nitrogen source. If compost is applied to meet nitrogen requirements, phosphorus may be greatly over applied. Over application can lead to nutrients running off the compost applied field, resulting with water quality issues like algae blooms. Not all the nutrients in compost are plant-available. Most of the nutrients are in an organic form. Plants use inorganic forms of nitrogen, phosphorus, and potassium. Microbes in the soil utilize the organic nutrients found in the compost and transform or mineralize them into plant-available nutrients. On the first year of a compost application, 15% of the total nitrogen can be expected to be plant-available in a conventional tillage system. If the compost is applied on a no-till system, approximately 20% of the total nitrogen will be plant-available. There will be a bump in fertility for five or so years following the field's compost application. 30% of the total phosphorus is mineralized in the first growing season and 70% the following year. 31% of the total potassium is mineralized the first year after compost is applied. Utilizing soil tests, compost tests, and a calibrated manure spreader will help ensure that crop yield goals are met. In summation, compost is an effective manure management tool. It greatly reduces manure volume that can offset hauling costs. Composting kills pathogens and weed seeds. In order to compost properly, a CN ratio of about 30 to 1 is needed. There needs to be adequate moisture in air. If these three things aren't met, the temperatures won't rise and the composting process won't occur properly. Composting converts manure into a soil-like product that improves many soil properties and adds fertility to the soil. Thank you for listening.