How Chicken Manure Could Save Lives



You might not want to hear this  but an important ingredient in our being able to feed the planet 50 years from now could well be made from animal manure.



It's not really as bad as it sounds; this magic material could also be made from peanut hulls, pecan shells, switchgrass, and even hardwood waste products. And we're not going to actually eat this stuff; it would be added to our soils, to make it possible for crops to get the most out of every possible drop of water lurking there.



The material is biochar, the charred biomass created from wood, plant material and even manure. It's been used to improve soil fertility and remediate environmental contaminants, but the scientists at the Agricultural Research Service (ARS) say it can do much, much more.



The ARS scientists are studying biochar's benefits at multiple locations, but they say preliminary results indicate that adding it to agricultural soils could not only rebuild soil fertility, but also boost nutrients and  perhaps best of all  water retention.



What's more, biochar is capable of "sequestering" carbon from plant materials by storing it underground, where it slowly decomposes and makes only a minimal contribution to the emission of the greenhouse gas carbon dioxide. So that charred animal manure can help clean up the air we breathe!



The ARS scientists have been carrying out their studies in Iowa, Idaho, Kentucky, Minnesota, South Carolina and Texas. They've found that hardwood biochar can improve soil structure and increase the ability of sandy soils to retain water.



But they're finding that not all biochar is created equal. How the biochar performs can vary widely, depending on the "starting material" (that is to say, whether it's made from hardwood leftovers, plant material or manure); the time that the biochar spends in the apparatus called a pyrolyzer, which is what's used to break down the biomass in the absence of oxygen; the temperature that's used during that process, called pyrolysis; the moisture content of the basic material; and other factors.



Because of structural differences, some biochars break down more quickly in soil than others. Biochars can also differ in particle size, porosity, surface area, pH, and biologically active and available compounds.



The ARS scientists are collaborating to manufacture what might be called "designer biochars," with properties tailored to remediate specific soil characteristics. For example, one study focused on figuring out which biochars could improve the sandy soils found on the Carolina coastal plain and in the silt loam soils of the Pacific Northwest, which are derived from volcanic ash and windblown sediment known as "loess."



In that study, the scientists made biochars from nut shells, poultry litter, switchgrass and hardwood waste products. By pyrolyzing the materials at different temperatures, they were able to produce nine different types of designer biochars.



Then they mixed the biochars into one type of sandy soil and two silt loam soils at the rate of about 20 tons per acre. The test soils were leached with water every two months.



After four months, the team found that the biochars based on switchgrass and hardwoods increased soil moisture storage in all three soils, but the biochar from the other biomass sources did not. They saw the greatest moisture increase in soils that had been treated to switchgrass biochar produced with high-temperature pyrolysisalmost 3 to 6 percent higher than in a soil sample without the biochar.



The biochars produced at higher temperatures also reduced soil acidity, and the biochar made from poultry litter greatly increased soil levels of available phosphorus and sodium.



But, you may be asking, how is this going to help feed the world of our grandchildren and our great-grandchildren?



Here's the answer: Adding the biochar made from switchgrass could extend the window of soil water availability by as much as 3.6 days for a soybean crop in coastal Carolina's sandy soils, and could increase soil water availability for crops grown in Pacific Northwest silt loam soils by as much as 2.5 days.



Some say the factor most likely to determine who gets to eat 100 years from now will be water availability  and biochar can make that water more available for more crops. So my hat's off to biochar!



The Agricultural Research Service is the chief in-house scientific research agency of the U.S. Department of Agriculture. You can read more about ARS discoveries at



By SANDY MILLER HAYS, Agricultural Research ServiceYou might not want to hear this  but an important ingredient in our being able to feed the planet 50 years from now could well be made from animal manure.It's not really as bad as it sounds; this magic material could also be made from peanut hulls, pecan shells, switchgrass, and even hardwood waste products. And we're not going to actually eat this stuff; it would be added to our soils, to make it possible for crops to get the most out of every possible drop of water lurking there.The material is biochar, the charred biomass created from wood, plant material and even manure. It's been used to improve soil fertility and remediate environmental contaminants, but the scientists at the Agricultural Research Service (ARS) say it can do much, much more.The ARS scientists are studying biochar's benefits at multiple locations, but they say preliminary results indicate that adding it to agricultural soils could not only rebuild soil fertility, but also boost nutrients and  perhaps best of all  water retention.What's more, biochar is capable of "sequestering" carbon from plant materials by storing it underground, where it slowly decomposes and makes only a minimal contribution to the emission of the greenhouse gas carbon dioxide. So that charred animal manure can help clean up the air we breathe!The ARS scientists have been carrying out their studies in Iowa, Idaho, Kentucky, Minnesota, South Carolina and Texas. They've found that hardwood biochar can improve soil structure and increase the ability of sandy soils to retain water.But they're finding that not all biochar is created equal. How the biochar performs can vary widely, depending on the "starting material" (that is to say, whether it's made from hardwood leftovers, plant material or manure); the time that the biochar spends in the apparatus called a pyrolyzer, which is what's used to break down the biomass in the absence of oxygen; the temperature that's used during that process, called pyrolysis; the moisture content of the basic material; and other factors.Because of structural differences, some biochars break down more quickly in soil than others. Biochars can also differ in particle size, porosity, surface area, pH, and biologically active and available compounds.The ARS scientists are collaborating to manufacture what might be called "designer biochars," with properties tailored to remediate specific soil characteristics. For example, one study focused on figuring out which biochars could improve the sandy soils found on the Carolina coastal plain and in the silt loam soils of the Pacific Northwest, which are derived from volcanic ash and windblown sediment known as "loess."In that study, the scientists made biochars from nut shells, poultry litter, switchgrass and hardwood waste products. By pyrolyzing the materials at different temperatures, they were able to produce nine different types of designer biochars.Then they mixed the biochars into one type of sandy soil and two silt loam soils at the rate of about 20 tons per acre. The test soils were leached with water every two months.After four months, the team found that the biochars based on switchgrass and hardwoods increased soil moisture storage in all three soils, but the biochar from the other biomass sources did not. They saw the greatest moisture increase in soils that had been treated to switchgrass biochar produced with high-temperature pyrolysisalmost 3 to 6 percent higher than in a soil sample without the biochar.The biochars produced at higher temperatures also reduced soil acidity, and the biochar made from poultry litter greatly increased soil levels of available phosphorus and sodium.But, you may be asking, how is this going to help feed the world of our grandchildren and our great-grandchildren?Here's the answer: Adding the biochar made from switchgrass could extend the window of soil water availability by as much as 3.6 days for a soybean crop in coastal Carolina's sandy soils, and could increase soil water availability for crops grown in Pacific Northwest silt loam soils by as much as 2.5 days.Some say the factor most likely to determine who gets to eat 100 years from now will be water availability  and biochar can make that water more available for more crops. So my hat's off to biochar!The Agricultural Research Service is the chief in-house scientific research agency of the U.S. Department of Agriculture. You can read more about ARS discoveries at www.ars.usda.gov/news/