G97-1315 Composting Manure and Other Organic Residues

Composting is becoming more common in Nebraska because of the many advantages it offers. This NebGuide provides information on the composting process and its management and related issues. The Composting Process Composting is the aerobic decomposition of manure or other organic materials in the thermophilic temperature range (104-149°F). The composted material is odorless, fine-textured, and low-moisture and can be bagged and sold for use in gardens, or nurseries or used as fertilizer on cropland with little odor or fly breeding potential. Composting improves the handling characteristics of any organic residue by reducing its volume and weight. Composting can kill pathogens and weed seeds. There are about 5,700 on-farm composters in the United States and the number is increasing

Ethanol Distiller By-product Phosphorus Concentration as Influenced by Corn Hybrid

Analysis of commercial corn hybrids indicated grain phosphorus concentrations ranged from 0.19% to 0.39%. This range of P concentration provides an opportunity to reduce P in the distiller’s by-products. Based on 90% starch conversion efficiency, the estimated P concentrations of ethanol by-product were 0.52% and 1.04% when using grain with P concentrations of 0.19% and 0.39%, respectively. This is a reduction of 50% when using low P instead of high P corn hybrids

Manure Matters, Volume 10, Number 7

Reducing Phosphorus Concentration of Ethanol Distiller Byproducts by Using Low Grain Phosphorus Corn Ethanol production plants are using about 800 million bu of corn each year to produce ethanol. In the ethanol production system, the starch is converted to ethanol and CO2 and the remaining grain material is called distiller byproduct (wet distiller grain plus soluble or dry distiller grain plus soluble). This byproduct is high in energy, protein, and P contents and is usually fed to feedlot cattle and other livestock. Removal of starch from grain concentrates P in the byproduct and when this high P material is added to ration, it increases P concentration of the ration and subsequently increases manure P concentration. Corn hybrids have different concentrations of P in grain. Results of a two-year field study conducted by the author in 1999 to 2000 indicated grain P concentration range of 0.21% to 0.33% among 12 commercial corn hybrids. Analysis of some other commercial hybrids in 2003 indicated that high P hybrids have P concentrations that can be more than double of those for low P hybrids. These low grain P hybrids can be used in rations to reduce its P content or can be used in ethanol production to reduce P content of the byproduct and hence make it a more environmentally friendly feedstuff. By reducing P concentration of the byproduct, the P concentration of manure will also reduce and that lessen the concern about soil P accumulation in the soil

Ethanol Distiller By-product Phosphorus Concentration as Influenced by Corn Hybrid

Analysis of commercial corn hybrids indicated grain phosphorus concentrations ranged from 0.19% to 0.39%. This range of P concentration provides an opportunity to reduce P in the distiller’s by-products. Based on 90% starch conversion efficiency, the estimated P concentrations of ethanol by-product were 0.52% and 1.04% when using grain with P concentrations of 0.19% and 0.39%, respectively. This is a reduction of 50% when using low P instead of high P corn hybrids

Managing Manure Phosphorus

Manure, a renewable resource, contains nutrients that are needed for plant growth. Phosphorus in manure can be utilized for crop production as a substitute for synthetic fertilizers. Phosphorus in manure can also be a source of surface or ground water contamination if not used properly. Increased P concentration can lead to eutrophication of surface waters. Management systems need to be developed to utilize manure P effectively without adverse effects on the environment

Temporal Changes in Nutrient Transport Following Land Application of Manure

Little information is currently available concerning temporal changes in nutrient transport following the addition of manure to cropland areas. This study was conducted to measure nutrient transport in runoff as affected by tillage and time following the application of beef cattle or swine manure to a site on which corn [Zea mays (L.)] was grown. Rainfall simulation tests were initiated 4, 32, 62, 123, and 354 days following land application. Three 30-min simulated rainfall events, separated by 24-hour intervals, were conducted at an intensity of approximately 70 mm hr-1. Dissolved phosphorus (DP), particulate phosphorus (PP), total phosphorus (TP), NO3-N, NH4-N, total nitrogen (TN), electrical conductivity (EC), and pH were measured from 0.75-m wide by 2-m long plots. Concentrations of DP, TP, and NH4-N, in general, declined throughout the year on both the no-till cattle and no-till swine manure treatments. Tillage did not significantly affect concentrations of DP, PP, TP, NH4-N or pH on the swine manure treatments, but significant variations in these variables were measured over time. Under no-till and tilled conditions on both the cattle and swine manure treatments, the smallest concentrations of DP, NO3-N, NH4-N, and TN occurred on the final test date. The increase in pH of runoff during the study is attributed to the addition of CaCO3 to the rations of beef cattle and swine. Tillage appeared to have less of an impact on runoff nutrient transport from cropland areas than length of time since manure application

Temporal Changes in Nutrient Transport Following Land Application of Manure

Little information is currently available concerning temporal changes in nutrient transport following the addition of manure to cropland areas. This study was conducted to measure nutrient transport in runoff as affected by tillage and time following the application of beef cattle or swine manure to a site on which corn [Zea mays (L.)] was grown. Rainfall simulation tests were initiated 4, 32, 62, 123, and 354 days following land application. Three 30-min simulated rainfall events, separated by 24-hour intervals, were conducted at an intensity of approximately 70 mm hr-1. Dissolved phosphorus (DP), particulate phosphorus (PP), total phosphorus (TP), NO3-N, NH4-N, total nitrogen (TN), electrical conductivity (EC), and pH were measured from 0.75-m wide by 2-m long plots. Concentrations of DP, TP, and NH4-N, in general, declined throughout the year on both the no-till cattle and no-till swine manure treatments. Tillage did not significantly affect concentrations of DP, PP, TP, NH4-N or pH on the swine manure treatments, but significant variations in these variables were measured over time. Under no-till and tilled conditions on both the cattle and swine manure treatments, the smallest concentrations of DP, NO3-N, NH4-N, and TN occurred on the final test date. The increase in pH of runoff during the study is attributed to the addition of CaCO3 to the rations of beef cattle and swine. Tillage appeared to have less of an impact on runoff nutrient transport from cropland areas than length of time since manure application

Greenhouse Gas Emissions and Soil Indicators Four Years after Manure and Compost Applications

Understanding how carbon, nitrogen, and key soil attributes affect gas emissions from soil is crucial for alleviating their undesirable residual effects that can linger for years after termination of manure and compost applications. This study was conducted to evaluate the emission of soil CO2, N2O, and CH4 and soil C and N indicators four years after manure and compost application had stopped. Experimental plots were treated with annual synthetic N fertilizer (FRT), annual and biennial manure (MN1 and MN2, respectively), and compost (CP1 and CP2, respectively) from 1992 to 1995 based on removal of 151 kg N ha-1 yr-1 by continuous corn (Zea mays L.). The control (CTL) plots received no input. After 1995, only the FRT plots received N fertilizer in the spring of 1999. In 1999, the emissions of CO2 were similar between control and other treatments. The average annual carbon input in the CTL and FRT plots were similar to soil CO2–C emission (4.4 and 5.1 Mg C ha-1 yr-1, respectively). Manure and compost resulted in positive C and N balances in the soil four years after application. Fluxes of CH4–C and N2O-N were nearly zero, which indicated that the residual effects of manure and compost four years after application had no negative influence on soil C and N storage and global warming. Residual effects of compost and manure resulted in 20 to 40% higher soil microbial biomass C, 42 to 74% higher potentially mineralizable N, and 0.5 unit higher pH compared with the FRT treatment. Residual effects of manure and compost on CO2, N2O, and CH4 emissions were minimal and their benefits on soil C and N indicators were more favorable than that of N fertilizer

Phosphorus Management

Soils with high levels of P can contribute to excess P in runoff and subsequently pollute the surface water. Excess P in the soil can be removed from the system by harvesting crops. The objectives of this study were to evaluate corn (Zea mays L.) P removal effects on soil P reduction, and to evaluate various corn hybrids and soybean [Glycine max (L.) Merr.] varieties for differences in grain P concentration and P removal. Soil with varying P levels as a result of annual or biennial beef cattle (Bos Taurus) feedlot manure or compost application was cropped to corn for 4 yr without any P addition. In other studies under various water and N regimes, corn hybrids and soybean varieties were evaluated for grain P concentration and P removal. Four years of corn production without P addition lowered surface soil (0–15 cm) extractable P level (Bray and Kurtz no. 1) from 265 mg kg-1 to 171 mg kg-1 in the biennial N-based compost treatment. Based on a decay equation, it would have required 10 yr of corn P removal P to lower the soil P level to the original 69 mg kg-1 that existed before treatment application. The rate of decrease in extractable soil P was greater when soil P was higher and reduced with decreasing soil P level. Most of the P in the plants was absorbed from the 0- to 15-cm soil depth since no significant reduction in soil P level was observed from 1996 to 1999 in the 15- to 30-cm soil depth. Across 2 yr, there was as much as 54% difference among corn hybrids for grain P removal. The differences in P concentrations among corn hybrids indicated that hybrids could be selected for low P uptake when P level in ethanol production by-product or in animal ration and subsequently in manure is desired. Soybean grain P concentration was nearly twice that for corn but grain P removal was less for soybean than for corn. Crop P removal can significantly reduce soil P level with time

Fractal Description of Soil Fragmentation for Various Tillage Methods and Crop Sequences

Soil structure has been difficult to quantify and, at best, has been studied semiquantitatively. Fractal representation of soil fragmentation can provide an indication of soil structure. The purpose of our study was to use fractal analysis to quantify soil fragmentation under various tillage and crop sequence treatments at different times during the growing season. We collected soil samples from four tillage treatments (established 10 yr earlier) of chisel, disk, no-till, and moldboard plow in factorial arrangement with two crop sequences of corn (Zea mays L.)-soybean [Glycine max (L.) Merr.]-corn (C-SC), and soybean- cornaoybean, (S-C-S) on a Sharpsburg (fine, montmorillonitic, mesic Typic Argiudoll) soil. Aggregate-size distribution was used to calculate fractal dimension (D) for each treatment. Higher D values indicate greater soil fragmentation and a soil dominated by smaller aggregates. The opposite is true for lower D values. Differences in soil fragmentation observed for tillage treatments after autumn tillage became even greater over winter. Soil fragmentation increased over autumn and winter, with D increasing in the order of plow \u3e chisel \u3e disk \u3e no-till. Formation of larger soil aggregates increased during the growing season for all tillage systems. The D values for C S C were smaller than S-C-S in the no-till, indicating that the previous year\u27s corn in CS-C provided more large aggregates. Soybean appears to have negative effects on large-aggregate formation in no-till. Aggregate densities, averaged across tillage and crop sequence, increased from 1.25 to 1.77 Mg m-3 as the aggregate diameter decreased from 6.38 to 0.162 mm. Fractal analysis was found to be useful in determining soil fragmentation differences due to different tillage methods and crop sequences