Leopold Center for Sustainable AgricultureResearch Reports Iowa State University
(funded by The Leopold Center for Sustainable Agriculture)

Leopold Center for Sustainable Agriculture's Support for Iowa Manure and Nutrient Management Efforts (1/98)

It is the goal of the Leopold Center for Sustainable Agriculture to develop socially and environmentally sound farming systems that profit the farmer and the farm community. Center initiatives are closely integrated with its systems approach to agricultural production, including research, demonstration, and education efforts such as keeping crop inputs on-site through effective streamside management and maximizing profitability of highly erodible land through grazing systems.
The Center has devoted considerable resources to development of animal management systems adaptable to all scales of farming, especially those who desire lower capital cost and management intensive systems, specifically farm owner-operators. The Center's programs have emphasized utilizing manure in crop production in a manner that minimizes off-site pollution while maximizing profitability.
In addition to supporting ISU Extension's Statewide Manure Management Education Initiative, the Leopold Center for Sustainable Agriculture has provided more than $967,990 (1988-1997) for manure and nutrient management research, demonstrations, and educational workshops. This includes 15 competitive grant projects, five years of research support for the Leopold Center's Manure Management Issue Team, 20 conferences and workshops attended by over 2,500 farmers, landowners, educators, and researchers, and facilities construction for the swine hoops systems initiative. An additional $108,000 is conditionally committed for ongoing grants, and$150,000 is conditionally committed for swine hoops systems work.

Manure and Nutrient Management Competitive Grants, past and present (Researcher affiliation listed is for the period of the project and may have since changed.)


Evaluation of Organic Soil Amendments for Certified Organic Vegetable and Herb Production. Kathleen Delate. Year 2 of 3. $12,500 (99-50); ISU Horticulture and Agronomy

After analysis for macronutrients, moisture and carbon/nitrogen ratio, several composts will be applied to productions systems and the composts compared through an evaluation of their impact of product yields, pest status, soil health indicators, product quality and economics. On-farm sites have been established near Kanawha and Ames, and a research farm site has been established in southeast Iowa at the Muscatine Island Research and Demonstration Farm. Types of amendments being tested include poultry litter, feathermeal, BioCalŪ and conventional fertilizer.

Nitrogen Conservation in Swine Manure Composting: Land Application Systems. Tom Richards, Tom Loynachan, and C.A. Cambardella. Year 2 of 2. $31,000 (99-62); ISU Agricultural and Biosystems Engineering, Agronomy and USDA-ARS National Soil Tilth Laboratory.

By quantifying nitrogen transformations as swine manure is composted with corn stalks and by quantifying carbon and nitrogen mineralization when composts of different maturities are applied to soil, researchers can understand how to develop compost products that synchronize nitrogen release and crop uptake and improve overall soil quality. In the first six months of this study, special nitrogen analysis and KCI extraction methods and special laboratory composting reactors were designed to deal with the high variability of the samples. Functional pilot scale reactors were constructed and initial analytical trials were conducted.

Socio-technical and Environmental Dimensions of Swine Manure Management Decisions. C. Hinrichs and T. Richards. Year 2 of 2. $7,598 (99-69); ISU Sociology and Agricultural and Biosystems Engineering.

Qualitative field interviews have been conducted during the spring of 1999 in the Raccoon River and Iowa River watershed regions to examine how farm operation characteristics and personal views on environment and technology influence swine producers’ manure management decisions on their farms. The research includes questions in four main areas: the biological, physical, social and economic characteristics of the farm operation; farmers’ perceptions about manure and features of their manure handling systems; farmer environmental and watershed perceptions, and current challenges and concerns of farmers.

Development and Implementation of Cost-effective Fertilization and Tillage Practices for Improving Soil Quality in Corn-Soybean Rotations, 1 year completed, $24,450, with 2 more years planned, $48,900 (#98-36); Antonio Mallarino, ISU Department of Agronomy

Project objectives include development of phosphorus, potassium, and starter fertilization recommendations for corn and soybean under different tillage systems; evaluation of improved diagnostic tools to assess P and K soil fertility in no-till and ridge-till; economic analysis of alternative fertilization and tillage practices; and demonstration of a methodology for on-farm research and demonstrations based on precision agriculture technologies.

Statewide Manure Management Education Initiative. Gerald Miller. Year 3 of 3. $25,000 (98-51); ISU Agronomy

Under leadership from ISU Extension, the Leopold Center, Iowa Veterinary Medical Association, soil and water conservation districts, and the Iowa Independent Crop Consultants' Association, this project will use intensive workshops with individualized participant plans to encourage appropriate decision making about utilization of manure nutrients.
In Iowa, manure management is rapidly becoming more complex as an economic, environmental and political issue. Iowa has the largest number of hogs of any state, it ranked fourth, as of 1994, in cow/calf production and is among the top ten states for numbers of all conventional livestock. For small to moderate-sized mixed crop and livestock farms, optimizing manure use for crop nutrients can be critical for maintaining profitability as the cost of all purchased inputs rises. The 1995 Iowa Farm and Rural Life Poll indicates that only 48% of crop producers with livestock adjust commercial fertilizer rates where manure has been applied. Excess soil fertility attributable to addition of fertilizer without taking adequate credit for manure applications is a potential surface and groundwater pollution risk over much of the state.
In the 1997 county extension program planning process, 49% of counties named manure management as their highest priority issue for programming. Field and campus extension staff have responded by developing a statewide manure management education initiative that is an immediate, critical need for Iowa producers. Objectives of the Statewide Manure Management Education Initiative are to reduce potential nitrate and bacterial pollution of surface and shall groundwater, and to enhance farm profitability by increasing the use of on-farm resources. In addition to ISUE, the initiative is supported by the Iowa Veterinary Medical Association, the Iowa Independent Crop Consultants Association, and the Leopold Center for Sustainable Agriculture.
During its first year of implementation (1997), 140 workshops on Manure Nutrient Management were conducted across the state, reaching nearly 800 livestock producers. Workshops will continue to be scheduled annually, during the winter, in all Iowa counties through 1999. All farmers with livestock operations, and crop producers who want to use a nearby available manure source, may attend the workshops free of charge.
Each workshop is taught by a team of Extension Field Specialist in the area of crop production, ag engineering, and farm management. Workshops use an innovative "fishbowl" format that fosters interaction and discussion among instructors and participants. Participants learn technical details of developing a "typical" management plan for their area, then work on individualized plans based on their own field and manure inventory information.
On their exit surveys, 26% of participants rated the workshops as "good" and 73% as "excellent" or "superior". Ninety-nine percent said they would recommend it to others. The majority planned to change important aspects of their manure and nutrient management based on what they had learned at the workshop. Follow-up surveys will continue to evaluate the effectiveness of the program.

Impacts of the Use of Poultry Manure for Agricultural Production Systems. Rameshwar Kanwar. Year 2 of 3. $ 18,300 (99-68); ISU Agricultural and Biosystems Engineering

The project will monitor two application rates of poultry manure and commercial fertilizer nitrogen on corn and soybean for leaching of NO3-N (nitrate-nitrogen) PO4-P (phosphate-phosphorus) and pathogenic bacteria to subsurface drainage water and shallow groundwater. Initial treatments of 150 lb. N/ac. from poultry manure resulted in the lower NO3-N concentrations in tile water than treatments with 150 lb. N/ac. from UAN and 300 lb. N/ac from poultry manure. PO4-P and fecal coliform concentrations in tile water from the 300 lb. N/ac. poultry manure were similar to 150 lb. N/ac. treatments either from poultry manure or from UAN fertilizer.

Demonstration of Swine Carcass Composting as Part of an Environmentally Friendly Production System. Jay Harmon. Year 1 of 2. $ 23,800 (2000-33); ISU Agricultural and Biosystems Engineering

Swine carcass composting demonstrations will be conducted at the ISU Rhodes Research Farm and the Lauren Christian Swine Farm near Atlantic. The projects will examine deep bedding, various co-composting materials (wood chips, straw and soybean residue), finishing swine mortality (Rhodes) and sow farm and nursery pig mortality and afterbirth (Atlantic).

Crop Response to Selected Micronutrients in Iowa. Randy Killorn. Year 1 of 3. $25, 696 (2000-04); ISU Agronomy

The purpose is to update ten-year-old research on crop response to micronutrients. At least ten sites will be evaluated, and the micronutrients to be tested will be decided upon in consultation with cooperators.

Soil Amendment Effects on Crop-Weed Interactions. M. Liebman and Tom Richard. Year 1 of 3. $ 18,430 (2000-11); ISU Agronomy and Agricultural and Biosystems Engineering

This research will investigate how amending soil with compost made from hog manure and cornstalks affects the growth and competitive ability of three weed species commonly found in Iowa corn fields (giant foxtail, velvetleaf and waterhemp). The manure and cornstalks will come from swine hoop structures, which are increasingly popular with Iowa pork producers.

Livestock and the Environment Project in Sioux County. Kris Kohl, Joel DeJong. Year 1 of 3. $ 29,545 (2000-36); Buena Vista and Plymouth County Extension, Storm Lake and LeMars

The Northwest Iowa Extension environmental team will investigate through survey and focus groups the barriers that deter producers from utilizing manure as a crop nutrient, and test a new pit-sampling method for producer acceptance. The goal is to define strategies that would measurably and positively impact manure management attitudes.

Optimizing Swine Hoop Manure Management for Soil Quality and Crop System Performance. Tom Richard, Matt Liebman, Rick Exner and C.A. Cambardella. Year 1 of 3. $ 29,432 (2000-42); ISU Agricultural and Biosystems Engineering and Agronomy, Practical Farmers of Iowa and USDA-ARS National Soil Tilth Laboratory.

Researchers plan to use on-farm and research station experiments to evaluate the impacts of alternative hoop manure management strategies (corn/soybean rotation, composted manure, bedded manure, spring and fall applications) on soil quality and cropping system performance. Observations will include farm management data, compost and bedding composition, soil biochemical properties, soil microbial biomass, crop biomass and macronutrient content, and seed yield data.

Dairy Manure Quantification and Characterization in Grazing Systems; Wendy Powers and Marjorie Faust. Year 2 of 2. $33,726 (99-16); ISU Animal Science

Good water quality is a key resource for Iowa’s future, and the use of Best Management Practices can help to minimize the degradation of water quality. Currently there are no guidelines for determining pasture stocking rates and storage needs that will protect water quality for intensive grazing dairies. Current estimates of manure excretion are based on a limited amount of outdated research and do not adequately reflect livestock operations of today. Both the animals and the management practices have changed dramatically over the last two decades. Increased environmental awareness dictates that producers manage manure properly, which, in turn, requires that producers be provided with accurate information regarding quantity and composition of manure excretions.
The proposed research project will focus on intensive grazing systems for dairy cows. These operations, in particular, need data on manure composition and quantity. Widely used table values (ASAE, 1994) were generated based on research conducted in confinement systems where cows were fed a combination of forage and concentrate. Thus, the effect of a total forage diet have not been assessed. Graziers need to have at their disposal the tools necessary to make environmentally sound decisions regarding stocking rate and storage capacity of milking area washwater and storage collection. Unique to climates such as Iowa is the additional need to have information available to graziers that documents manure quantity and composition during periods when pasturing is not possible and animals must be housed with manure collection and storage. During this time, the diet is much different than that during the grazing period, representing a combination of forage and concentrate in the diet.
Two grazing dairy operations will be used in this project, each representing different breeds of cows. The project entails year-round sample collection of milk and manure from cows selected within each herd. Fecal and urine samples will be collected monthly from the selected cows and analyzed for water quality measures such as nitrogen, phosphorus, and chemical oxygen demand. Influence of milk components and additional cow factors such as bodyweight, breed, parity, and production level on manure constituents will be evaluated.
Based on the quantified influence of these factors, prediction equations will be developed for use in estimating manure composition and quantity. Data generated from the equations can then be assembled into table format, thereby providing regulatory agencies and producers with better estimates that represent age and weight ranges as well as dietary differences among animals than currently available. Nutrition-based models will be evaluated on their ability to accurately predict excretions from cows in a grass-based system. Verification of some of the currently available models will provide additional tools for use in planning and predicting the environmental impact of management decisions in grazing systems.

Leopold Center for Sustainable Agriculture
For more information, contact the Leopold Center at 515/294-3711 or email leocenter@iastate.edu


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