Nitrogen know-how.

Posted in: Environment by admin on January 1, 1997 | No Comments

In order to be able to meet the plants requirements with the correct application rates, it is essential to be able to determine the nutrient content of the manure. Some commercially available devices to determined rapidly the N content of organic manure are on the market. ADAS and IGER have evaluate the performances of six moderately priced devices: N meters (2 models) which measure the volume of NH3 gas produced following a reaction between the ammonium in the manure and added hypochlorite ions; Conductivity meter that measure the conductivity of the manure; Ion-specific electrode that measures ammonium-N; Reflectometer using paper strips that in contact with the manure will take a certain color for specific ammonium content and finally, Slurry hydrometer which measurement relate to manure dry matter. Manure sampling were tested in laboratory for high accuracy analysis in order to make comparisons with the results obtained with the 6 devices. The results showed that the best devices are the 2 N meters with the liquid manure. None of the devices was effective while testing solid manure.
Nitrogen content is important to determine for fertilization but should be considered alone for the application rate only if no constraint come from other nutrients such as phosphorus. Periodically, complete manure analysis would have to be performed for a specific farm in order to verify the exactitude of the results obtained with the device and also to monitor the phosphorus content.

How to Calibrate Your Liquid Manure Spreader – Fact Sheet

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This publication presents the steps and equations necessary to calibrate different manure application systems such as : tanker, drag hose, irrigation gun or boom. Traveling speeds are discussed for the different systems and equations are given to evaluate the actual application rate.
This publication gives all the elements to evaluate the application rates for a given equipment and so the person applying manure is able to follow the rates given by nutrient management plans.

Modeling Odor Intensity for Swine Units

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The intensity of an odor can be perceived directly without knowing its corresponding concentration. A relationship doing the link between odor concentration and odor intensity could helpful in the analysis of early research and also in the definition of standards and regulations as odor threshold could be used with the odor intensity in defining more the odorous situation. Different mathematical models were evaluated (Weber-Fechner law model, the power law model, the Stevens model, and the Beidler model) in associated to odor threshold and odor intensity evaluations (on a 6 points scale) of a panel using olfactometry to analyze odorous samples from farrowing, finisher, gestation and nursery rooms. The results from those models and the panel evaluations showed that the widely used Weber-Fechner law model did not fit the odor intensity and threshold panel’s data for swine building. Better estimations for the odor intensity were obtained with the power law and the Beidler model; this last model showing the best fit of the experimental data; it was thus chosen to represent the relationship between odor threshold and odor intensity.

As mentioned in the paper more experiments would be needed to verify the conclusion of this study. The development of such tool is important because when those kind of tools are reliable less costly direct measurements have to be done to represent a given situation.

Assessment of the protection distance to avoid annoyance by odour sensation caused by livestock husbandry by Austrian guideline

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Different guidelines have been developed and are used in some European countries to define minimum distances that should be respected to separate livestock buildings from residential areas, these distances being considered necessary for odour dilution thus limiting nuisance from livestock production activities. The Austrian guidelines are presented and are in some ways similar to existing guidelines. An odour number is calculated using the following parameters: number of farm animals, their category and their housing system, characteristics of the outlet and the exhaust air velocity, the manure management inside and outside the building and the feeding strategy. Odour dispersion is first evaluated using the wind direction mean distribution at the site and secondly by evaluating the predominant local winds the last consideration is the legal claim of protection by the surrounding residential areas. This analysis results in a final protection distance dependent on the direction to the neighbors. This paper present the Austrian guideline and discuss the differences from Switzerland, Germany and the Netherlands guidelines.

The protection distances considering fattening pigs are compared graphically in the publication ( the protection distance as a function of the number of fattening pigs) and no trends can be seen of one country being consistently more restrictive than the other.

Anaerobic Digestion – A Holistic Approach to Odor Control

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Odor is one of the primary public relations problems that have to face the livestock industry with the nuisance complaints and potentially damaging litigation. The solutions of this situation pass by the management of both odor and manure produced by the intensive livestock operations. An optimal manure management system should aim minimal environmental impacts and maximal resource recovery. The anaerobic digestion, realized under controlled conditions, presents a holistic treatment solution that control odors, produces usable energy, minimizes environmental impact and optimize fertilizer, water recovery and reuse.

Considering the low cost of fossil fuels, this technique is not cost effective. However with the changes in the technology, the value of the secondary products ( fertilizer, recycling of treated flush water) and possible incentive in the future to use renewable energy systems, the anaerobic digestion systems could become interesting.

European Interlaboratory Comparaison of Olfactometry – Overall results and implication

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The working group CEN/TC264/WG2 ‘Odours’ has prepared a draft European Standard for olfactometry for the CEN (Comite europeen de normalisation). Before enquiry and voting, this method had to be validated and this process, an International Olfactometry Comparison (ICO), was realized by 19 European Laboratories (who had been vetted) in the summer 1996. The odour source used for the comparisons was n-butanol at concentrations ranging from 15 to 400 ppm/v equivalent to 375 to 10000 oue/m3 (European odour units). The Dutch laboratories (8) also tested a complex environmental odour at the demand of the Netherlands Council for Accreditation/Netherlands Calibration Organization (NKO). For n-butanol, 5 of the 14 audit-compliant laboratories met the quality criteria on accuracy and repeatability and for the tests done with the complex odour in Dutch laboratories, 2 out of 6 attained both criteria. Considering these results, the quality criteria set in the draft European Standard are attainable and the document will be forwarded by CEN/TC264/WG2 ‘Odours’ for public enquiry among CEN organization members at the end of 1997 who should vote on it in 1998.
Even when meeting accreditation requirements, odour concentration measurement in the Netherlands is now 2/3 lower in cost compare to the 1980 level even with no consideration for inflation.

The results obtained in the ICO gave CEN/TC264/WG2 ‘Odours’ enough confidence to recommend the draft European Standard for olfactometry to the CEN for voting. Strict methods and procedures have to be followed to meet the quality criteria and as stated in the proceeding, ongoing internal quality control in a laboratory is making a difference in meeting those criteria. As mentioned in another conference, the panel selection is very important because it has a direct impact on the results.

Soil Compaction by Manure Spreaders Equipped with Standard and Oversized Tires and Multiple Axles

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Tests were realized with manure spreaders of different capacities from 5,5 cubic meters (spreader weight equal 95,5 kN), to 18,0 cubic meters (corresponding to 218 kN). Spreaders exceeding 154 kN correspond to 12,3 cubic meters tanks or of bigger capacity. As multiple axles spreaders have bigger tank capacity, they compare or have higher ground pressures than smaller spreader with tandem.

Bio-engineering Properties of Feedlot Wastes

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Feedlot wastes are affected by many factors, including animal species; size and age, animal feed and water intake, microenvironment on the feedlot and climate. These properties are further modified after excretion by the waste handling system and biochemical activities.
Properties of feedlot wastes may be classified as physical, chemical and biological parameters. The most important physical parameters are quantity and solids content. The physical properties that are relevant are temperature, color, taste, odor, specific gravity, hydrophilic properties, with the most important being bulk density, particle size and viscosity.
Biochemical parameters with significance in feedlot wastewaters include biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC) and soil oxygen demand (SOD). TOC is useful in monitoring efficiencies of treatment plants but is not used as a design parameter.
The important chemical parameters are pH, electrical conductivity, metals (toxic), fertilizer plant nutrients and other chemicals with biocidal properties. The fertilizer plant nutrients include nitrogen, phosphorus and potassium.
The final parameters are miscellaneous but still useful in feedlot waste management plans. These include population equivalent, animal equivalent and animal unit. With all the factors that go into feedlot waste management, it is impossible to arrive at a design value that would be suitable for all feedlot wastes. The numerical values given in this study are expected ranges and average values which may be used as guidelines in planning, not in detailed design.

Modeling dust concentration in livestock buildings.

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Limited research has investigated the spatial variability of dust within livestock building. Research is needed to gain a better understanding of the transport and removal of particulate contaminants within these facilities. This study was conducted to model dust concentration distribution in enclosed livestock buildings. Existing mathematical models that can be used for predicting spatial and temporal distribution of particulates contaminants within ventilated spaces were reviewed. Based on these models, a simplified macroscopic model was developed. The model considers the effects of turbulent diffusive deposition, gravitational settling, coagulation and airflow. Effects of particles size were also investigated. Results of the implementation of the initial version of the model are presented.

Evaluation of Different Methods of Measuring NH3 Emission in Naturally Ventilated Animal Houses with Deep Litter

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The results obtained from this study are about 5 times higher (50 g NH3 / animal per day vs. 3 to 18 in other studies). Experimental conditions could be accountable for those differences but no further analysis is made.