Estimation of Canadian manure and fertilizer nitrogen application rates at the crop and soil-landscape polygon level

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1 Estimation of Canadian manure and fertilizer nitrogen application rates at the crop and soil-landscape polygon level T. Huffman 1, J. Y. Yang 2, C. F. Drury 2, R. De Jong 1, X. M. Yang 2, and Y. C. Liu 1 1 Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON, Canada K1A 0C6; and 2 Greenhouse & Processing Crops Research Centre, Agriculture and Agri-Food Canada, 2585 County Rd 20, Harrow, Ontario, Canada N0R 1G0. Received 6 March 2007, accepted 25 May Huffman, T., Yang, J. Y., Drury, C. F., De Jong, R., Yang, X. M. and Liu, Y. C Estimation of Canadian manure and fertilizer nitrogen application rates at the crop and soil-landscape polygon level. Can. J. Soil Sci. 88: In support of national environmental and economic modeling of agri-environmental indicators, greenhouse gases, carbon sequestration and policy assessment, fertilizer and manure nitrogen application rates were estimated for individual crops at the scale of the 1:1 m Soil Landscapes of Canada polygons. This data base provides an estimate of the amount of nitrogen applied to each crop and is based on provincial fertilization recommendations, the type and number of livestock and manure produced and reported amounts of fertilizer sold. The data base is being incorporated into ongoing programs related to international reporting, environmental performance and policy formulation at Agriculture and Agri-Food Canada. This paper describes the procedures developed to estimate fertilizer and manure nitrogen inputs for each crop type within each polygon. These procedures include:(i) the compilation of soil-specific recommended nitrogen application rates from provincial extension guidelines and experts; (ii) the calculation of total manure nitrogen production from animal numbers and excretion rates; (iii) the calculation of manure nitrogen available after land application losses and (iv) the adjustment of total fertilizer nitrogen applied to match reported sales at the provincial level. The calculation procedures were incorporated into the Canadian Agricultural Nitrogen Budget model, with provisions for transferring the data to other models and for other applications. Key words: Fertilizer nitrogen, manure nitrogen, nitrogen application rates, nitrogen model, Soil Landscapes of Canada, Census of Agriculture Huffman, T., Yang, J. Y., Drury, C. F., De Jong, R., Yang, X. M. et Liu, Y. C Estimation des taux d application d azote du fumier et des engrais au Canada au niveau des cultures et des polygones de pe do-paysage. Can. J. Soil Sci. 88: Les auteurs ont estime les applications d azote des engrais et du fumier aux cultures a` l e chelle 1:1 m des polygones de pe do-paysage canadiens en vue de faciliter la modélisation environnementale et e conomique des indicateurs agroenvironnementaux, des gaz à effet de serre et de la séquestration du carbone, ainsi que l e valuation des politiques. Cette base de données permet d estimer la quantite d azote applique e a` chaque culture et s appuie sur les recommandations provinciales en matie` re d amendement, sur le type et le nombre d animaux d e levage, sur la quantite de fumier produite et sur les ventes d engrais. Elle sera intégrée aux programmes actuels de rapports internationaux, d e tude de la performance environnementale et d élaboration de politiques d Agriculture et Agroalimentaire Canada. L article de crit les me thodes qui ont permis d estimer les apports d azote des engrais et du fumier pour chaque sorte de culture au niveau des polygones. Ces me thodes comprennent :(i) la compilation des taux d application d engrais azote recommande s dans les manuels de vulgarisation et par les experts provinciaux en fonction de l analyse du sol, (ii) le calcul de la quantite totale d azote issue du fumier selon le nombre d animaux d e levage et leur taux d excre tion, (iii) le calcul de l azote disponible venant du fumier apre` s les pertes re sultant de l e pandage et (iv) l ajustement de la quantite totale d azote applique e selon les ventes d engrais signale es a` l e chelon provincial. Ces me thodes ont e té incorporées au modèle canadien du bilan azote pour l agriculture et les donne es pourraient être transfére es a` d autres mode` les pour des applications diffe rentes. Mots clés: Engrais azote s, azote du fumier, taux d application de l azote, mode` le de l azote, pe do-paysages du Canada, recensement de l agriculture A variety of national environmental projects currently being conducted in Canada, such as the National Agri- Environmental Health Analysis and Reporting Program (NAHARP), the National Carbon and Greenhouse gas Accounting and Verification System (NCGAVS) and the establishment of environmental targets for the Agricultural Policy Framework (APF) rely on modeling the relationships between production practices and their environmental impacts. In Canada, a majority of farms apply commercial fertilizer (Statistics Canada 2008a) and more than half apply manure (Dumanski et al. 1994; Statistics Canada 2008b), so realistic estimates of commercial fertilizer and manure nitrogen (N) inputs to crop production are important. Since many of the 619

2 620 CANADIAN JOURNAL OF SOIL SCIENCE modeling efforts are conducted at the regional scale of the Soil Landscapes of Canada (SLC) (Soil Landscapes of Canada Working Group 2005), researchers have used general nitrogen recommendation rates as estimates of nitrogen input levels (MacDonald 2000). These "general" crop rates are provided by provincial agronomists and soil testing laboratories and vary by soil type or crop heat unit, depending on the source. This approach leads to varying, undocumented and unvalidated estimates, as there is no assurance that producers actually use recommended rates. Further, rates for the same crop and soil type may differ depending on the source of the information, they may be out of date, they may be unavailable for new or minor crops and/or they may not include adjustments for manure management. Two data sources provide estimates of actual fertilizer use in Canada; fertilizer industry reports of the number of tonnes of N fertilizer sold each year at the provincial level and Census of Agriculture (Statistics Canada 2007) estimates of farm expenditures on fertilizers. However, these estimates provide no differentiation on the basis of crop types, area of application or soil types. Estimating nitrogen application rates is also complicated by the fact that manure N is applied to some crops in some areas, effectively reducing the amount of fertilizer N required to meet recommended rates. Various amounts of N are also contributed to the soil through fixation by leguminous crops, mineralization from soil organic matter and atmospheric deposition. The objective of this study was to develop a uniform, documented nitrogen application database that reflects actual amounts of manure produced and actual amounts of fertilizer N sold. The database provides an estimate of the amount of N applied per crop (in kg N ha 1 ), from both fertilizer (FertN) and manure (ManN). Data used to construct the database included fertilizer recommendation rates, annual fertilizer sales by province, the number of each type of livestock by SLC polygon, manure N excretion rates by livestock type and the area of each crop type by SLC polygon. The methodology involved:(1) linking soil-specific recommended N application rates from provincial extension guidelines to SLC polygons, (2) calculating total manure N production and available manure N after handling losses, (3) calculating total recommended fertilizer N applications and adjusting them to annual N sales and (4) estimating actual fertilizer N and manure N application rates for each crop at the SLC polygon level. METHODOLOGY Spatial Framework Canada s land is subdivided in a hierarchical ecostratification (National Ecological Framework), which provides an ecological basis for scaling spatial information from the local to the national levels (Ecological Stratification Working Group 1996). The smallest spatial units are soil-landscape polygons, which comprise the national Soil Landscapes of Canada (SLC) database and are derived from detailed soil survey maps at scales ranging from 1: to 1: SLC polygons were developed at a scale of 1:1 M, and they vary in size from approximately 1000 to ha. The SLC map products and associated component files are regularly revised and updated, and for this study version 3.0 was used (for detailed information regarding the database see: The SLC polygons were used not only as a spatial framework, but the Great Group (Soil Classification Working Group 1998) of the dominant soil component within each polygon was used as the link to the recommended nitrogen fertilization rate for each crop within the polygon. Census of Agriculture The national Census of Agriculture database, collected every 5 yr on every farm in Canada by Statistics Canada (Statistics Canada 2007), provides information on over 100 variables, including crop areas, numbers of each type of livestock and fertilizer expenses. Agriculture and Agri-Food Canada (AAFC), in collaboration with Statistics Canada, has interpolated data for all Census years from 1981 to 2001 to the spatial framework of the Soil Landscapes of Canada v3.0 (Huffman et al. 2006). However, Statistics Canada is bound by confidentiality provisions, which prohibit releasing data in a manner that would allow it to be attributed to an individual or single business entity, and the database is thus subject to a certain amount of data suppression in areas or variables with few farms reporting. There are approximately 3300 SLC polygons in Canada that have agricultural activities. Recommended N Rates Published fertilization guidelines are available from British Columbia Ministry of Agriculture, Food and Fisheries ( ), Alberta Agriculture, Food and Rural Development (2004), Saskatchewan Agriculture (1988), Manitoba Agriculture, Food and Rural Initiatives (2006), Ontario Ministry of Agriculture, Food and Rural Affairs (2003), Centre de réfe rence en agriculture et agroalimentaire du Que bec (2005) and New Brunswick Ministry of Agriculture, Fisheries and Aquaculture (2001). No appropriate recommendations were found for Prince Edward Island, Nova Scotia and Newfoundland. In Alberta and Saskatchewan, the recommended rates are provided by major soil Great Groups such as Brown, Dark Brown and Black Chernozems, while in Manitoba, Quebec and New Brunswick recommendations are provided only by crop, with no biophysical or spatial distinctions. In Ontario, different rates for some crops such as corn (Zea mays L.) are provided on the basis of crop heat units (CHU), while in British Columbia different rates are provided for the humid areas, the dry interior and organic soils. In almost all cases, a range of application rates is provided for each of

3 HUFFMAN ET AL. * MANURE AND FERTILIZER NITROGEN APPLICATION RATES 621 the significant crops in the province, with the specific value depending on the previous crop, anticipated moisture conditions or management practices such as irrigation. A single rate for each of 24 crops and two pasture types (improved and unimproved) grown on each soil Great Group was established by averaging ranges and duplicate recommendations, interpreting regional specifications (e.g., by crop heat unit) with reference to soil maps and interpolating missing values from the nearest appropriate value. For example, the rate for Black Chernozems was calculated as the average of the Manitoba provincial rate and the Alberta and Saskatchewan rates for a crop on stubble on that soil type. In Ontario, the rate for areas with under 2500 CHU was applied to Great Groups that occur predominantly in the northern portions of the province (Dystric Brunisol, Podzol and Gleysol), while rates for areas with greater than 2500 CHU were applied to soils that occur predominantly in southwestern Ontario and the St Lawrence valley (Melanic Brunisols, Humic Gleysols and Gray Brown Luvisols). Nitrogen application rates for crops grown in Prince Edward Island, Nova Scotia and Newfoundland were estimated based on New Brunswick, Quebec and Ontario rates. Examples of recommended rates for wheat (Triticum aestivum L.), oat (Avena sativa L.) and barley (Hordeum vulgare L.), corn, canola (Brassica napus and B. rapa L.), tame hay and pasture, potatoes (Solanum tuberosum L.) and vegetables on the principal soil Great Groups are shown in Table 1. The recommended N rates were allocated to SLC s based on the Great Group of the dominant soil landscape component within the polygon, as obtained from the SLC component Table. Since the recommended rates serve only as a relative measure on which to allocate estimated actual amounts of manure and fertilizer, the rates were assumed to apply for both manure N (ManN) and fertilizer N (FertN). Recommended rates of nitrogen application on legumes and unimproved pasture are generally very low or nil, so these land use types were assumed to receive ManN only. The total recommended amount of N for a given crop and SLC was calculated as the product of the N recommendation rate for the crop and the area of the crop, while the total recommended N for the polygon was calculated as the sum of recommended amounts for all crops, as represented by Eq. 1. TotNrcmd(j) X24 i1 Nrcmd(i; j) Area(i; j) (1) where TotNrcmd(j) is the total amount of N fertilizer (kg) recommended for SLCj, Nrcmd(i,j) is the recommended rate (kg N ha 1 ) of N fertilization for crop i in SLCj, and Area(i,j) is the area (ha) of crop i in SLC j. Fertilizer N The total amount of agricultural fertilizer nutrients (nitrogen, phosphate and potash) sold annually, in tonnes, at the provincial level (except for Newfoundland and Labrador, Prince Edward Island, New Brunswick and Nova Scotia, which are aggregated) for the years 1972 to 2002 have been compiled from a variety of industry and government sources by Korol (2002). Although these figures are not available at the SLC level, aggregate producer expenditures on fertilizer are provided at the SLC level through the interpolated Census. We used the proportional relationships of the producer expenditures to allocate the provincial nitrogen sold figures to SLC polygons. The amount (kg) of N sold at the provincial level was allocated to individual SLCs based on the polygon s proportion of the provincial total of producer s fertilizer expenses, as depicted in Eq.2. This calculation was carried out for each Census year Nsold(j)Nsold(p) COAfert$(j) (2) COA$(p) where Nsold(j) is the amount (kg) of fertilizer N sold in SLC(j), Nsold(p) is the amount (kg) of fertilizer N sold in the province, COAfert$(j) is the value ($) of producer expenses on fertilizer in SLCj, and COA$(p) is the sum ($) of producer expenses on fertilizer in the province. Finally, the rate (kg N ha 1 ) of fertilizer N actually applied on each crop in each polygon was estimated by adjusting the recommended rate by the ratio of the total N sold in the SLC to the total N recommended in the SLC, as depicted in Eq. 3. FNapplied(i; j)nrcmd(i; j) Nsold(j) (3) TotNrcmd(j) where FNapplied(i,j) is the amount of N (kg N ha 1 ) actually applied on crop i in SLCj. Manure N The total amount of manure N produced (MNtotal) was calculated as the sum, for all livestock types, of the animal population multiplied by the appropriate manure excretion rate and their N content. Nitrogen excretion rates for different animal types were based on coefficients published by the American Society of Agricultural Engineers (2003) with modifications to account for slightly different animal husbandry practices in Canada (Hofmann and Beaulieu 2006). The amount of manure N deposited directly on pasture (MNpast) was calculated by multiplying the total amount of manure N from each livestock type by the appropriate proportion of the provincial animal population that is raised on pasture. Estimates of the proportion of each type of livestock on pasture was developed through an expert opinion survey conducted by researchers at the

4 622 CANADIAN JOURNAL OF SOIL SCIENCE Table 1. Recommended rates of nitrogen application for selected crops and soil Great Groups in Canada Recommended nitrogen application rate (kg N ha 1 ) Soil Great Group Wheat Corn Canola Hay & pasture Potato Black Chernozem Dark Brown Chernozem 46 N/A N/A Brown Chernozem 35 N/A N/A Gray Luvisol 77 N/A N/A Dark Gray Chernozem 76 N/A Gray Brown Luvisol Humic Gleysol Vertisol 35 N/A N/A Solodized Solonetz 62 N/A N/A Melanic Brunisol Regosol 46 N/A N/A Humo-Ferric Podzol Solonetz 55 N/A N/A N/A, crop not typically grown on this soil type. University of Guelph and presented in an internal report to Environment Canada entitled "Determining Manure Management Practices for Major Domestic Animals in Canada" (M. Marinier, unpublished data). Table 2 presents manure N excretion rates and the percentage of manure that is deposited on pasture by province and livestock type. Assuming that all manure not deposited directly on pasture is stored and eventually applied on crops and pasture, then the amount of manure N stored and applied equals the sum of total manure N from all livestock types minus the sum of all manure N deposited directly on pasture. Since manure tends to lose N content during storage and land application, the amount available to plants (MNavail) was calculated as the amount of manure N applied minus N losses during handling and application. N-loss coefficients for different manure types and application methods were developed on the basis of the best available literature and expert opinion (Dr. E. C. Beauchamp, personal communication, University of Guelph, Guelph, ON), and are used in extension information produced by the Ontario Ministry of Agriculture, Food and Rural Affairs. Although these factors were derived for Ontario conditions, they were assumed to be applicable across Canada and so were multiplied by provincial distributions of manure management practices as compiled from the 2001 Farm Environmental Management Survey (Bourque and Koroluk 2003; Beaulieu 2004) to produce a provincial factor Percent of Manure N Remaining (PMNR) after application for each livestock type (Table 3). PMNR includes both mineral and organic N. Calculation of the amount of N available after application in SLC(j) is represented in Eq. 4. MNavail(j) (MNtotal(j) MNpast(j)) PMNR (4) where MNavail(j)is the amount (kg) of manure N available after field application in SLC(j), MNtotal(j) is the amount (kg) of manure N produced by all livestock in SLC(j), MNpast(j)is the amount (kg) of manure N deposited directly on pasture in SLC(j), and PMNR is the percent of N remaining in manure after field application. The total amount of manure N applied on each crop (i) in each polygon (kg) was calculated by multiplying the amount of manure N available in the polygon by the ratio of total N recommended for the crop to the total N recommended for the polygon (Eq. 5). Nrcmd(i; j) MNapplied(i; j)mnavail(j) (5) TotNrcmd(j) where MNapplied(i; j) is the total amount of manure N (kg) applied on crop (i) in SLC(j). The estimated rate of manure N applied (kg ha 1 )on each crop was then calculated by dividing the total amount of manure N applied on the crop by the area of the crop. [B1] Total N Applied The total nitrogen applied to each crop (kg ha 1 ) equals the sum of the manure N applied plus the fertilizer N applied (Eq. 6) TNapplied(i; j) MNapplied(i; j)fnapplied(i; j) (6) where TNapplied(i; j) is the total amount of N applied (kg ha 1 ) on crop (i) in SLC(j), Equations 1 through 6 were implemented in the Canadian Agricultural Nitrogen Budget (CANB v2.0) (Yang et al. 2007), with the ability to generate external databases for each Census year (1981, 1986, 1991, 1996, 2001 and future) and all levels in the ecostratification hierarchy, for use in other models and applications.

5 Table 2. Manure N excretion rates and proportion of animals depositing manure directly on pasture, by province and livestock type Animal type Proportion of animals depositing manure directly on pasture (%) N excretion rate (kg N head 1 yr 1 ) BC AB SK MB ON QC NB NS PE NL Broilers Laying hens Pullets Turkeys Calves Steers Heifers Beef cattle Dairy cows Bulls Boars Hogs Weaners Sows Sheep Goats Horses Elk, deer HUFFMAN ET AL. * MANURE AND FERTILIZER NITROGEN APPLICATION RATES 623

6 624 CANADIAN JOURNAL OF SOIL SCIENCE Table 3. Proportion of Manure N Remaining (PMNR) after application on cropland Manure N remaining (%) Province Poultry Cattle Pigs Others BC AB SK MB ON QC NB NS PE NL CANB is used to calculate the agri-environmental indicators Residual Soil Nitrogen (Drury et al. 2007) and Indicator of the Risk of Water Contamination by Nitrogen (De Jong et al. 2007), while other current applications include modeling greenhouse gas emissions and carbon sequestration and providing a base for predicting the impact of policy scenarios on environmental quality. RESULTS AND DISCUSSION The calculations as outlined above provide an estimate of actual N application rates (kg N ha 1 ) from both manure and fertilizer, for each of 24 crops, at the SLC level of spatial stratification, for each Census year from 1981 to Selected results by soil type, provincial and national levels are presented below. Examples of the minimum and maximum SLC values of estimated N application rates (kg N ha 1 ) for selected crops by soil type (Great Group) are given in Table 4. Comparing these values with recommended rates from Table 1 reveals that the range of estimated values encompasses the recommended rate for all crops in all soil types with the exception of Solonetzic soils, in which even the maximum value falls below the recommended rate. The consistently low estimated rates on Solonetzic soils may reflect generally low rates of fertilization on these soils, whose poor physical and chemical properties increases the risk of having poor crop yields (Cairns and Bowser 1977). A range in estimated rates is probably consistent with actual practices that use soil test results and/or consider soil texture, previous crops and weather conditions to adjust nitrogen application rates. Total manure N deposited directly on pasture, lost during storage and handling and applied on crops, and fertilizer N applied on crops at the national scale for each Census year from 1981 to 2001 are presented in Table 5. Total N applied from both manure and fertilizer increased gradually from a national average of 20 kg N ha 1 in 1981 to 35 kg N ha 1 in During this period the increases were primarily contributed by fertilizer N, with a slight increase in manure N. With respect to national manure N, Table 5 shows that, in 2001, approximately 35% was deposited directly on pasture and 65% was handled mechanically (in barns and feedlots) for application on pasture and crops. Of the 706 Mt N in manure for crops, 33% was lost during handling and 67% was available to crops. Provincial averages of manure N produced (before losses) and fertilizer N sold in 1981, 1991 and 2001 are shown in Fig. 1. Low manure N application rates are found in the prairies, while Quebec, Nova Scotia and Newfoundland show the highest rates. The highest average rates of fertilizer N application are in Prince Edward Island, Manitoba, Ontario, Quebec and New Brunswick. Several improvements in our methodology can be suggested. One of the primary points to address with the current methodology is our calculation and use of an average of a range of recommended rates provided in extension bulletins. In many cases, extension bulletins Table 4. Estimated minimum and maximum total N (Manure N plus Fertilizer N) application rates by soil type and crop, 2001 Estimated minimum and maximum total N application rates (kg N ha 1 ) Wheat Corn Canola Hay and pasture Potato Black Chernozem Dark Brown Chernozem 8156 N/A N/A Brown Chernozem N/A N/A Gray Luvisol N/A N/A Dark Gray Chernozem N/A N/A Gray Brown Luvisol Humic Gleysol Vertisol 1949 N/A N/A Solodized Solonetz 1370 N/A N/A Melanic Brunisol Regosol N/A N/A Humo-Ferric Podzol Solonetz 1942 N/A N/A N/A, crop not typically grown on this soil type.

7 HUFFMAN ET AL. * MANURE AND FERTILIZER NITROGEN APPLICATION RATES 625 Table 5. Total manure N and fertilizer N deposited and applied on pasture and crops in Canada, Census years from 1981 to 2001 Manure N applied on crops (Mt) Year Total manure N (Mt) Manure N deposited on pasture (Mt) Lost during handling Available to plants Fertilizer N applied on crops (Mt) Total N applied on crops (Mt) Farm area (M ha) Average rate of total N applied on crops (kg N ha 1 ) kg N ha -1 kg N ha (a) Manure N produced before losses BC AB SK MB ON PQ NB NS PE NF (b) Fertilizer N sold BC AB SK MB ON PQ NB NS PE NF Fig. 1. (a) Manure N produced before losses, and (b) fertilizer N sold, by province in 1981, 1991 and recommend a range of application rates for the same crop depending on soil texture, soil moisture at planting, planting into stubble vs fallow and crop rotation (i.e. perennial vs annual, legume vs non-legume). Certainly the texture of the dominant soil component within an SLC could be used to ascribe the recommended application rate, but whether or not that would be an improvement over the Great Group would need to be tested. The areal distribution of different soil textures within each SLC polygon can be determined from the soils database, but use of that information would require some method of allocating crop areas to soil texture areas. Similarly, the incorporation of crop rotations (including the incidence of summerfallow) would require the use of one or more typical rotations for each SLC polygon and the allocation of rotations to soil types and crop areas to rotations. The use of weather data and/or climate models to estimate spring soil moisture to adjust recommended rates for groups of SLC polygons seems feasible. In addition to the suggestions concerning improvements in the determination of recommended rates outlined above, several other methodological improvements can be suggested. The estimated rates of N application are a function of the amount of nitrogen we estimate to be available in each SLC, which in turn relates to the Census estimates of livestock numbers and farm expenditures on fertilizer. We assume that all manure produced within an SLC is applied within that same polygon, which in some cases results in high rates of N application. For example, if a beef feedlot or hog barn with thousands of animals lies in a relatively small soil polygon, the estimated manure N application rate can be well above the recommended rate for all crops. This may reflect the actual situation, but information on manure management practices of large, high-density livestock facilities would help to determine whether our model should "move" some to neighbouring polygons or incorporate some other adjustment procedure. Estimated rates significantly below recommended rates may be due to either low fertilization rates on all crops or to our assumption that all crops are fertilized relative to recommended rates. We suspect that many producers under-fertilize (with respect to recommended rates) perennial crops such as tame hay and pasture, and in polygons with large proportions of those crops that practice could translate to estimated rates being much lower than recommended rates for all crops. Information that is becoming available from a recent Farm Environmental Management Survey (FEMS) (Statistics Canada 2008c) of Canadian farmers will help us to establish the proportion of each crop that receives fertilizer and manure in different regions, and to estimate whether fertilizer application rates are reduced on crops which receive manure. CONCLUSIONS This paper describes steps and methods used to develop a database of fertilizer and manure N application rates for individual crops at the scale of the 1:1 million Soil Landscapes of Canada polygons. The database provides an estimate of the actual amount of N applied per crop and per hectare, based on provincial fertilization recommendations, the number and types of livestock and manure produced and reported amounts of

8 626 CANADIAN JOURNAL OF SOIL SCIENCE fertilizer sold. The estimated N rates are sensitive to both N recommendations and manure N adjusting factors such as handling losses and deposition on pasture. The calculation procedures have been incorporated into the CANB model and have been used to calculate fertilizer and manure N application rates at the soil-landscape, provincial and national scales. The results as reported here have been exported as a database and are being incorporated into other studies and programs related to environmental monitoring and policy scenario evaluation. Since the procedures are programmed as a model, input data, coefficients and the procedures can be updated on an ongoing basis as research and surveys provide new information, and as additional years of Census data become available. Planned improvements include the incorporation of different nitrogen recommendation rates based on soil texture and whether the crop is planted in stubble or fallow, the development of an apportioning routine to apply manure and fertilizer to only a portion of the area of a crop, formulation of a ranking to establish crop priority to receive manure and incorporation of a routine to reduce the fertilization rate on manured crops. Over the longer term, accounting for crop rotations which include legumes, and dealing realistically with manure from intensive livestock operations are priorities. ACKNOWLEDGEMENTS We are particularly indebted to Dr. Bruce MacDonald for his innovation and support in developing N estimation methods and coefficients, and we thank Bruce, Dr. Eric Beauchamp and Christine Brown for their gracious responses to our enquiries. We also thank Dr. Con Campbell for his support with Alberta and Saskatchewan fertilizer recommendations and his helpful comments on a draft of this paper. Alberta Agriculture, Food and Rural Development Alberta fertilizer guide. Agdex [Online] Available: [2007 Jan 23]. American Society of Agricultural Engineers ASAE D384.1 FEB03. Manure production and characteristics. [Online] Available: ASAEStandard.pdf. [2007 Jan. 18]. Beaulieu, M. S Manure management in Canada. Catalogue no MIE-No. 002, Statistics Canada. Ottawa, ON. [Online] Available: downpub/listpub.cgi?catno mie [2007 Jan. 18]. Bourque, L. and Koroluk, R Manure storage in Canada. Catalogue no MIE Statistics Canada. [Online] Available: MIE/ /article.htm [2007 Jan. 18]. British Columbia Ministry of Agriculture, Food and Fisheries Soil fertilization:publication series. [Online] Available: soilfertiliz [2007 Jan. 23]. Cairns, R. R. and Bowser, W. E Solonetzic soils and their management. Agriculture and Agri-Food Canada, Ottawa, ON. Publication no Centre de référence en agriculture et agroalimentaire du Que bec Guide de référence en fertilisation, 1e` re édition. [Online] Available: [2007 Jan. 23]. De Jong, R., Yang, J. Y., Drury, C. F., Huffman, E. C., Kirkwood, V. and Yang, X. M The indicator of risk of water contamination by nitrate-nitrogen. Can. J. Soil Sci. 87: Drury, C. F., Yang, J. Y., De Jong, R., Yang, X. M., Huffman, E. C., Kirkwood, V. and Reid, K Residual soil nitrogen indicator for agricultural land in Canada. Can. J. Soil Sci. 87: Dumanski, J., Gregorich, L. J., Kirkwood, V., Cann, M., Culley, J. L. B. and Coote, D. R The status of land management practices on agricultural land in Canada. Technical Bulletin E. Centre for Land and Biological Resources Research, Agriculture and Agri-Food Canada, Ottawa, ON Ecological Stratification Working Group A national ecological framework for Canada. [Online] Available: sis.agr.gc.ca/cansis/publications/ecostrat/intro.html [2007 Jan. 23]. Huffman, T., Ogston, R., Fisette, T., Daneshfar, B., Gasser, P- Y., White, L., Maloley, M. and Chenier, R Canadian agricultural land-use and land management data for Kyoto reporting. Can. J. Soil Sci. 86: Hofmann, N. and Beaulieu, M. S A geographical profile of manure production in Canada, [Online] Available: [2007 Jan. 18]. Korol, M Canadian fertilizer consumption, shipments and trade [Online] Available: index_e.php?s1pub&s2canfert&pageintro [2007 Jan. 16]. MacDonald, K. B Residual nitrogen. Pages in T. McRae, C. A. S. Smith, and L. J. Gregorich, eds Environmental sustainability of Canadian agriculture. Report of the Agri-Environmental Indicator Project, Agriculture and Agri-Food Canada, Ottawa, ON. Manitoba Agriculture, Food and Rural Initiatives General fertilizer recommendations without a soil test. Revised March 2001 [Online] Available: agriculture/soilwater/soilfert/fbd02s17.html. [2007 Jan. 25]. New Brunswick Agriculture, Fisheries and Aquaculture Crop fertilization guide. 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9 HUFFMAN ET AL. * MANURE AND FERTILIZER NITROGEN APPLICATION RATES 627 Soil Landscapes of Canada Working Group Soil landscapes of Canada Version 3.0. [Online] Available: sis.agr.gc.ca/cansis/nsdb/slc/v3.0/index.html [2008 Jan. 15]. Statistics Canada census handbook. [Online] Available: [2007 Jan. 15]. Statistics Canada. 2008a. Land use, tenure, and land management practices:land inputs. [Online] Available: htm#inputs [2008 Jan. 15]. Statistics Canada. 2008b. Land use, tenure, and land management practices:manure and manure application methods. [Online] Available: [2008 Jan. 15]. Statistics Canada. 2008c. Farm environmental management survey (FEMS). [Online] Available: Daily/English/080314/d080314e.htm [2008 Apr. 23]. Yang, J. Y., De Jong, R., Drury, C. F., Huffman, E., Kirkwood, V. and Yang, X. M., Development of a Canadian agricultural nitrogen budget (CANB v2.0) model and the evaluation of various policy scenarios. Can. J. Soil Sci. 87: