Effect of Irrigation and Nutrient Management on Yield and Quality of Timothy Hay. Final Report

Transcription

1 Effect of Irrigation and Nutrient Management on Yield and Quality of Timothy Hay Part 1: Effect of Nutrient Management on Yield and Quality of Timothy Hay Final Report by Pat G. Pfiffner 1, Ross H. McKenzie 1, Allan. B. Middleton 1, Eric Bremer 2, Tracy Dow 1, Masahito Oba 3, Alan Efetha 1 and Roger Hohm 1 1 Alberta Agriculture and Rural Development, Lethbridge, Alberta, Canada T1J 4V6; 2 Symbio Ag Consulting, Lethbridge, Alberta, Canada T1K 2B5; 3 Department of Agricultural Food and Nutritional Science, University of Alberta. Funding Agencies Alberta Crop Industry Development Fund Agrium Green Prairie International Inc. Global Forage Alliance/Transfeeder Inc. Wilbur-Ellis Company of Canada Boot Hay Producers Ltd. (Eric Boot - AB. & SK.) Sommer Green Forages Inc. (Broderick SK.) AVG Farms Ltd. (Albert Van Genderen) Agricultural Policy Framework

2 Abstract Timothy (Phleum pratense L.) hay production for export markets has expanded considerably in western Canada over the past decade. Fertilization practices for optimum yield and quality of irrigated timothy were investigated over a four-year period at two locations in southern Alberta. The efficacy of spring-broadcast urea and ammonium nitrate (AN) were similar and greater than that of controlled-release urea. The optimum N rate for dry matter yield was approximately 130 kg N ha -1 for the first cut and 110 kg N ha -1 for the second cut, depending on crop and fertilizer prices. Both green color and brown leaf ratings increased with N rate, with optimum color for the first cut obtained with 100 to 150 kg N ha -1. Digestibility was unaffected by N rate except when crops were very deficient in N. At the location that was responsive to P fertilization, yields were similar with annual broadcast applications of 13 kg P ha -1 or pre-seeding application of 86 kg P ha -1. Timothy yield and quality were not responsive to K fertilization, although high K removal rates may shorten the period until K deficiencies develop. High yields of timothy hay (average 11 Mg ha -1 y -1 ) were consistently obtained in this study with adequate N fertilization and, if required, P fertilization. ii

3 Table of Contents 1.0 Introduction Objective Materials and Methods Experimental Design, Location and TreatmentsError! Bookmark not defined Data Collection and Analysis Forage Yield and Quality Factors Yield and Protein Digestibility Components Sugar, Ash, Macronutrients and Micronutrients Field Activities and Soil Analysis Field Activities Soil Moisture, Rainfall and Irrigation Soil Analysis Results Experiment 1 Nitrogen type and rate Experiment 2 Timing of nitrogen application Experiment 3 Phosphorus application placement method and rate Experiment 4 Potassium source and rate Acid Detergent Fiber Test and Neutral Detergent Fiber Test Summary Results Experiment 1 Nitrogen Type and Rate Yield, Protein, Color and Lodging Results ADF, NDF and NDF-30 Results Sugar, Ash and Macronutrient Results Micronutrient Results iii

4 6.2 Experiment 2 Type and Timing of Nitrogen Application Yield, Protein, Color and Lodging Results ADF, NDF and NDF-30 Results Sugar, Ash and Macronutrient Results Experiment 3 Phosphorus Application Placement Method and Rate Yield, Protein, Color and Lodging Results ADF, NDF and NDF-30 Results Sugar, Ash and Macronutrient Results Micronutrient Results Experiment 4 Potassium Source and Rate Yield, Protein, Color and Lodging Results ADF, NDF and NDF-30 Results Sugar, Ash and Macronutrient Results Micronutrient Results Summary Results Experiment 1 Nitrogen Type and Rate Yield and Protein Results ADF, NDF and NDF-30 Results Experiment 2 Type and Timing of Nitrogen Application Yield and Protein Results ADF, NDF and NDF-30 Results Experiment 3 Phosphorus Application Placement Method and Rate Yield and Protein Results ADF, NDF and NDF-30 Results Experiment 4 Potassium Source and Rate Yield and Protein Results ADF, NDF and NDF-30 Results Digestibility, Macronutrients and Micronutrients Results Summary Results Experiment 1 Nitrogen Type and Rate Yield and Protein Results ADF, NDF and NDF-30 Results iv

5 8.2 Experiment 2 Type and Timing of Nitrogen Application Yield and Protein Results ADF, NDF and NDF-30 Results Experiment 3 Phosphorus Application Placement Method and Rate Yield and Protein Results ADF, NDF and NDF-30 Results Experiment 4 Potassium Source and Rate Yield and Protein Results ADF, NDF and NDF-30 Results Digestibility, Macronutrients and Micronutrients Results Summary Agronomic and Nutrient Management Recommendations for Timothy Production in Alberta Agriculture Nitrogen Fertilizer Form and Rate Recommendations Nitrogen Type and Timing Recommendations Phosphorus Application Placement Method and Rate Recommendations Potassium Source and Rate Recommendations Acknowledgments v

6 1.0 Introduction Timothy is a high value crop grown under irrigation in southern Alberta. In 2002, the contribution margin for Timothy was second only to potatoes in per acre, for irrigated crops (Business Management, Production Economics 2002 Cropping Alternative). Irrigated Timothy in Southern Alberta has grown from 8,000 acres in 1998, to 41,000 acres in 2002 and to over 50,0000 acres in 2005 an increase of 625 %. Irrigated timothy yields an average of 4 tonnes per acre per yr (first cut average is tonnes per acre and second cut average is tonnes per acre) and is purchased by the double compressed forage processors. Assuming 50,000 acres of irrigated timothy in 2005 and using conservative yields and a crop value of $170 per tonne, the industry has a farm gate value of over $36 million annually. If average yield can be increased by 0.5 t per acre the increased return could be an additional $4.25 million per year. Currently, the export market is purchasing timothy hay primarily for feed for dairy cattle (90% dairy cattle 10% other). From a nutritional standpoint, timothy hay is sold to provide livestock with adequate amounts of fiber. Protein, macro and micronutrients levels are sometimes low or deficient in timothy hay although by providing various supplements, the nutritional requirements can be met. Ultimately, the current marketing criteria for export timothy hay are based on color, coarseness, and head size. There is however, a strong indication that palatability may become an important marketing consideration. Brown leaf is a major factor in processed timothy being down-graded in the export market. Although there is no direct scientific evidence, the incidence of brown leaf may be reduced as a result of less frequent irrigations and optimum fertility regime. The timothy processing industry has identified nutrient and irrigation management as the two most limiting production factors. There is no scientific information available for making nutrient or irrigation management decisions in irrigated timothy production. There is a perception that timothy is shallow rooted and requires water to be managed in the top 30 cm of the root zone. Timothy processors have developed excellent markets but continue to have difficulty accessing sufficient quantities of high quality product that meets the strict requirements for export. Development of recommendations for nutrient management and irrigation practices would greatly improve the production of high quality timothy hay. This report summarizes the research results of the four nutrient management experiments conducted at two locations over four years. 2.0 Objective The two objectives of this study are to determine: the response of timothy to varying nutrient regimes and irrigation management. This report focuses on the four nutrient management experiments conducted for this project. The developed information will be provided to growers to achieve optimum timothy yield and quality for this rapidly expanding market. 3.0 Materials and Methods 3.1 Experimental Design, Location and Treatments Field trials focusing on developing nutrient management for irrigated timothy production were located at Lethbridge and Bow Island, while the field trials at Picture Butte and Bow Island focus on irrigation management (Table 3.1). The Lethbridge site was seeded and established in

7 the fall of 2003 while the remainder of the sites, were seeded in the spring of All sites were seeded using certified Aurora timothy seed. For the nutrient management trials, Experiment 1 treatments were arranged as a factorial design (N type X N rate). Nitrogen fertilizer types included ammonium nitrate, urea, and coated urea. Nitrogen rates for the first cut were 0, 50, 100, 150, 200 kg ha -1 and 0, 30, 60, 90 and 120 kg ha -1 for the second cut. Total nitrogen applications were 0, 80, 160, 240, and 320 kg ha -1 each year. Experiment 2, was arranged as a randomized complete block design and examined nitrogen rate timing. Treatments for both first and second cut included a control (0 kg ha -1 ), 100 kg ha -1 fall broadcast coated urea, 100 kg ha -1 spring broadcast ammonium nitrate, 100 kg ha -1 spring banded ammonium nitrate and 75 kg ha -1 spring broadcast ammonium nitrate plus 25 kg ha -1 foliar ammonium nitrate. Experiment 3, was arranged as a randomized complete block to examine phosphorus rates. Treatments included three phosphorus rates including a control (0 kg ha -1 ), 30 kg ha -1, and 60 kg ha -1 either broadcast or banded, and with or without 200 kg ha -1 of phosphate banded at the time of establishment. Experiment 3 received a blanket application of 120 kg/ha N (AN) in the spring and 90 kg ha -1 N after the first cut. Experiment 4 examines response to potassium fertilizer and treatments were arranged as a factorial design (K 2 O type X K 2 O rate) and tested two forms of potassium (KCl and KNO 3 ) and five potassium rates of 0, 50, 100, 200, and 400 kg ha -1. Experiment 4 received a blanket application of 50 kg ha -1 P 2 O 5 ( ) and 120 kg ha -1 N (AN) each spring and a blanket application of 90 kg ha -1 N (AN) after the first cut. Table 3.1 Location, objective and soil zone of each research site. Location Objective Soil Zone Soil Series Bow Island Nutrient Management Brown Chin Loam Lethbridge Nutrient Management Dark Brown Lethbridge Loam Bow Island Irrigation Management Brown Chin Loam Picture Butte Irrigation Management Dark Brown Lethbridge Loam 3.2 Data Collection and Analysis Timothy plots were harvested using a Hege plot forage harvester. A 1.2 m by 7 m swath was cut (8.4m 2 ). The plot harvester is equipped with load-cells, which allows for total plot weight (kg per 8.4m 2 ). A chopped sub-sample was collected from each plot and was weighed immediately to determine wet weight. Sub-samples were then oven dried (35-40 o C) for approximately five days and weighed to determine dry weight. From this data, a dry matter kg ha -1 yield was determined. Wet chemistry analysis for: protein, ADF (Acid Detergent Fiber), NDF (Neutral Detergent Fiber), NDF-30, sugar, ash, calcium, phosphorus, magnesium, potassium, sodium, sulfur, iron, manganese, zinc, and copper were determined by Cumberland Valley Analytical Services in Hagerstown, Maryland. Soil samples were taken in the fall of Samples were obtained by taking five samples per experiment and combining them to get one bulk sample for the; 0 to 15 cm, 15 to 30 cm, 30 to 60 cm, and 60 to 90 cm depths. These samples were then air-dried and analyzed by Alberta Agriculture Irrigation Branch Soil Lab, for routine analysis, including N, P, K, S, ph, and electrical conductivity (E.C.). Automatic recording rain gauges were set up at all locations during the growing season. Four neutron probe access tubes were installed at both the Lethbridge and Bow Island for weekly soil moisture monitoring using a neutron probe. 2

8 Analysis of variance, GLM procedure (Statistical Analysis Systems Institute - SAS), was used to determine the significance of treatment differences. Student-Newman-Keuls was used for mean separation, where significant treatment effects were noted. 3.3 Forage Yield and Quality Factors Yield and Protein Total yield was calculated by converting the dry matter plot weight in kg 8.4 m -2 to total dry matter yield in kg ha -1. Crude protein content was calculated on a percentage basis using a dried and ground sub-sample. Crude protein content is usually related to nitrogen fertility, yield and maturity of the stand Digestibility Components, Color and Lodging When feed quality is measured, Acid Detergent Fiber test (ADF) and Neutral Detergent Fiber test (NDF) are used to describe the digestibility of feedstuffs. ADF consists of cellulose, lignin, acid-detergent-insoluble nitrogen and acid-insoluble ash. NDF consists of the same components with the addition of hemicellulose. ADF is a good indicator of overall digestibility and represents the least digestible portion of roughage therefore, the higher the ADF level the lower the digestible energy. NDF gives a close approximation of the fiber content and correlates with total dry matter intake therefore, the higher the NDF level the lower the forage quality. Although Table 3.2 correlates ADF % with forage quality, the export market purchases timothy for fiber and therefore do not necessarily deem high fiber (>42%) hay as poor quality. Since the chemical and physical properties of feed affect the determination of fiber, it becomes difficult to accurately predict the energy values from ADF and NDF. Also, ADF and NDF levels increase with the maturity of the plant therefore, to draw a valid comparison between forages, the relative maturity of the forage should be noted. While ADF and NDF are calculated on an as received basis, NDF-30 is calculated after a 30 hour incubation. The NDF-30 is therefore a more accurate measure of actual fiber content of feedstuffs. The portion that remains following the incubation likely has little or no digestible energy remaining. KD is the rate of NDF digestion expressed as a percentage per hour and correlates closely with NDF-30 values. Net Energy for Lactation NEL is the prediction of energy from chemical analysis (Mcal lb -1 ) and adjusted NEL uses the actual NDF values determined by the in vitro equation. Total Digestible Nutrients (TDN) uses ADF and NDF to calculate the total percentage of digestible feed. Non-Structural Carbohydrates (NFC) are the non fiber components of the feed which are rapidly digestible. In 2004, the only digestibility data included was ADF and NDF was the commencement year of in-depth nutrition analysis completed by Cumberland Valley Analytical Services in Hagerstown, Maryland. Table 3.2 ADF scale of forage quality ADF (%) Quality < 31 Excellent Very Good Good > 41 Poor 3

9 Timothy color was determined by using the True Grade Hay Scanner System. The dried (not ground) sample is placed in a chamber and is then scanned by the hay scanner. This scanner is endorsed by the Canadian Hay Association (CHA) and is used by the local industry to maintain consistency in grading timothy for color. There are three sets of data that are determined by the scanner; color value, green stuff and grade score. Color value is measure of how close the sample is to celery green which has been deemed as the optimum color. Green leaf is a ratio of brown to green leaf and is expressed a decimal (ie. green leaf score of is 93% green). The gradescore uses both color value and green leaf to grade timothy for overall color. The CHA has assigned timothy color grades to corresponding grade-scores. Originally, there were a total of five timothy color grades. In August of 2005, the CHA felt the need to add one more color grade into the system and also change the grade-score values. Color data from the first cut used the old grade-score values (the five grades and values are outlined in Table 2), while the data from the second cut used the new grade-score system (the six grades and values are outlined in Table 3). The hay scanner was only used in 2005 on a trial basis. In subsequent years we discontinued use of the hay scanner because we could not use a compacted hay bale sample like the industry uses. Therefore, we felt that an in-crop visual color rating would be a more suitable method of assessing color. Visual rating for determination of green color, was assessed on a scale of 1 3 and was as follows: 1-pale green, 2-rich green and 3-deep green. Visual determination of brown color, was assessed on a scale of 0-3 and was as follows: 0-minimal, 1-slight, 2-moderate and 3-heavey grown leaf. Table 2. Grade and grade-score values prior to August Grade Grade Score Supreme Premium Choice Standard Utility Table 3. Grade and grade-score values after August Grade Grade Score Supreme Premium Choice Standard Fair Utility 1-23 Lodging ratings were completed prior to Timothy harvest. A scale of 1 9 was used to grade lodging, where a grade of 1 is considered completely up-right and a grade of 9 is fully lodged Sugar, Ash, Macronutrients and Micronutrients All sugar, ash, macro and micronutrient where analyzed as wet chemistry and are expressed as a percentage. Sugar content is the rapidly digested portion of the feed. Timothy hay has relatively low levels of sugar. Feeds containing greater than 25 % sugar may be to rich and cause digestive problems such as bloat. Ash content is a measure of all the inorganic components 4

10 of the feed (such as minerals). The macronutrients that were analyzed were calcium, phosphorus, magnesium, potassium, sodium, chloride and sulfur. The micronutrients that were analyzed were iron, manganese, zinc and copper. Analysis of macro and micronutrients are important to buyers since it allows them to determine the amount of minerals needed for feed supplementation and to ensure that levels are not at a toxic level. 4.0 Field Activities and Soil Analysis 4.1 Field Activities All field research activities are reported in Tables 4.01, 4.02, 4.03, 4.04, 4.05, and 4.06 for 2004, 2005, 2006, and 2007 respectively. The Lethbridge site was fertilized and then seeded on August 14, The site was seeded in a cross-seeded pattern (seeded in two passes 90 o to each other) and targeted a total seeding rate of 6 kg ha -1 (using 18 cm row spacing). Irrigation prior to and following seeding resulted in excellent emergence and very good stand establishment. The first two cuts were taken during the summer of The Bow Island site was originally fertilized and then seeded in mid August Although emergence was good, grasshopper infestation during the latter part of August and September resulted in poor stand establishment and resulted in the need to re-seed. Re-seeding took place on May 19 th 2004 without additional fertilization. This site was also seeded in a crossseeding pattern (seeded in two passes 90 o to each other) and targeted a total seeding rate of 6 kg ha -1 (10 rows with 18 cm row spacing). Frequent rainfall and supplemental irrigation resulted in excellent emergence and very good stand establishment. The Bow Island site was mowed but not harvested in Table 4.01 Plot work dates at all locations in Banding Date Seed Date Herbicide Date 1 1 st Cut Harvest 2 nd Cut Site Harvest Bow Island Aug 8, 2003 May 19, 2004 July 5, Lethbridge Aug 11, 2003 Aug 14, 2003 April 26, 2004 July 6, 2004 Sept 22, Lethbridge site sprayed with 2-4-D and Bow Island sprayed with Spectrum. 2. Bow Island was not harvested, as 2004 was the establishment year. Table 4.02 Plot work dates work dates for Banding Date Fall Coated Urea In Crop N Site Application 1 st Cut Harvest 2 nd Cut Harvest Bow Island April 23, 2005 Oct. 25, 2004 June 1, 2005 July 7, 2005 Sept. 28, 2005 Lethbridge April 11, 2005 Oct. 27, 2004 May 31, 2005 July 6, 2005 Sept. 30, 2005 Table 4.03 Fertilizer application dates for Banding Date Fall Coated Urea 2 nd Cut N Broadcast Site Bow Island April 12, 2006 Oct. 27, 2005 July 11, 2006 Lethbridge April 10, 2006 Oct. 27, 2005 July 11, 2006 Table 4.04 Foliar fertilizer, herbicide application and harvest dates for st Cut Foliar 2 nd Cut Foliar Herbicide 1 st Cut Harvest Site Application 1 Date 2 nd Cut Harvest Date Bow Island June 13, 2006 Aug. 14 th, July 6, 2006 Sept. 27, 2006 Lethbridge June 13, 2006 Aug. 14 th, 2006 May 11, 2006 July 5, 2006 Sept. 26, Curtail M sprayed. 5

11 Site Table 4.05 Fertilizer application dates for Fertilizing Date Fall Coated Urea 2 nd Cut N Broadcast Site Bow Island April 18, 2007 November 7, 2006 July 5, 2007 Lethbridge April 17, 2007 November 7, 2006 July 5, 2007 Table 4.06 Foliar fertilizer, herbicide application and harvest dates for st Cut Foliar 2 nd Cut Foliar Herbicide 1 st Cut Harvest Application 1 Date 2 nd Cut Harvest Date Bow Island June 7, 2007 August 7, June 28, 2007 September 26, 2007 Lethbridge June 7, 2007 August 7, 2007 May 16, 2007 June 27, 2007 September 26, Curtail M sprayed. 4.2 Soil Moisture, Rainfall and Irrigation Precipitation and irrigation totals are listed in Tables 4.07, 4.08, 4.09, 4.10 and 4.11 for 2004, 2005, 2006, and 2007 respectively. Precipitation, irrigation and soil moisture are graphed in Figures 1, 2, 3, and 4 for the Lethbridge site for 2004, 2005, 2006, and 2007 respectively. Table 4.07 Total rainfall and irrigation for Lethbridge in Rainfall (mm) Irrigation (mm) Total (mm) Site Lethbridge Rainfall and irrigation measured from May 7, 2004 to October 13, Table 4.08 Total rainfall and irrigation for both research locations in Rainfall (mm) 1 Irrigation (mm) Total (mm) Site Lethbridge Bow Island Rainfall data measured from April 11, 2005 October 31, Site Site Table 4.09 Total rainfall and irrigation for both research locations in 2006 Rainfall (mm) 1 Irrigation (mm) Total (mm) Lethbridge Bow Island Rainfall data measured from April 11, 2006 October 31, Table 4.10 Total rainfall and irrigation for both research locations in 2007 Rainfall (mm) 1 Irrigation (mm) Total (mm) Lethbridge Bow Island Rainfall data measured from April 11, 2007 October 31,

12 Demo Farm Timothy 2004 irrig rain % soil moisture May 17-May 20-May 25-May 31-May 8-Jun 14-Jun 21-Jun 28-Jun 5-Jul 1st cut July 6th 2nd cut Sept. 22 Date (Month/Day) 12-Jul 27-Jul 3-Aug 9-Aug 16-Aug 24-Aug 26-Aug 7-Sep 13-Sep 20-Sep 4-Oct 13-Oct Figure 4.1. Average soil moisture (%), total rainfall and total irrigation for Lethbridge timothy from May 7, 2004 to October 13, Demo Farm Timothy 2005 irrig rain mm of moisture % soil moisture st cut (July 6) 2nd cut (Sept 30) mm of moisture 0 14-Apr 15-May 14-Jun 3-Jul 24-Jul 14-Aug 5-Sep 28-Sep Date Figure 4.2. Average soil moisture (%), total rainfall and total irrigation for Lethbridge timothy from May 7, 2005 to October 13,

13 140 Demo Farm Timothy 2006 irrig rain % soil moisture mm of moisture Julian Date Figure 4.3 Average soil moisture (%), total rainfall and total irrigation for Lethbridge timothy from May 7, 2005 to October 13, Demo Farm Timothy 2007 irrig rain % soil moisture mm of moisture Julian Date 0 Figure 4.4. Average soil moisture (%), total rainfall and total irrigation for Lethbridge timothy from April 17, 2007 to September 25,

14 4.3 Soil Analysis Soil fertility samples were taken and analyzed separately for all four replicates in August Tables 4.12, 4.13, 4.14 and 4.15 show soil fertility results for Experiments 1, 2, 3 and 4. Nitrogen levels at Bow Island and Lethbridge were low, while phosphorus levels were high at Bow Island and marginal at Lethbridge. Potassium levels were high at both sites, while sulphur levels were high at Bow Island and adequate at Lethbridge. Table 4.12 Soil analysis results for Experiment 1. Location System Depth NO 3 -N 1 P 2 K 2 SO 4 -S 3 ph 4 EC 4 (cm) --ppm- Bow Island Irrigated Lethbridge Irrigated M KCl extraction solution 2. Saskatchewan modified Kelowna method of analysis M CaCl extraction solution. 4. 2:1 extraction. Table 4.13 Soil analysis results for Experiments 2. Location System Depth NO 3 -N 1 P 2 K 2 SO 4 -S 3 ph 4 EC 4 (cm) --ppm- Bow Island Irrigated Lethbridge Irrigated M KCl extraction solution 2. Saskatchewan modified Kelowna method of analysis M CaCl extraction solution. 4. 2:1 extraction. Table 4.14 Soil analysis results for Experiment 3. Location System Depth NO 3 -N 1 P 2 K 2 SO 4 -S 3 ph 4 EC 4 (cm) --ppm- Bow Island Irrigated Lethbridge Irrigated M KCl extraction solution 1. Saskatchewan modified Kelowna method of analysis M CaCl extraction solution. 4. 2:1 extraction. 9

15 Table 4.15 Soil analysis results for Experiment 4. Location System Depth NO 3 -N 1 P 2 K 2 SO 4 -S 3 ph 4 EC 4 (cm) --ppm- Bow Island Irrigated Lethbridge Irrigated M KCl extraction solution 2. Saskatchewan modified Kelowna method of analysis M CaCl extraction solution. 4. 2:1 extraction Results 5.1 Experiment 1 Nitrogen type and rate The results of nitrogen type and nitrogen rate on yield, protein, ADF and NDF are provided in Table 5.1. There was a significant yield response to nitrogen fertilizer type for the first cut. The urea and ammonium nitrate treatments yielded significantly higher than the coated urea treatments (urea treatments yielded 1066 kg ha -1 higher than coated urea and the ammonium nitrated treatments yielded 946 kg ha -1 higher than coated urea treatments). The coated urea treatments likely did not release all N prior to the first cut resulting in significantly lower yield. There was no significant yield response for the second cut, and no protein response for the first or second cut. There was a highly significant yield response to applied nitrogen fertilizer rate for both first and second cuttings. Results for both cuttings, show that yields increased significantly to the 150 kg ha -1 treatment (3737 kg ha -1 over the control on the first cut and 3721 kg ha -1 over the control on the second cut). Protein response to applied nitrogen show that protein content increased significantly to the 200 kg ha -1 treatment for both first and second cuts (4.5 % over the control on the first cut and 4.7 % over the control on the second cut). 5.2 Experiment 2 Timing of nitrogen application The results of nitrogen type and nitrogen rate on yield, protein, ADF and NDF are provided in Table 5.2. Data for the first cut shows that the 100 kg ha -1 fall broadcast (CU) treatment yielded significantly lower than the remainder of the nitrogen treatments. For the second cut however, the 100 kg ha -1 coated urea treatment yielded significantly higher than the remainder of the nitrogen treatments. The coated urea treatment (second cut) likely had residual N from the fall application, which caused significant yield increase for the second cutting. There was no significant protein response among the nitrogen treatments. 10

16 5.3 Experiment 3 Phosphorus application placement method and rate The results of phosphorus type and phosphorus rate on yield, protein, ADF and NDF are provided in Table 5.3. The effect of phosphorus placement / rate on yield was not significant for the first and second cut. Protein results for the first cut shows that the banded 60 kg ha -1 phosphorus treatment had significantly lower protein than the remainder of the treatments. There was no significant protein response to applied phosphorus on the second cut. 5.4 Experiment 4 Potassium source and rate The results of potassium type and potassium rate on yield, protein, ADF and NDF are provided in Table 5.4. The effect of potassium form / rate on yield was not significant for either the first or second cut. There was a significant protein response to potassium form on the second cut, as the KCl treatment had a significantly higher protein than the KNO 3. There was no significant protein response to potassium rates on the first or second cut. 5.5 Acid Detergent Fiber Test and Neutral Detergent Fiber Test Experiment 1 had a significant ADF response to nitrogen form and rate for both first and second cuts. Although there is statistical significance for ADF values for N form, feed values all fall into the good feed quality category (34% 39 %). For N rates on the first and second cuts however, the control and the 50 kg ha -1 treatments had significantly better forage palatability than the remainder of the N rates. ADF results for experiment 2 were statistically significance, but from a feed value perspective there is little difference among treatments. For experiments 2 and 3, there was no statistical significance for ADF Summary For N fertilizer form, the ammonium nitrate treatment yielded significantly higher for the first cut. There was a highly significant yield and protein response to N rate for both the first and second cuts. Forage yield increased with increasing rates of N to a peak of 8095 kg ha -1 (1 st cut) and 4451 kg ha -1 (2 nd cut). Protein response to applied nitrogen increased significantly to a peak of 12.8 % (1 st cut) and 14.5 % (2 nd cut). In Experiment 2 the 100 kg ha -1 fall broadcast coated urea treatment yielded the lowest on the first cut, but on the second cut yielded the highest. Coated urea carry-over likely contributed to these results. The addition of phosphorus or potassium fertilizer did not significantly increase yield on either first or second cuts. Protein results were highest on the 60 P treatment, and the KCl fertilizer resulted in significantly higher protein than the KNO 3 fertilizer. Forage quality (ADF and NDF) related inversely to forage yield. Lower yielding second cut timothy had the highest palatability as did the low N treatments. 11

17 Table 5.1. Experiment 1. Effect of nitrogen form and rate on timothy yield, protein, ADF and NDF. Treatment Yield (kg/ha) Protein (%) Lethbridge 1 st Cut ADF NDF Yield (kg/ha) Lethbridge 2 nd Cut Protein ADF (%) NDF Form AN 7143 a ab a 54.2 a Urea 7295 a a a 53.9 a CU 6229 b b b 52.9 b N Rate c 8.3 c 35.4 b d 9.8 d 26.8 d 48.9 d b 8.7 c 36.9 a c 9.4 d 28.1 c 51.1 c b 10.6 b 37.1 a b 10.6 c 30.5 b 54.9 b a 11.9 a 37.0 a a 11.9 b 31.8 a 56.7 a a 12.8 a 36.8 a a 14.5 a 31.6 a 56.7 a Rep N Rate < < < < < < Form < Form X N Rate C.V

18 Table 5.2. Experiment 2. Effect of nitrogen application timing/method on timothy yield, protein, ADF and NDF. Treatment Yield (kg/ha) Protein (%) Lethbridge 1 st Cut ADF NDF Yield (kg/ha) Lethbridge 2 nd Cut Protein ADF (%) NDF N Rate and Timing c b c c 50.8 c 100 FBR CU 6927 b ab a ab 55.8 ab 100 SBR AN 8242 a a ab ab 55.0 ab 100 SBD U 7912 ab a b bc 53.6 bc 75 SBD AN + 25 Foliar 8221 a a a a 57.8 a Rep N Timing/Method < < C.V

19 Table 5.3. Experiment 3. Effect of phosphorus application rate/timing on timothy yield, protein, ADF and NDF. Treatment Yield (kg/ha) Protein (%) Lethbridge 1 st Cut ADF NDF Yield (kg/ha) Lethbridge 2 nd Cut Protein ADF (%) NDF P Rate and Timing ab BR a BR abc BD ab BD c E a BR E a BR E abc BD E bc BD E abc Rep P Rate C.V

20 Table 5.4. Experiment 4. Effect of potassium form and rate on timothy yield, protein, ADF and NDF. Treatment Yield (kg/ha) Protein (%) Lethbridge 1 st Cut ADF NDF Yield (kg/ha) Lethbridge 2 nd Cut Protein ADF (%) NDF Form KCL a KNO b K 2 O Rate Rep K 2 O Rate Form Form X K Rate C.V

21 Results 6.1 Experiment 1 Nitrogen Type and Rate The results of nitrogen type and nitrogen rate for Lethbridge first cut are provided in Tables 6.01 and 6.02 and for second cut in Tables 6.03 and The results of nitrogen type and nitrogen rate for Bow Island first cut are provided in Tables 6.05 and 6.06 and for second cut in Tables 6.07 and Yield, Protein, Color and Lodging Results At Lethbridge on the first cut, there was a significant yield response to both nitrogen type and rate. For nitrogen type, the coated urea treatments yielded significantly lower than both the urea and ammonium nitrate treatments. The urea treatments yielded 983 kg ha -1 higher than the coated urea treatments, while the ammonium nitrate treatments yielded 734 kg ha -1 higher. For nitrogen rate, there was a significant yield increase up to the 150 kg ha -1 treatment. Although yield peaked at the 200 kg ha -1 treatment (8297 kg ha -1 ), it was not significantly greater than the 150 kg ha -1 treatment (8066 kg ha -1 ). On the second cut, there was no significant yield response for nitrogen type. For nitrogen rate however, yield increased significantly for each rate to a maximum of 5064 kg ha -1 on the 200 kg ha -1 treatment. For first cut at Bow Island, yield results for nitrogen type and rate were significant. For nitrogen type, the coated urea treatments yielded significantly lower than the urea and ammonium nitrate treatments. The ammonium nitrate treatments yielded 2772 kg ha -1 higher than the coated urea treatments and the urea treatments yielded 2714 kg ha -1 higher. For nitrogen rate, yield increased significantly to the 150 kg ha -1 level (6068 kg ha -1 ). Although not significant, the 200 kg ha -1 treatment resulted in the highest yield (6250 kg ha -1 ). Yield results on the second cut resulted in no significant difference for nitrogen type. For nitrogen rate, there was a significant yield difference. Yields increased significantly up to the 150 kg ha -1 level (3496 kg ha -1 ). Protein results on first cut timothy at Lethbridge were significant for both nitrogen type and rate. When comparing the three types of nitrogen, the coated urea treatments had significantly lower protein levels than the urea and ammonium nitrate treatments (8.5% - CU and 9.2 % - U and AN). These results indicate that nitrogen release of the coated urea did not contribute to an increase in yield or protein. When various rates of nitrogen were applied, results at Lethbridge indicate that the protein increased significantly as nitrogen rates increased. The highest nitrogen rate (200 kg ha -1 ) resulted in significantly higher protein (11.3%) than any of the remaining treatments. For the second cut, there was no significant protein response for nitrogen type. Protein content differences where not significant between the 0 kg ha -1, 50 kg ha -1 and 100 kg ha -1 treatments although, differences between the 100 kg ha -1 and 150 kg ha -1 and 150 kg ha -1 and 200 kg ha -1 treatments were significant (peaked at 10.9 % on the 200 treatment). At Bow Island on the first cutting, there was no significant protein response for nitrogen type although, the coated urea treatment does show a trend of decreased protein content (7.2% - CU, 8.2% - AN and 8.0% - U). Protein response to nitrogen rate was significant. The 200 kg ha -1 treatment resulted in the significantly higher protein levels (10.0%) than the remainder of the nitrogen rate treatments. Second cut protein content was significant for nitrogen type and rate. For nitrogen type, the coated urea treatments yielded significantly higher than the urea and ammonium nitrate treatments. The relatively slower release of the coated urea may have allowed the available nitrogen fertilizer to be allocated to protein content versus yield. For nitrogen rate, protein content increased with an increase in nitrogen rate. The highest level of protein was on the 200 kg ha -1 treatment (10.6%). 16

22 There was a significant difference in color for nitrogen rates on first cut timothy at Lethbridge. The 50 kg ha -1 treatment resulted in a significantly lower grade-score than the 200 kg ha -1 treatment. For the second cut, the color value and grade-score of the coated urea treatments were significantly higher than the urea and ammonium nitrate treatments. There was no significant color difference for nitrogen rates on the second cut. At Bow Island, there was a significant difference in grade-score and green stuff values for nitrogen form. The lowest yielding coated urea treatments resulted in a significantly higher grade-score and green stuff than the urea and ammonium nitrate treatments. There was no significant color difference for nitrogen rate on the first cut at Bow Island. On the second cut, there were significant color value, green stuff and grade-score difference for nitrogen type as the coated urea resulted in significant higher values. For nitrogen rate, there was a significant gradescore and green stuff significance, as the control (0 kg ha -1 ) treatment resulted in the highest values. At Lethbridge, although not significant, the incidence of lodging was higher on the ammonium nitrate treatments for nitrogen form and on the 150 kg ha -1 and 200 kg ha -1 treatments for nitrogen rate. There ware no lodging differences at Bow Island. There was no incidence of lodging on second cut timothy at either Lethbridge or Bow Island ADF, NDF and NDF-30 Results There was a significant ADF, NDF and NDF-30 response for nitrogen rates at Lethbridge for both first and second cut. For first cut timothy at Lethbridge, both ADF and NDF values were the lowest on the low yielding 0 kg ha -1 treatments. Interestingly, the NDF-30 results indicate that following 30-hour incubation, the 0 kg ha -1 treatment then resulted in significantly higher values (higher fiber) than the remainder of the treatments. These results indicate that when comparing the as received NDF values with the incubation NDF values, conclusions regarding feed value can vary significantly. For second cut, there was no significant ADF and NDF difference for nitrogen type. For nitrogen rate, the 150 kg ha -1 and 200 kg ha -1 treatments resulted in significantly higher ADF and NDF values than the remainder of the nitrogen rates. For NDF-30, both nitrogen type and rate were significant. For NDF-30, the coated urea type and the 0 kg ha -1 and 50 kg ha -1 rates resulted in the highest values. At Bow Island on the first cut, there was a significant ADF, NDF and NDF-30 response for nitrogen type and rate. For nitrogen type, the coated urea treatments resulted in significantly lower ADF and NDF values than the urea and ammonium nitrate treatments. For NDF-30 however, the coated urea treatments resulted in significantly higher values than the other two forms of nitrogen. On the second cut, there was a significant ADF response for nitrogen type, as the coated urea treatments had significantly lower ADF than the ammonium nitrate treatment. There was no significant NDF or NDF-30 response for nitrogen type and no ADF, NDF or NDF- 30 response for nitrogen rates on the second cut Sugar, Ash and Macronutrient Results There was a significant calcium, phosphorus, magnesium, and potassium response to nitrogen type on first cut timothy at Lethbridge. For calcium, phosphorus and magnesium, the urea and ammonium nitrate treatments resulted in significantly higher values than the coated urea treatments. Potassium values on the ammonium nitrate treatments were significantly higher than the coated urea treatments. With the increase of nitrogen rates, levels of calcium, phosphorus, magnesium, and potassium also increased significantly. Ash content was significantly highest on the 0 kg ha -1 and 100 kg ha -1 treatments. On the second cut, there was a significant ash, magnesium and potassium response for nitrogen type. The coated urea treatments resulted in significantly higher ash and potassium levels than urea and ammonium nitrate while magnesium 17

23 levels were significantly lower on the coated urea treatments. For nitrogen rate, there was a significant sugar, ash, calcium, phosphorus, magnesium and sulfur response. Ash, calcium and phosphorus all decreased significantly with at the 50 kg ha -1 rate of nitrogen. Sugar decreased significantly with the addition of 150 kg ha -1, sulfur decreased with 100 kg ha -1 and magnesium increased up to the 200 kg ha -1 level. At Bow Island first cut, varying nitrogen type resulted in a significant sugar, phosphorus, magnesium and sulfur response. The coated urea treatments resulted in the highest sugar content and the lowest magnesium and sulfur content. The ammonium nitrate treatment resulted in significantly higher phosphorus content that the coated urea treatment. For nitrogen rates, sugar content was the highest on low fertility treatments, while ash, calcium, phosphorus, magnesium, potassium, and sulfur all increased significantly with increasing rates of nitrogen. On the second cut, the coated urea treatments resulted in significantly higher phosphorus and potassium levels than the other forms of nitrogen. For nitrogen rate, ash and sugar content was significantly highest on the 50 kg ha -1 treatment, sugar and calcium tended to decrease with increasing rates of nitrogen, and phosphorus and potassium initially decreased at the 50 kg ha -1 level and than increased again with increased rates of nitrogen Micronutrient Results There was no significant effect on micronutrient content to nitrogen type on first cut timothy at Lethbridge. However, when varying nitrogen rates, there was a significant iron and copper response as both micronutrients increased as nitrogen rate increased. For the second cut, manganese content on the coated urea treatment was significantly higher than the urea treatment. For nitrogen rate, both manganese and zinc content were significant. Manganese content decreased significantly with the addition nitrogen as the 0 kg ha -1 treatment resulted in the highest manganese content. Zinc content of the 0 kg ha -1 treatment was significantly higher than the 200 kg ha -1 treatment. Nitrogen type resulted in no significant effect on micronutrient content on the first and second cut at Bow Island. For nitrogen rates on the first cut, iron and magnesium content increased significantly as nitrogen rates increased. On the second cut, manganese content decreased with the addition of nitrogen. 6.2 Experiment 2 Type and Timing of Nitrogen Application The results of nitrogen type and timing for Lethbridge first cut are provided in Tables 6.09 and 6.10 and for second cut in Tables 6.11 and The results of nitrogen type and timing for Bow Island first cut are provided in Tables 6.13 and 6.14 and for second cut in Tables 6.15 and Yield, Protein, Color and Lodging Results At Lethbridge, there was a significant yield and protein response to nitrogen type and timing of application for first and second cut. Yield results for first cut indicate that the fall applied coated urea treatment yielded significantly lower than the in-crop ammonium nitrate treatment and spring-applied ammonium nitrate with in-crop nitrogen treatment. On the second cut, the fall applied coated urea treatment yielded lower than the remainder of the nitrogen treatments. These results suggest that the release of the coated urea fertilizer is either too slow or is more prone to volatilization upon release and is not as effective as ammonium nitrate or urea on increasing yield for first cut timothy. The effect of nitrogen type and timing on protein content 18

24 was significant on first cut timothy. On the first cut, protein content of the spring-applied urea was significantly higher than the fall applied coated urea and the spring applied ammonium nitrate. On the second cut there was no significant protein response to nitrogen types and timings. At Bow Island, there was a significant yield response to nitrogen type and timing. For both first and second cut, the coated urea treatments resulted in significantly lower yield than the remainder of the nitrogen treatments. Protein content on the first cut was significantly lowest on the coated urea treatment however, on the second cut the coated urea treatment resulted in the highest protein content. These results may suggest that on the first cut, nitrogen release on coated urea treatments was complete since there was no spike in protein content. Considering that all the treatments received the same amount of total nitrogen, the extremely low yield of the coated urea treatment may be related to either incomplete nitrogen release or volatilization. On the second cut at Bow Island, there was a significant increase in protein content on the coated urea treatment, indicating that nitrogen release was too slow for yield contribution but available for protein response. Color results for first cut timothy at Lethbridge, indicate that there was a significant green stuff response to nitrogen type and timing. The fall broadcast coated urea treatment resulted in significantly higher green stuff values than the spring broadcast ammonium nitrate with in-crop nitrogen. There were no significant color differences on the second cut. At Bow Island on the first cut timothy, there was a significant color value, grade-score and green stuff difference between nitrogen types and timing. For color value and grade-score, the control (0 kg ha -1 ) treatment had significantly higher values than the spring broadcast urea. For green stuff, the fall broadcast coated urea resulted in significantly higher green stuff values than the remainder of the treatments (excluding the control). On the second cut, the control (0 kg ha -1 ) treatments resulted in the highest grade-score and green stuff values. There was no lodging on either first or second cut timothy at Lethbridge or Bow Island ADF, NDF and NDF-30 Results There were no significant ADF, NDF, or NDF-30 differences between nitrogen type and timing at Lethbridge or Bow Island Sugar, Ash and Macronutrient Results On the first cut at Lethbridge, the ash content on the fall-applied coated urea treatment was significantly lower than on the spring applied ammonium nitrate treatment. On the second cut, calcium was the highest (significant) on the coated urea treatment, potassium content of the coated urea was significantly higher than the ammonium nitrate with in-crop nitrogen, and iron content of the coated urea treatment was significantly higher than the urea treatment. At Bow Island on first cut timothy, the sugar content of the urea treatment the lowest (significant) while phosphorus and sulfur content was significantly lowest on the coated urea treatment. On the second cut, there was a significant calcium, phosphorus, magnesium, potassium, and sulfur response to nitrogen type and timing, as the coated urea and ammonium nitrate with in-crop nitrogen treatments resulted in relatively higher levels than urea and ammonium nitrate treatments. 19