Haby, Vincent A.

Hons, Frank M.

Rouquette, F. M., Jr.

Stout, S. A.

English

Texas A&amp;M Repository

  PUBLICATIONS 1998  1TREATMENT AND SEASONAL EFFECTS ON ALFALFACRUDE PROTEIN CONTENTS. A. Stout, V. A. Haby, F. M. Hons, and F. M. Rouquette, Jr.Background. Excellent-quality alfalfa can be grown on the acid soils of East Texas.Research conducted over the last eight years at Texas A&M-Overton has shown that yieldsapproaching 6 tons/ac are possible when alfalfa is no-till planted on well-drained, adequately limed,and properly fertilized acid soils. Economic evaluation of farming practices required to produce theseyield levels has shown that alfalfa is economical even in the seedling year. Data on quality of thisalfalfa were obtained during the fourth, fifth, and sixth years post~stablishment on a Darco loamy finesand. 'Alfagraze' alfalfa was drilled into bermudagrass in rows spaced 9, 18,27, and 36 inches apartin major plots that measured 50 by 20 feet. Over the six-year period, sub-plots (10' x 20') werefertilized with nitrogen (N) rates of 0,25, 50, 75, and 100 lb/ac after each harvest. Additional ECCE72 limestone was applied to the N plots at 0, 0.5, 1.0, 1.5, and 2.0 tons/ac, respectively, on 5 Oct.1994. One ton of ECCE 72 limestone/ac was applied to all plots on 28 Sept. 1995. Alfalfa washarvested at 10% bloom and forage was sampled for dry matter and protein analysis. Alfalfa wasfertilized as shown in Table 1.Table 1. Fertilizer history (lb/ac) for the fourth through sixth years of alfalfa.Date P20S K20 Mg S B Cu Zn Mo8-2-93 100 23-14-94 0.0846-7-94 72 150 19 33 1.25 0.6 0.7510-12-94 150 22 45 24-28-95 150 22 45 23-4-96 72 150 19 33 1.25 0.6 0.75Research Findings. Fertilizer N applied to the alfalfa-bermudagrass mixture had no effecton crude protein of the alfalfa in years 4-6 (Table 2). This indicates that the alfalfa was adequatelynodulated for symbiotic N-fixation. Row spacing had minimal effect on protein of alfalfa. Thegreatest change in alfalfa protein occurred in mid- to late-season. As expected, the earliest harvest hadthe highest protein content. Late-season alfalfa contained about 20% crude protein. This decline inprotein and overall nutritive value of alfalfa during the summer months follows a predictable trendcreated by length of day, temperature, drought, and other climatic conditions that affect physiologicalfunction.11Application. Alfalfa had the highest protein in early spring-early summer. During periodsof highest protein, however, climatic conditions in East Texas may not be favorable for curing hay.Other altemat:ve methods of forage utilization may be necessary for the first couple of potentialharvest dates (silage, graze, green chop). Although nutritive value declined 20 to 30% wit". s~asonand maturation, the lowest quality alfalfa harvested (20% protein) was more than adequate to meetnutritive requirements for recreational livestock, beef, dairy, or other domestic-exotic livestock.Dr uction, row spacmJ?; 0 a, an arvestm , ,anTreatment Nrate Harvest 1 Harvest 2 Harvest 3 Harvest 4 Harvest 5 Harvest 61994 Ib/ac -------------------------------------------%------------------------------------------No 0 27.24 at 26.66 ns 22.36 ns 21.04 a 19.98 ns 20.13 nsN) 25 26.52 a 28.21 24.19 18.75 b 20.63 19.87N2 50 28.31 a 27.24 25.65 19.29 ab 19.92 20.63.N3 75 27.26 a 34.93 25.34 20.12 ab 19.50 20.81N4 100 27.07 a 28.63 24.19 19.50 ab 20.54 20.78inchesRS)+ 9 27.94 a 28.04 25.27 19.79 a 20.36 20.77RS3 27 26.61 b 27.73 23.71 19.69 a 19.87 20.121995 N.lb/acNo 0 25.15 ns 23.17 ns 24.71 a 22.20 ns 21.83 nsN) 25 24.96 22.88 25.31 a 22.86 22.87N2 50 24.48 23.69 24.40 a 22.45 22.29N3 75 24.76 23.59 24.50 a 22.08 22.36N4 100 24.28 24.11 25.65 a 21.86 23.13inchesRS) 9 24.87 23.70 25.93 a 21.97 22.94RS3 27 24.58 23.30 23.89 b 22.61 22.041996 N,lb/acNo 0 29.89 ns 21.74 ns 23.69 ns 26.66 a 21.67 ns 23.12 nsN) 25 29.42 20.68 23.71 27.38 a 22.29 23.34N2 50 30.08 21.77 22.18 27.30 a 20.40 24.03N3 75 27.93 20.50 22.05 28.11 a 21.85 23.29N4 100 30.02 21.11 24.52 27.19a 21.89 24.08inchesRS) 9 29.68 20.94 23.02 28.06 a 21.29 22.81RS3 27 29.26 21.36 23.61 26.59 b 21.95 24.34Table 2. Crude protein percentage in alfalfa as affected by nitrogen applied for Coastal berrnudagrassod . . f alfalf d h . 1994 1995 d 1996tNumbers followed by the same letter are not statistIcally dIfferent at alpha = 0.05.+RSx refers to spacing between rows of alfalfa.12

Treatment and Seasonal Effects on Alfalfa Crude Protein Content

Texas A&M University

https://oaktrust.library.tamu.edu/bitstream/1969.1/189796/1/article238.pdf

Treatment and Seasonal Effects on Alfalfa Crude Protein Content

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Treatment and Seasonal Effects on Alfalfa Crude Protein Content

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