Effect of second-pond dairy effluent on turnip dry matter yield, nutritive characteristics, and mineral content
J. L. Jacobs A B and G. N. Ward AA Department of Primary Industries, 78 Henna Street, Warrnambool, Vic. 3280, Australia.
B Corresponding author. Email: joe.jacobs@dpi.vic.gov.au
Australian Journal of Agricultural Research 58(9) 884-892 https://doi.org/10.1071/AR06409
Submitted: 21 December 2006 Accepted: 9 May 2007 Published: 28 September 2007
Abstract
Dairy farms in southern Australia generally use a 2-pond system to manage dairy shed effluent. This system consists of a deep anaerobic first pond and a shallow aerobic second pond. The liquid in the second pond contains a range of nutrients that may have agronomic benefits for forages.
The effect of applying second-pond dairy effluent to a summer turnip (Brassica rapa L.) crop over 3 consecutive summer periods was measured. Effluent was applied at 6 rates, 0, 15, 30, 45, 60, and 75 mm, approximately 6–8 weeks after turnips were sown each year. Turnips were assessed for dry matter (DM) accumulation, nutritive characteristics, and mineral content. In addition, total annual production for years 1 and 2 was calculated by including the DM accumulation from annual ryegrass grown from autumn to spring each year.
Concentrations of nutrients within the effluent as an average over the 3 years were 31, 454, 20, and 149 kg/ML for phosphorus (P), potassium (K), sulfur (S), and nitrogen (N), respectively. In addition, effluent also contained 152 kg/ML of calcium (Ca), 225 kg/ML of magnesium (Mg), and 529 kg/ML of sodium (Na).
Soil pH was generally unaffected with effluent application, while soil EC and total soluble salt (TSS) content increased with effluent addition. In the first year, application of effluent at 15 mm and higher resulted in increases in available K; however, in subsequent years, rates of 45 mm and higher led to an increase in available K, while for the control and lower effluent rates there was a marked decline in K status.
In all years there was a linear increase (P < 0.05) in leaf, root, and total DM yields with applied effluent. For leaf, responses were 19, 50, and 26 kg DM per mm applied effluent and for roots, 10, 39, and 25 kg DM per mm applied effluent for years 1, 2, and 3, respectively. In years 2 and 3, turnip leaf crude protein (CP) content increased (P < 0.05) in a linear manner at rates of 0.046 and 0.044% per mm applied effluent, respectively. There was also a linear increase (P < 0.05) in turnip root CP in years 2 and 3 of 0.033 and 0.021% per mm applied effluent, respectively. In all years there was a linear increase (P < 0.05) in leaf K content, while for root K there was a quadratic trend (P < 0.05) for year 1 and a linear increase (P < 0.05) for years 2 and 3.
The results from this study indicate that the use of dairy effluent can increase DM yield and improve the nutritive value of turnips through an increase in CP content. The data also indicate that this effect can be maintained over consecutive years, which in turn may provide greater flexibility for returning effluent to farm land. While results appear to indicate that the primary responses are due to N, further work is required to determine the effects of water and other nutrients within dairy effluent.
Acknowledgments
The authors acknowledge the Victorian Government, Dairy Australia, WestVic Dairy, and the Geoffery Gardiner Foundation for providing financial assistance for this experiment. We also thank DemoDAIRY for the use of land on their farm to undertake the experiment. The technical support of Stewart Burch, Troy Jenkin, and Phillip Maskell and biometrical analyses by Gavin Kearney are also acknowledged.
Bolan NS,
Horne DJ, Currie LD
(2004) Growth and chemical composition of legume-based pasture irrigated with dairy farm effluent. New Zealand Journal of Agricultural Research 47, 85–93.
Clarke T,
Flinn PC, McGowan AA
(1982) Low cost pepsin-cellulase assays for prediction of digestibility of herbage. Grass and Forage Science 37, 147–150.
| Crossref | GoogleScholarGoogle Scholar |
Earle DF, McGowan AA
(1979) Evaluation and calibration of an automated rising plate meter for estimating dry matter yield of pasture. Australian Journal of Experimental Agriculture 19, 337–343.
| Crossref | GoogleScholarGoogle Scholar |
Hattey JA,
Sabbe WE,
Batten GD, Blakeney AB
(1994) Nitrogen and starch analysis of cotton leaves using near infrared reflectance spectroscopy (NIRS). Communications in Soil Science and Plant Analysis 25, 1855–1863.
Jacobs JL,
McKenzie FR, Ward GN
(1999) Changes in the botanical composition and nutritive characteristics of pasture, and nutrient selection by dairy cows grazing rainfed pastures in western Victoria. Australian Journal of Experimental Agriculture 39, 419–428.
| Crossref | GoogleScholarGoogle Scholar |
Jacobs JL, Ward GN
(2007a) Effect of second-pond dairy effluent applied in spring to silage regrowth of perennial ryegrass based pasture in southern Australia. 1. Dry matter yield and botanical composition changes. Australian Journal of Agricultural Research 58, 137–143.
| Crossref | GoogleScholarGoogle Scholar |
Jacobs JL, Ward GN
(2007b) Effect of second-pond dairy effluent applied in spring to silage regrowth of perennial ryegrass based pasture in southern Australia. 2. Changes in nutritive characteristics and mineral content. Australian Journal of Agricultural Research 58, 145–151.
| Crossref | GoogleScholarGoogle Scholar |
Jacobs JL,
Ward GN, Kearney G
(2004) Effects of irrigation strategies and nitrogen fertiliser on turnip dry matter yield, water use efficiency, nutritive characteristics and mineral content in western Victoria. Australian Journal of Experimental Agriculture 44, 13–26.
| Crossref | GoogleScholarGoogle Scholar |
Jacobs JL,
Ward GN,
McDowell AM, Kearney G
(2001) A survey on the effect of establishment techniques, crop management, moisture availability and soil type on turnip dry matter yields and nutritive characteristics in western Victoria. Australian Journal of Experimental Agriculture 41, 743–751.
| Crossref | GoogleScholarGoogle Scholar |
Jacobs JL,
Ward GN,
McDowell AM, Kearney G
(2002) Effect of seedbed techniques, variety, soil type and sowing time, on brassica dry matter yields, water use efficiency and crop nutritive characteristics in western Victoria. Australian Journal of Experimental Agriculture 42, 945–952.
| Crossref | GoogleScholarGoogle Scholar |
Kemp A, Hart ML
(1957) Grass tetany in grazing milking cows. Netherlands Journal of Agricultural Research 5, 4–17.
Lautenenschlaeger W
(1989) Atomic spectroscopy advances. Microwave digestion in a closed-vessel, high pressure system. Spectroscopy 4, 16–21.
Longhurst RD,
Roberts AHC, O’Connor MB
(2000) Farm dairy effluent: a review of published data on chemical and physical characteristics in New Zealand. New Zealand Journal of Agricultural Research 43, 7–14.
Moate PJ,
Dalley DE,
Roche JR,
Grainger C,
Hannah M, Martin K
(1999) Turnips and protein supplements for lactating dairy cows. Australian Journal of Experimental Agriculture 39, 389–400.
| Crossref | GoogleScholarGoogle Scholar |
Nakashima S,
Sturgeon E,
Willie SN, Berman SS
(1988) Acid digestion of marine samples for trace element analysis using microwave heating. Analyst 113, 159–163.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Shenk JS, Westerhaus MO
(1991) Population definition, sample selection and calibration procedures for near infrared reflectance spectroscopy. Crop Science 31, 469–474.
van Soest PJ, Wine RH
(1967) Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell wall constituents. Journal – Association of Official Analytical Chemists 50, 50–55.
Wang H,
Magesan GN, Bolan NS
(2004) An overview of the environmental effects of land application of farm effluents. New Zealand Journal of Agricultural Research 47, 389–403.
Yemm EW, Willis AJ
(1954) The estimation of carbohydrates in plant extracts by anthrone. Biochemistry 57, 508–514.
