Workshop: Good groundwater & agriculture

Transcription

1 Workshop: Good groundwater & agriculture Agronomic measures towards groundwater protective farming in the Murtal Univ. Doz. Dr. Johann Fank JOANNEUM RESEARCH, Institut for Water Resources Management Hydrogeology and Geophysics Dipl. Ing. Franz Feichtinger FEDERAL AGENCY FOR WATER MANAGEMENT, Institute for Land & Water Management Research Dipl. Ing. Dr. Georg Dersch AUSTRIAN AGENCY FOR HEALTH AND FOOD SAFETY, Institut für Bodengesundheit und Pflanzenernährung Dipl. Ing. Dr. Johannes Robier VERSUCHSREFERAT DER STEIRISCHEN LANDWIRTSCHAFTSSCHULEN 1 2 1

2 Höhenlage der Stationen: Graz-Thalerhof 337 m ü.a. Leibnitz 273 m ü.a. Bad Radkersburg 28 m ü.a. Groundwater protective farming Measures towards groundwater protective farming have the goal to keep Nitrate concentration in seepage water above the groundwater table (below the root zone) below 5 mg l -1 as a mean value (emission evaluation). Local relations (soil, weather, crop rotation ) have to be taken into consideration. Nitrogen loads from balancing have to be used for assessment. Pollution depends on groundwater recharge rate as well as on nitrate concentration. The evaluation of agricultural measures on the basis of groundwater data on nitrate concentration (imission evaluation) is influenced by dilution effects (rivers, lakes ) and will lead to complete different agricultural management principles at the same local relations. 3 Murtal Monatssumme Niederschlag [mm] Monatsmittel Reihe Lufttemperatur [ C] 6 JAN FEB M AR APR M AI JUN JUL AUG SEP OKT NOV DEZ Graz-Thalerhof (823 mm) Leibnitz (892 mm) Bad Radkersburg (832 mm) Graz-Thalerhof (8.7 C) Leibnitz (9. C) Bad Radkersburg (9.3 C) At the hydro-meteorological conditions of the Murtal the mean yearly sum of the climatic water balance is positve. Precipitation is up to 2 mm higher than evapotranspiration. 2

3 Nitrat [mg*l -1 ] GWSP [m ü.a.] Groundwater in the Murtal aquifer Max. ( ) Min. ( ) Mittel ( ) Agricultural land use and stock breeding Agricultural land use (without forests, settlement areas ) ~ 9 % arable farm land, 1 % meadows, pastures. ~ 7 % of arable land used for corn production (+ 1 % since 2); Pumpkins for oil production is of increasing importance (13 2 %). Close to the city of Graz market gardening is relevant. Stock breeding (development in the last 1 years) Number of farms (-32 %) and livestock owners (-38 %) is decreasing 47 % of the livestock units are living in farms with more than 2 livestock units (+ 7 %) Livestock breeding in the region is not too high should be kept Nitrogen from livestock breeding is < 6 kg ha -1 a -1 (- 1 kg ha -1 a -1 ) Amount of farm fertilizer in the Murtal region is not a problem of magnitude but a problem of disposition 6 3

4 Corn yield at test area Wagna (different amount of fertilization) Corn yield at test area Wagendorf (different amount of fertilization) 8 4

5 Pumpkin yield at test area Kalsdorf (different amount of fertilization) 9 N min after corn harvesting Wagna Reststickstoff in NO3N+NH4N kg/ha StandardversuchWagna, Anfang Oktober 28 oben mitte unten O A B C D E F G H I K L Versuchsreferat Steiermark 1 5

6 N min after corn harvesting Wagendorf Reststickstoff in NO3N+NH4N kg/ha StandardversuchWagendorf, Anfang Oktober oben mitte unten O A B C D E F G H I K L M Versuchsreferat Steiermark 11 N min after corn harvesting at randomly selected field in the region Reststickstoff in NH4N+NO3N kg/ha oben mitte unten Maisfelder im Jahr 28 Versuchsreferat Steiermark 12 6

7 N (kg / ha) Large lot test field Wagna N-removal by catch crops Klee (org. biol.) Perko nach Getreide Grasuntersaat Kürbis Grünschnittroggen nach Mais y =.357x R 2 = y =.333x R 2 = GTM (kg / ha) 13 N-balance at soil surface In a stable system is N-surplus at the surface equal the N-leaching to the groundwater At a groundwater recharge rate of ~ 3 mm N-surplus must not exeed 3-35 kg N ha -1 to keep nitrate concentration < 5 mg l -1 in seepage water. 14 7

8 Szenarios for groundwater protective farming in the region 15 Regional measures for groundwater protective farming Fertilisation based on the Austrian guidelines for appropriate fertilisation (6. print run, 26) with a mean estimated yield in the region. N-Balance Taking into account N deposition from atmosphere (1 kg N ha -1 a -1 ) an N-surplus at the surface of N-Import - N-Export <= 25 kg N ha -1 a -1 has to be kept. Balancing should be done für crop rotation periods (5 years). For balancing we need data on harvested yield, N-content in yield and amount of fertilization (including N-content of farm fertilizers) No N-fertilization in autumn N-fertilization in spring as short as possible before seeding or fertilization of growing plants Siting of catch crops during winter months (avoiding fallow periods over the year) N-management of legumes is critical and has to be considered specifically 16 8

9 Options for implementation and control Education and advanced training of the farmers Farmers must identify themselves with groundwater protection. Principles of sustainability must be considered Implementation of further test areas at different locations in the region to integrat heterogeneity of soil, weather and agricultural management Implementation of a nitrate information service (Internet) to disseminate the results of test areas and recommendations on groundwater protective farming to the stakeholders Ecological oriented advicing of the farmers to help them in N- balancing and to get necessary data Recording of data on harvested yield, fertilizer amount and N-content of manure will be a certification for groundwater protective farming. 17 Thank you very much for your attention Agronomic measures towards groundwater protective farming in the Murtal Univ. Doz. Dr. Johann Fank JOANNEUM RESEARCH, Institut for Water Resources Management Hydrogeology and Geophysics Dipl. Ing. Franz Feichtinger FEDERAL AGENCY FOR WATER MANAGEMENT, Institute for Land & Water Management Research Dipl. Ing. Dr. Georg Dersch AUSTRIAN AGENCY FOR HEALTH AND FOOD SAFETY, Institut für Bodengesundheit und Pflanzenernährung Dipl. Ing. Dr. Johannes Robier VERSUCHSREFERAT DER STEIRISCHEN LANDWIRTSCHAFTSSCHULEN 18 9