Situation of soil humus content of soils in Upper-Austria

Transcription

1 Situation of soil humus content of soils in Upper-Austria DI Christian Krumphuber Chamber of agriculture; Dept. of plant-production

2 Austria Upper-Austria /Folie 2

3 Humus Definition based on SCHEFFER: Humus in narrow sense or classical meaning is stalled organic matter in and onto soil and being arranged in a permanent process of degradation, conversion and build-up. This process is set in motion and operated by biochemical processes. Definition based on OEHMICHEN: Basic material for humification are first and foremost crop residues (roots, leaves, straw ), catch crops (green manuring) and marginal soil organisms Humus: google: hits /Folie 3

4 Sustainability means sufficient content of organic matter in soil(s) Content of organic matter in soil is directly linked to soil fertility Extended use of biomass for energetic use can lead to reduced organic matter in soil, as there might be an unsufficient refeed of biomass Further aspect: climate change Soil is one of the most important carbon-stores Higher temperatures lead to higher degradation of organic matter in soil; leads to higher CO 2 -emission reinforcing global warming /Folie 4

5 Factors influencing humus-concentration factors of site climate type of soil ground water Humus (content, quality) cultivation Crop-rotation fertilisation tillage soil-characteristics Biological activity, nutritives Stability of aggregates, water capacity Chemical and physical functions Depending on characteristics of site and factors of cultivation a specific amount of humus will be set up /Folie 5

6 Austria s programm of sustainable farming Since 1995 Austria has implemented a widely applied programm of sustainable farming (ÖPUL = Österreichisches Programm für umweltgerechte Landwirtschaft) Measures for all type of agriculture (organic farming, arable land, grassland, wineyards, measures concerning biodiversity,.) Precautionary measures for protecting soil and water Implementation of system wintergreen by catch-crops Implementation of reduced tilling systems like mulch-seed and direct-seed The main reason at the beginning was fighting erosion and nitrogen-leaching Improving the humus-situation is getting more important and a colateral benefit (maybe becoming more important) /Folie 6

7 System evergreen (wintergreen) /Folie 7

8 Measures of soil- and water protection ;Austrian programme of sustainable farming (2008) System wintergreen, hectars Hectars of direct and/or mulchseed following system wintergreen Austria Upper-Austria /Folie 8

9 Catch-crops - tillage High-quality-catch-crops lead to an increase of humus Most important: right time of sowing the catch-crop Fertilisation depending on catch-crop important influence for biomass-production No incubation of biomass in autumn catch-crops stay on field till they freeze off (more lignin, more longchain carbohydrates leads to better humification) Type of catch-crop is less important regarding humification Blended seeds of catch-crops are nice for biodiversity but less important regarding humification or protecting from erosion Tillage As spare as possible Combined seed-measures if possible (Direkt-seed, seed in mulch) /Folie 9

10 Mainly used catch-crops for system wintergreen Cruciferous plants Mainly mustard (yellow), oil radish Advantages: cheap, quickly covering soil, poor seed bed preparation possible, good consumers of farm manure, freezing safely in winter Disadvanteges: causing phytosanitary problems in crop rotation with rape-seed Phacelia (Phacelia tanacetifolia) Advantages: good root penetration, no affinity to main crop plants causing any phytosanitary problems, best bee-pasture, safely freezing in winter, direct seed in spring for following crop recommended Disadvantages: seed bed preparation more intensive, costs of DI Franz Xaver Hölzl, seed Hannes -Recheis, sometimes Bodenschutzberatung /Folie 10

11 Soil research chamber of agriculture Upper- Austria Different projects of soil-analysis within : 486 samples in arable land 2005: 627 samples in grassland 2008: about 700 samples arable land/grassland 2009: Big project soil analysis in Upper-Austria farmers, samples ( ph-value, phopsphate/potash-content, humus-content) Not yet finished we are still working /Folie 11

12 Humuscontent in crop area in Upper Austria humuscontent % in crop area in Upper Austria (number of samples = 342) mean: 2,92 (range: 1,59 bis 10,92) % 90,0 80,0 70,0 60,0 50,0 40,0 30,0 20,0 10,0 0,0 83,6 9,1 7,3 A (< 2) C (2-4,5) E (< 4,5) /Folie 12

13 humus % How much organic matter humus does soil need? 4,5 4 3,5 3 2,5 2 1,5 1 0,5 untere Grenze obere Grenze clay % Orientation for required organic matter in soil depending on clay content (Körschens et. Al., 1986) /Folie 13

14 content humus % Humus content /soil consistance 5,0 Humus- and soilgravity in Upper Austria 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1, clay fraction % /Folie 14

15 Carbon/nitrogen-relation in soils in Upper Austria Distribution of der C-N-Relation of upper-austrian soils (n = 266) mean : 9,6 (range: 7,92 bis 13,14) % ,0 91,0 53,0 24,0 2,0 < 8, > /Folie 15

16 Humus content % Influencing humus content on arable land 4,5 Quelle: Dr. Georg Dersch, AGES 4,0 3,5 minimum tillage crop residues 10 t org. manure 3,0 2,5 10 t organic manure irrigation 2,0 Crop residues Crop residues 1,5 1, /Folie 16 clay content %

17 Summary humus content is an important parameter for (sustainable) soil fertility humus content can be managed within narrow borderlines dedicated by natural influences like climate, soil type Changes in cultivation ( System wintergreen, straw manuring, reduced tillage) within the last years have brought improvements in humus content High quality catch crops (best growing time, fertilisation if necessary) brings essential improvement in humus content We believe, that humus content is mainly satisfying humus content in our soils is mainly in a good range to fulfill the requirements of climate - as well as water protection /Folie 17