SOIL SALINITY: CAUSES and CURES

Transcription

1 SOIL SALINITY: CAUSES and CURES by Les Henry NORTHEAST AG RESEARCH FOUNDATION MELFORT OCTOBER 16, 2014 Soil Salinity by Les Henry OCTOBER 16,

2 $ Cash or Cheque GST included 2 Soil Salinity by Les Henry OCTOBER 16, 2014

3 A HISTORY LESSON: 1960s DRY 1961 major drought 1970s WET 1973/74 huge snow melt 1980s DRY- 1987/88 Major drought 1990s on dry side enough rain for fair crops 2002 Major Drought except southwest 2005 Major snow melt and wet ever since : 5 Irrigation years in a row. 3 Soil Salinity by Les Henry OCTOBER 16, 2014

4 1970s Saline Soils- Big Problem MOOSE JAW- EXTENSION MEETING LATE 1970S. SOIL SALINITY -BIG PROBLEM NEED ALL DAY MEETING BROUGHT ALL THE BIG GUNS - ALL DAY END OF THE DAY: FARMER REACTION YOU TOLD US WHAT WE ALREADY KNEW IN LANGUAGE WE COULD NOT UNDERSTAND AND TOOK ALL DAY TO DO IT ( and he was right!!!) ON THE DRIVE HOME WE KNEW A DIFFERENT APPROACH WAS NEEDED 4 Soil Salinity by Les Henry OCTOBER 16, 2014

5 Field Studies Earl Christiansen Bill Meneley 5 Soil Salinity by Les Henry OCTOBER 16, 2014

6 CAUSES 6 Soil Salinity by Les Henry OCTOBER 16, 2014

7 SOIL SALINITY IS A WATER PROBLEM * Water Table High - Suction Lift * Evaporation > precipitation Soil Salinity by Les Henry OCTOBER 16,

8 THINK - Water Table High - Evaporation > precipitation -?????????????? Soil Salinity by Les Henry December 13,

9 TAKE HOME MESSAGE: 1. SOIL SALINITY CAUSED BY HIGH WATER TABLE 2. NEED EVAPORATION>PRECIPITATION. GROUNDWATER MOVEMENT REQUIREDTO MAINTAIN WATER TABLE IN DRY PERIODS 2. MUST KNOW GROUNDWATER MOVEMENT TO UNDERSTAND THE PROBLEM Soil Salinity by Les Henry December 13,

10 Mechanisms to Maintain High Water Table in Dry Times * Side-Hill Seep * Evaporitic( Bathtub) Ring around sloughs * Artesian Discharge Soil Salinity by Les Henry OCTOBER 16,

11 Artesian Discharge: Dominant Mechanism in Sask. Flowing Wells Common Soil Salinity by Les Henry OCTOBER 16,

12 WATER TABLE IS NOT STATIC ; IT VARIES GREATLY IN SPACE AND TIME Soil Salinity by Les Henry OCTOBER 16,

13 When a soil is at Field Capacity moisture : Add ONE INCH of rain : The water table rise will be: * 6 Inches for a sandy soil *One FOOT for a Clay soil 13 Soil Salinity by Les Henry OCTOBER 16, 2014

14 MORAL OF THE STORY: If you do not know where water table is MEASURE IT 14 Soil Salinity by Les Henry OCTOBER 16, 2014

15 Dutch auger 2 extensions Water Table: Rain July m July m Jul16 23mm July m Aug m 2m well July Elevation ~2030 FASL 2 PVC 3m Central Vac Soil Salinity by Les Henry NW W3 Contours by Farmer s Edge December 13,

16 Alfalfa and the Water Table Paul Brown USDA Montana 1970s-1980s 16 Soil Salinity by Les Henry OCTOBER 16, 2014

17 Rosewood Subdivision: Saskatoon Alfalfa 7 years Aug inches of gentle rain Impact on water table under alfalfa = 0 Adjacent fallow- water table rise = 4 FEET 17 Soil Salinity by Les Henry OCTOBER 16, 2014

18 MELFORT OBSERVATION WELL : 1967: Meneley Well Depth : 35 feet : Water level now 15 feet below ground OBSERVATION WELL: MELFORT LAND LOCATION: NE W2 HYDROGRAPH OF MEDIAN MONTHLY WATER LEVELS WATER SECURITY AGENCY DATUM: M DEPTH: M WATER LEVEL ELEVATION (M) ABOVE SEA LEVEL YEAR 18 Soil Salinity by Les Henry OCTOBER 16, 2014

19 Observation Well Data Available at: (Water Security Agency Moose Jaw) 19 Soil Salinity by Les Henry OCTOBER 16, 2014

20 CURES 20 Soil Salinity by Les Henry OCTOBER 16, 2014

21 MANAGING SALINE LAND: SELL IT IN THE WINTER TIME Same color in July Soil Salinity by Les Henry OCTOBER 16,

22 RECLAIMING SALINE SOILS Kelley,W.P The reclamation of alkali soils. Calif. Ag Exten Bull #717. * Ca + Mg Salts - Drain + Leach * Na Salts - Saline-Sodic Add gypsum, drain and leach Soil Salinity by Les Henry OCTOBER 16,

23 RECLAIMING SALINE SOILS 1. Drainage PLUS 2. Leaching 3. See 1 PLUS 2 Soil Salinity by Les Henry OCTOBER 16,

24 DRAINAGE : Huge Political Issue England swamp and bush when Romans came Red R Valley -MB and ND- farms rely on drainage 1922 North Dakota - Drains everywhere 24 Soil Salinity by Les Henry OCTOBER 16, 2014

25 ! Brown House-Sperling MB : Built all amenities All because of land drainage

26 Tile Drainage Alone = Not a Complete Solution Soil Salinity by Les Henry OCTOBER 16,

27 LEACHING:University of Saskatchewan : Goodale Farm Well Depth 100 feet Head Above Ground m 11 feet m 8 feet m 14 feet Soil Salinity by Les Henry OCTOBER 16,

28 Leaching Alone Looks Good Short Term BUT?? Soil Salinity by Les Henry OCTOBER 16,

29 Water Table: Soon at Soil Surface Soil Salinity by Les Henry OCTOBER 16,

30 Outlook : CSIDC; Terry Hogg, Laurie Tollefson Drainage + Leaching = Long Term Solution (Google: SCIDC Outlook Sask: for report) Applied 6 feet of water in fall over 6 years Soil completely reclaimed to grow any crop Soil Salinity by Les Henry OCTOBER 16,

31 Measuring Soil Salinity in the Field 1. EM38 2. Veris 31 Soil Salinity by Les Henry OCTOBER 16, 2014

32 EM = 35/24 Soil Salinity by Les Henry OCTOBER 16,

33 Mapping Salinity with EM38 Soil Salinity by Les Henry OCTOBER 16,

34 Salinity Mapping with Veris Technology Soil Salinity by Les Henry OCTOBER 16,

35 Available on Sask Ag Website Soil Salinity by Les Henry OCTOBER 16,

36 THE END??????????????????? Soil Salinity by Les Henry OCTOBER 16,

37 North Dakota experiment Agvise labs (John Lee) Tile Drainage Salinity Results Topsoil salt levels decreased over the years as long as excessive rainfall was received. Several crops now produce good yields Corn, soybeans, sunflowers Iron chlorosis severity in soybeans is much less Subsoil salt levels take longer to be decrease High subsoil salt levels do not affect crop growth as much as high topsoil salt levels. Salinity stayed the same or increases in dryer years, even with tile drainage.

38 Monthly Rainfall (Grand Forks) 5 yr Ave April -October April May Jun July Aug Sep ? Oct ? Tota l Red number indicates a month or year with rainfall higher than 5 year average ??