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1 Click to edit Master text styles Second level Irrigation Water Management Third level Fourth level Sarah Sommerfeld PAg Irrigation Branch, Saskatchewan Agriculture Soil & Water Workshop February 24,

2 Click to edit Master text styles Second level Third level Fourth level Fifth level Irrigation Scheduling 2

3 What is Irrigation Scheduling? Click to edit Master text styles Second Ensures level that water is consistently Third available level to the plant and that it is applied Fourth according level to crop requirements Fifth Improve level water use efficiency Improve profitability 3

4 Determining Soil Texture Click to edit Master text How? styles Second level Third level Fourth level By feel Refer to your Agro- Environmental Report or soil test report 4

5 Moisture Click to edit Master text styles Second level Third level Fourth level Water Holding Capacities Texture Available inches/foot Loamy Sand (LS) 0.84 Sandy Loam (SL) 1.68 Fine Sandy Loam (FL) Very Fine Sandy Loam (VL) Silt Loam (SiL) 2.02 Loam (L) 2.01 Clay Loam (CL) 2.23 Clay (C)

6 Soil/Water Relationships Click to edit Master text styles Second level Third level Fourth level 6

7 Soil/Water Relationships Click to edit Master text styles Second level Third level Fourth level 7

8 Crop Water Relationships Rooting Click to zone edit Master text styles determines the amount of water available to crop Second level Third level Fourth level Shallow rooting depth = Fifth smaller level zone to extract water 8

9 Soil/Water Relationships Allowable Click to depletion edit Master text styles % Second level Amount of water that Third level can be removed from the Fourth soil before level an irrigation Fifth level application Crop specific Crop Allowable Depletion (%) Alfalfa 60 Grass 50 Potatoes 40 Faba beans 35 Corn Silage 50 Wheat Hard 50 Soft 50 Canola 50 Flax 50 Peas 40 Barley Forage 50 Malt 50 Dry beans 40 9

10 Click to edit Master text styles Second Keep soil level available moisture (AM) between Third field capacity level (FC) and the allowable Fourth depletion level (AD) limit Irrigation Scheduling Readily Available Moisture (RAM) Amount of water to apply to reach FC depends on the soil texture 10

11 Determining Soil Moisture Soil Click based to edit Master text styles Direct Second Measurement level Third level Soil probe and gravimetric analysis Feel method Fourth level Fifth Indirect level Measurement Moisture monitoring equipment Tensiometers, Watermark sensors (electrical resistance) 11

12 Click to edit Master title Clay style loam Click to edit Master text styles Second level Third level Feel Fourth level Method Loamy sand Sandy loam 25-50% 50-75% Clay Silty clay loam % 12

13 Click to edit Master text styles Second level Third level Fourth level Soil Moisture Monitoring Equipment Watermark sensor Tensiometer Gypsum blocks 13

14 Irrigation Scheduling so far. Click to edit Master text styles Second Soil texture level and water holding capacity Third Know level how much water can be removed Fourth AD limit level Fifth Keep level AM between FC and AD Monitor AM weekly Next Determine and monitor the crop water use 14

15 Evapotranspiration Click to edit Master (ET) text styles Amount Second of level water used by plant for growth and Third cooling level plus the water Fourth that level is lost from soil surface Total seasonal ET = crop consumptive use Crop Water Requirements Crop Seasonal Crop Water Use (mm) Alfalfa 620 Grass 500 Potatoes 520 Faba beans 610 Corn Silage 470 Wheat Hard 460 Soft 480 Canola 480 Flax 410 Peas 400 Barley Forage 390 Malt 430 Dry beans

16 Crop Alfalfa 8.0 Click to edit Master text styles Potatoes 6.0 Second level Corn Third level Wheat Fourth level Peak Moisture Use (mm/d) Grass 7.0 Faba beans 8.0 Silage 6.0 Hard 7.0 Soft 7.0 Canola 7.0 Flax 7.0 Peas 6.0 Barley Forage 7.0 Malt 7.0 Dry beans 6.0 Crop Water Requirements Alfalfa Crop Grass Wheat: Hard spring Soft spring Barley Canola Flax Corn: Grain Grazing Silage Peas Potatoes Dry beans Faba beans Critical Water Requirement Period All the time, especially after cutting All the time Tillering and flowering Tillering and flowering Tillering through flowering Late vegetation/spiking through flowering and pod development Flowering Tasseling and grain filling Tasseling and grain filling Tasseling and grain filling Beginning of flowering Tuber initiation and tuber bulking Late bud through pod formation Beginning of flowering 16

17 Irrigation Scheduling Click to edit Master text styles Second Know how level much water can be removed Third AD limit level Fourth Monitor level AM and calculate RAM in root Fifth zone level (usually top 60 cm) Keep AM between FC and AD limit Determine weekly crop water use Provide a scheduling recommendation 17

18 Scheduling Scenario Field Click Situation to edit Master text styles Second SL soil (top level 2 feet) Third Canola level at flowering stage Fourth Weather level is 25 0 C or higher (mid-july) Fifth Field level at 65% Field Capacity 18

19 Scheduling Scenario Text Click Book to edit Facts Master text styles Second SL soil holds level 1.68 inches/foot at FC Third Canola level at flowering uses.27 inches/day Fourth Allowable level depletion for canola is 50% of Fifth FC level Plant under stress when below 50 % of 1.68 or.84 inches/foot 19

20 Scheduling Scenario Calculations Click to edit Master text styles Second Field is at level 65% FC Third Water level below 50% FC is not readily available Fourth level 15% of total water is available Fifth 15% level x 1.68 inches/foot =.25 inches/foot 2 feet x.25 =.5 inches RAM Crop use is.27 inches/day 20

21 Scheduling Scenario Recommendation Click to edit Master text styles Second Only 2 days levelof RAM in top 2 feet Third Need level to start irrigating ASAP Fourth Apply level inches over 5-6 days to Fifth meet level crop demands 21

22 Click Assumptions: to edit Master text styles Second level Third level Fourth level What is adequately irrigated? Stored soil moisture and precipitation = 8.5 inches (cereals, oilseeds, pulses, potatoes) Stored soil moisture and precipitation = 9.5 inches (corn, perennial forages) Source: ICDC Economics and Agronomics

23 Click to edit Master text styles Second level Third level Fourth level What is adequately irrigated? Inches Applied Lentil Dry bean Peas Malt barley HRSW Barley silage Flax Feed barley Durum CPS Potato Inches Applied SWSW Grain corn Alfalfa Timothy Canola Grazing corn Pasture Silage corn Potato Potato Potato 23

24 Irrigation Operation Click Canola to can edit require Master 11 text inches stylesirrigation Second Centre pivot levelefficiency = 0.80 Third Irrigation levelapplied = 14 inches Fourth Designed level for 7 US gal/minute/acre (900 Fifth gpm) level 0.3 inches/acre/day Need to operate system 47 days to apply 14 inches 24

25 Click to edit Master Thank text you! styles Second level Third level Fourth level Questions?? 25