Soil Management Handbook - Ministry of Agriculture and Lands

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• Increased soil bearing strength, which improves trafficability and extends the opportunity days (when the watertable is 50 cm or more below the soil surface between 8 a.m. and 4 p.m., this gives an indication of the trafficability of the soil as well as the dryness of the potential rooting zone of the crop), by as much as 6 weeks earlier in spring and an extended harvest period. See Table 15, for an example of a fully drained versus undrained site. • Enhanced timeliness of field operations, permitting more efficient distribution of labour and machine use. • Rooting depth is increased, providing roots with a greater volume of soil from which to draw nutrients and water. • Increased aeration, providing more oxygen for plant roots. Table 15 Example Opportunity Days*Summary • Increased soil temperatures, permitting earlier germination and growth. Underdrainage is the most effective means of controlling the watertable in most cases. In modern systems, lightweight, continuous flexible, perforated plastic drain tubing is installed using highspeed drain trenchers or drain plows. Drains will work effectively in many soils without additional measures, but some special conditions require additional precautions. Porous envelopes are recommended in tight, slowly pervious soils, and sandy soils require drain filters to prevent sand from entering drain tubes and clogging them. Organic soils settle and decompose rapidly after they are drained, and the watertable should be more carefully controlled to minimize subsidence. Refer to Section 4.4, Management of Peat and Muck Soils. Drainage systems should be designed according to sound design principles and a topographic survey. Year Fully Drained Undrained 1982 84 34 1983 83 19 1984 90 4 1985 89 29 1986 90 3 1987 89 33 1988 84 17 1989 79 34 1990 76 13 1991 82 13 1992 88 24 1993 81 0 Mean 85 19 Range 76-90 0-34 * Results from: Boundary Bay Water Control Project, 8 am - 4pm watertable depth > = 50 cm midway between drains March 1 – May 31, 92 days Soil Management Handbook – Okanagan-Similkameen Valleys 57
Detailed information is provided in the publication, B.C. Agricultural Drainage Manual. 3.6 Drainage in Upland Soils Most upland soils are moderately well or well drained. However, soils that occur in depressional areas, or have compact slowly permeable layers close to the surface, are poorly to very poorly drained. Springs may also be present in upland sites, therefore, they should/could be intercepted with underdrains to remove wet spots. If the land is sloping, saturated soils will not hold additional water and surface runoff and soil erosion will occur. Uncontrolled soil erosion can bring about substantial, permanent damage to many upland soils, so that soil productivity and manageability are greatly reduced and the livelihood of the land user is threatened. Refer to Section 3.3, Soil Management for Erosion Control, for more information on erosion control in upland areas. Generally, perforated plastic drain tiles should be placed across the field contour between a 0.2/100 and 0.4/100 grade. The laterals should feed into non-perforated mainlines running down slope. A mainline grade should not exceed 5%. The mainlines should discharge into concrete or plastic junction boxes (sumps) before the water is discharged from the field. To discharge water from the junction boxes off the field, a flexible polyethylene pipe can be used. This pipe should be anchored or buried and discharge into rip rap in a stream or ditch bottom. Refer to the B. C. Agricultural Drainage Manual for more information. 3.6.1 Generalized Soil Drainage Guide This guide presents guidelines for drainage and is a supplement to the B.C. Agricultural Drainage Manual which deals with detailed design procedures. It was developed based upon many years of practical experience in the Fraser Valley. The aim is to help in the identification of drainage requirements without the need of having to go through the detailed investigations described in the Drainage Manual. The basis of this guide is a set of generalized soil profiles or soil categories which are distinctly different in regard to drainage and soil management requirements, see Table 16 (pages 60 to 61). Drainage requirements were formulated for each soil category, see Table 17 (page 62). Since the recommendations of this guide are based on average conditions and generalized soil profiles, it is possible that, on occasion, site specific conditions are at variance with those for which the guidelines were formulated. It is for this reason, that caution must be used in applying the recommendations. Only through on-site investigation, can the necessary information for completely accurate drainage recommendations be provided. 3.7 Salt Affected Soils Soils containing sufficient soluble salts to impair their productivity are considered to be either saline or sodic. The major salt constituents of saline or sodic soils are sodium, calcium, magnesium, potassium, carbonates, sulphates and chlorides. In semi-arid and arid regions, like the Okanagan, deep percolation of rain water does not occur frequently enough to leach salts. Any leaching that does occur is usually only local and a result of irrigation, so salt removal is held to a minimum. Salt movement may result in a concentration of salts in "seeps" or salt affected areas within a field particularly where shallow till or glacial lacustrine soils overlie calcareous bedrock. Salinity is usually caused by natural processes. Salts in the groundwater may become concentrated in the plow layer when water evaporates from the surface, leaving the salts behind. Salinity may also develop from the application of salty irrigation water applied to poorly drained or undrained land. Repeated applications of excessively high fertilizer rates, without crop use or leaching, can also lead to salinity. Salt affected soil are classified into three groups: E.C E.S.P pH 1. Saline >4 15 >8.5 2. Non-Saline-Alkali or sodic 15 >8.5 E.C. = Electrical Conductivity, dS/m E.S.P. = Exchangeable Sodium Percent 58 Soil Management Handbook – Okanagan-Similkameen Valleys
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Soil Management Handbook For The Ok
Page 4 and 5:
Preface The Soil Management Handboo
Page 6 and 7:
Table Of Contents Preface..........
Page 8 and 9:
Table of Contents Con't. Page 3.6 D
Page 10 and 11:
List Of Soil Management Groups And
Page 12:
List Of Tables Table1: Farm Conserv
Page 15 and 16:
To obtain information about the soi
Page 17 and 18:
List of Definitions for Table 1 Con
Page 19 and 20: Well Suited Crops • All necessary
Page 21 and 22: Soil Depth refers to the depth to e
Page 23 and 24: Grapes: grape suitability is strong
Page 25 and 26: Soil Management Groups This section
Page 27 and 28: Gammil Soil Management Group Soil S
Page 29 and 30: Greata Soil Management Group Soil S
Page 31 and 32: Kelowna Soil Management Group Soil
Page 33 and 34: Munson Soil Management Group Soil S
Page 35 and 36: Postill Soil Management Group Soil
Page 37 and 38: Rumohr Soil Management Group Soil S
Page 39 and 40: Skaha Soil Management Group Soil Se
Page 41 and 42: Summerland Soil Management Group So
Page 43 and 44: Miscellaneous Soils Soil Series: Ar
Page 45 and 46: Soil Management Guide This section
Page 47 and 48: Table 5 Soil Particle Size and Char
Page 49 and 50: Table 6 Physical Characteristics of
Page 51 and 52: plant roots and organic matter. The
Page 53 and 54: The bulk density of high organic mi
Page 55 and 56: Other management practices, such as
Page 57 and 58: Figure 11 Schematic drawing of the
Page 59 and 60: 1 m, etc., in an orchard block wher
Page 61 and 62: 3. Water Management High rainfall d
Page 63 and 64: Table 12 Availability Coefficients
Page 65 and 66: Impact of large drops of water disp
Page 67 and 68: The single most important soil fact
Page 69: land. Drainage systems are also nec
Page 73 and 74: Table 16 Generalized Soil Profile D
Page 75 and 76: Table 17 Drain Recommendations Base
Page 77 and 78: is very susceptible to structure de
Page 79 and 80: vertically into the soil and as it
Page 81 and 82: Figure 19 Schematic drawing of the
Page 83 and 84: Case 1: Well Structured Soils If th
Page 85 and 86: fracture requires the soil to expan
Page 87 and 88: "tie up" some soil nitrogen, althou
Page 89 and 90: efer to the following Factsheets: S
Page 91 and 92: contaminate groundwater. Water cont
Page 93 and 94: Table 18 N, P and K Content of Vari
Page 95 and 96: field access is possible, manure ap
Page 97 and 98: Annual or permanent cover will redu
Page 99 and 100: agricultural production, its impact
Page 101 and 102: References Published Sources Agricu
Page 103 and 104: Stevenson, D.S. and Brownlee, C.H.
Page 105 and 106: Appendix A-2 Figure 2 Typical summe
Page 107 and 108: Appendix A-4 fall frost. The angle
Page 109 and 110: Appendix A-6 Abbreviations Used in
Page 111 and 112: Appendix B: Soil Series And Locatio
Page 113 and 114: Greata Soil Management Group Greata
Page 115 and 116: Postill Soil Management Group Eanea
Page 117 and 118: Miscellaneous Soils Armstrong (A:er
Page 119: FOR FURTHER INFORMATION CONTACT B.C
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Soil Management Handbook - Ministry of Agriculture and Lands

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