5.8: System Characteristics
- Page ID
- 44405
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Characteristics of irrigation systems are listed in Table 5.4. The values listed in this guide are average quantities for the respective systems. The table is useful in the preliminary stages of developing and managing irrigation systems. The actual value of the various parameters can vary considerably depending on both design and management.
There has been much written and said about the selection of irrigation systems to fit specific properties of a site. Some factors affecting the selection of a water application method are listed in Table 5.5. The reader should consider these criteria to be general. Since this text deals with managing irrigation systems, it is important to operate the system as efficiently as possible. The practitioner will find that many systems have been installed and operated quite economically even though they do not conform to traditionally defined limits on the irrigation method. An Irrigation Consumer Bill of RightsTM has been developed which provides several questions to ask when discussing the selection of an irrigation system with a dealer (ITRC, 2019).
| System Type | Maximum Slope (%) | Pressure Required (psi) | Labor Required (hr/ac/irrig) | ELQ (%) | Nominal Application Depth (in) |
|---|---|---|---|---|---|
| Surface | |||||
| Furrow gated pipe without reuse | 2 | 0.5–10 | 0.5–1.0 | 40–70 | 2.0–6.0 |
| Furrow gated pipe with reuse | 2 | 0.5–10 | 1.0–1.5 | 60–85 | 2.0–6.0 |
| Furrow siphon tube | 2 | 0 | 0.2–1.0 | 35–65 | 2.0–6.0 |
| Graded border | 2–4 | 0–10 | 0.05–0.5 | 50–85 | 1.5–6.0 |
| Level basin | 0 | 0–10 | 0.05–0.5 | 70–85 | 1.5–6.0 |
| Sprinkler: | |||||
| Hand move | 20 | 50–70 | 0.5–1.5 | 60–80 | 1.0–6.0 |
| Solid-set | No limit | 50–70 | 0.05–0.1 | 60–85 | 0.5–4.0 |
| Side roll & towline | 10 | 50–70 | 0.1–0.3 | 60–80 | 1.0–6.0 |
| Boom | 5 | 60–80 | 0.2–0.5 | 55–75 | 1.5–4.0 |
| Traveler | 5–15 | 70–100 | 0.1–0.3 | 55–75 | 0.25–2.0 |
| Center pivot | 10–20 | 20–70 | 0.05–0.15 | 75–90 | 0.25–2.0 |
| Pivot with corner system | 10–20 | 30–70 | 0.05–0.2 | 70–85 | 0.25–2.0 |
| Linear move | 5–8 | 20–50 | 0.1–0.3 | 75–90 | 0.2–2.5 |
| Micro, drip, trickle: | |||||
| Point source | No limit | 20–50 | 0.05–0.2 | 70–90 | small |
| Lateral (continuous) source | No limit | 20–50 | 0.05–0.2 | 70–90 | small |
| Water Application Method |
Factors Affecting Selection Land Slope |
Factors Affecting Selection Water Intake Rate of Soil |
Factors Affecting Selection Water Tolerance of Crop |
Factors Affecting Selection Wind Action |
|---|---|---|---|---|
| Sprinkler | Adaptable to both level and sloping ground surfaces. | Adaptable to any soil intake rate. | Adaptable to most crops. Typical systems may promote fungi and disease on foliage and fruit. | Wind may affect application efficiency and uniformity. |
| Surface | Land area must be leveled or graded to slopes less than 2% for most systems. It issometimes possible to flood steeper slopes that are sodded. | Not recommended for soils with high intake rates of more than 2.5 in/hr or with extremely low intake rates such as peats or mucks. | Adaptable to most crops. May be harmful to root crops and to plants which cannot tolerate water standing on roots. | No effects. |
| Trickle/drip micro | Adaptable to all land slopes. | Adaptable to any soil intake rate. | No problems. | No effects. |
| Subsurface drip irrigation | Adaptable to all land slopes. | Best adapted to medium and fine-textured soils with moderate to good capillary movement. | Adaptable to most crops. Saline water tables limit application | No effects. |
| Below surface subirrigation | Land area must be level or contoured. | Adaptable only to soils which have an impervious layer below the root zone, or a high, controllable water table. | Adaptable to most crops. Saline water tables limit application | No effects. |