**Basic Storage Period, SPb = Days**

Enter average monthly Evapotranspiration(**ET**) from OSU Extension
Publication 8530, Oregon Crop Water Use and Irrigation Requirements, and
Precipitation(**Ppt**) Data from Climatic Station-

**Crop-**

a\. Determine last day for the month of the year when 3/4 of Annual ET
is exceeded-

3/4 of Annual ET = 0.75 x = Inches

**L =** Last Day for Month Accum ET exceeds 3/4 of Annual ET

**L** = **Days**

b\. Determine first day for the month of the year when ET \>= Ppt-

**E =** First Day of Month ET \>= Ppt

**E = Days**

c\. **SPb =** 365 - ( L - E ) = 365 - ( - ) = **Days**

**Sheet 1 of 5**

**Management Factor, Fm =**

![](media/image1.emf)

**Soils Factor: Fs~LIQUID~ = Fs~SOLID~ =**

**Sheet 2 of 5**

**Location Factor, Fl =**

![](media/image2.emf)

**Nutrient Loading Factor, Fn =**

![](media/image3.emf)

**Application Method Factor: Fa~LIQUID~ = Fa~SOLID~ =**

![](media/image4.emf){width="3.2909722222222224in"
height="2.0840277777777776in"}

**Sheet 3 of 5**

**Adjusted Storage Period: ASP~LIQUID~ = Days ASP~SOLID~ = Days**

**ASP** **=** SPb X Fm X Fs X Fl X Fn X Fa

**ASP~LIQUID~ =** X X X X X

**ASP~SOLID~ =** X X X X X

Adjusted earliest Day of Year for application, **E~a~ =** ASP - (365 -
L)

**E~a\ LIQUID~ =** - (365 - ) =

**E~a\ SOLID~ =** - (365 - ) =

**Storage Period: SP~LIQUID~ = Days SP~SOLID~ = Days**

The storage period must span the seasonal flooding conditions. The
storage period must also span frozen ground and snow conditions where
the land slope exceeds 5% and a buffer strip of less than 100 feet
exists next to open water courses that affect the application area-

a\. Enter **L** from Sheet 1 and determine the Day of Year **L~f~** when
seasonal frozen ground, snow or flooding conditions are first
anticipated for the application area-

**L = Days L~f~ = Days**

If L~f~ comes before L then L~sp~ = L~f~

If L~f~ comes after L or there is no seasonal frozen ground, snow or
flooding then L~sp~ = L

**L~sp~ = Days**

b\. Determine the Day of Year **E~f~** when seasonal frozen ground, snow
or flooded conditions are no longer anticipated for the application
area-

**E~f~ = Days**

If E~f~ comes after E~a~ then E~sp~ = E~f~

If E~f~ comes before E~a~ or there is no seasonal frozen ground, snow or
flooding then E~sp~ = E~a~

**E~sp\ LIQUID~ = Days E~sp\ SOLID~ = Days**

c\. **SP~LIQUID~ =** 365 - (L~sp~ - E~sp\ LIQUID~) = 365 - ( - ) = Days

**SP~SOLID~ =** 365 - (L~sp~ - E~sp\ SOLID~) = 365 - ( - ) = Days

d\. **Earliest date(E~sp~) for manure application (month-day):**

**E~sp\ LIQUID~** **=**

**E~sp\ SOLID~** **=**

e.  **Latest date(L~sp~) for manure application (month-day) =**

**Sheet 4 of 5**

**Day of Year Calendar**

Month

Day of Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec\
month

1 1 32 60 91 121 152 182 213 244 274 305 335

2 2 33 61 92 122 153 183 214 245 275 306 336\
3 3 34 62 93 123 154 184 215 246 276 307 337\
4 4 35 63 94 124 155 185 216 247 277 308 338\
5 5 36 64 95 125 156 186 217 248 278 309 339

6 6 37 65 96 126 157 187 218 249 279 310 340\
7 7 38 66 97 127 158 188 219 250 280 311 341\
8 8 39 67 98 128 159 189 220 251 281 312 342\
9 9 40 68 99 129 160 190 221 252 282 313 343\
10 10 41 69 100 130 161 191 222 253 283 314 344

11 11 42 70 101 131 162 192 223 254 284 315 345\
12 12 43 71 102 132 163 193 224 255 285 316 346\
13 13 44 72 103 133 164 194 225 256 286 317 347\
14 14 45 73 104 134 165 195 226 257 287 318 348\
15 15 46 74 105 135 166 196 227 258 288 319 349

16 16 47 75 106 136 167 197 228 259 289 320 350

17 17 48 76 107 137 168 198 229 260 290 321 351\
18 18 49 77 108 138 169 199 230 261 291 322 352\
19 19 50 78 109 139 170 200 231 262 292 323 353\
20 20 51 79 110 140 171 201 232 263 293 324 354

21 21 52 80 111 141 172 202 233 264 294 325 355

22 22 53 81 112 142 173 203 234 265 295 326 356\
23 23 54 82 113 143 174 204 235 266 296 327 357\
24 24 55 83 114 144 175 205 236 267 297 328 358\
25 25 56 84 115 145 176 206 237 268 298 329 359

26 26 57 85 116 146 177 207 238 269 299 330 360

27 27 58 86 117 147 178 208 239 270 300 331 361\
28 28 59 87 118 148 179 209 240 271 301 332 362\
29 29 88 119 149 180 210 241 272 302 333 363\
30 30 89 120 150 181 211 242 273 303 334 364

31 31 90 151 212 243 304 365

**Sheet 5 of 5**