DSSAT - soil

 以下的資料是從soil.soil的表頭，可以觀察到的是，DSSAT把所有的土壤資料都放在同一個資料夾裡面，如果往後要做批次模擬的話，就要在這個檔案裏面增加內容。

目前測試的結果是，我們只要輸入質地、有機質含量資料，DSSAT會自動計算水利參數。

表頭有講到總體密度、lower limit (LL)- 近似萎凋點, drainage upper limit (DUL)- 近似田間容水量、SAT-飽和水分含量的估計方法所使用的paper，另外有一個質地和物理性質的對照表，頗實用的。

*SOILS: General DSSAT Soil Input File! DSSAT v4.7; 09/01/2017
!
! Standard Soil Profiles
!
! The following generic information was developed by A.J. Gijsman:
!
! - BD was estimated as BD = 100 / (SOM% / 0.224 + (100 - SOM%) / mineral BD)
!   (Adams, 1973; Rawls and Brakensiek, 1985).
! - LL and DUL are according to Saxton et al., 1986.
! - SAT was taken as a fraction of porosity (Dalgliesh and Foale, 1998):
!   0.93 for soil classes S, SL and LS; 0.95 for soil classes L, SIL, SI,
!   SCL and SC; and 0.97 for soil classes C, CL, SIC and SICL.
!   For this, porosity was estimated as: POR = 1 - BD / APD (in which APD
!   is the adjusted particle density, i.e. corrected for SOM; Baumer and Rice, 1988).
! - The ranges of LL and DUL values were calculated by stepping through the
!   complete texture triangle in steps of 1% sand, 1% silt and 1% clay (>5000
!   combinations), but with the texture limitations that Saxton set for his method
!   taken into consideration. For SAT, these limitations do not hold, as this was
!   based on POR and not on Saxton. See Gijsman et al., 2002.
! - The root growth distribution function SRGF was was calculated as:
!   SRGF = 1 * EXP(-0.02 * LAYER_CENTER); SRGF was set 1 for LAYER_BOTTOM <= 15.
!
! SOIL CLASS       BD         LL            DUL            SAT
! ========== ============= ================================
!   C     1.129 - 1.512   0.220 - 0.346   0.330 - 0.467   0.413 - 0.488
!   CL    1.243 - 1.502   0.156 - 0.218   0.282 - 0.374   0.417 - 0.512
!   L     1.245 - 1.483   0.083 - 0.156   0.222 - 0.312   0.415 - 0.501
!   LS    1.353 - 1.629   0.059 - 0.110   0.137 - 0.185   0.355 - 0.416
!   S     1.446 - 1.574   0.055 - 0.085   0.123 - 0.158   0.374 - 0.400
!   SC    1.501 - 1.593   0.195 - 0.294   0.276 - 0.389   0.376 - 0.409
!   SCL	  1.475 - 1.636   0.132 - 0.191   0.213 - 0.304   0.360 - 0.418
!   SI    0.978 - 1.464   0.096 - 0.099   0.299 - 0.307   0.442 - 0.488
!   SIC   1.307 - 1.446   0.224 - 0.326   0.379 - 0.456   0.455 - 0.489
!   SICL   1.248 - 1.464   0.155 - 0.219   0.324 - 0.392   0.448 - 0.511
!   SIL   0.968 - 1.464   0.082 - 0.152   0.240 - 0.333   0.439 - 0.547
!   SL    1.142 - 1.647   0.066 - 0.133   0.164 - 0.243   0.348 - 0.499

如果要建立新的土壤資料，點選Soil DATA的按鍵，就會進入SBuilde程式當中，首先我們可以看到，程式打開的資料夾是Soil.SOL，建立的土壤屬性資料就會記錄在這個檔案的最底端。從這裡，我們可以先聯想一下，以後建立全台灣的土壤資料庫，另存成一個資料夾即可提供使用。

點擊Profile → New 就可以建立新的土壤資料檔案