OPTIMUM WATER TABLE DEPTH FOR ACRA-Part 5 (2)
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Transcript of OPTIMUM WATER TABLE DEPTH FOR ACRA-Part 5 (2)
OPTIMUM WATER TABLE DEPTH FOR ACRA:
PART 5: WATER TABLE DEPTH AND MVOL INVENTORY 2.0 YRS-R3
IN PEATLAND USING TPK 6-PAR AND REVISED PIMS’s DATA
By Dedi K. Kalsim and Dwinata Aprialdi
Workshop Nasional Kebijakan dan Tata Kelola Lahan Gambut di Indonesia, KLHK dan Wetlands International
Hotel Mirah, Bogor 27 May 2015
1 D.K. KALSIM and DWINATA APRIALDI
DRAINAGE DESIGN CRITERIA
WATER LEVEL SHOULD BE DESIGNED AS HIGH AS POSSIBLE
BUT AS LOW AS REQUIRED BY THE CROP
D.K. KALSIM and DWINATA APRIALDI 2
OBJECTIVE-METHODOLOGY • OBJECTIVE
– To study How is the relationship between MVOL and WT for ACRA
• METHODOLOGY – There are 45 compartments data of weekly WT and MVOL
2 yrs R-3
– The wt depths are classified into: • (0) wt < 0 or flooding, (1) wt 0-40 cm, (2) wt 40-70 cm, (3) wt 70-
90 cm, (4) wt 90-110 cm, and (5) wt>110 cm.
– The frequency relative of occurrence each wt class was calculated for each compartment.
– The SPSS-19 is used to analyze
3 D.K. KALSIM and DWINATA APRIALDI
RESULTS AND DISCUSSION
• The model linear is MVOL = 7.821 + 59.418 (wt>110) + 55.885 (wt90-110) + 44.737 (wt70-90) + 40.062 (wt40-70) – 152.297 (wt0-40) – 387.142 (wt<0), R2=0.482
• It means 48% of variance can be described by the model, but 52% can not be described and could be influenced by other factors than WT depth.
4 D.K. KALSIM and DWINATA APRIALDI
MVOL COMPUTED-DATA
5
y = 0.4515x + 25.245 R = 0.4709
20,00
25,00
30,00
35,00
40,00
45,00
50,00
55,00
60,00
65,00
20,00 30,00 40,00 50,00 60,00 70,00 80,00 90,00
Dat
a (m
3/h
a)
Computed (m3/ha)
MVol Data - Computed
mvol Linear (mvol)D.K. KALSIM and DWINATA APRIALDI
D.K. KALSIM and DWINATA APRIALDI 6
WT VS YIELD IN THE WORLD
Sugarcane vs WT and number of days WT<0.5 m, in Queensland, Australia (Rudd and Chardon, 1977)
Winter wheat vs average WT in heavy clay soils 5 yrs observation (FDEU, Min. Agr., UK)
Relative yields (%) of crops with different depth of WT in a muck soil (Harris et.al. 1962. Soil Science, 94 pp 158-161)
Crop Number of
years
Depth of WT (m)
0.4 0.6 0.8 1.0
Potatoes 12 46 94 97 100
Onion 11 63 109 113 100
Sweet corn 4 61 100 92 100
Carrots 4 59 93 96 100
Average 57 99 99.5 100
D.K. KALSIM and DWINATA APRIALDI 7
0
20
40
60
80
100
120
0,2 0,4 0,6 0,8 1 1,2
Re
lati
ve Y
ield
(%
)
Average WT depth (m)
Relative Yield (%) vs WT depth
YIELD (t/ha)
RESULTS AND DISCUSSION
• Increasing frequency of wt>110 up to 0.40, will increase the MVOL from 40 to 62 m3/ha (Fig 1, R=0.354).
8 D.K. KALSIM and DWINATA APRIALDI
• Increasing frequency of wt90-110 up to 0.50, will increase the MVOL from 37 to 68 m3/ha (Fig 2, R=0.511).
RESULTS AND DISCUSSION
9 D.K. KALSIM and DWINATA APRIALDI
• Increasing frequency of wt70-90 up to 0.60, will increase the MVOL from 37 to 52 m3/ha (Fig 3, R=0.249).
RESULTS AND DISCUSSION
10 D.K. KALSIM and DWINATA APRIALDI
• Increasing frequency of wt40-70 up to 0.90, will decrease the MVOL from 58 to 32 m3/ha (Fig 4, R=0.464).
RESULTS AND DISCUSSION
11 D.K. KALSIM and DWINATA APRIALDI
• Increasing frequency of wt0-40 up to 0.11, will decrease the MVOL from 50 to 28 m3/ha (Fig 5, R=0.330).
RESULTS AND DISCUSSION
12 D.K. KALSIM and DWINATA APRIALDI
• Increasing frequency of wt<0 (flooding) up to 0.03, will decrease the MVOL from 50 to 35 m3/ha (Fig 6, R=0.446).
RESULTS AND DISCUSSION
13 D.K. KALSIM and DWINATA APRIALDI
CONCLUSIONS • The optimum water table is 90-110 cm, MVOL 2
yr R3 ± 68 m3/ha. RAPP proposed 60-80 cm (± 52 m3/ha)
• WT 0-40 with frequency 0.11 and wt<0 (flooding) with frequency 0.03, the MVOL 2 yr R3 ± 25 m3/ha – Reduce 63% - 48%
• Increasing WT 0-40 frequency (>0.11) will be more reducing MVOL
• Flooding more than 6 weeks resulting mortality >70% (Bakung-Langgam)
14 D.K. KALSIM and DWINATA APRIALDI