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THE AGRICULTURAL MODEL INTER-COMPARISON AND IMPROVEMENT PROJECT (AGMIP) END OF PROJECT REPORT TENYWA MOSES MAKERERE UNIVERSITY

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Page 1: THE AGRICULTURAL MODEL INTER-COMPARISON … · THE AGRICULTURAL MODEL INTER-COMPARISON AND IMPROVEMENT PROJECT (AGMIP) ... Uganda, located in eastern ... Biofuels currently account

THE AGRICULTURAL MODEL INTER-COMPARISON AND IMPROVEMENT PROJECT (AGMIP)

END OF PROJECT REPORT

TENYWA MOSES

MAKERERE UNIVERSITY

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1. Introduction

Uganda, located in eastern Africa has a population of 32.3 million people and one of the highest

population growth rates in the world at 3.56% per annum (UNDP, 2010). With 199,807.4 Sq.km

land area (accounting for 82.7% of all surface area) Uganda relies on its agricultural sector

contributing 23.2% of the GDP, and supporting more than 70% of the population for their

livelihood. Uganda’s industrial sector is composed mainly of food processing engaging up to

65% of total employment. The agricultural sector is supported by vast fertile soils suitable for

production of a range of food crops including banana, maize, beans, cassava, millet, rice, wheat,

fresh vegetables and pulses. Coffee, tea and tobacco are her main cash crops. Ugandans keep

animals (especially cows, goats and sheep) and crops (both cash and food crops) on vast soils

largely regarded as ‘fertile’. Farmers are grouped into three major categories: Subsistence

farmers (70%); Semi commercial farmers (25%) and Commercial farmers (5%) (AGRA, 2010).

The agricultural sector is also sustained by the diverse climate patterns and the influence of

several large rivers, bodies of water, and mountain ranges to the east and west.

Uganda, like many other countries in SSA is continuing to record very low levels of farm

productivity. Available evidence indicates that farm level yields are several times lower than at

agricultural research stations for similar crops. Farmers achieve between thirteen and thirty %

attainable yield at research stations (MAAIF, 1996). This gap is likely to be widened by climate

change and variability, if proper climate change adaptation practices are not put in place.

Furthermore, the use of some agricultural land for bio-fuel production, which is projected to

double in the next decade, is likely to reduce further the agricultural production and therefore

contribute to food insecurity. Biofuels are estimated to reduce greenhouse gas emissions by 10–

90 % relative to fossil fuels, depending on the type of feedstock and production technology.

Biofuels currently account for 0.2 % of total global energy consumption, 1.5 % of total road

transport fuels, 2 percent of global cropland, 7 percent of global coarse grain use and 9 percent of

global vegetable oil use. The increase in bio-fuel use has been driven largely by policy support

measures in the developed countries, seeking to mitigate climate change, enhance energy

security, and support the agricultural sector.

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2. Methodology

2.1 Study area description

In Uganda, the study was conducted in two districts located in the Albertine region, namely

Hoima and Masindi, that straddle the Lake Albert bordering Uganda and DRC (Fig.1). The two

districts are located in the western Mid-Altitude Farmlands and Semliki Flats (MAFSF) Agro-

ecological zone (Wortmann and Eledu, 1992). Hoima district is located between 1° 00'-2° 00' N

and 30° 30'-31°45' E. It is bordered by Lake Albert in the west, Bundibugyo and Kibaale in the

south, Masindi in the northeast and Kiboga in the east. The district lies within an altitude range

of 621 m and 1,158 m above sea level, making it one of the lowest and hottest areas in the

country. It has an area of 5,932 sq km (Table 1), of which 2,268.6 sq km is occupied by water

bodies (mostly Lake Albert) and 712.3 sq km is forest. Masindi District is located next Hoima in

the Western Region of Uganda between 1o

22'-2o

20' N and 31o

22'-32o

23' E. It borders Gulu in

the north, Apac in the east, Nakasongola in the southeast, Kiboga in the south, Hoima in the

southwest and the Democratic Republic of Congo in the west. Both district lies at an altitude

range of 621m to 1,158m above sea level (Table 2). It comprises a total area of 9,326 sq km, of

which 8,087 sq km is land, 2,843 sq km wildlife-protected area, 1,031 sq km forest reserves, and

799.6 sq km water (Table 1).

Fig. 1. Map showing target areas AGMIP project in Hoima and Masindi in Uganda.

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Table 1: Land use and area coverage in the districts of Hoima and Masindi

Particulars Land size (sq km)

Hoima Masindi

Total area 5,932.80 9,326.90

Broad leaved plantation 0.5 2.8

Conifers 4.3 1.1

Fully stocked forests 484.4 509.7

Degraded forests 267 20

Woodland 848.9 3,934.20

Bush land 86 267.30

Grassland 715.60 2,014.60

Swamp 58.20 130.40

Subsistence farmland 1,183.20 1,645.10

Large-scale farmland 12.90 108.90

Built up area 3.40 9.4

Open water 2,268.70 799.6

Open water (% of total district area) 38.24 8.46

Impediments (rocks) 0 0.1

Source: SCRIP (IFPRI, Kampala) for PRIME-WEST

The average annual rainfall in Hoima and Masindi ranges between 700-1,000 and 800-1630 mm,

respectively with a bi-modal distribution and peaks in March-May and August-November.

Table 2: Altitude and climate in the studied Agro-ecological zone of Uganda

Agro-ecology District Altitude (m) Mean

Temperature

(0C)

Annual Rainfall (mm)

Mid-Altitude Farmlands

and Semliki Flats

(MAFSF)

Masindi 621-1158 22.7-24.2 800-1630

Hoima 621-1158 23.4-25.6 700 -1000

Majority of the people in the region are smallholder farmers. The dominant farming systems in

the region are the western banana coffee cattle system and banana millet cotton system (Osiru,

2006). Major crops in the region under large-scale farming are maize, tea, sugarcane, while

small-scale farming includes beans, ground-nuts, rice, sweet potatoes, cassava, millet, pigeon

peas, banana, and simsim (Mubiru et al., 2007). However, the productivity of most smallholder

farms vary from high to low potential and depends on soil type and management. Most of the

farmers rarely use the inorganic fertilizer and a few apply organic manure.

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Table 3: Characteristics of smallholder farms in the studied agro-ecological zone of Uganda

(AGMIP survey, 2012)

District Mean

Household

size

Mean

Fertilizer use

(kg N/ha)

Dominant maize

variety

Average

maize yields

(kg/ha)

Hoima 7 0 kg ha-1

Local (traditional) 1521

Longe 5 1725

Longe 9 1917

Masindi 6 0 kg ha-1

Local (traditional) 1478

Longe 5 1769

Longe 9 2128

2.2. Soils of the study area

The dominant soils in the region include Hoima catena (Petric Plinthosols), Naitondo series

(Dystric Regosols), and Kigumba series (Acric Ferralsol). The distribution of the three soils in

the districts of Hoima and Masindi is given in Figure 2. The productivity of these soils are

believed to be lowest in with Hoima catena, medium for Kigumba and highest for Naitondo.

Figure 2: Distribution of soils in Hoima and Masindi districts

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The Hoima catena (a low productive soil unit) covers a large part of south-west Bunyoro

overlying the sedimentary beds predominated by tillites and phyllites with subsidiary counts of

sandstones and conglomerates as basal members (Table 4a). The soils are usually very acid, poor

in bases and available phosphorus and with lower amounts of organic material than their dark

colour would suggest.

Table 4a: Hoima profile of Petric Plinthisols (Low productivity)

Depth (cm) Silt

(%)

Clay

(%)

Ca

(m.e/100g

soil)

Mg

(m.e/100g

soil)

K

(m.e/100g

soil)

Na

(m.e/100g

soil)

Mn

(m.e/100g

soil)

Total

bases

(m.e/100g

soil)

Exch

H

(m.e

%)

CEC

(m.e)

% BS pH OC (%) Truog

P205

(ppm)

20 8 35 1.4 1 0.16 0 0.11 2.67 8.2 10.87 24.6 4.9 1.46 2

50.8 5 5 0.8 0.6 Tr. 0 0 1.4 9.7 11.1 14.4 5.1 0.59 2

Critical

values

5.2 0.5 0.22 <1.0 5.5 1.75

0.14%N in top 0-20 cm, C/N = 10.8 with low P205 and bases

The Dystric Regosols are believed to be a variant of the Hoima catena overlying the valley

slopes with deeper accumulation of soil material giving rise to reddish-brown clay loams. It

occurs at lower altitude. Magnesium and potassium contents are rather variable and calcium

seldom shows a deficiency. Soil reaction throughout is very acid which appears to be a fairly

constant feature of these phyllite soils even when bases are present in adequate amounts (Table

4b). Crop growth is poor on the shallow acid members of this catena and intensive cultivation is

confined mainly to the deeper soils on the valley slopes (Soil Memoirs, 1960).

Table4b: Naitondo Profile of Dystric Regosols of High Productivity

Depth (cm) Silt

(%)

Clay

(%)

Ca (m.e/100g

soil)

Mg

(m.e/100g

soil)

K (m.e/100g

soil)

Na (m.e/100g

soil)

Mn

(m.e/100g

soil)

Total bases

(m.e/100g

soil)

Exch

H (m.e

%)

CEC

(m.e)

% BS pH OC

(%)

Truog

p205

(ppm)

20 10 23 1.8 2.4 0.14 0 0.19 4.53 10.6 15.13 15.1 5.4 2.69 21

43 20 33 0.8 0.3 0.16 0 0.86 10 10.86 7.9 4.8 0.98 12

81 14 39 1 0.3 0.14 0 1.14 7.9 9.04 12.6 4.8 0.91 7

117 14 43 1.6 0.3 0.15 0 0.13 1.88 9 10.88 17.3 4.7 0.41 8

173 18 35 2 0 0 0 0 2 7.6 na na 4.8 0.31 6

203 20 23 0.4 0.3 0.13 0 0.02 0.15 5.5 5.65 2.7 4.9 0.05 7

Critical

values

5.2 0.5 <1.0 5.5 1.75

0.26%N for top 0-20 cm C/N 10.5 with high Mn & acidity as well

The Acric Ferralsols (Kigumba series) are reddish-brown loams to clay loams. This soil lies with

topography that appears as broad flat-topped or very slightly convex ridges separated by wide

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swamp tracts. The pH values are fairly steady around 5.0, bases are low, deficient in magnesium

and the amounts reduce with depth (Soil Memoirs, 1960).

Table 4c: Kigumba profile under Acric Ferralsols of medium productivity

Depth (cm) Silt

(%)

Clay

(%)

Ca

(m.e/100g

soil)

Mg

(m.e/100g

soil)

K

(m.e/100g

soil)

Na

(m.e/100g

soil)

Mn

(m.e/100g

soil)

Total

bases

(m.e/100g

soil)

Exch

H

(m.e

%)

CEC

(m.e)

% BS pH OC

(%)

Truog

P205

(ppm)

13 6 26 2.7 0.8 1.27 0 0.03 4.8 7.4 12.2 39.4 5.1 2.78 29

46 4 40 0.6 0.3 0.63 0 0.1 1.33 8.3 9.63 13.8 4.8 0.92 2

84 8 42 1.3 0.3 0 0.3 0.12 2.02 5.6 7.62 25.5 5 0.51 5

122 8 42 1.1 0.4 0 0.5 0.08 2.08 4.3 6.38 32.6 5.3 0.35 7

152 4 38 1.1 0.3 0 0.5 0.03 1.63 4.2 5.83 28 5 0.22 7

183 4 42 1.1 0.7 0.08 1.1 0.02 3 4.5 7.5 40 4.9 0.2 12

213 4 32 0.4 0.3 0 +1 0.01 1 5.3 6.8 15.9 4.6 0.32 8

Critical

values

5.2 0.5 0.22 <1.0 5.5 1.75

0.14%N in top 0-13 cm, C/N 19.8 low P2O5 & bases

2.3 Data and methods of assessment

The assessment used soil conditions that are homogeneous with regard to their capacity to support

production of a wide range of food and cash crops as the unit for evaluating the impacts of climate

variability and change. Relevant data required to calibrate, validate and apply climate, crop and

economic models was collected publications (Kaizzi et al., 2004), East African Seed, Soroti Catholic

Diocese Integrated Development Organisation (SOCADIDO), and Sango Bay maize farm. In addition, a

survey was carried out in all the target regions to characterize the smallholder farming systems (farms

enterprises, management, productivity, sources of non-farm income). Table 5 shows the number of

households surveyed per district.

Table 5: Sampled households in each AEZ

Country AEZ District Number of HHs

Uganda MAFSF Hoima 76

Masindi 231

2.3.1 Climate Data and Scenarios in Uganda

Long-term daily observed historical climate data (1980-2010) was obtained from the Department of

Meteorology in Uganda for Masindi district. For Hoima district (Kyangwali), the NASA’s Modern Era-

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Retrospective Analysis for Research and Applications (MERRA) (Rienecker et al., 2011) was

applied. MERRA is the NASA’s climate model data repository. MERRA data are produce using

their 4-Dimensional Variational (4D-Var) assimilation system and were provided in AgMIP

extension (Ruane and Goldberg, in preparation). MERRA data were used to fill temperature gaps

for Masindi and its rainfall data from Kyangwali was adjusted using ten year data obtained from

Bulindi weather station. The period 1980-2009 was considered as reference period because of the

availability of complete MERRA climate data sets. The data collected include rainfall, minimum

and maximum temperature, wind, relative humidity and solar radiation. This information was

used to characterize the variability in the observed climate, develop future scenarios and also for

use in DSSAT and APSIM crop simulation models. The minimum data set required for this

analysis included daily records of rainfall, minimum and maximum air temperatures and solar

radiation.

In order to assess the climate change scenarios, we used a significance test (Δs), that is the delta

method. The delta method was used to downscale the different projected climate scenarios for

both Masindi and Hoima districts.

2.3.2 Household survey -sampling scheme

The number of households surveyed in three different soil units were 87 for Hoima catena, 98 for

Kigumba series, and 122 for Naitondo. The summary statistics from the household survey were

compiled. The variables generated included: yield, planting dates, planting density, harvesting

dates, soil type, moisture levels, soil fertility, fertilizer application rates, manure application

rates, maize variety, plot area, days to harvesting, seeding rate and yield. These variables were

provided for each of the 308 farm households interviewed for the survey for five crops of

interest: Maize, Beans, Cassava, Groundnuts and Banana. Two observations were excluded due

to incomplete information on all variables. Labour costs were computed using labour

requirement for men, women and children involved in various activities. Family labor was

excluded from the computation of variable labor costs. All monetary values were converted to

US dollars using the prevailing exchange rate. Below are summary statistics (means, standard

deviations and coefficients of variation) of prices, yield, acreage, total variable costs and net

returns from the 5 enterprises (Table 6).

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Table 6: Summary statistics: Prices, output, area and yield of crops – Survey Data Measure Maize Beans Groundnuts Cassava Banana

Prices Shs/Kg 492.8 1152.978 1404.2 607.17 306.94

$/kg (1$=2500) 0.197 0.46 0.56 0.24 0.12

Standard Dev 172.34 423.54 603.73 321.86 149.71

Coefficient of Variation 34.97 36.73 42.99 53.01 48.78

Area Mean (ha) 0.63 0.34 0.35 0.41 0.07

Standard dev 0.37 0.11 0.09 0.13 0.075

Coefficient of Variation 57.83 32.79 23.95 30.57 107.11

Yield Mean (Kg/Ha) 1,892.64 1,266.74 755.39 1,516.90 5,030. 6

Standard dev 3,268.59 6,231.54 785.43 2,349.39 7,989.9

Coefficient of Variation 172.70 491.94 103.98 154.88 158.83

TVC Mean ($/farm) 94.67 82.21 75.25 402.13 78.59

Standard dev 140.86 111.79 110.22 1377.40 322.50

Coefficient of Variation 148.79 135.98 146.47 342.52 410.38

Net returns Mean 429.98 316.11 259.35 50.43 100.64

Standard dev 867.25 1329.20 269.66 480.86 264.49

Coefficient of Variation 201.70 420.48 103.98 953.47 262.80

As shown by the high values of coefficient of variation in Table 1 above, variability in these

variables was high due to a number of reasons: seasonality, subsistence production and poor

information flow. First, agricultural prices in the study area and in Uganda in general tend to

depress during the peak season (bumper harvest) and rise during the off peak season. Farmers’

level of knowledge regarding prices and whether the farmer participates in the market either as a

buyer or as a seller affects prices. In most rural areas of the country, farmers hardly participate in

the market. In other words, most farmers carry out subsistence production hence because no

participation in the market they may not have a true picture of what is prevailing in the market.

Hence the high variability may be due the few farmers who know exactly what is prevailing in

the market and the majority of the farmers who do not what may be prevailing in the market. The

situation is further compounded by market imperfections in the rural areas; because the

equilibrium price between the farmer and the trader is largely dependent on each other’s level of

knowledge regarding the market situation. Variability in output per farm is brought about by

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some farmers adopting/using improved technologies which are yield enhancing resulting into

high yields compared to other farmers who were using traditional technologies which are less

rewarding hence low yields. The high variability in yield is also attributed to seasonality in

agricultural production and weather conditions. Very good climatic conditions lead to good

production whereas poor climatic conditions lead to poor yields.

Data handling involved annualizing seasonal yields, costs, revenues and returns. The raw data

was plotted into graphs to check for outliers and extreme values were replaced with the stratum

means.

2.3.3 Crop and soil Data calibration

Two crops models that is DSSAT and APSIM, were used to simulate the likely impact of climate

change on maize yield as depicted by the twenty GCMs downscaled in the study area for the

different projected climate scenarios. The two crop models were calibrated using data from

previous experimental research conducted in Uganda (Kaizzi et al., 2012). During the survey,

information on soil and crop management including varieties, inorganic fertilizer inputs, planting

windows/date, number of plants per hectare, days to maturity, amount of manure were collected.

In addition, each household farm was geo-referenced and the coordinates over-laid on soil maps

of the study area to extract information on type of soil. The number of households surveyed in

the three soil units were 87 for Hoima catena (Petric Plinthic), 98 for Kigumba series (Acric

Ferralsol), and 122 for Naitondo (dystric Regosols). In each soil unit, household farms were

categorised into good, medium, poor fertility based on farmers’ perceived historical land use

productivity. All soil profile data were obtained from the Uganda soil memoirs (Table 4a, 4b,

4c). For the model runs, each soil type in the agro-ecological zone was categorised into three

levels, that is, low, medium and high productive soil types based on total soil organic carbon

content (Table 7).

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Table 7. Soil profile characteristics used in DSSAT and APSIM crop models in Uganda

Soil

layer

base

depth

Lower limit Drained

upper limit

Saturation Bulk

density

Organic C Clay Silt Coarse

fraction

(stones)

pH Cation

exchange

capacity

Sat. hydraulic

conductivity,

macropore,

cm mm3/mm3 mm3/mm3 mm3/mm3 g/cm3 g[C]/100g % % % cmol/kg cm h-1

Petro Plinthic Good 15 0.155 0.366 0.512 1.290 2.770 23.00 8.00 0.00 5.50 3.50 0.10

35 0.172 0.370 0.496 1.330 1.530 29.00 10.00 0.00 5.60 3.50 0.18

70 0.205 0.400 0.503 1.320 1.100 37.00 8.00 0.00 4.40 3.50 0.13

101 0.232 0.423 0.585 1.360 0.460 43.00 4.00 0.00 4.60 3.70 0.10

Medium 15 0.153 0.359 0.502 1.320 2.355 23.00 8.00 0.00 5.50 3.50 0.10

35 0.171 0.368 0.491 1.350 1.301 29.00 10.00 0.00 5.60 3.50 0.18

70 0.204 0.399 0.598 1.330 0.935 37.00 8.00 0.00 4.40 3.50 0.13

101 0.232 0.423 0.596 1.340 0.391 43.00 4.00 0.00 4.60 3.70 0.10

Poor 15 0.150 0.351 0.490 1.350 1.939 23.00 8.00 0.00 5.50 3.50 0.10

35 0.170 0.365 0.486 1.360 1.071 29.00 10.00 0.00 5.60 3.50 0.18

70 0.204 0.398 0.593 1.340 0.770 37.00 8.00 0.00 4.40 3.50 0.13

101 0.232 0.423 0.593 1.340 0.322 43.00 4.00 0.00 4.60 3.70 0.10

Dystric regosols Good 15 0.160 0.406 0.561 1.160 3.228 23.00 10.00 0.00 5.40 15.13 0.10

43 0.189 0.408 0.524 1.260 1.176 33.00 20.00 0.00 4.80 10.86 0.18

81 0.216 0.425 0.530 1.250 1.092 39.00 14.00 0.00 4.80 9.04 0.13

117 0.235 0.444 0.613 1.290 0.492 43.00 14.00 0.00 4.70 10.88 0.10

173 0.195 0.403 0.593 1.340 0.372 35.00 18.00 0.00 4.80 5.65 0.10

203 0.138 0.335 0.448 1.460 0.060 23.00 20.00 0.00 4.90 5.65 0.18

Medium 15 0.164 0.399 0.553 1.190 2.690 23.00 10.00 0.00 5.40 15.13 0.13

43 0.188 0.405 0.515 1.290 0.980 33.00 20.00 0.00 4.80 10.86 0.10

81 0.216 0.424 0.525 1.260 0.910 39.00 14.00 0.00 4.80 9.04 0.10

117 0.235 0.444 0.610 1.200 0.410 43.00 14.00 0.00 4.70 10.88 0.18

173 0.194 0.403 0.591 1.350 0.310 35.00 18.00 0.00 4.80 5.65 0.13

203 0.138 0.335 0.448 1.450 0.050 23.00 20.00 0.00 4.90 5.65 0.10

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Poor 15 0.159 0.384 0.534 1.230 2.152 23.00 10.00 0.00 5.40 15.13 0.10

43 0.187 0.403 0.510 1.300 0.784 33.00 20.00 0.00 4.80 10.86 0.18

81 0.215 0.422 0.616 1.280 0.728 39.00 14.00 0.00 4.80 9.04 0.13

117 0.235 0.444 0.605 1.310 0.328 43.00 14.00 0.00 4.70 10.88 0.10

173 0.194 0.402 0.588 1.360 0.248 35.00 18.00 0.00 4.80 5.65 0.10

203 0.138 0.335 0.448 1.460 0.040 23.00 20.00 0.00 4.90 5.65 0.18

Acric Ferralsol Good 13 0.175 0.405 0.564 1.150 3.336 26.00 6.00 0.00 5.10 12.20 0.13

46 0.219 0.411 0.525 1.260 1.104 40.00 4.00 0.00 4.80 9.63 0.10

84 0.229 0.427 0.613 1.290 0.612 42.00 8.00 0.00 5.00 7.62 0.10

122 0.228 0.426 0.604 1.310 0.420 42.00 8.00 0.00 5.30 6.38 0.18

152 0.208 0.396 0.587 1.360 0.264 38.00 4.00 0.00 5.00 5.83 0.13

183 0.181 0.364 0.471 1.400 0.240 32.00 4.00 0.00 4.80 7.50 0.10

213 0.182 0.367 0.479 1.380 0.384 32.00 4.00 0.00 4.60 6.30 0.10

Medium 13 0.175 0.402 0.561 1.160 2.780 26.00 6.00 0.00 5.10 12.20 0.18

46 0.219 0.410 0.518 1.280 0.920 40.00 4.00 0.00 4.80 9.63 0.13

84 0.228 0.426 0.609 1.300 0.510 42.00 8.00 0.00 5.00 7.62 0.10

122 0.228 0.426 0.601 1.320 0.350 42.00 8.00 0.00 5.30 6.38 0.10

152 0.208 0.395 0.585 1.370 0.220 38.00 4.00 0.00 5.00 5.83 0.18

183 0.181 0.363 0.468 1.410 0.200 32.00 4.00 0.00 4.80 7.50 0.13

213 0.182 0.366 0.476 1.390 0.320 32.00 4.00 0.00 4.60 6.30 0.10

Poor 13 0.171 0.388 0.543 1.210 2.240 26.00 6.00 0.00 5.10 12.20 0.10

46 0.218 0.409 0.511 1.290 0.736 40.00 4.00 0.00 4.80 9.63 0.18

84 0.228 0.426 0.604 1.310 0.408 42.00 8.00 0.00 5.00 7.62 0.13

122 0.228 0.425 0.599 1.330 0.280 42.00 8.00 0.00 5.30 6.38 0.10

152 0.208 0.395 0.582 1.370 0.176 38.00 4.00 0.00 5.00 5.83 0.10

183 0.181 0.363 0.468 1.410 0.160 32.00 4.00 0.00 4.80 7.50 0.15

213 0.181 0.363 0.470 1.410 0.256 32.00 4.00 0.00 4.60 6.30 0.16

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Soil parameters such as hydraulic conductivity, Drainage Upper Limit (DUL) and Lower Limit

(DLL), air dry, saturation, bulk density were estimated using soil water characteristics Program

(Rawls et al., 1982) based on soil texture, soil organic carbon content, gravel content, salinity

and compaction. The soil profile depth in the models was arranged to a fixed depth per layer

(Table 7). In APSIM, values of soil organic carbon pools (Fbiom, Finert, HumC, BiomC,

InertC) as described in the model were dependant on SOC. In DSSAT, initial soil conditions of

stable SOC were set at 44%. The C/N ratio in both models was derived by calculation.

In DSSAT, site descriptions such as slope per cent, run-off curve numbers, drainage rate, run-off

potential, and soil fertility factor were estimated based on available literature (Soil memoirs). All

root growth factors were set at 1.0 as non-limiting in all soil profiles.

2.3.4 Crop management based on on-farm surveys

Crop management parameters used in setting up simulations for individual farms were derived

from the results of the survey conducted in Hoima and Masindi districts. Parameters used in

setting up on-farm simulations were derived from data collected in the survey. Varieties that are

most dominant in the region are local traditional, longe 5, and longe 9. Detailed Information on

Longe 5 and Longe 9 varieties was obtained from NASECO seeds. For the local traditional

variety, Katumani information was used because of similarities in physiology, phenology and

yield potential.

Table 8: Maize varieties used by farmers and the identified equivalent in the model

Variety used by farmer Duration (days) Grain Yields

(t ha-1

)

Variety in the Model

Nafa, Ndele, Longe 1,

Longe 4

100-105 1.5-1.8 Local traditional

(Katumani)

Longe 5, dk 115 4-5 Longe 5

Longe 2H, Longe 6H,

Longe 10H

120 7-8 Longe 9

Others Considered as local Local- traditional

Katumani

Source: NASECO seeds Ltd, Kampala, Uganda

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Plant population that were estimated for each individual farms were set based on the amount of

seed used by farmers. The plant population normally ranged between 40,000 to 60,000 plants per

hectare. Three major categories were used ad per Table 7. In the survey, majority of the farmers

did not use inorganic fertilizers. While setting up the models for individual farmers, 5 kg N

fertilizer amounts was applied to allow model sensitivity. All model runs for the survey data was

conducted using AGMIP tools QuadUIi and ACMO UI that can be availed at

www.tools.agmip.org.

Table 9: Number of farmers using different plant populations in the three soil types in Uganda

Plant population

(plants/ha)

Acric Ferralsols Petric

Plinthisols

Dystric

Regosols

Total

40,000 60 69 53 162

50,000 18 16 32 66

60,000 20 18 21 59

Source: Uganda AGMIP survey data, 2012

2.3.5 Crop Model calibration and validation

APSIM and DSSAT Models were calibrated for Longe 5 and Longe 9 using experimental data

from Bulindi Zonal Agricultural Research Institute in Hoima (Kaizzi et al., 2012). Validation of

model outputs was done using information from National Agricultural Research Laboratories,

Kawanda (NARL). Both experiments were conducted for the two rain seasons of 2010. Crop

management and growth measurements over the seasons and growing period were conducted as

described by Kaizzi et al. (2012). All model parameter coefficients for DSSAT and APSIM

were derived after adjusting existing varieties typical of tropical conditions (Table 10 and 11)

and also by manipulating various growth parameters until the simulated phenology and yields

matched the observed. Models were run and relationship between the observed and simulated

was demonstrated using observed and simulated days to flowering, days to maturity, stover and

grain yield (Figure 3). All APSIM and DSSAT model runs were compared to observed values

using the highest fertilizer rates of 100 and 150 kg N ha-1

since model runs were under non-

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limiting conditions of phosphorus, acidity, micronutrients and pH, thus providing highest yield

potential.

Table 10a: Data for calibration and validation of the crop models (Longe 5) in Uganda

Treatmen

t (N

kg/ha)

Stover

weight

Grain weight TOP

weight

Planting

date

(2009)

Anthesis

date

Physiological

maturity Date

Harvest

Date

2009B Julian Days

Long rain

(longe 5)

1 0 3.83 1.32 5.15 252 306 2(2010) 40 (2010)

2 50 4.69 2.96 7.65 252 306 2(2010) 40 (2010)

3 100 4.86 3.43 8.29 252 306 2(2010) 40 (2010)

4 150 5.23 3.54 8.77 252 306 2 (2010) 40 (2010)

2010A

Short rain

(Longe 5)

5 0 4.55 1.47 6.02 78 136 203 234 (2010)

6 50 7.25 3.66 10.91 78 136 203 234 (2010)

7 100 7.35 3.5 10.85 78 136 203 234 (2010)

Sourced from Kaizzi et al., 2005

Table 10b: Data for calibration and validation of the crop models (Longe 9 and local traditional

varieties) in Uganda 2010A Treatmen

t (N

kg/ha)

Stover

weight

Grain

weight

TOP

weight

Planting

date

(2009)

Anthesis

date

Physiological

maturity Date

Harvest

Date

Julian Days

Long rain

(longe 9)

1 0 5.25 4.16 9.41 78 136 199 230 (2010)

Long rain

(longe 9)

2 100 5.15 5.20 11.35 78 136 199 230 (2010)

Sourced from NASECO seeds Ltd

Long rain

(Local

tradition)

1 0 3.25 1.16 4.31 78 137 208 236 (2010)

Long rain (local

tradition)

2 100 4.33 3.02 7.35 78 138 208 238 (2010)

Sourced from AGMIP on-farm survey

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Table 11. DSSAT model calibration crop coefficients for the three varieties in Uganda.

Cultivar

ID

Variety name P1 P2 P5 G2 G3 PHINT

IC0005 Long 5 200.8 . 0.500 508.5 450.0 10.50 45.60

IC0006 Longe 9 208.6 0.500 554.0 460.0 10.50 45.00

IC0007 Local tradition

(Katumani)

180.0 0.600 600.0 680.0 8.70 40.0

Where P1 = Thermal time from seedling emergence to the end of the juvenile phase (expressed in degree days above a base temperature of 8 oC) during which the plant is not responsive to changes in photoperiod. P2=Is the extent to which development (expressed as days) is delayed for each hour increase in photoperiod above the longest photoperiod at which development proceeds at a maximum rate (which is considered to be 12.5 hours P5= is the Thermal time from silking to physiological maturity (expressed in degree days above a base temperature of 8 oC).\ G2 = Maximum possible number of kernels per plant G3 is the Kernel filling rate during the linear grain filling stage and under optimum conditions (mg/day). PHINT is the Phylochron interval;

the interval in thermal time (degree days) between successive leaf tip appearances.

Table 12. APSIM model calibration crop coefficients for the three varieties in Uganda

Katumani (Uganda

local)

Longe 5 Longe 9

hi_incr (1/days) 0.018 0.018 0.018

hi_max_pot (g/g) 0.55 0.55 0.55

head_grain_no_max () 450 610 750

grain_gth_rate (mg/grain/day) 10.5 9.17 8.0

tt_emerg_to_endjuv (o C day) 150 210 240

est_days_endjuv_to_init () 20 20 20

pp_endjuv_to_init 10 10 10

tt_endjuv_to_init ( oC day) 0.0 0.0 0.0

photoperiod_crit1 (hours) 12.5 12.5 12.5

photoperiod_crit2 (hours) 24.0 24.0 24.0

photoperiod_slope ( oC/hour) 10.0 10.0 0

tt_flower_to_maturity (oC day) 660 660 980

tt_flag_to_flower (oC day) 10 10 50

tt_flower_to_start_grain ( oC

day)

120 120 120

tt_maturity_to_ripe (o C) 1 1 1

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Figure 3. Simulated and observed yield and top weight for Longe 5, Longe 9 and local traditional

variety

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2.3.6 Model sensitivity for APSIM and DSSAT in Uganda

Table 13 compares the average maize yields over 30 years simulated by the two models under different

climatic conditions under good soil conditions, 50 kg N ha-1 fertilization and longe 9 variety. APSIM

simulated high grain yield as compared to DSSAT. Both models were sensitive to changes in temperature

and rainfall. Simulations with APSIM showed an increase in yield parameters with increase temperature

and rainfall compared to the baseline. However, DSSAT showed an opposite trend.

Table 13: Model sensitivity to changes in climatic conditions in Uganda

Treatment

APSIM DSSAT

Biomass Yield

(kg/ha)(CV)

Grain Yield

(kg/ha)(CV)

Biomass Yield

(kg/ha) (CV)

Grain Yield

(kg/ha)(CV)

Effect of temperature and rainfall

Base Climate 5748 (18.9) 2753.72 (15.13) 11087 (6.8) 3126 (12.2)

Base+10C

9007 (7.2) 4755.15 (12.4) 10716.8 (7.4) 2924 (12.1)

Base+30C

7901(8) 4136(15) 10579 (6.9) 2825 (15.3)

Base+50C 6926(9) 3431(19)

9139 (11.52) 1971 (20)

Base+10C+10%RF

9060 (5.5) 4843(11.5) 7774 (7) 2270.8 (9.3)

Base+30C+10%RF

7976 (6.4) 4227 (12.9) 7678 (7) 2088 (10.6)

Base+50C+10%RF

7020 (7.4) 3486 (17.2) 7334 (8) 1666 (12.2)

Base+10C-10%RF

8948 (10.9) 4659 (18) 8310 (41.7) 2061.3 (59.8)

Base+30C-10%RF

7793 (11) 4070 (17) 853 1 (38.5) 2174.9 (52.7)

Base+50C-10%RF

6833 (11) 3378 (20.4) 9342 (22) 2664.5 (22.8)

2.3.7 Comparison of DSSAT and APSIM model runs with on-farm observed for Uganda

After the calibration, APSIM and DSSAT model were used to simulate the yields of 307 households

farms that were conducted in the studied agro-ecological zone in Uganda. The on-farm survey was set up

by considering specific on-farm climate, soil, and crop and management parameters. In all, simulated

yields of DSSAT were much higher than that of APSIM. There was no relationship between the on-farm

yield and the two models simulated values with R2<0.2 (Figure 8).

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Figure 4: Relationship between DSSAT and APSIM simulated yields and yields reported in on-farm

survey in Uganda (Red dotted line is 1)

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2.4 Socio-economic impact assessment

TOA model was used to assess the socio-economic impacts of future climate to the households

in the studied area. For parameterization of system 1, the survey yield was normalized to the

current period by computing a unitless factor β obtained as a ratio of historical yield to the

average per farm survey yield. This factor was used to adjust the survey yield thus:

ij = βx per farm survey yield in kg per farm

The per farm output obtained asij x Area was used to obtain per farm net returns given prices

and costs of operation for each crop activity in the farmer’s enterprise mix.

To parameterize system 2, outputs, costs, revenues and net returns were computed using the

following procedures:

1. The per farm output for system 2 was obtained by factoring system 1 output with the per

farm relative yield.

2. The per farm output for system 1 was obtained by adjusting system 1 per farm output

using the relative yield obtained as a ratio between the simulated future yield and the

simulated baseline yield.

3. Crop returns were computed as the product of prices, area and per farm system 2 output.

4. The costs to returns ratio was used to adjust system 1 costs to obtain costs per returns for

system 2

5. Net revenue for system 2 was obtained as the difference between revenue and costs

To obtain results for the first objective, the model was set up with system 1 being the current

production system under current climate while system 2 was future climate under the unchanged

production system (i.e the case of no adaptation to climate change) thus:

Climate change without adaptation: System 1 = base climate, base technology (1980-2010)

System 2 = changed climate, base technology (2040-70)

The second objective was achieved using two procedures: The first procedure was to establish

the expected trend in producer prices and rain-fed production using global economic models.

The next stage was to conduct representative agricultural pathways (RAPs) to determine the

changes both in the direction and magnitude of key socio-economic variables including

enterprise composition, production, labor and other costs, area, changes in demographic

composition). This analysis scenario involved setting up TOA with these systems

Climate change with trend: System 1 = base climate, base technology (1980-2010)

System 2 = changed climate, changed technology (2040-70)

The above processes and procedures generated (5 climate models x 2 crop models x 2 economic

scenarios =) 20 sets of TOA-MD simulations.

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To compute the growth rates of each variable X, the following three-part procedure was

performed:

1. Obtaining the change in growth of the variable

ΔXt Where X = Price, Productivity, Acreage,

Costs

2. Obtaining the mean of the growth rate

ɸ

3. Computing the mean over the period of analysis

ɣ=(1+ ɸ)T

This process resulted into the following growth rates which were then used to adjust system 1

variables, supplemented with information from the RAPs and from literature including published

reports and databases. Table 5 shows the assumptions, data sources and variables used for system

2.

Table 14: With Adjustment factor (for Trend)

Activity Productivity Prices Acreage Costs

Maize Factor +495% +220% +5.6% +213%

Source Global models Global models RAPs

+20% in farm size

per farm but 12%

decline in number of

farms

Global models and

RAPs

Beans Factor +50% 60% +5.6% +10%

Source RAPs RAPs RAPs RAPs Rise in

agricultural wages

Groundnuts Factor +190% +101% 5.6% +194%

Source Global models Global models RAPs Global models and

RAPs

Cassava Factor +7% 7% 5.6% +10%

Source Literature RAPs RAPs Rise in agricultural

wages

Banana Factor -10% 0% -21% +35%

Source RAPs

Diseases

RAPs

Most production is

not value added,

Not traded on

international market

Shift to less land-

demanding

enterprises

RAPs

Disease management

Rise in agricultural

wages

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3. Integrated Assessment Results

3.1 Climate characteristics of the studied Agro-ecological zone

Masindi and Hoima district receive more than 1000 mm annually with Masindi slightly higher than

Hoima. In both locations, rainfall is bi-modal with short-rain season (August-November) receiving

slightly higher rainfall than the long-rain season (March-May) (Table 11). The difference in rainfall

amounts between the two seasons is more pronounced in Hoima (39.6% higher) than in Masindi (2.2%).

Generally, annual rainfall amounts at both sides show a low temporal variability with a CV of <16%

(Table 4). This was even lower for both seasons with a CV less than 10%. Temperature tends to be

relatively higher in Hoima than in Masindi, and during the long rain season than the short rain season.

Annual rainfall amounts were not showing any trends overtime. However, analysis of variability of long

rains in Hoima showed a rapid decline in the CV from 30% in 1980-1985 to less than 15 % in 1990 and

later remained stable up to 2000 before another increase to 30% in 2005. For the short rains, CV slightly

increased gradually from 13% to 19% in 1995, declined to about 10% in 2000 and increased to 20% in

2005. In Masindi, the long-rain CV fluctuated between 20 and 15% up to 1990. Since then, it stabilised

to about 20%. For the short-rain, CV declined gradually from 27% to 15% around 1990; increased

slightly, and then fluctuated slightly within 18- 21% (Table 15)

Table 15: Key climate characteristics at the studied agro-ecological zones in Uganda

Variable Hoima Masindi

Avg annual rainfall (mm) 1197.0 (15.5) 1292 (12.3)

Average LR season rainfall (mm) 346.9 (7.7) 412 (6.3)

Average SR season rainfall (mm) 483.8 (6.9) 421 (7.2)

Average annual Temperature (0C) 24.3 23.5

Average annual MaxT (0C) 30.0 29.2

Average annual MiniT (0C) 18.6 17.8

Average LR season Temperature (0C) 24.7 24.2

Average LR season MaxT (0C) 30.3 29.6

Average LR season MiniT (0C) 19.07 18.7

Average SR season Temperature (0C) 23.8 23.1

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Average SR season MaxT (0C) 29.3 28.6

Average SR season MiniT (0C) 18.4 17.5

Note: Figures in parenthesis represent Coefficient of Variation (CV)

Generally, average temperature within the short and long rain seasons were increasing in both locations of

Masindi and Hoima (Figure 5). The increase in temperature became pronounced in Hoima sites in 1997

for both seasons. In Masindi, temperature increase during the short rain is observed since 1981 (Figure

6).

Figure 5: Ten year moving coefficient of variation (CV) of rainfall starting from 1980 during short rain

season at the two sites in Hoima and Masindi districts Uganda

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Figure 6: Average air temperature during short and long rain season during the period 1980-2010 (bars

represent observed average values and line represents five year moving average) in Hoima and

Masindi district, Uganda

3.2 Future climate projections

The projected climate change and variability in both Masindi and Kyangwali are presented in Figure 5

and Figure 6. Most of the models projected an increment in rainfall, Tmax and Tmin for both sites,

except CSIRO-Mk3-6-0, MIROC5 and MIROC-ESM which predicted negative change in rainfall. However,

the magnitude of the change varied from one model to another. High value rainfall increments were

predicted by BNU-ESM, GFDL-ESM2M, IPSL-CM5A-LR, IPSL-CM5A-MR, lowest rainfall increments were

predicted by MRI-CGCM3, Inmcm4, CSIRO-Mk3-6-0, bcc-CSM1 and Access1-0 for both sites. High values

of change in temperature were predicted by ACCESS1-0, CanESM2, bcc-CSM1-1, CSIRO-Mk3-6-0,

HadGEM2-ES, HadGEM2-CC, IPSL-CM5A-LR, IPSL-CM5A-MR and MRI-CGCM3. HadGEM2-CC predicted

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small negative change in rainfall for 4.5 Mid Century and 4.5 End Century, while HadGEM2-ES, predicted

same trend for 4.5 Mid Century.

Figure 7: Projected change in Rainfall, Minimum and Maximum Temperature of Masindi district,

Uganda

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Figure 8: Projected change in Rainfall, Minimum and Maximum Temperature of Hoima district,

Uganda

3.2 Sensitivity of current agricultural production systems to climate change

Simulations were carried out with both DSSAT and APSIM for baseline and climate change scenarios for

all combinations of RCPs 4.5 and 8.5 and time periods mid and end centuries for all the 20 AOGCMs.

Generally, both APSIM and DDSAT predicted that maize yields will reduce for all soils and seasons under

future climate scenarios, except for the petric plinthisols were there will be a relative increment for RCP

4.5. Magnitude of the reduction varied from one crop model to another. DSSAT seems to show higher

relative changes than APSIM for RCP 8.5.

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Fig 9: APSIM predicted future maize yield

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-35

-30

-25

-20

-15

-10

-5

0

Both LR SR Both LR SR Both LR SR

Acric Ferralsol Dystric regosol Petric Plinthisols

% D

evia

tio

n

DSSAT

4.5MID

4.5END

8.5MID

8.5END

Fig 10: DSSAT predicted future maize yield

3.3 Socio-economic implications

Table 15 below shows the means, standard deviations of the variables disaggregated by strata.

Three strata based on soil type were identified.

Table 15: Yields, Total variable costs and Net returns disaggregated by soil type

Soil Type Maize Beans Groundnuts Cassava Banana

Total Variable Costs ($/ha) Acric 95.99 98 95 240 50

Dystric 68.91 72 59 624 81

Petric 129.41 78 76 273 107

Yields (Kg/ha) Acric 1685.00 761.54 688.02 1040.65 3952.57

Dystric 2043.13 1846.13 818.42 1011.51 6385.39

Petric 1917.22 1029.99 743.61 932.51 4360.55

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Mean net returns Acric 407.39 198.67 231.05 24.62 115.48

Dystric 446.15 449.70 286.39 40.73 92.81

Petric 432.94 262.61 253.62 93.00 94.83

Standard Deviation of net

returns Acric 750.16 162.48 177.95 495.51 326.57

Dystric 1126.65 2063.96 315.61 584.56 179.44

Petric 510.45 498.30 284.98 252.16 287.23

Fig. 11: Total variable costs of Maize

Fig. 12: Survey data – Maize yields

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Fig. 13: Comparison between the average of DSSAT yields and baseline yield

Table 15 above shows that by comparison, APSIM simulated yields were lower than DSSAT

simulated yields. Figure 14 below shows that with the exception of the model CCSM4, all the

other models show no significant divergence between average DSSAT yields of the three

different soil types. It is evident that although the average simulated yields of CCSM4 are higher

than both the baseline yields and observed yields, they are lower than simulated yield averages of

the other 4 models – GFDL, HadGEM-2, MIROC-5 and MPI-ESM. In fact, a further assessment

shows that simulated average yields of GFDL and MIROC-5 are not different from each other

implying that these two models predict similar yields. Figure 6 below also shows a near perfect

match for HadGEM-2 and MPI-ESM. These comparisons indicate that simulation results are

likely to be similar for models that predict similar patterns and for the three different soil types.

In addition, these yields may be an indication that the study population was homogenous in terms

of soil type – that yields across soil types do not vary significantly. It is important to note that

within each soil type, there were variations in quality ranging from poor to good in which case

comparable yields were obtained from different soil types of relative equality.

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Fig 14: Comparison of DSSAT simulated Base scenario yields by soil type/stratum

Fig 15: Comparison of APSIM simulated Base scenario yields by soil type/stratum

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Fig 16: DSSAT Simulated yields in comparison with observed by stratum

Fig 17:.APSIM Simulated Base scenario yields in comparison with observed by stratum

The figures below show results of TOA model simulations using DSSAT yields. With the

exception of CCSM4, all other models predict a higher percentage of gainers within the stratum

Petric followed by Dystric and lastly Acric Feralsols. The four models predict that the gainers (as

a percentage of farms) are fewer in acric soil type compared to the other two soil types.

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The table below shows results of DSSAT model runs for the Base Scenario. The per capita

income ranges from 461.56$ per person per year to 477.63$ per person per year depending on

the GCM. GFDL model predicts the lowest poverty rate of 51.08% compared with 52.09%

predicted by the CCSM4 model.

Table 17: Gainers, net returns and poverty rate

GCM Model

Gainers

(%)

Net Returns

(%/person/year)

Population

Poverty Rate (%)

Percapita income

($/person/year)

CCSM4 53.21 1005.22 52.09 461.56

GFDL 64.77 1082.45 51.08 477.63

HadGEM2 62.27 1064.34 51.38 473.49

MIROC-5 64.49 1079.64 51.12 477.07

MPI-ESM 61.83 1059.97 51.44 472.53

Fig 18.Adoption rates under different models for the base scenario.

Figure 18 above shows that with the exception of CCSM4, the other 4 models predict above 60%

adoption rate. This implies that the percent gainers are higher than 50% of the population.

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Table 18: Correlations between net returns

Rho Crops in

system 1

Crops in

system 2

Acric 0.866567 0.0119 0.0119

Dystric 0.957566 0.01163527 0.01163527

Petric 0.973811 0.103 0.103

Fig 19: Opportunity cost and adoption rate

Overall, 58% of farms would adopt system 2. These are the farms whose opportunity cost of

adoption is less than zero. However this general picture masks the differences within the

different soil types. For instance, within farms under acric soil type, the threshold adoption rate is

53.5% while for Dystric and Petric farms, the adoption rate is higher than the overall at 59.4%

(Figure 18). However, the area under the graphs is higher for acric soil types implying that there

are higher gains under acric soil type compared to farms under Dystric or Petric soils. These

figures indicate that climate change is likely to have different effects across farms under different

soil types.

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Fig 20: Adoption rate disaggregated by strata

The gains from climate change are shown below. The results show that mean net returns are

higher for Petric and Dystric soil types before and after climate change.

In general results showed that there are benefits to climate change, though the gains are low and

vary by soil type.

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Fig 21: Cumulative gains with adoption disaggregated by strata: DSSAT results

From DSSAT model runs, gains from adoption are rising for farms under all soil types.

However, farms under petric soil types do not have any benefits to adoption before the 35% level

of adoption while at that level of adoption, farms under acric or dystric soil types have 15% and

10% gains from adoption. Additionally, there are no further benefits to adoption beyond 42%

level of adoption for farms under dystric soil types (Figure 21).

The poverty rate of the adopters and the poverty rate of the overall population is equal at zero

percent adoption and declines upto a point of optimum adoption rate (of 58%). On the other

hand, the poverty rate of non-adopters increases with adoption and is equal to the poverty rate of

the overall population at maximum adoption (of 100%). Overall in the population, as adoption

increases (upto the threshold of 58%) poverty rate decreases. Switching from system 1 to system

2 improves welfare before the threshold point. However, there are variations by strata. The figure

below shows that up to the optimum adoption rate, switching from system 1 to system 2 reduces

the poverty rate. However, climate change does not have a significant effect on poverty rate on

farms under petric much soils as it has on the other two strata.

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Fig 21: Poverty rate and CC

Fig 22: Net returns from adoption among adopters, non adopters and the entire population

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Fig 23: Per capita income across the entire population, among the adopters and non

adopters

As adoption increases, the per capita income of adopters reduces. In the same vein, as more

farms adopt, the per capita income of non-adopters increases.

Figure 24: Poverty rate across the entire population, among the adopters and non adopters

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4. Stakeholders involvement and feedback

Results from this study were shared with stakeholders (see appendix) and the AGMIP protocols

have been used in a number studies in Uganda and D.R. Congo. A stakeholder meeting was

organized at Makerere University on 13th

June 2014 with the objective of sharing the results of

the project and get feedback from them.

Four presentations were made by the AGMIP-Uganda group members summarizing the key

findings of the projects. Questions and comments were collected and discussion and working

groups formed.

Fig 25: Participants to the stakeholders meeting organized on 13th June 2014, Makerere University,

Kampala-Uganda

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Fig 26: Group discussion during the stakeholders meeting organized on 13th June 2014, Makerere

University, Kampala-Uganda

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All participants agreed on the climate trends that:

The short rains have changed too (Sept-early Nov) but extended to December in Western

Uganda

The long rain season is much longer (March-May) but now to June, depending on

location

There is a very short dry season (in JULY)

There is change in rainfall distribution pattern but not the total amount

Temperature increase evident like in Kabale and Kasese districts

Economic patterns in results expected

and confirmed that projected values are within the range projected by different authors in the

region.

The following are the key recommendations of the stakeholders’ working groups:

a) Awareness

Create awareness on climate variability and training of the farmers on soil and land

management practices

b) Policy and byelaw

Need of bylaws to regulate the use of agricultural inputs at the farm and the households

Need to strengthen land management practices and use

c) Crop husbandry and agricultural inputs

Matching crop to season length eg. Late maturing for long crops and Early maturing for

short seasons

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Develop of short and long maturing varieties

Increasing rain water harvesting techniques for LR to short rains seasons

Following timely agronomic practices like timely planting, fertilizer use, weeding etc

Adoption of tolerant cultivars to very dry and wet conditions

Application of adequate fertilizers to make use of long-rains and maximize yields

d) Early warning

Timely access and utilization of weather forecasts and data

In addition the AGMIP protocol was used to downscale climate projections for 32 stations across

Uganda for the Climate Change Task Force (Uganda Climate Change Unit), for 3 stations for

Environmental Alert (NGO in Uganda), IUCN-Uganda and WWF-DR. Congo. Three students

have been trained to use the script for downscaling climate projection, and ten of them trained in

the use of the crop models.

References

Wilby, R.L., Charles, S., Zorita, E., Timbal, B., Whetton, P., Mearns, L.2004. Guidelines for use of

climate scenarios developed from statistical downscaling methods. In: IPCC Supporting Material,

available from the DDC of IPPC TGCIA.

Moss, R.H., Edmonds, J.A., Hibbard, K.A., Manning, M.R., Rose, S.K., van Vuuren, D.P., Carter,

T.R., Emori, S., Kainuma, M., Kram, T., Meehl, G.A., Mitchell, J.F.B., Nakicenovic, N., Riahi, K.,

Smith, S.J., Stouffer, R.J., Thomson, A.M., Weyant, J.P., Wilbanks, T., 2010. The next generation

of scenarios for climate change research and assessment. Nature 463, 747–756.

Page 44: THE AGRICULTURAL MODEL INTER-COMPARISON … · THE AGRICULTURAL MODEL INTER-COMPARISON AND IMPROVEMENT PROJECT (AGMIP) ... Uganda, located in eastern ... Biofuels currently account

Taylor K.E., R.J. Stouffer, and G.A. Meehl. 2012: An overview of CMIP5 and the experiment design.

Bulletin of the American Meteorological Society 93(4):485-498, doi: http://dx.doi.org/

10.1175/BAMS-D-11-00094.1

Rosenzweig, C., Jones, J., Hatfield, J., Antle, J., Ruane, A., Boote, K., Thorburn, P., Valdivia, R.,

Porter, C., Janssen, S., Mutter, C. 2013. AgMIP Guide for Regional Integrated Assessments:

Handbook of Methods and Procedures Version 5.0.

Rienecker, M. R. and co-authors, 2011: MERRA - NASA's Modern-Era Retrospective Analysis for

Research and Applications. J. Climate 24, 3624–3648.

Ruane, A.C., and R. Goldberg: "AgMIP Hybrid Baseline Climate Datasets: Shifted Reanalyses for Gap-

filling and Historical Climate Series Estimation" (In preparation).

MAAF.1996. Modernisation of Agriculture in Uganda. The Way forward 1996-2001. Medium-term

Agricultural sector modernisation plan for Ministry of Agriculture Animal Industry and Fisheries, Uganda.