Adapting agriculture to climate risk: a case study of Ceres - South Africa. Abiodun Ogundeji1, Henry Jordaan1 and Jan Groenewald1 Department of agricultural economics University of the Free State, South Africa. November 21, 2018November 21, 2018

Introduction Climate change and the impact upon already scarce water resources are of global importance Acute for water scarce countries such as South Africa Changes in the water supply will inevitably affect the water availability for different users. Water demand pressure driven by global temperature surges, population growth, degradation of water quality, lack of efficient water management (accentuate water scarcity).

Introduction Economic impact on agriculture changes in farm profitability, prices, supply, demand, trade, and regional comparative advantage. Both the demand for and supply of water for irrigation will be affected by changes in the hydrological regimes concomitant increases in future competition for water with non-agricultural users, owing to population and economic growth. Climate change is also expected to affect future winter chill potentially have a major impact on fruit species with chilling requirements

Introduction Insufficient winter chill can severely affect fruit yields and fruit quality, leading to: delayed foliation reduced fruit set and fruit quality inconsistent bud break and leaf development, and non-consistent fruit growth Significant impact on the productivity of such tree crops and also the economy of the production region and country

problem statement Integrated models applied in CC adaptation The focus of most previous studies was on the regional impacts of climate change and the adaptation thereof (Callaway et al. 2008 and Louw et al. 2012). What about farm level impacts? Research on crop water use has received much attention in the recent past (Grove, 2007, Annandale et al., 2011, Van Averbeke et al., 2011) very few have considered future climate. Attention has been paid to increase in temperature (e.g. Callaway et al., 2009 and Louw et al., 2012) failed to relate it to chill unit and future chill accumulation.

To calculate and incorporate the impacts of future crop water requirement and chill unit, Two additional modules, namely the crop water module and chill unit accumulation module, were developed. The modules were linked together using the basic features of the farm model developed by Callaway et al. (2008) and Louw et al. (2012) to form the Ceres Dynamic Integrated Model (CDIM).

Aim of the study The aim of this study is to develop an integrated model that can simulate the impact of CC on farm structure (crop combination, water use and welfare of the farmers) evaluate the impact of different adaptation strategies to CC on the agricultural sectors

Study area

The study area/2 Ceres is the administrative centre of the Witzenberg Local Municipality An important agricultural town surrounded by affluent export-oriented fruit farmers One of the largest deciduous fruit and vegetable producing districts in South Africa Ceres produces large quantities of fruit juices (the local juicing plant is the largest in South Africa).

Farmers experience of CC Climate change experienced Same annual rainfall but less rainy days and rain more intense Winter is coming later – May is drier, September wetter More extremes, cold + hot Evaporation increased – higher irrigation demands Cold units are marginal – ideal is 1000 to 1200, they are only getting 800

Resources are scarce

Adaptation What kind of adaptations? Changing cultivars Storage facilities Drip irrigation cannot be applied to all circumstances – most important is more efficient irrigation and scheduling Need for the use of rest break chemicals and more spraying – increase in input costs

The model

The Model The objective function of the model is to maximise aggregated net disposable income (NDI) of individual farms in Ceres over the planning horizon. The model maximises an economic objective function, subject to constraints.

Future projected change in climate parameters for H10C station Summary of climate projections applied in hydrological modelling based on A2 emission scenario. Period University of CapeTown (UCT) Present (1971 - 1990) IPSL-CM4 (“Low”) ECHAM5/MPI-OM (“High”) Intermediate future (2046 - 2065) Future projected change in climate parameters for H10C station   Change in mean annual rainfall Change in mean annual temperature Change in Penman Monteith reference potential evaporation Low +10% +20% +11% High +8% +12% +7%

Results and discussion Estimated accumulated Richardson chill unit Years Present (1971 – 1990) Intermediate Future (2046-2065) 1 1298 869 2 1226 760 3 1110 612 4 1416 908 5 1445 992 6 1278 814 7 1203 1038 8 1136 603 9 1297 778 10 1194 664 11 1422 967 12 1276 815 13 1518 1051 14 1354 823 15 1066 692 16 1270 730 17 1180 689 18 1202 697 19 1441 980 20 1481 1036 Apples Richardson Chill Unit requirements Golden delicious 1400 Top red / starking Royal gala 1200 Pears   Forelle 850 Williams bon chretien Abate Fetel Apricots Soldonne 650 Bebeco 700 Ladisun 500 Suaprieight 450 Plums Angeleno 400 Southern belle 600 Fortune African delight 250

Impact of CC on crop water requirement   Sprinkler Drip Base Future +% Change +% Change Vegetables (m3/ha) Potatoes 4130 4650 13 2740 3080 12 Tomatoes 4220 4860 15 2770 3190 Onion 7780 8680 2390 16 Cabbage 3600 4020 2240 2530 Cauliflower 4300 4720 10 2840 3220 Carrots 3920 4390 2180 2490 14 Peas 4460 5050 2650 3050 Pumpkin 3460 3930 2260 2610 Squash 2980 3830 29 1990 2660 34 Butternut 4310 4570 6 2820 3070 9 Lettuce 3560 4450 25 1830 2510 37 Spinach 4520 5130 2570 2920 Beetroot 2790 1970 Melon 3740 4210 2580 2960

Impact of Climate change – Base comparison Impact of Crops (Ha) IPSL-CMA Base (Present) Base (Future) Fruits Apples 9.7 4.9 Apricots 3.0 1.5 Pears 219.5 235.0 Nectarine 22.3 12.6 Peaches 117.0 58.5 Wwine 5.9 2.9 Plums 30.5 15.3 Total 407.9 330.7 Vegetables Potatoes 0.2 0.3 Tomatoes 0.4 Onions 96.8 142.4 Cabbage 51.1 74.1 Cauliflower 37.8 58.2 Beetroot 47.7 60.1 Other vegetables 2.1 2.8 235.9 338.3 Pastures 8.8 2.4 Cereals 11.7 7.6

Scenario Development Scenario Explanation Scenario 1 Farm dam capacity for emerging farmers, with winter water rights Scenario 2 20% increase in farm dam capacity for emerging farmers, winter water right allocation Scenario 3 20% increase in farm dam capacity for emerging farmers, winter water right allocation increased by 20 %. Scenario 4 10% increase in water use efficiency Scenario 5 10% increase in water tariff

Farm dam and winter water right adaptation scenario Crops(Ha) IPSL-CMA Base (Future) Scenario 1 2 3 Fruits Apples 4.9 Apricots 1.5 Pears 235.0 245.8 Nectarine 12.6 13.1 14.0 Peach 58.5 Wwine 2.9 Plums 15.3 Total 330.7 342.0 342.9 Vegetables Potatoes 0.3 Tomatoes 0.4 Onions 142.4 146.9 Cabbage 74.1 72.6 71.9 Cauliflower 58.2 65.5 67.5 Beetroot 60.1 63.3 64.8 Other vegetables 2.8 16.3 5.6 338.3 351.8 354.6 Pastures 2.4 3.0 3.1 Cereals 7.6

Farm dam and winter water right adaptation scenario

Farm dam and winter water right adaptation scenario

Water use efficiency adaptation scenario Crops IPSL-CMA Base (Future) Scenario 4 Fruits (ha) Apples 4.9 Apricots 1.5 Pears 235.0 239.6 Nectarine 12.6 12.4 Peaches 58.5 Wwine 2.9 Plums 15.3 Total 330.7 335.1 Vegetables Potatoes 0.3 Tomatoes 0.4 Onions 142.4 144.3 Cabbage 74.1 72.7 Cauliflower 58.2 60.3 Beetroot 60.1 66.2 Other vegetables 2.8 338.4 347.0 Pastures 2.4 2.6 Cereals 7.6

Increase in water tariffs adaptation scenario Crops IPSL-CMA Base (Future) Scenario 5 Fruits Apples 4.9 Apricots 1.5 Pears 235.0 234.5 Nectarine 12.6 12.7 Peaches 58.5 Wwine 2.9 Plums 15.3 Total 330.7 330.3 Vegetables Potatoes 0.3 Tomatoes 0.4 Onions 142.4 Cabbage 74.1 74.5 Cauliflower 58.2 Beetroot 60.1 60.3 Other Vegetables 2.8 338.3 339.2 Pastures 2.4 Cereals 7.6

Conclusion Evaluation and adaptation decisions related to agriculture can be made in an integrated framework. A change in the profile can be expected as a result of climate change and adaptation thereto. It is unlikely that high water tariffs will reduce the level of water used for production. Farm dam capacity and winter water allocations seems to be a good adaptation strategy caution should be taken when considering such an adaptation option

Farm dam is a capital intensive infrastructure if the farm dams don’t fill up, it may worsen the situation of farmers Benefit and cost of considering a dam as an adaptation option should be done to justify the usage of public funds On going research

Increasing water use efficiency is a good adaptation option for the farmers A “no regret” adaptation measure Water resources management strategy is important in ensuring that agricultural production can withstand the stresses caused by climate change Farmers must be equipped with a collection of management or adaptation tools to overcome climatic differences.

Thank You Dankie Mercie Abiodun Ogundeji Department of Agricultural Economics ogundejiaa@ufs.ac.za T: +27(0)51 401 3352