Ethiopia

Estimating Meher crop production using rainfall in the 'Long Cycle' region of Ethiopia - revised 6 Oct 2003

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Meher season crop production is well correlated with April-May rainfall in the Ethiopian 'long cycle' crop growing region. This relationship is used to estimate 2003 Meher small farmer gross production at 87 =B1 10 million quintals (8.7 million MT2 =B1 1 million MT) of cereals, pulses and other crops, using data from the Central Statistical Authority (CSA). Assuming recent levels of commercial and food aid imports, Belg production and population growth, this estimate will produce a food deficit of about 23 million quintals (2.3 million MT) for 2003-04, smaller than the one experienced during 2002-03 (34 million Qt, or 3.4 million MT), but similar to the deficit experienced in 1997-98. A long-term negative rainfall trend in the southwestern highlands may be aggravating the situation. Increasing food requirements and decreasing precipitation point toward chronic food shortages in the near future.

Highlights

  • National Meher yield and production correlate well with April-May rainfall in the 'long cycle' crop growing region of Ethiopia.
  • Rainfall in April-May 2003 suggests Meher production will be about average when compared to the last seven years.
  • Population growth (1.8 million per year) adds 3.3 M Qt per year to the national consumption requirement, nearly half the annual food aid received.
  • A simple food balance shows that about 13 million people would meet none of their food needs at all in 2003-04, assuming equal distribution of all available supplies.
  • Food balance projections suggest that 12.8 million Ethiopians will meet none of their food needs in the 2004-05 production year, increasing to 14.3 million in 2005-06, 15.8 million in 2006-07 and 17.3 million in 2007-08.
  • The western portion of the 'long cycle' crop-growing region has experienced a strongly negative rainfall trend since 1961, with potentially adverse consequences for production.
  • Ethiopia will need to refocus its national development goals to reduce reliance on rain fed agriculture.
Introduction

Despite massive relief operations and development efforts, serious levels of food insecurity persist in Ethiopia, with recent assessments recommending an increase in the number of beneficiaries to 13.2 million (or 22.6% of the nation's rural population).3 Recent Water Requirement Satisfaction Index (WRSI) anomaly images for the Belg season (approximately March-May) and field reports suggest that agroclimatic conditions in 2003 were generally better than those over the past four years. While these improved conditions are reassuring, Belg production typically accounts for only 5-10% of total annual production, while Meher rainy season (approximately June-September) crops harvested in September-December make up the bulk of food production (90-95%). June-September imagery from the USGS shows near-median WRSI values across most of the country. Our study estimates the September-December 2003 Meher yields based on April-May 2003 rainfall.4 Using average area-planted (CSA data), this study produces a rough estimate of national Meher production.5 The estimated national yield is close to the seven-year average, and thus agrees fairly well with WRSI values based on data from June-September.

The Meher crop production in Ethiopia combines high yield 'long cycle' crops (planted in the Belg season in March and harvested in September-December, after the end of the Meher season in September, see Figure 1), and lower-yield 'short cycle' (June-September) varieties. Long cycle maize crops with the recommended agricultural inputs (fertilizer and improved seeds) yield about 2.5 -- 3.0 tons per hectare, but short cycle maize (improved or local varieties) yields about 0.8 -- 1.0 tons. Long cycle sorghum varieties with the necessary inputs yield about 1.5 tons, while short maturing varieties yield about 0.9 tons/ha. The higher yielding long cycle crops contribute about 50% of national production, compared to about 40-44% for short cycle Meher crops. These results imply that national Meher production is strongly dependent on rainfall within the long cycle region6.

Fig 1. Long cycle crop growing regions of Ethiopia

The significant production of long cycle crops, and the dependence of these crops on April-May rainfall, means that considerable information regarding prospective September-December Meher cereal and pulse production becomes available as soon as May rainfall estimates are processed in early June. April-May rainfall totals can explain about half the variance (R2=0.5) of end-of-season long cycle maize Water Requirement Satisfaction Index values (Figure 2), strongly suggesting that rainfall deficits at this critical stage can negatively impact yields of crops harvested in September-December. Another factor linking April-May rainfall to Meher production is the tendency for April-May precipitation anomalies to persist into August-September (R2~0.4) in long cycle growing areas. In short, these factors suggest that April-May rainfall in the long cycle crop region of Ethiopia is a good indicator of national Meher production.

Fig 2. Scatter plot of ranked Ethiopia long cycle WRSI and April-May precipitation

Footnotes

1 This report was prepared by Chris Funk, Alemu Asfaw, Phil Steffen, Gabriel Senay, Jim Rowland and Jim Verdin. This document is an update of the original report (issued on June 21, 2003) and contains a revised estimate of precipitation trends in the western long cycle region, using interpolated rainfall station data, instead of a combination of station and satellite rainfall estimates.

2 We use the following abbreviations for units in this report: Qt for quintal, MT for metric ton, M for million, mm for millimeter, kg for kilogram and ha for hectare.

3 Ethiopia Network on Food Security Monthly Report, August 14, 2003 and FEWS NET/Ethiopia Emergency Alert of August 29, 2003.

4 The study, therefore, explicitly ignores important factors such as agricultural inputs, the tendency to reduce production following a bumper harvest, and the year-to-year variation in area planted.

5 National yields are calculated by dividing national production by national area planted, and thus will not always be representative of yields at the zonal or woreda level. Gross production figures are used in our estimates, and net production figures will be typically about 17% lower. CSA production figures are typically lower than FAO/WFP figures (e.g. 20% lower for 2002 Meher production). To help generalize our results, our findings are presented in percent deviations, as well as metric tons and quintals.

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