Decision Support Tool for Rufiji Basin, Tanzania

Introduction

An important possible adaptation to climate change effects is to plant newer varieties that may be more resilient to changing temperatures such as during the dry, winter season. A comparison is shown between the yield of Supa, a commonly grown variety that is known for it good taste and aroma, and an improved variety known as TXD-85.

Current

The difference in simulated yield between Supa and TXD-85 is very large, particularly where rice growing conditions are best and if sufficient amounts of fertilizer are applied. In cold or drier areas, neither variety yields well.

Supa

Future model using minimum temperature, CCSM4

TXD-85

Future model using minimum temperature, MPI

Difference

Future - 2050

In 2050, the difference in yield between Supa and TXD-85 appears even greater, with TXD-85 yielding high especially in the wettest and warmest areas east of the Highlands. Yields of Supa, on the other hand, remain low.

CCSM4

Supa

TXD-84

Difference between TXD-85 and Supa

MPI

Supa

TXD-85

Difference between TXD-85 and Supa

Change

The change in yield maps confirm that rice yields indeed rise with projected climate change for both varieties. Temperatures warm and become more conducive during the dry, winter season.

However, TXD-85 yields rise more than those of Supa throughout the lowlands. The difference between the two varieties is even larger than during the rainy season, because water is sufficient with irrigation and the improved variety has a higher potential.

In the warmest area of the Basin near the Indian Ocean coast, rice yields do not rise much for either variety due to hot temperatures restricting yield even during the dry winter season.

CCSM4