improving management of vertisols to enhance agricultural water productivity

Improving Management of Vertisols to Enhance Agricultural Water Productivity

Teklu Erkossa, Amare Haileslassie and Charlotte Macalister

3rd International Forum on Water and Food

14-17 November, 2011, Tshwane, South Africa

Importance and Management Challenges

o Vertisols are among the high Vertisols are among the high potential soils potential soils

o Cover about 12 million ha, 8 Cover about 12 million ha, 8 million ha in highlands, 12% of the million ha in highlands, 12% of the Abbay BasinAbbay Basin

o Located in areas with favorable Located in areas with favorable climate climate

o Productivity is constrained by Productivity is constrained by severe water logging and hardness severe water logging and hardness when drywhen dry

Required level

Deficit

Water Management Challenges

Growing Season

Excess Water logging

Deficit

• BBF was recommended by research, but not universaly accepted– BBM too heavy, planting time not

flexible, local alternative (RF) available

• RF involves late planting, but bed size too small (20 cm)

•Late planting on flat bedsLate planting on flat beds•Tolerant cropsTolerant crops•Guie- soil burningGuie- soil burning•Surface drainage systems (Handmade Surface drainage systems (Handmade BBF, RF, BBF)BBF, RF, BBF)

Management Options

Hand made BBF

BBF made by BBM

Sketch of the bed types

Hand made BBF

The farm tools used for bed preparation

•RF was Modified and made with a new tool (40 cm wide instead of 20 cm)•Compared with BBF (80 cm and RF (20 cm)

Effect of the treatments

•Late planting on wide ridge and furrows (LWRF) gave the highest crop water productivity•The gain in milk yield due to increased straw yield was also the highest with LWRF

Crop Water Productivity

0

0.2

0.4

0.6

0.8

1

BBF EWRF ERF LWRF LRF

kg

m-3

T ET Rainfall

Milk Production

Key messages

•Integrating livestock into the value chain enhances overall SWP

•Decisions of technology choice with or without considering livestock may be different

•In this case, it is the same