Abstract:
As a result of water resource shortage and the need for food self-sufficiency in Ethiopia, it has
become essential to improve the productivity. In this study, an attempt was made to evaluate
the impact of alternate furrow irrigation technique on yield and water productivity. Alternate
furrow irrigation versus every furrow, fixed furrow and farmer practice (open-ended and
unstructured furrow) were evaluated at full crop water requirement. The experimental design
used was randomized complete block design with four treatment replicated five times. Results
obtained revealed that average water application efficiency of alternate furrow irrigation was
85% which was high as compared to other irrigation methods at all irrigation events. Average
application efficiencies of ever furrow irrigation, fixed furrow irrigation and farmer practice
were 61.5%, 73.4% and 42% respectively. The average distribution uniformity of alternate
furrow irrigation and every furrow irrigation methods were 89.3% and 85.3% respectively,
which showed no significant difference between the two methods. However, average
distribution uniformity of fixed furrow irrigation was 75.4%, which showed significant
difference between alternate furrow and fixed furrow irrigation methods. Farmer practice
showed poor water distribution uniformity of 63.8%. Alternate furrow irrigation method
produced total tuber yield of 33198kg/ha which showed insignificant difference as compared
with that obtained under every furrow irrigation ( 33369kg/ha). Total tuber yield harvested
from fixed furrow irrigation and farmer practice were 30177kg/ha and 30098kg/ha
respectively, which showed insignificant difference between the two methods. High marketable
yield of 32667.8kg/ha was recorded from alternate furrow irrigation whereas, low marketable
yield of 28266.7kg/ha was recorded from farmer practice. Water productivity of
11.2kg/m3,10.7kg/m3,6.1kg/m3and 4.1kg/m3 were produced under alternate furrow, fixed
furrow, and every furrow and farmer practice respectively. It was found that alternate furrow
irrigation method saved 50% of water as compared with every furrow and 68.4% as compared
with farmer practice. Therefore, it is recommended alternate furrow irrigation method with
appropriate irrigation interval is suitable irrigation method; for humid climate where soil is
dominated by clay soil and water is liming factor for potato crop production.
