Droughts, short growing seasons and poorly distributed rainfall are major constraints to maize production in eastern semi-arid
region of Rwanda. In situ rain water harvesting offers an alternative option to reduce rainwater runoff, increase infiltration and
storage of water in soil and reduce the effects of drought stress on maize grain yield. The objective of the study was to assess
the effects of in situ water harvesting techniques on soil moisture content, maize growth and grain yield in Nyagatare, Rwanda
in the 2011-2012 seasons. The study comprised of four treatments: pot holing, tied-ridging and mulching compared to control
treatment of planting on the flat. The experimental design was randomized complete block with three replicates. Soil moisture
content and maize plant dry weight were measured at 8, 11 and 14 weeks after emergence (WAE). There was a significant
increase (P<0.001) in soil moisture content and maize plant dry weight from planting on the flat (control), pot hole, tied ridges
to mulching at 8, 11 and 14 WAE. Yield components (ear mass, number of grains per ear and 100 grain weight) and grain
yield significantly increased (P<0.001) from planting on the flat, pot holes, tied ridges and were highest in the mulched
treatment. Maize grain yield increased(P<0.001) by 49.6, 103 and 136% of the maize grain yield harvested from the flat
planting(1593.36 kg ha-1
) in the pot-holing, tied ridging and mulching treatments, respectively. The results of this study
indicate that mulching, tied ridges and pot holes, in decreasing order of effectiveness, have potential to increase soil moisture
content and reduce the damage caused by drought stress to maize growth and grain yield and therefore recommended for
farmers in Nyagatare and other drought prone regions