Erratic rainfall and temperature regimes, strongly affect agricultural productivity. To address the reduction in production, this study assessed the effect of Zai pit depths on selected soil properties and cowpea growth and grain yield. Zai pit technology was tested in two locations falling under Agroecological Zone IV (relatively dry areas) i.e. Machakos in Machakos County and Naivasha in Nakuru County, Kenya, aiming to determine the combined effect of four Zai pit depths and two levels of manure (plots with manure and plots without manure) on selected soil properties, growth and yield of cowpea. Experiment was laid out in split plot arrangement, with manure levels as the main plot factor and Zai pit depths (Flat: Z 0 , 30 cm: Z 30 , 45 cm: Z 45 and 60 cm: Z 60 ) as subplot factor, replicated four times. Cowpea (M66 variety) was used as the test crop. Inorganic nitrogen (N in ) and extractable phosphorus (P ex ) were significantly (P < 0.05) higher, at 1.37 mg•kg −1 for N in and 80.4 mg•kg −1 for P ex in Zai pits compared to flat plots which were at 0.91 mg•kg −1 for N in and 47.1 mg•kg −1 for P ex . The values of N in and P ex also varied depending on depths, with Z 45 having highest N in at 1.17 against the least, at 0.89 in the Z 0 , while Pex was highest in Z 30 at 102.3 mg•kg −1 while Z 0 having the least P ex of 89.7 mg•kg −1 . Generally, crops in Zai pitted plots were larger in diameter (0.46 cm) and height (34.20 cm) than crops in flat plots at (0.42 cm) and (18.11 cm) diameter and height respectively. Better performance was observed in yield, with Z 45 yielding 853.33 kg•Ha -1 against 685.0 kg•Ha -1 in Flat plots in Machakos while 931.66 kg•Ha -1 in Z 45 against 563.33 kg•Ha -1 from Flat plots in Naivasha. This study demonstrated great potential of Zai pit technology on crop production, as reflected on improved growth and yield of cowpeas. Combining Zai pits with manure increases soil N in , P ex and is a guarantee of great crop performance in terms of high final yields.