*3.4. Direct Effects of Farming and Irrigation Systems on Water Use and Crop Yield*

A one-tailed paired t-test was used to analyze the impacts of soil and water management practices on the amount of water applied (irrigation plus effective rainfall), Table 5. The mean water use was significantly reduced (α = 5%) under CA for all vegetables (Table 5). The mean water uses of garlic, cabbage, and potato mean water uses were reduced, respectively, by 18%, 8%, and 9% under CA when compared to CT. However, the water use difference was not statistically significant (α = 5%) between drip and overhead water application systems, both under CA practice.


**Table 5.** The mean value of crops totals water uses under different tillage (CA versus CT) and water management (drip versus overhead water application) systems.

Note: N, SEM, Max., Min., \*\*\* are sample size, standard error of the mean, maximum, minimum, and significance at *p* < 0.001, respectively.

Crop yields were significantly increased under CA and drip irrigation systems (Table 6) for all crops (i.e., irrigated vegetables and rainfed maize production). The mean crop yields of the garlic bulb, fresh cabbage, potato tuber, and maize grain were increased by 170%, 42%, 43%, and 15% under CA when compared with CT, respectively, though water applications were significantly reduced under CA practice. Similarly, the mean crop yields of potato tuber and onion bulb were significantly increased under the drip irrigation system when compared with the overhead water application using a hose, though both irrigation systems were under CA practice. Potato and onion yields were increased by 43% and 36%, respectively, under drip water application when compared to overhead water application using a hose. On the other hand, farmers were able to harvest from about 5 t ha−<sup>1</sup> to 12.5 t ha−<sup>1</sup> of forage biomass beside 7.2 t ha−<sup>1</sup> of maize production without using irrigation
