Soil Water Storage under Selected Maize Varieties (Zea mays L.) for Rain-fed Conditions in Zambia

Abstract

Aim: To evaluate soil water storage under 30 maize varieties differing in maturity for rain-fed conditions in Zambia.  Materials and Methods: The study was conducted at the University of Zambia Agricultural Demonstration Center during the 2014-2015 rainy season in a randomized complete block design with 3 replications. Soil water storage was determined from gravimetric soil water measurements on selected dates during the crop growing season, while changes in soil water storage, drainage and runoff were estimated using the AquaCrop model.  Measured parameters were subjected to Analysis of Variance and differences declared significant at P < .05.  Results: Significant differences were observed in storage and runoff (P < .001), and drainage (P = .00) of early maturing maize varieties. Maize varieties MRI 514, SC 513 and PAN 413 consistently had the lowest soil water storage in the profile, while SC 525 and SC 403 consistently had highest soil water storage throughout the growing season. Among medium maturing maize varieties, there was net depletion of water in the soil profile. However, no significant differences were observed in storage (P = .12), runoff (P = .11) and drainage (P = .84). PHB 30G19 and P 3812w maize varieties had, respectively, the lowest and highest amount of stored soil water in the root zone. No significant differences were observed in storage (P = .64), runoff (P = .30) and drainage (P = .22) for late maturing maize varieties. Nevertheless, PAN 8M 93 consistently had the lowest soil water storage, while ZMS 720 had the highest amount of stored soil water.  Conclusion: The study concludes that soil water storage was dictated largely by the magnitude of drainage and runoff due to the sandy textured nature of the studied soil. Therefore, there is need to integrate effective management strategies that can enhance soil water storage especially on soils with low water holding capacity and such strategies are henceforth recommended.