Evaluation of different rainwater harvesting techniques for improved maize productivity in semi‐arid regions of Zimbabwe with sandy soils

Abstract

Background Maize production in semi‐arid areas has been hindered by moisture stress and poor soil fertility. Long frequent droughts and shortening of growing seasons have been causing yield reduction. Limited knowledge of soil water management by farmers is another key contributor to poor maize yields in the smallholder sector. Therefore, the objective of the study was to investigate the effects of contour‐based and field‐based water harvesting technologies on maize grain yield and rainwater use efficiency under rain‐fed conditions on three farms (Jera, Kudzeeta and Manjengwa) with sandy soils in the Marange smallholder farming area of Zimbabwe. The experiment was laid out as a split plot in a randomised complete block design with three replications at each site. Contour‐based rainwater harvesting structures were the main treatments comprising tied contour (TC), standard contour (STDC) and infiltration pits (IP). Field‐based rainwater harvesting structures were the subplot treatments comprising tied ridges (TR), pot holing (PH) and the flat system (FLAT). Results Results showed that the contour‐based water harvesting structures significantly influenced (p < 0.05) maize grain yields. TCs had the highest maize grain yields compared with infiltration pits and STDCs over two cropping seasons. Maize yields on field‐based TR were significantly higher (p < 0.05) than on the FLAT but were not different (p > 0.05) with what was obtained on PH. The combination of TC and TR water harvesting technologies resulted in significantly higher maize yields (p < 0.05) than other combinations. TR and STDC also gave higher maize grain yield at Jera farm which was significantly different from other two farms. Rainwater use efficiency followed the same trend as maize grain yields, with TC having higher values but not significantly different (p > 0.05) from STDC. Conclusion It can be concluded that farmers in semi‐arid areas adopt a combination of TC with either TR or PH to improve rainwater use efficiency and maize yields.

Microdosing of nitrogen fertiliser and cattle manure under in situ rainwater harvesting to improve maize production in smallholder farming system in a semiarid area of Zimbabwe

“…The use of TRs had better maize grain yields because they have capacity to capture more rainwater, increase infiltration and reduce soil erosion. This concur with studies by Mudatenguha et al (2014) and Chiturike et al (2023) who reported increased maize grain yields with the use of TR. Limited use of RWH practices was explained by Nyamadzawo et al (2013) and Nyagumbo et al (2019) who reported that adoption of soil and water conservation techniques have been very low in semiarid areas due to high labour requirements and lack of technical knowledge.…”

“…Maize grain yield is mainly constrained by soil infertility due to inadequate nutrient supply and soil moisture stress in rainfed agriculture especially in semiarid areas of SSA (Chiturike et al, 2023).…”

“…Maize grain yield is mainly constrained by soil infertility due to inadequate nutrient supply and soil moisture stress in rainfed agriculture especially in semiarid areas of SSA (Chiturike et al, 2023). This call for measures needed to mitigate effects of climate change caused by rainfall variability and soil infertility in semiarid areas of SSA to improve crop production and reduce food insecurity (Bado et al, 2022; Kugedera, Mandumbu, & Nyamadzawo, 2023; Mahinda et al, 2018).…”

Evaluating effects of selected water conservation techniques and manure on sorghum yields and rainwater use efficiency in dry region of Zimbabwe

“…Land degradation and unreliable rainfall in semi-arid areas influences crop production under rainfed agriculture [ 1 , 2 ]. Land degradation is caused by high rainfall intensity and lack of soil cover especially in semi-arid areas dominated by sandy-to-sandy loam soils [ [3] , [4] , [5] ].…”

“…Land degradation is caused by high rainfall intensity and lack of soil cover especially in semi-arid areas dominated by sandy-to-sandy loam soils [ [3] , [4] , [5] ]. Smallholder farmers in semi-arid areas have limited knowledge on proper water and soil fertility management [ 2 , 6 , 7 ]. Sorghum grain yield under rainfed agriculture in smallholder farming environments has been low (<0.3 t ha −1 ) [ 8 ], increasing risk of food insecurity and poverty [ [9] , [10] , [11] ].…”