Investigation of the optimum planting dates for maize varieties using a hybrid approach: A case of Hwedza, Zimbabwe

Hillary Mugiyo,Teddious Mhizha,Vimbayi.G.P Chimonyo,Tafadzwanashe Mabhaudhi

doi:10.1016/j.heliyon.2021.e06109

Hillary Mugiyo, Teddious Mhizha + Show 2 more

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https://doi.org/10.1016/j.heliyon.2021.e06109

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Journal: Heliyon	Publication Date: Feb 1, 2021
Citations: 9	License type: cc-by

Affiliation: University of Zimbabwe, University of KwaZulu-Natal

Abstract

Water scarcity and unreliable weather conditions frequently cause smallholder farmers in Zimbabwe to plant maize (Zea mays L.) varieties outside the optimum planting timeframe. This challenge exacts the necessity to develop sowing management options for decision support. The study's objective was to use a hybrid approach to determine the best planting windows and maize varieties. The combination will guide farmers on planting dates, dry spell probability during critical stages of the crop growth cycle and rainfall cessation. To capture farmer's perception on agroclimatic information, a systematic random sampling of 438 smallholders was carried out. An analysis of climatic data during 1949–2012 was conducted using INSTAT to identify the best planting criterion. The best combination of planting criterion and maize varieties analysis was then achieved by optimizing planting dates and maize varieties in the DSSAT environment. It was found that 56.2% of farmers grew short-season varieties, 40.2% medium-season varieties and 3.6% long-season varieties. It was also established that the number of rain days and maize yield had a strong positive relationship (p = 0.0049). No significant association was found amongst maize yield (p > 0.05), and planting date criteria, Depth (40mm in 4 days), the AREX criterion- Agricultural Research Extension (25 mm rainfall in 7 days) and the MET Criterion-Department of Meteorological Services (40 mm in 15 days). Highest yields were simulated under the combination of medium-season maize variety and the AREX and MET criteria. The range of simulated yields from 0.0 t/ha to 2.8 t/ha formed the basis for the development of an operational decision support tool (cropping calendar) with (RMSE) (0.20). The methodology can be used to select the best suitable maize varieties and a range of planting time.

Highlights

In rural sub-Saharan Africa (SSA) and resource-constrained smallholder, rain-fed agriculture is the most important sector for providing food security (Gowing and Palmer, 2008)
There is high variability in rainfall characteristics which translates to high variability in maize yield per hectare
The validated Decision Support System for Agrotechnology Transfer (DSSAT) model and INSTAT were used to select the best combination of planting criteria and maize variety

Summary

Introduction

In rural sub-Saharan Africa (SSA) and resource-constrained smallholder, rain-fed agriculture is the most important sector for providing food security (Gowing and Palmer, 2008). Rain-fed crop production is becoming more unreliable, yet 90% maize farmers of rural farming communities relay of rain-fed agriculture as a livelihood strategy (Kirkegaard et al, 2014; Sheffield et al, 2014). Maize production in Zimbabwe decreased dramatically over the past decade, yet over 50 percent of maize human consumption is imported from African, America, Asian and European countries (FNSWG, 2015). The production of maize in Zimbabwe varies from 950 000 tonnes (1 500 000 ha) to 2 500 000 tonnes (2 000 000 ha) per annum (OECD and FAO, 2016). In Zimbabwe, maize is a strategic crop, improving its production through good agricultural practices, especially in marginal areas, will reduce food insecurity.

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