The VCI was chosen over other drought indices as it is one of the most commonly used remotely sensed index for drought and crop condition monitoring and has been successfully applied across a number of agricultural landscapes in Africa (Unganai and Kogan 1998; Kuri et al. Sorghum (Sorghum bicolor L.) is one of the most important food crops promoted in semi-arid regions where precipitation and fertility are low and highly variable. Limited research studies exist with significant detail in space and time on sorghum grain yield response under rainwater harvesting practices (Tonitto and Ricker-Gilbert, 2016). Figure 1. In contrast, results at the 3-month scale show relatively higher specificity than at the monthly scale implying concurrence of the two indices in detecting absence instead of drought presence (Table 5). This could suggest that crops in wetter regions are more sensitive to changes in water availability than those in higher rainfall areas. Although the crop is widely recognized as well as adapted to semi-arid environments it fails in some years (Nyamudeza and Maringa, 1992) because production is entirely rain-fed in small-scale farming systems (Ndlovu etal., 2020). stream (2011) into low (030 kg N/ha) medium (30100 kg N/ha). Another important result of this study is that there is better correlation between VCI and SPI in wetter than drier regions at both 1-month and 3-month scale (Table 3). Contrasting results were also observed by Nyakudya etal. Ripper planting reduced grain yield significantly (p < 0.05) (1.06 t/ha) in soils with 2035% clay. On a spatial scale, the highest frequency of droughts was observed in the districts of Hurungwe and the south and north-western parts of the country i.e., Beitbridge and Hwange mostly located in Agro-ecological region 5. /Rotate 0 Did you know that with a free Taylor & Francis Online account you can gain access to the following benefits? This work was partial supported by International Foundation for Science (IFS) (grant number C4569-2). (2014) who showed that combining infiltration pits and planting pits did not improve soil moisture and yields in the Rushinga district of Zimbabwe, a semi-arid farming area with heterogeneous soils. << Ronald Mandumbu: Conceived and designed the experiments; Contributed reagents, materials, analysis tools or data. Singh et al. Advantages of the VCI are that as a satellite-based agricultural drought index, it provides near real time data across spatial scales and overcomes the problem of sparse network of meteorological stations that are characteristic of most developing countries such as Zimbabwe (Dhakar et al. There was no substantial improvement in sorghum grain yield in planting basins, ripper, and tied ridges rainwater harvesting practices compared with conventional farming practices under the different soil textural categories in Zimbabwe. The high frequency of drought occurrence in most parts in the southern, south-eastern, western, and northern parts of the country during the first part of the season may also be due to late onset of the rainfall season. /Filter /FlateDecode Careers. On a yearly scale, droughts were detected in 2002, 2006, 2008, 2009 and 2018 while at the monthly scale November had the highest frequency of drought occurrence. >> In moderate rainfall (6001000 mm), ripper planting had a significant overall effect size (p < 0.05) with a weighted mean difference of 0.32 t/ha (Figure2a). The results suggest that basins, rippers, and tied ridges did not improve sorghum grain yield across all agronomic conditions. Proceedings of the Third Annual Scientific Conference. This was observed throughout the period under study except for Agro-ecological region 1 and few isolated pockets in Agro-ecological regions 2a and 2b (Figure 6). We did not classify droughts based on intensity as our interest was on drought detection regardless of the drought intensity. sharing sensitive information, make sure youre on a federal 2021), few have characterised agricultural drought in across temporal scales relevant for agricultural planning e.g., monthly scale or sub-seasonal scale. There was no yield advantage for planting basins over conventional planting, while tied ridges showed considerable yield depression There was no experimental data on ripper planting in areas with less than 600 mm of rainfall. /Parent 2 0 R zimbabwe region crisis map bbc africa Frequency of drought occurrence for the months of a) October, b) November, c) December, d) January, e) February, f) March and g), April. %PDF-1.4 endobj Zambrano et al. Mashingaidze N., Twomlow S., Madakadze I.C., Mupangwa W., Mavunganidze Z. Weed growth and crop yield responses to tillage and mulching under different crop rotation sequences in semi-arid conditions. /MediaBox [0 0 439.37 666.142] Stata/MP 16.0 statistical software was used to perform the effect size in meta-analysis. Effects of tillage and mulching over two seasons on grain yield of sorghum bicolor at Matopos , Zimbabwe. >> ns denotes no significant differences. /TrimBox [0 0 439.37 666.142] 2020). /Version /1.4 FAO . /ExtGState << Figure 10. Variations in monthly SPI based on rainfall measured from 1981 to 2020 at Nyanga weather station in Zimbabwe. (2021) who observed the tendency of the VCI and TCI to perform well in monitoring long-term drought conditions. (2008) and Rockstrm etal. Results from this study further emphasise the need for not only identifying areas at risk of agricultural drought but the specific periods during which droughts are experienced thereby providing spatially and temporally specific information that is key in making interventions in the agricultural sector such as irrigation. 2018). Spatially, areas with the highest frequency droughts are in the southern and northern parts of the country which coincide with Agro-ecological region 5.

The yield of sorghum had not increased over the years because smallholder growers lack adequate sustainable production knowledge to increase yields above subsistence level even in years of good rainfall. In addition, the high frequency of droughts directly threatens agricultural dependent economies and livelihoods and impedes the attainment of the United Nations Sustainable Development Goals, particularly, goals number one, two and three, that is, no poverty, zero hunger, and good health and wellbeing, respectively (Frischen et al. (2001), and Thiombiano and Meshack (2009). Overall, results showed that droughts are a recurrent phenomenon with an average of six out of 19years having experienced drought. Allen, R.G., Pereira, L.S., Raes, D. and Smith, M., Assessment and monitoring of agricultural droughts in maharashtra using meteorological and remote sensing based indices, Assessment of drought conditions using HJ-1A/1B data: A case study of Potohar region, Pakistan, Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data, Detecting climate changes of concern in highly variable environments: Quantile regressions reveal that droughts worsen in Hwange National Park, Zimbabwe, Rainfall prediction for sustainable economic growth, Drought monitoring for Masvingo Province in Zimbabwe: a remote sensing perspective, Reclassification of agro-ecological zones in Zimbabwe-the rationale, methods and expected benefits: The case of Masvingo Province, The South Indian convergence zone and interannual rainfall variability over Southern Africa, Study on inter-seasonal and intra-seasonal relationships of meteorological and agricultural drought indices in the Rajasthan State of India. A meta-analysis was conducted to provide a comprehensive quantitative synthesis of biophysical conditions (rainfall, soil texture, N fertility, mulch) under which basins, rippers, and tied ridges affected sorghum yields in semi-arid areas of Zimbabwe. Metrics used to validate the satellite derived drought index based on SPI calculated from six rainfall stations across Agro-ecological regions of Zimbabwe. Tied ridges showed considerable grain yield reduction compared with farmer's practice (conventional practice) when rainfall was <600 mm suggesting the absence of yield benefits of the rainwater harvesting practice. In a meta-analysis, Nyamangara etal.

/T1_1 10 0 R 1993) (SPI) at the monthly and 3-month timescales. During drought years these regions can receive less than 60% of their long term average annual rainfall (Nangombe, 2015). Drought is a complex phenomenon whose dimensions are still poorly understood (Frischen et al. George Nyamadzawo; Justice Nyamangara: Conceived and designed the experiments. The best growth responses and economic benefits are expected when moisture is not a limitation (Gotosa etal., 2019). The most intense drought was detected in the years 2002 and 2008 and its spatial coverage also varied spatially. On the contrary, ridges and tied ridges showed failures and successes (Nyamudeza, 1993). The two soil fertility categories of <30 kg N/ha and 30100 kg N/ha had WMD of 0.03 t/ha and 0.12 t/ha respectively. Drought is a recurrent natural phenomenon, with adverse impacts on socio-economic development and the environment in general (Wilhite et al; Aswathi et al. Some lessons from Zimbabwes agricultural recovery programme. /ColorSpace << The resultant Boolean maps were then overlayed in a GIS environment to create a confusion matrix, indicating the number of times a drought or no drought condition was detected or missed by these two indices in ILWIS GIS (ITC, 2000). No additional information is available for this paper. Motsi K.E., Chuma E., Mukamuri B.B. The operational definition of drought thus depends on the component of the biophysical or socio-economic system affected (Winkler et al. The .gov means its official. Spatial variation in drought frequency at the annual scale across Agro-ecological regions of Zimbabwe for the years a) 2000, b) 2001, c)2002, d) 2003, e) 2004, f) 2005, g) 2006, h)2007, i) 2008, and, j) 2009. 2010; Muthumanickam et al. A weighted mean difference of 0.29 t/ha was shown, implying no yield difference between tied ridges and conventional planting. Mean differences between treatments and control were used (Eq.

In contrast, areas located in Agro-ecological regions 1 (eastern), 2a and 2b (central to eastern) experienced fewer drought episodes compared to the rest of the country. Seasonal forecasting of the Ethiopian summer rains. Data were collected from peer-reviewed articles (journal articles, refereed book chapters and books, and published refereed conference papers). In this study, the Vegetation Condition Index (VCI) was used to characterize drought occurrence in Zimbabwe. Continuous or measurable variables are frequently reported as weighted mean difference (WMD), and for ease of understanding and making inference, mean differences were used for the analysis (Corbeels etal., 2014; Nyamangara etal., 2014; Rusinamhodzi etal., 2011). The finding that the southern and western districts of the country such as Beitbridge, Chiredzi, Gwanda and Mwenezi are highly susceptible to droughts across all temporal scales is consistent with previous studies. Therefore, the importance of studies aimed at understanding drought progression over time cannot be over-emphasized especially in rain-fed Agro-based economies. 3099067

In fact, few studies have taken advantage of the unique opportunities offered by satellite sensors such as wide spatial coverage in addition to availability of data at consistent temporal and spatial dimensions, suitable for farm-scale drought analysis (Unganai and Kogan 1998; Mutowo and Chikodzi 2014; Kuri et al. /MC0 << >> Table 1. >> /T1_0 9 0 R /ProcSet [/PDF /Text] Zimbabwe is located in southern Africa and is surrounded by Mozambique to the east, Zambia to the north, Botswana to the west and South Africa to the south (Muchadeyi et al. Suitable for livestock, fodder, and cash crop production.

PROBA-V Normalized Difference Vegetation Index (NDVI) data were used to fill the gap (1 June 2014 to 31 December 2018). /TrimBox [0 0 439.37 666.142] 2018; 2020). Globally, droughts have resulted in significant loss of life. The quest for alternative food policies, Simulating drought in Southern Africa using sae surface temperature variations, Effect of farmer management strategies on spatial variability of soil fertility and crop nutrient uptake in contrasting agro-ecological zones in Zimbabwe, Comparison of the predicted and observed secondary structure of T4 phage lysozyme, Investigating changes over time of annual rainfall in Zimbabwe, The relationship of drought frequency and duration to time scale, Proceedings of the Eighth Conference on Applied Climatology, Anaheim, California, Investigating remote sensing indices to monitor drought impacts on a local scale (case study: Fars province, Iran), The political economy of land acquisition and redistribution in Zimbabwe, 1990-1999, Assessing the spatio-temporal variability of NDVI and VCI as indices of crops productivity in Ethiopia: a remote sensing approach, Geomatics, Variation in village chicken production systems among agro-ecological zones of Zimbabwe, Re-classification of agro-ecological regions of Zimbabwe in conformity with climate variability and change, Spatio-temporal dynamics of drought in Zimbabwe between 1990 and 2020: a review, Drought assessment and monitoring through remote sensing and GIS in western tracts of Tamil Nadu, India, Remote sensing based drought monitoring in Zimbabwe, Fluctuations in the onset, termination and length of the growing season in Northern Nigeria, Drought trends based on the VCI and its correlation with climate factors in the agricultural areas of China from 1982 to 2010, Evaluating the utility of the Vegetation Condition Index (VCI) for monitoring meteorological drought in Texas, A new potential method to estimate abundance of small game species, Assessing agricultural drought at a regional scale using LULC classification, SPI, and vegetation indices: case study in a rainfed agro-ecosystem in Central Mexico, Climate change scenarios, perceptions and crop production: a case study of Semi-arid Masvingo Province in Zimbabwe, Vegetation and temperature condition indices from NOAA AVHRR data for drought monitoring over India, Changes in growing-season rainfall characteristics and downscaled scenarios of change over southern Africa: implications for growing maize, Addressing drought conditions under current and future climates in the Jordan River region, Establishing a drought index incorporating evapotranspiration, Drought monitoring and corn yield estimation in Southern Africa from AVHRR data, Comparative evaluation of drought indices for monitoring drought based on remote sensing data, Understanding: The drought phenomenon: The role of definitions, Identifying droughts affecting agriculture in Africa based on remote sensing time series between 20002016: rainfall anomalies and vegetation condition in the context of ENSO, Sixteen years of agricultural drought assessment of the BioBo region in Chile using a 250 m resolution Vegetation Condition Index (VCI), Remote sensing strategies to characterization of drought, vegetation dynamics in relation to climate change from 1983 to 2016 in Tibet and Xinjiang Province, China. AReview3rd African Association of Agricultural Economists (AAAE) and 48th Agricultural Economists Association of South Africa (AEASA) Conference. The results on ripper + mulch farming practice were in tandem with findings by Masaka etal. The Essential Guide to Effect Sizes: Statistical Power, Meta-Analysis, and the Interpretation of Research Results. zimbabwe forecasts mugabe zambia forecasting chinhoyi mobilisation endobj /T1_1 11 0 R Cambridge University Press; 2010. $:,-fhRod%A+>-)gfd'g?\W?f$]^&y/6+JBlg0Ib7X1&=x[w4Xf3q{fckwKO\?Y+s6[%3KC/|7Y6 Learn more Results show that sensitivity (True Positive Rate) is generally higher than specificity (True Negative Rate) across all six stations considered in this study suggesting that the two metrics agree on drought occurrence more than they agree on the non-occurrence of drought. John Wiley & Sons; 2015. Soko T. UZeScholar Institutional Repository; 2012. Studies by Mupangwa etal. (2011) into Sand (<20 % clay), Loam (2035 % clay), and Clay (>35 % clay). Agronomic Practices for the Low Rainfall Regions of Zimbabwe. >> This study utilised multi-temporal satellite data to characterize droughts across the five Agro-ecological zones (AEZ) of Zimbabwe at monthly, seasonal, sub-seasonal and annual scales (2000 to 2018) using a combination of Satellite Pour l'Observation de la Terre (SPOT) Vegetation (VGT) and Project for On-Board Autonomy-Vegetation (PROBA-V) derived Vegetation Condition Index (VCI). /CropBox [0 0 439.37 666.142] This causes low crop responses to rainwater harvesting and inorganic fertilizer use resulting in low benefits on crop yields as reflected by the marginal weighted mean difference under the two fertility categories. Mupangwa W., Twomlow S., Walker S. Dead level contours and infiltration pits for risk mitigation in smallholder cropping systems of southern Zimbabwe. 2016). This is further supported by a moderate to relative strong agreement between the two drought indices as reflected by high accuracy values and F1 Scores. mudzi smallholder participation groundnut determinants francesconi etosha aoba