Abstract
Climate is one of the major factors controlling agricultural productivity in Africa. Changes in meteorological variables such as rising temperatures, changes in precipitation and increase in atmospheric carbon dioxide levels affect crop production. The objective of this study was to evaluate the impacts of climate change and variability, and crop management on yield of maize (Zea mays L.) grown in the southern part of Tanzania. Using the Decision Support System for Agrotechnology Transfer Cropping System Model (DSSAT-CSM), a series of sensitivity experiments were conducted to evaluate the response of maize yields to a range of principal changes in rainfall and temperatures. The sensitivities were estimated under two management practices, one with traditional farming practices, and the other with application of external farm inputs. Dry-spells during the growing season caused yield losses of all cultivars of up to 43% for the prolonged dry-spells of 20 days. Increased rainfall intensity, during vegetative and reproductive stages, caused the decrease in yield of 5 and 2%, respectively. A 50-100% decrease in rainfall intensity during the growing season caused a loss of yields between 40-100%. Increased or decreased temperatures from the baseline values reduced or increased days to flowering and to physiological maturity, respectively. In addition, a decrease in temperature from the baseline values to 2 o C had an overall impact of yields loss for all cultivars. However, yields increased with an increase of temperature by up to 2.5 °C (UH6303 and H628) and 4.5 °C (PAN691). Growing seasons with lower total rainfall (<50 mm) and temperature (<1°C) from their climatological values, caused yield loss as much as 71 and 15%, respectively for PAN691 cultivar. Generally, the impacts depended on the management, cultivar, soil characteristics, magnitude, timing and duration of the stress.Keywords: DSSAT, rainfall, temperature, Zea mays
Highlights
Among the major factors controlling agricultural productivity in Africa is climate (Sivakumar, 1988; Moore et al, 2012)
According to Mourice et al (2014), the reason why farms with YARA-SYNGENTA_SUA practice (YSSP) management experience higher yield losses compared to farmers practice (FP), could be because plants under high nitrogen supply are more vulnerable to water stress since they possess large leaf area through which a lot of water escapes via evapotranspiration
It is clear that both dry spells and decreased rainfall intensity in the growing season have negative impacts to yields as expected
Summary
Among the major factors controlling agricultural productivity in Africa is climate (Sivakumar, 1988; Moore et al, 2012). Temperature increase over the season in an area suffering from water stress may increase evapotranspiration, which could trigger drought stress of plants (Mati, 2000; Tao et al, 2003). This may reduce the growing period of the crop from sowing to maturity, resulting in yield reduction (Tao and Zhang, 2011). Dry spells may affect crop growth and final yields, even without significant reductions in seasonal rainfall totals (Barron et al, 2003). For example, appears to be relatively tolerant to water deficits, during the vegetative growth stage, but not during tasselling and ear formation (Çakir, 2004)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
