Search

Extended Range of Forecast Service (ERFS) is highly useful for planning of cropping season and midterm correction at the farm level. The medium-range and long-range forecast validation have many studies, whereas ERF has less that needs to be studied. Maize is an important field crop in India after rice and wheat. Therefore, the prediction of maize yield has significant importance. In the present study, ERFS data were validated by correlation analysis using monthly observed rainfall frequency and intensity. This data was imported to DSSAT (Decision Support System for Agro-technology Transfer) to simulate maize yield of Erode district of Tamil Nadu. The model output and actual yield data from Erode were compared. Forecasted monthly total rainfall was correlated at a rate of 0.97r value with that observed. Yield simulation of maize was done using DSSAT by integrating ERFS data and the observed monthly data. Mean per cent deviation among the yields of observed weather and the disaggregated one tended to be -15.7 %. The average deviation between the yields of ERF forecasted weather data and actual yield was very high (-29.7 %) for Erode. Mean % deviation between the yields of observed weather and the actual yield was - 14.7 %. Downscaled and accurate weather forecasts could be facilitated for yield prediction of crops by DSSAT model. Yield prediction by the model under observed weather was convenient and usable. Model under-predicted the yields when using ERF data. Both model and ERF forecast need to be improved further for higher resolution. [ABSTRACT FROM AUTHOR]

Among the pulses, bengal gram (Chickpea) has been considered for the present study in the scenario of uncertain monsoon behaviour where it is an excellent crop benefiting the farmers since its ability to withstand drought condition with lesser rainfall. The present study was under taken intentionally to assess the trends in area, production, productivity and Efficient cropping zones (ECZ) of the emerging pulse crop (Bengal gram) of Tamil Nadu, to identify and analyse the factors influencing the area, production and productivity of bengal gram as well as to key note the available niches over the state (Tamil Nadu). The zones were identified for latest 10 year average (2005-2014). The trend analysis was carried out for 1950-2014, 1950-1979 and 1980-2009 and at decadal scale for state level. The results showed that the trend in area, production and productivity were increasing with the new technologies that could further extend the crop over the efficient cropping zones. The compound growth rate of 2.44 per cent per annum over Tamil Nadu during the time period of 1950-2014 could be achieved as a whole. Coimbatore, Tiruppur, Dindigul and Dharmapuri districts of Tamil Nadu during the latest ten years, 2005 to 2014 were found to be the efficient cropping zones for bengal gram from this study. [ABSTRACT FROM AUTHOR]

Global climate change has increased the events and intensity of extreme events. Tamil Nadu is located in the southern peninsula region of India, which has benefitted both from the south-west monsoon (SWM) and the north-east monsoon (NEM). Although variations in the monsoon pattern increased events of drought. The IMD gridded (1991–2020) and projected global climate model data (EC_Earth3_Veg_LR) were used to anticipate the drought-risk-prone zones over Tamil Nadu by using the standardized precipitation index. During both the SSP245 and SSP585 scenarios of the near (2021–2050) and mid (2051–2080) century periods, an increase in rainfall amount was expected with a high coefficient of variation (CV) across the region. The CVs of the future SWM and NEM seasons were expected to range from 20% to 60% and 25% to 50% respectively. Increased variability often leads to an increase in number of drought events. Regardless of scenarios, the southern zone was expected to experience more drought events, followed by the northwestern zone during SWM. Drought events during the NEM were expected to increase in northeastern zone districts. Changes in cropping patterns and policymaking for future risk-prone areas were undertaken as a proactive response to mitigate potential agricultural challenges. [ABSTRACT FROM AUTHOR]

To assess the drought hazard for different agro-climatic zones of Tamil Nadu (TN), India, the present study deals with temporal trend and spatial pattern of drought over the period 1981-2019. Standardized Precipitation Index (SPI) has been used to detail the geographical variations of drought intensity, duration and frequency at multiple time steps. The spatial rainfall variability of the Southwest monsoon (SWM) ranged from 69.3 mm (Tuticorin) to 772.8 mm (the Nilgiris), and that for the Northeast monsoon (NEM) ranged from 277.8 mm (Krishnagiri) to 825.9 mm (Nagapattinam), while annual rainfall variability ranged from 558.8 mm (Tuticorin) to 1466.8 mm (the Nilgiris) for TN. Irrespective of all the regions, the frequency of moderate drought occurrence was higher compared to other drought nomenclature. The NEM season recorded on par and higher number of drought occurrences with respect to SWM season. Out of 39 years, TN experienced severely dry to extremely dry climate during 2002. The result underlines the potential of SPI in drought identification and also revealed that the rainfall is strongly linked to drought policies and measures implemented for the state. [ABSTRACT FROM AUTHOR]