Monsoon variability, crop water requirement, and crop planning for kharif rice in Sagar Island, India.
24 Apr 2015-International Journal of Biometeorology (Springer Berlin Heidelberg)-Vol. 59, Iss: 12, pp 1891-1903
TL;DR: The present study highlights the adaptive capacity of crop planning including abiotic stress-tolerant cultivars to monsoon rainfall variability for sustaining rainfed rice production vis-à-vis food and livelihood security in vulnerable islands of coastal ecosystem.
Abstract: In the Sagar Island of Bay of Bengal, rainfed lowland rice is the major crop, grown solely depending on erratic distribution of southwest monsoon (SM) rainfall. Lack of information on SM rainfall variability and absence of crop scheduling accordingly results in frequent occurrence of intermittent water stress and occasional crop failure. In the present study, we analyzed long period (1982–2010) SM rainfall behavior (onset, withdrawal, rainfall and wetness indices, dry and wet spells), crop water requirement (CWR, by Food and Agriculture Organization (FAO) 56), and probability of weekly rainfall occurrence (by two-parameter gamma distribution) to assess the variability and impact on water availability, CWR, and rice productivity. Finally, crop planning was suggested to overcome monsoon uncertainties on water availability and rice productivity. Study revealed that the normal onset and withdrawal weeks for SM rainfall were 22nd ± 1 and 43rd ± 2 meteorological weeks (MW), respectively. However, effective monsoon rainfall started at 24th MW (rainfall 92.7 mm, p > 56.7 % for 50 mm rainfall) and was terminated by the end of 40th MW (rainfall 90.7 mm, p 7 days in duration and reflected a significant (p < 0.05) increasing trend (at 0.22 days year−1) over the years (1982–2010). The present study highlights the adaptive capacity of crop planning including abiotic stress-tolerant cultivars to monsoon rainfall variability for sustaining rainfed rice production vis-a-vis food and livelihood security in vulnerable islands of coastal ecosystem.
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TL;DR: In this article, the authors conducted a household survey to understand how local farmers perceive climate change in general, prevailing freshwater aquaculture scenarios and potential impacts of the climate change on aqua-ulture, and which strategies aquaulture farmers employ to cope with the perceived risks.
Abstract: Freshwater aquaculture provides employment and offers often reliable income to impecunious communities in the Sundarban delta of India, a UNESCO declared world heritage site while it has been threatened by recent environmental and climatic changes. Based on household survey our study provides data on i) how local farmers perceive climate change in general, ii) prevailing freshwater aquaculture scenarios and potential impacts of the climate change on aquaculture, and iii) which strategies aquaculture farmers employ to cope with the perceived risks. The study reveals that farmers are aware of climatic variability and express their experiences of changes in temperature, rainfall, tropical cyclones and sea level rise. The production methods of freshwater aquaculture in Sundarban can be termed as ‘semi-improved low-input carp polyculture’. Cyclones and storm surges are the most significant climatic phenomena and severely affect freshwater aquaculture due to subsequent coastal flooding, and sea-level rise that cumulatively lead to salinity intrusion, followed by rising air temperature and drought. In relation to perceived risks, farmers are currently dealing with the problems through short-term coping measures which need scientific improvements to give long-term relief to the farmers. Considering the effects of climate change on freshwater pond aquaculture in the delta, we propose some preliminary policy recommendations that need to be introduced to cope with the challenges.
55 citations
Abstract: The present study assessed climate change vulnerability in agricultural sector of low-lying Sagar Island of Bay of Bengal. Vulnerability indices were estimated using spatially aggregated biophysical and socio-economic parameters by applying principal component analysis and equal weight method. The similarities and differences of outputs of these two methods were analysed across the island. From the integration of outputs and based on the severity of vulnerability, explicit vulnerable zones were demarcated spatially. Results revealed that life subsistence agriculture in 11.8% geographical area (2829 ha) of the island along the western coast falls under very high vulnerable zone (VHVZ VI of 84–99%) to climate change. Comparatively higher values of exposure (0.53 ± 0.26) and sensitivity (0.78 ± 0.14) subindices affirmed that the VHV zone is highly exposed to climate stressor with very low adaptive capacity (ADI= 0.24 ± 0.16) to combat vulnerability to climate change. Hence, food security for a population of >22 thousands comprising >3.7 thousand agrarian households are highly exposed to climate change. Another 17% area comprising 17.5% population covering 20% villages in north-western and eastern parts of the island also falls under high vulnerable (VI= 61%–77%) zone. Findings revealed large spatial heterogeneity in the degree of vulnerability across the island and thus, demands devising area specific planning (adaptation and mitigation strategies) to address the climate change impact implications both at macro and micro levels.
19 citations
Cites background from "Monsoon variability, crop water req..."
...This poses a serious threat to the predominant paddy based (Oryza sativa L) rainfed agrarian system vis-à-vis food grain and livelihood security of the rapidly growing population in the island (Mandal et al. 2015)....
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...The live subsistence agrarian economy solely depends on erratic distribution of monsoon rainfall results in prolonged mid monsoon break, increasing dry spells and subsequent intermittent water stress during peak crop growing periods (Mandal et al. 2015)....
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...During peak crop growing season (summer/rainy season), these areas depend on risk prone rainfed farming and as a result, crop failure often occurred either due to flooding or prolonged long dry spell frommid monsoon break (Mandal et al. 2015)....
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...…population) on climate sensitive rainfed agrarian economy and at the same time, high exposure to climate-driven hazards has made Sagar Island as one of the most vulnerable zones to sustain agrarian economy and rural livelihood (Bhusan et al. 2012; Mandal and Choudhury 2014; Mandal et al. 2015)....
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TL;DR: In this paper, a study comprehensively assessed soil site suitability for selected winter crops in the coastal saline agro-ecological environment of Sagar Island, India by integrating land limitation and crop suitability evaluation framework of FAO Soil properties (eg texture, pH, organic carbon; SOC, electrical conductivity; EC and available macronutrients- NPK) were obtained through extensive grid-based soil sampling and estimation in the laboratory following standard procedures.
19 citations
TL;DR: In this article, water stress assessment for rainfed maize crop is carried out for kharif (June-October) and rabi (October-February) cropping seasons which coincide with two major Indian monsoons.
Abstract: Water stress due to uneven rainfall distribution causes a significant impact on the agricultural production of monsoon-dependent peninsular India. In the present study, water stress assessment for rainfed maize crop is carried out for kharif (June–October) and rabi (October–February) cropping seasons which coincide with two major Indian monsoons. Rainfall analysis (1976–2010) shows that the kharif season receives sufficient weekly rainfall (28 ± 32 mm) during 26th–39th standard meteorological weeks (SMWs) from southwest monsoon, whereas the rabi season experiences a major portion of its weekly rainfall due to northeast monsoon between the 42nd and 51st SMW (31 ± 42 mm). The later weeks experience minimal rainfall (5.5 ± 15 mm) and thus expose the late sown maize crops to a severe water stress during its maturity stage. Wet and dry spell analyses reveal a substantial increase in the rainfall intensity over the last few decades. However, the distribution of rainfall shows a striking decrease in the number of wet spells, with prolonged dry spells in both seasons. Weekly rainfall classification shows that the flowering and maturity stages of kharif maize (33rd–39th SMWs) can suffer around 30–40% of the total water stress. In the case of rabi maize, the analysis reveals that a shift in the sowing time from the existing 42nd SMW (16–22 October) to the 40th SMW (1–7 October) can avoid terminal water stress. Further, AquaCrop modeling results show that one or two minimal irrigations during the flowering and maturity stages (33rd–39th SMWs) of kharif maize positively avoid the mild water stress exposure. Similarly, rabi maize requires an additional two or three lifesaving irrigations during its flowering and maturity stages (48th–53rd SMWs) to improve productivity. Effective crop planning with appropriate sowing time, short duration crop, and high yielding drought-resistant varieties will allow for better utilization of the monsoon rain, thus reducing water stress with an increase in rainfed maize productivity.
14 citations
Cites background from "Monsoon variability, crop water req..."
...Therefore, understanding the variations in monsoon-based rainfall over a considerable time frame serves as an essential step towards sustainable food production in the future (Mandal et al. 2015)....
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TL;DR: In this article, future groundwater demand (domestic, agricultural, and livestock sector) in the fragile Sundarbans ecosystem was estimated considering different human population growth rates (high, low, and current) for 2011-2050.
Abstract: Coastal regions are the residence of an enormously growing population. In spite of rich biodiversity, coastal ecosystems are extremely vulnerable due to hydroclimatic factors with probable impact on socio-economy. Since the last few decades, researchers and policymakers were attracted towards the existing water demand–resource relationship to predict its future trends and prioritize better water resource management options. Water Evaluation And Planning (WEAP) serves the wholesome purpose of modeling diverse aspects of decision analysis using water algorithm equations for proper planning of water resource management. In this study, future groundwater demand (domestic, agricultural, and livestock sector) in the fragile Sundarbans ecosystem was estimated considering different human population growth rates (high, low, and current) for 2011–2050. The results showed that the sustainability of coastal aquifer-dependent rural livelihood is expected to face great danger in the near future. The total groundwater demand is expected to rise by approximately 17% at the current growth rate in the study area to fulfill the domestic and agricultural requirement, while this value goes up to around 35% for a higher growth rate and around 4% for a lower growth rate. The impact of increasing groundwater demand was analyzed further to identify any socio-economic shifts in this region.
6 citations
References
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Book•
01 Jan 1998
TL;DR: In this paper, an updated procedure for calculating reference and crop evapotranspiration from meteorological data and crop coefficients is presented, based on the FAO Penman-Monteith method.
Abstract: (First edition: 1998, this reprint: 2004). This publication presents an updated procedure for calculating reference and crop evapotranspiration from meteorological data and crop coefficients. The procedure, first presented in FAO Irrigation and Drainage Paper No. 24, Crop water requirements, in 1977, allows estimation of the amount of water used by a crop, taking into account the effect of the climate and the crop characteristics. The publication incorporates advances in research and more accurate procedures for determining crop water use as recommended by a panel of high-level experts organised by FAO in May 1990. The first part of the guidelines includes procedures for determining reference crop evapotranspiration according to the FAO Penman-Monteith method. These are followed by updated procedures for estimating the evapotranspiration of different crops for different growth stages and ecological conditions.
21,958 citations
"Monsoon variability, crop water req..." refers background or methods in this paper
...Till date, no such efforts were made for crop scheduling through comprehensive analysis of monsoon rainfall variability (onset, withdrawal, dry spells (DSs), and probability of weekly rainfall (PWR)) and CWR during sensitive growth stages of rainfed rice in the island....
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...Crop Kc for this region at different stages was taken from Food and Agriculture Organization (FAO) 56 method (Allen et al. 1998), and ETo was computed from the daily weather data by Penman-Monteith FAO 56 method (Allen et al. 1998)....
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...When monsoon spell was considered, the average monsoon rainfall received was 1,706±27.4 mm, of which 1, 353.1±5.2 mm was CWR for rice-growing periods (seed to seed)....
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...Followingwater balance approach, CWR at different stages of rice growth (May–October) was computed from ETc. as well as seepage and deep percolation (PERC) losses in the rice fields....
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...CWR means the amount of water required to compensate the crop evapotranspiration (ETc.) loss from the cropped field....
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Book•
01 Jan 1970
TL;DR: In this article, a complete revision of a classic, seminal, and authoritative book that has been the model for most books on the topic written since 1970 is presented, focusing on practical techniques throughout, rather than a rigorous mathematical treatment of the subject.
Abstract: From the Publisher:
This is a complete revision of a classic, seminal, and authoritative book that has been the model for most books on the topic written since 1970. It focuses on practical techniques throughout, rather than a rigorous mathematical treatment of the subject. It explores the building of stochastic (statistical) models for time series and their use in important areas of application forecasting, model specification, estimation, and checking, transfer function modeling of dynamic relationships, modeling the effects of intervention events, and process control. Features sections on: recently developed methods for model specification, such as canonical correlation analysis and the use of model selection criteria; results on testing for unit root nonstationarity in ARIMA processes; the state space representation of ARMA models and its use for likelihood estimation and forecasting; score test for model checking; and deterministic components and structural components in time series models and their estimation based on regression-time series model methods.
19,748 citations
TL;DR: This revision of a classic, seminal, and authoritative book explores the building of stochastic models for time series and their use in important areas of application forecasting, model specification, estimation, and checking, transfer function modeling of dynamic relationships, modeling the effects of intervention events, and process control.
Abstract: From the Publisher:
This is a complete revision of a classic, seminal, and authoritative book that has been the model for most books on the topic written since 1970. It focuses on practical techniques throughout, rather than a rigorous mathematical treatment of the subject. It explores the building of stochastic (statistical) models for time series and their use in important areas of application forecasting, model specification, estimation, and checking, transfer function modeling of dynamic relationships, modeling the effects of intervention events, and process control. Features sections on: recently developed methods for model specification, such as canonical correlation analysis and the use of model selection criteria; results on testing for unit root nonstationarity in ARIMA processes; the state space representation of ARMA models and its use for likelihood estimation and forecasting; score test for model checking; and deterministic components and structural components in time series models and their estimation based on regression-time series model methods.
12,650 citations
10,523 citations
Additional excerpts
...…model is defined as follows (Subash et al. 2011): P X ≤xð Þ ¼ F α;β; xð Þ ¼ Z x 0 f xð Þdx ¼ 1 Γβα Z x 0 xα−1e −x βdx ð3Þ Methodology adopted in trend analysis Mann-Kendall trend test (Mann 1945; Kendall 1975) has been applied to detect the trends of weekly weather variables and monsoon rainfall....
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TL;DR: In this article, a simple and robust estimator of regression coefficient β based on Kendall's rank correlation tau is studied, where the point estimator is the median of the set of slopes (Yj - Yi )/(tj-ti ) joining pairs of points with ti ≠ ti.
Abstract: The least squares estimator of a regression coefficient β is vulnerable to gross errors and the associated confidence interval is, in addition, sensitive to non-normality of the parent distribution. In this paper, a simple and robust (point as well as interval) estimator of β based on Kendall's [6] rank correlation tau is studied. The point estimator is the median of the set of slopes (Yj - Yi )/(tj-ti ) joining pairs of points with ti ≠ ti , and is unbiased. The confidence interval is also determined by two order statistics of this set of slopes. Various properties of these estimators are studied and compared with those of the least squares and some other nonparametric estimators.
8,409 citations
"Monsoon variability, crop water req..." refers methods in this paper
...The magnitudes of such trends also quantify using Sen’s slope (Sen 1968)....
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