Evapotranspiration paradox at a semi-arid location in India

Paradox of decreasing evaporation and evapotranspiration under increasing temperature conditions in the semi-arid tropics assumes greater importance as agriculture in these areas is more vulnerable to climate change. Trends in annual reference crop evapotranspiration (ETo) at Patancheru, Andhra Pradesh indicated a reduction of about 200 mm from 1850 mm to 1650 mm during the past 35 years. Contribution of energy balance term to the total ETo has shown an increasing trend while aerodynamic term has a decreasing trend. Wind speed has shown a strong negative trend leading to the dramatic fall of the aerodynamic term and consequently the ETo. Rate of reduction in evapotranspiration demand was about 10% for kharif (Jun-Oct) and about 14% for rabi (Nov-Feb). At Patancheru, measured temperature and solar radiation showed opposite trends and at locations where no measured solar radiation data available and if solar radiation is estimated from air temperature alone for use as an input in crop modelling, outputs under such conditions need to be interpreted with caution. Present study highlights the need for climate change impact studies at a local level in addition to those based on regional and global circulation models

Increased arid and semi-arid areas in India with associated shifts during 1971-2004

Climate change is one of the major challenges in 21st century faced by Agriculture in India, more so in the Semi-Arid Tropics (SAT) of the country. In recent years, natural and anthropogenic factors have impacted climate variability and contributed to a large extent to climate change. Based on one degree gridded data of India Meteorological Department (IMD) for 34 years (1971-2004), climatic water balances are computed for 351 pixels in India and used for classifying in to six climate types following Thornthwaite’s moisture regime classification and areas falling under different climatic zones in India are delineated. Considerable changes in the country’s climate area observed between the two periods; 1971-90 and 1991-2004. Increased semi-arid area by 8.45 M ha in five states viz., Madhya Pradesh, Bihar, Uttar Pradesh, Karnataka and Punjab, and decreased semi-arid area by 5 M ha in eleven states, contributed to overall increase in SAT area of 3.45 M ha in the country.Overall, there has been a net reduction of 10.71 M ha in the dry sub-humid area in the country. Results indicated that dryness and wetness are increasing in different parts of the country in the place of moderate climates existing earlier in these regions. ICRISAT’s Hypothesis of Hope through Integrated Genetic and Natural Resources Management (IGNRM) using climate ready crops and Integrated Watershed Management could be a potential adaptation strategy by bridging the yield gaps for developing climate resilient agriculture in the country

Dietary supplementation with a natural carotenoid mixture decreases oxidative stress

Objective: To determine whether dietary supplementation with a natural carotenoid mixture counteracts the enhancement of oxidative stress induced by consumption of fish oil. Design: A randomised double-blind crossover dietary intervention. Setting: Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, Whiteknights PO Box 226, Reading RG6 6AP, UK. Subjects and intervention: A total of 32 free-living healthy nonsmoking volunteers were recruited by posters and e-mails in The University of Reading. One volunteer withdrew during the study. The volunteers consumed a daily supplement comprising capsules containing fish oil (4 x 1 g) or fish oil (4 x 1 g) containing a natural carotenoid mixture (4 x 7.6 mg) for 3 weeks in a randomised crossover design separated by a 12 week washout phase. The carotenoid mixture provided a daily intake of beta-carotene (6.0 mg), alpha-carotene (1.4 mg), lycopene (4.5 mg), bixin (11.7 mg), lutein (4.4 mg) and paprika carotenoids (2.2 mg). Blood and urine samples were collected on days 0 and 21 of each dietary period. Results: The carotenoid mixture reduced the fall in ex vivo oxidative stability of low-density lipoprotein (LDL) induced by the fish oil (P = 0.045) and it reduced the extent of DNA damage assessed by the concentration of 8-hydroxy-2'-deoxyguanosine in urine (P = 0.005). There was no effect on the oxidative stability of plasma ex vivo assessed by the oxygen radical absorbance capacity test. beta- Carotene, alpha-carotene, lycopene and lutein were increased in the plasma of subjects consuming the carotenoid mixture. Plasma triglyceride levels were reduced significantly more than the reduction for the fish oil control (P = 0.035), but total cholesterol, HDL and LDL levels were not significantly changed by the consumption of the carotenoid mixture. Conclusions: Consumption of the natural carotenoid mixture lowered the increase in oxidative stress induced by the fish oil as assessed by ex vivo oxidative stability of LDL and DNA degradation product in urine. The carotenoid mixture also enhanced the plasma triglyceride-lowering effect of the fish oil