Climate change adaptation,greenhouse gas mitigation and economic profitability of conservation agriculture: Some examples from cereal systems of Indo-Gangetic Plains

Achieving sustainability of the cereal system in the Indo-Gangetic Plains(IGP)of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable way.This paper examines conservation agriculture(CA)from the perspective of:(i)increased yield and farm income,(ii)adaptation to heat and water stresses,and(iii)reduction in greenhouse gas(GHGs)emissions.The analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of IGP.Our analyses show that CA-based system substantially reduces the production cost(up to 23%)but produces equal or even higher than conventional system;thereby increasing economic profitability of production system.CA-based production systems also moderated the effect of high temperature(reduced canopy temperature by 1–4°C)and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of IGP.Our continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional systems.This is the first time that CA and its components are synthesized and analyzed from food security-climate change nexus.From this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.     

Multi-polarized Radarsat-2 satellite sensor in assessing forest vigor from above ground biomass

Accurate estimates of forest biomass are increasingly important in relation to sequestration of carbon by forest trees.Satellite remote sensing is a useful tool for biomass estimation and monitoring of forest ecological processes.Microwave synthetic aperture radar(SAR) can increase the accuracy of estimations of forest biomass in comparison to optical remote sensing, due to the unique capacities of SAR, including high penetrability, volumetric scattering, interaction with surface roughness, and dielectric property.We studied the potential of multi-polarized C-band Radarsat-2, a SAR technology, with HH, HV and VV polarization for estimating biomass of moist tropical Indian forest.Backscatter values are correlated with fieldbased biomass values and are regressed to generate models for estimating biomass.HH polarization provided maximum information regarding tree biomass.A coefficient of determination of 0.49 was calculated for HH polarized C-band image with in situ measurements.An exponential model was proved to be best suited for estimating forest biomass.Correlation of 0.62 and RMSE of 24.6 t ha~(-1) were calculated for the relationship between estimated and predicted biomass values for the best fit model.The average absolute accuracy of the model was 61%, while Willmott's index of agreement was 0.87.Results suggest that most of the biomass of the area ranged within70 t ha~(-1) a probably due to the saturation of C-band around 60–70 t ha~(-1) for tropical forests.     

Diversity,structure and standing stock of wood in the homegardens of Kerala in peninsular India

A survey was conducted in 17 selectedthaluks (revenue sub-divisions) of Kerala state to elucidate the floristic structure, composition and the extent of similarities and diversities in the composition of homegardens of Kerala, with particular reference to small (below 0.4 ha), medium (0.5 to 2 ha) and large (>2.0 ha) holding size categories. Besides attempts wer also made to characterize the potential of homegardens to supply commercial timber and fuelwood. Two hundred and fifty two farmers were selected through a stratified random process. In addition to gathering general information on crop and livestock production enterprises, all scattered trees and shrubs (15 cm girth at breast height) on the homestead and border trees except palms and rubber were enumerated.There was tremendous variability both in the number of trees and shrubs present and species diversity of the selected homesteads in different provinces. The small, medium and large sized holdings also exhibited profound variability in the number of woody taxa and individuals present. In total, 127 woody species (Girth at Breast Height (GBH) 15 cm) were encountered. The mean number of woody taxa found in the homegardens ranged from 11 for Pathanapuram to 39 in Perinthalmanna. Floristic diversity was higher in the smaller homesteads. It decreased with increasing the size of holdings. Mean Simpson's diversity index for the homesteads ranged from 0.251 (Kochi) to 0.739 (Kottarakkara) suggesting that floristic diversity of homegardens was moderate to low compared to a value over 0.90 for the species-rich evergreen forests of the Western Ghats. The Sorensen's similarity indexes suggested a moderately high degree of similarity for the different tree species encountered in the homesteads of Kerala.No clear cut planting pattern was discernible in the homegardens of Kerala. The homegarden trees and shrubs were either scattered throughout the homestead or on farm boundaries. Farmers tend to prefer timber trees such as ailanthus (highest frequency) and teak besides fruit trees such as mango, jack, cashew and the like. Major homegarden species were represented in all diameter classes. The diameter structure, however, exhibited a slightly skewed (+) distribution pattern, having the highest frequency in the 20–30 cm classes ensuring adequate regeneration status and in that process making homegardens a sustainable as well as dynamic land use system.Standing stock of timber and firewood in the homestead of differentthaluks are presented. Average commercial standing stock of homesteads ranged from 6.6 to 50.8 m³ ha^–1 and fuel wood volume was of the order of 23 to 86 m³ ha^–1. Implicit in the high commercial timber volume and fuel wood volume is that a substantial proportion of the society's wood demands are met from the homesteads. Palms, however, constituted the dominant component of standing commercial timber and fuel wood volumes accounting as much as 63% and 72%, respectively, of the total wood in these categories.     

Cardioprotective effect of 'Marutham' a polyherbal formulation on isoproterenol induced myocardial infarction in Wistar rats

Myocardial infarction is the number one killer disease in many parts of the world. The cardioprotective effect of Marutham, a polyherbal formulation on serum and heart tissue lipids, serum lipoproteins and heart membrane bound enzymes in isoproterenol induced myocardial infarction was studied in Wistar rats. Pretreatment with Marutham at different doses of 30, 60 and 90 mg kg(-1) to isoproterenol treated rats significantly prevented the altered lipid profile and membrane bound enzymes to near normal status. The results of our study showed the cardioprotective potential of Marutham on isoproterenol induced myocardial infarction in rats.     

Carbon input, loss and storage in sub-tropical Indian Inceptisol under multi-ratooning sugarcane

Changes in residue management and incorporation of organic manures may help in carbon sequestration, restoring soil organic carbon (SOC) and sustaining the productivity of land under a cropping system. An experiment of multi-ratooning sugarcane (Saccharum officinarum L.) was initiated in 2003 in Inceptisols of Indian subtropics, to assess the effect of different organic manures and chemical fertilizer, on the crop productivity and soil quality. The annual sugarcane shoot biomass production in organic manure treatments was at par with the chemically fertilized treatment. Gross input of carbon (GIC) by the sugarcane crop was estimated to be 11.7–12.4 t ha⁻¹ y⁻¹ in different organic manure treatments compared to 8.4 and 5.0 t ha⁻¹ y⁻¹ in NPK and control treatments, respectively. The respiratory loss of C (RLC) increased linearly with increasing input of C in soil and it ranged from 3.3 to 4.1 t ha⁻¹ y⁻¹ in different treatments with maximum in FYM and minimum in control treatment. The sugarcane biomass added in the soil humified at a rate constant of 0.38 in sub-tropical conditions and an addition of 3.9 t C ha⁻¹ y⁻¹ is required to maintain SOC in equilibrium. After 5 years of sugarcane cropping (one plant + four ratoons) an increase of 2.3–17.1 t ha⁻¹ in SOC over initial content was recorded with different treatments. Results in coming years from this long-term experiment shall add to the present calculated relationships between carbon addition and storage in sugarcane multi-ratooning crop production system under sub-tropical condition of India.