A.K. Singh

Cable-bolting-based semi-mechanised depillaring of a thick coal seam

Based on simple rock mechanics principles, the idea of using a grouted steel rope under tension for supporting a high roof as well as an overlying coal band, and to improve the safe span of overhanging strata near the goaf edge for semi-mechanised depillaring of a thick coal seam standing on pillars was first applied at New Chirimiri Ponri Hill (NCPH) colliery of the Chirimiri area of the South Eastern Coal Field Limited (SECL), India. Taking advantage of the massiveness of the coal seam and pattern of stress redistribution around a depillaring face, field application of this technique made it possible to extract the full thickness (6.5 m) of the No. 3 seam of the colliery (developed along floor with 2.5 m gallery height) in a single lift. The success of this field trial triggered a number of applications of the technique in many other collieries of India due to its technical superiority over the conventional method for underground extraction of thick and developed coal seams. Thus, this paper deals with the efficacy of cable bolting in semi-mechanised depillaring of a thick coal seam as observed at NCPH colliery.

In vitro multiplication of banana (Musa sp.) cv. Grand Naine

A micropropagation method is described for banana ( Musa Spp .) Cv. Grand Naine. Suckers were surface sterilized with HgCl 2 (0.1%) for 6 min which gave minimum contamination with maximum culture establishment. Of various treatment combinations, Murashige and Skoog (MS) medium + BAP 4.00 mg/l with IAA 2.00 mg/l resulted in maximum establishment of cultures in lesser time. MS medium + BAP 4.00 mg/l + IAA 2.00 mg/l gave maximum multiple shoots. Maximum rooting was obtained on MS medium (half strength) supplemented with IBA 1.00 mg/l and activated charcoal 200 mg/l. Keywords: Grand naine, micro propagation, murashige and skoog medium, Musa spp. and suckers. African Journal of Biotechnology , Vol 13(27) 2696-2703

Changes in carbon pools and biological activities of a sandy loam soil under medium-term conservation agriculture and diversified cropping systems: Soil health under conservation agriculture

SUMMARY: Conservation agriculture (CA) practices such as zero tillage (ZT) and permanent raised beds (PB) accelerate deposition of soil organic matter and augment associated biological properties of soil through enhanced inputs of organic carbon. However, the potential benefit of CA under intensive cereal‐based systems for key soil health indicators (such as carbon pools and biological activities) is only partially known. Therefore, we analysed the effect of three medium‐term tillage practices and four intensive crop rotations on selected soil organic carbon pools and microbial properties. The tillage practices consist of ZT, PB and conventional tillage (CT) in main plots and four crop rotations (MWMb, maize–wheat–mungbean; MCS, maize–chickpea–Sesbania; MMuMb, maize–mustard–mungbean; MMS, maize–maize–Sesbania) in subplots. The experimental design was split‐plot with three replications. After 6u2009years, we observed a significant positive effect of CA practices on soil organic carbon (SOC) content, labile SOC fractions, soil microbial biomass carbon (MBC) and dehydrogenase activity (DHA). The total organic carbon (TOC) was greatly affected by medium‐term tillage and diversified cropping systems; it was larger for CA and MCS and MWMb systems. The interaction effect between tillage and cropping systems for SOC content was not significant at all soil depths. Significantly larger contributions (8.5–25.5%) of labile SOC pools to TOC at various soil depths were recorded in PB and ZT. There was a significant positive effect of CA practices and diversified crop rotations on MBC and DHA at all the soil depths and sampling times, but the interaction effect between tillage and cropping systems was not significant. Thus, our medium‐term (≥u20095‐years) study showed that the combination of CA (PB and ZT) practices and appropriate choice of rotations (MCS and MWMb) appears to be the most appropriate option for restoration and improvement of the soil health of light‐textured Inceptisols through the accumulation of soil organic matter (SOM) and improvement in soil biological properties. HIGHLIGHTS: Effect of conservation agriculture (CA) on soil labile carbon inputs and biological properties. Observed changes in SOC stock and C‐pools at different soil depths after 6u2009years. Significant effects of tillage and crop rotations observed for labile‐C pools. Adoption of ZT and PB enhanced SOC stock, C‐pools and microbial activity compared to CT.

Harnessing Genetic Resources in Field Crops for Developing Resilience to Climate Change

Abstract The three major challenges of the 21st century are managing climate change, overcoming poverty and food insecurity. Global population has reached 7.0 billion in 2011 at the same, in contrary to the popular belief, the world food production has also increased and kept pace with population. But the percapita food availability interms of all essential food grains and access to food has come down. The challenging situation is further aggravated by global climate change. This necessitates multidimensional approach to solve the issue of food grain production. In this context biodiversity is the most important the basic resources on which human scope lies. However, biodiversity is negatively impacted by climate change. Conversely, biodiversity through ecosystem services contributes to climate-change adaptation and mitigation. Selection of suitable food crops and their varieties for a given edaphic and biotic conditions is a sensible decision because it provides scope for utilisation of genetic variability to enhance yield and adaptability. In this chapter, different breeding techniques and biotechnological tools available for exploiting genetic resources in field crops so as to address the climate change are discussed. It is also prudent to mention conservation methods for field crops so that the benefit of biodiversity is passed on to the future generations.

Diversification of Island Agriculture – A Viable Strategy for Adaptation to Climate Change

Abstract The islands, whether located in the tropics or higher latitudes, have characteristics which make them especially vulnerable to the effects of climate change, sea level rise and extreme events. The major farming systems practised in these islands are, rice and rice-tree, highland mixed, rainfed mixed, coastal artisanal fishing, coconut-based, lowland rice, root tubers, tree crop mixed and coastal plantation, and mixed farming. In many of these islands, agriculture and primary activity are still the major contributors of national GDP with less agricultural diversification. This makes these islands more vulnerable to climate change and inefficient to meet the challenge posed by population growth. In the Indian Ocean region, coconutxa0+xa0spices-based mixed farming system with value addition holds greater promise for diversification. Caribbean islands have to move away from the traditional and sugarcane-based economy to high value agriculture with processing. However, Pacific islands should improve their performance of animal component by integrating with coconut-based farming system and product diversification.

Climate Resilient and Livelihood Security – Perspectives for Mauritius Island

Abstract Biodiversity is of high importance to the Republic of Mauritius. Apart from the essential role forests, agriculture, inland water, wetlands, coastal and marine biodiversity play in providing important ecosystem services and livelihood of local population, they represent a key component of mitigation and adaptation measures for climate change impacts, disaster risk reduction, economy and human well being. As a Small Island Developing States (SIDS), Mauritius faces several challenges as a consequence of climate change that impacts its biodiversity, basic livelihood, critical infrastructures and other socio-economic interests. Therefore the government has initiated number of measures to infuse climate resilience to the economic activity and biodiversity that provides livelihood to the island population. The details of total biodiversity, climate change impact and climate resilient measures for Mauritius are discussed in this chapter.

Impact of legume intensified crop rotations and tillage practices on maize productivity vis-à-vis C and N dynamics of a sandy loam soil in north-western Indo-Gangetic Plains of India

The study was conducted to evaluate long-term effect of legume intensified maize based crop rotations and contrasting tillage practices and a experiment was laid out in split plot design with three tillage practices i.e. zero tillage (ZT), permanent bed (PB) and conventional tillage (CT) as main plot treatments and four legume intensified crop rotations (MWMb - maize-wheat-mungbean, MCS - maize-chickpea-Sesbania, MMuMb - maize-mustard-mungbean and MMS - maize-maize-Sesbania) as sub-plot treatments. Adoption of CA based tillage practices (ZT/PB) significantly improved maize protein yield (MPY). ZT/PB gave 7.7-14.2% higher MPY(Maize protein yield and 7.4-13.0% higher MPYA (maize protein yield for adults) over CT. Similarly, the MPY and MPYA under legume intensified cereal based rotations were invariably higher in MCS and MWMb systems compared to MMuMb and MMS rotations.The total soil nitrogen (TSN) content increased by 15.4-17.4 and 20.32-20.91% with ZT and PB over CT in 0-15 and 15-30 cm soil depths, respectively. However, among the legume intensified rotations the maize planted under MCS and MWMb rotations registered 11.3-18.0% (0-15cm) and 8.4-11.0% (15-30cm) higher TSN over MMuMb and MMS rotation. Similarly, adoption of the CA practices (ZT/PB) resulted into significant improvement in soil organic carbon (SOC) stocks compared to CT. ZT and PB among the tillage practices and MCS crop rotations among the sub-plot treatments registered higher Leaf area index (LAI) and net assimilation rate (NAR) compared to other management practices. Interaction effect of tillage practices and crop rotations were significant for MPY, MPYA, TSN and SOC stocks and all these parameters were reported maximum with ZT-MCS. Thus, our study suggests that CA based crop management with legume diversified maize based rotations (MCS and MWMb) can be advocated as sustainable intensification strategy in north-western India and other similar agro-ecologies of South Asia.