Raghavendra Singh

Excitation Function Studies of (α, xpyn) Reactions for 63,65Cu and Pre-Equilibrium Effect

Excitation functions of tone reactions (α, n), (α, 2n), (α, pn) for 63 Cu and (α, n), (α, 2n), (α, 3n), (α, p3n) for 65 Cu have been measured with stacked foil activation techniques for projectile energies below 40 MeV α-particle. A large-volume Ge(Li) detector was used. Theoretical excitation functions for the above reactions have also been calculated with and without inclusion of pre-equilibrium particle emission in the framework of a geometry-dependent-hybrid model using ALICE/LIVERMORE 82 computer code. It is found that the pre-equilibrium contribution is more pronounced in the high-energy tail region of the excitation function and the experimental data are explained only when the pre-equilibrium emission phenomena is also taken into account along with the equilibrium decay.

A Review on Recycling of Sunflower Residue for Sustaining Soil Health

Modern agriculture is now at the crossroads ecologically, economically, technologically, and socially due to soil degradation. Critical analysis of available information shows that problems of degradation of soil health are caused due to imbalanced, inadequate and promacronutrient fertilizer use, inadequate use or no use of organic manures and crop residues, and less use of good quality biofertilizers. Although sizeable amount of crop residues and manure is produced in farms, it is becoming increasingly complex to recycle nutrients, even within agricultural systems. Therefore, there is a need to use all available sources of nutrients to maintain the productivity and fertility at a required level. Among the available organic sources of plant nutrients, crop residue is one of the most important sources for supplying nutrients to the crop and for improving soil health. Sunflower is a nontraditional oil seed crop produced in huge amount of crop residue. This much amount of crop residues is neither used as feed for livestock nor suitable for fuel due to low energy value per unit mass. However, its residue contains major plant nutrients in the range from 0.45 to 0.60% N, 0.15 to 0.22% P, and 1.80 to 1.94% K along with secondary and micronutrients, so recycling of its residue in the soil may be one of the best alternative practices for replenishing the depleted soil fertility and improving the physical, chemical, and biological properties of the soil in the present era of production. However, some researchers have reported allelopathic effects of sunflower residue on different crops. So, selection of suitable crops and management practices may play an important role to manage the sunflower residue at field level.

Fast neutron radiative capture cross-sections in fission product isotopes of neodymium

Fast neutron radiative capture cross-sections for Nd-148 and Nd-150 have been measured at about 10 neutron energies between 0.46 and 3.44 MeV using enriched isotopes and the activation technique. Experimental results are also compared with the theoretical one using FISPRO II computer code.

Bacterial inoculation effect on soil biological properties, growth, grain yield, total phenolic and flavonoids contents of common buckwheat (Fagopyrum esculentum Moench) under hilly ecosystems of North-East India

Field experiments were carried out at Research Farm, ICAR Sikkim Centre, Tadong during two consecutive Rabi seasons of 2012 and 2013 to determine the effect of different microbial inoculants on selected soil biological properties, growth, yield, and quality of common buckwheat, and then identify the best inoculant for application for local common buckwheat production in hilly ecosystem of North-East India. The results indicated that seed inoculants applied to common buckwheat effectively increased plant growth, chlorophyll content (SPAD), yield attributing characters, total phenolic and flavonoid content, grain yield, and soil biological properties. Among the different inoculations, combined application of Azotobacter spp. and Azospirillum spp. was found most efficient and resulted in maximum values of plant growth parameter, yield attributing characteristics, grain yield (1.23 Mg/ha), soil microbial biomass carbon (SMBC) and dehydrogenase activities at all the growth stages of common buckwheat. Key words: Buckwheat, dehydrogenase activities, flavonoid content, phenolic content, microorganisms, yield.

Influence of tillage and organic nutrient management practices on productivity, profitability and energetics of vegetable pea (Pisum sativum L.) in rice-vegetable pea sequence under hilly ecosystems of north-east India

Fixed plot field experiments were conducted at Research Farm, ICAR Sikkim Centre during 2013–14 and 2014–15 to identify the efficient tillage practices and organic nitrogen sources for achieving higher productivity, profitability and energy use efficiency of vegetable pea (Pisum sativum L.) in rice-vegetable pea cropping system of eastern Himalayas. Pooled data of two years showed that among the tillage practices, significantly higher values of yield attributes viz., pod length (8.3 cm), pods/plant (9.9), pod weight (8.3 g), green pea seeds/pod (8.0) and yields [green pod yield (5.89 t/ha) and stover yield (7.49 t/ha)] were recorded with no-tillage (NT) over reduced tillage (RT) and conventional tillage (CT). Similarly, significantly higher gross returns (125.4 x 103Rs./ha), net returns (96.1 x 103Rs./ha) and B: C ratio (3.27) were recorded with NT over RT and CT. Energy use efficiency was also significantly higher with NT (6.29%) over RT (4.29%) and CT (3.12%). NT required 44 and 28.3% less energy as compared to CT and RT, respectively. Amongst the organic nitrogen sources, significantly higher values of yield attributing characters, green pod yield (6.33 t/ha) and stover yield (6.67 t/ha) were recorded with the application of 50% RDN (recommended dose of nitrogen) through FYM+50% RDN through VC (vermicompost)+BF (biofertilizer) over other organic nitrogen sources. This resulted in 24.9% enhancement in green pod yield over the farmers practices. In terms of profitability and energetics, application of 50% RDN through FYM+50% RDN through VC+BF was found statistically superior to others and recorded 29.5% higher net returns and 9.9% higher energy use efficiency over the farmers practice (FYM @ 1.0 t/ha) of the region.

Cereal-Legume Cropping System in Indian Himalayan Region for Food and Environmental Sustainability

The Indian Himalayan Region (IHR) is extended from Jammu and Kashmir to the northeastern part of the country and shows a great differentiation in climatic, edaphic, geological, vegetation, and other features due to complex variegation of agroecosystems which leads to diverse agroecological zones. Agriculture is the important source of livelihood of the region, and rice (Oryza sativa L), wheat (Triticum aestivum L.), and maize (Zea mays L.) are the main crops of the entire IHR. Unsustainable agricultural practices, such as monocropping, conventional tillage, indiscriminate use of fertilizers and pesticides, etc., apart from land degradation and cropland scarcity have serious implications for livelihood security in IHR. Under such scenario, there is a need to diversify cropping pattern to make the entire agricultural system sustainable and environmentally secure. Inclusions of legumes in cereal-based cropping system either as intercrop or in sequence of crop rotation are the most promising options for diversified sustainability of the system and enhance the cropping intensity. Diverse habitat of IHR favors the growth and development of an amazing variety of legumes and other crops which make this region the rich hub for agricultural crop diversity specifically the legume crops. Broad bean (Vicia faba), horse gram (Macrotyloma uniflorum), field pea (Pisum sativum), black gram (Vigna mungo), adzuki bean (Vigna angularis), cowpea (Vigna unguiculata), soybean (Glycine max), lentil (Lens esculenta), green gram (Vigna radiata), beans (Phaseolus sp.), lathyrus (Lathyrus sativus), pigeon pea (Cajanus cajan L), etc. are some of the legumes cultivated by the farming communities in IHR. Rice bean [Vigna umbellata (Thunb.) Ohwi and Ohashi and mucuna/velvet bean [ Mucuna pruriens (L.) DC.] are some of the specific legumes grown abundantly in the eastern IHR which has immense food and natural resource conservation values. Albeit the legume species provides food, fuel, fodder, etc. and has multifarious roles in agriculture and natural resource conservation, their ability to fix atmospheric nitrogen in root nodules and subsequently contributions to the soil fertility give them the unique identity. Legume-based systems improve several aspects of soil fertility, such as soil organic carbon (SOC) and humus content and nitrogen and phosphorus availability, suppress weed growth through smothering effects, increase production per unit area, enhance land use efficiency, reduce runoff and soil loss, etc. Inclusion of legume provides sustainability to nonlegume cereal component by enriching soil fertility and increasing system productivity and returns. Significant reductions in the release of greenhouse gases, viz., carbon di-oxide, nitrous oxide etc., are a logical consequence of reduced fertilizer and energy use in arable systems with legumes. Pulses are considered the key crops for intensification of rice and maize-fallows of IHR due to their short-duration, hardy, and low-input requiring nature, hence offers a tremendous opportunity to utilize residual soil moisture.

Weed dynamics and production potential of direct-seeded rice cultivars as influenced by weed management

The field study was undertaken during rainy season of 2012 and 2013 to evaluate the rice cultivars and weed management effects on weeds growth and yield of direct-seeded rice (DSR) cultivars. The associated weed flora include Echinochloa colona, Echinocloa crus-galli, Cynodon dactylon as grasses; Cyperus rotundus, Cyperus iria as sedges; Caesulia auxillaries and Eclipta alba as broadleaved weeds. Bispyribac-sodium + azimsulfuron (25 + 35 g/ha) + 0.25% NIS as post-emergence at 15-20 DAS was found to be most effective in minimizing weed density, biomass and in enhancing the weed control efficiency 40.9% and 38.0% during 2012 and 2013 at 60 DAS, respectively. The maximum rice grain, straw and biological yield was found with application of bispyribac + azimsulfuron (25 g + 35 g/ha) + 0.25% NIS as post-emergence at 15-20 DAS and was significantly superior over rest of the treatments during both the years of study.

Effect of organic nitrogen sources on growth, yield, quality, water productivity and economics of rice (Oryza sativa L.) under different planting methods in mid-hills of Sikkim Himalayas

In order to evaluate the effect of organic sources of nitrogen on growth, yield, water productivity and economics of rice under different methods of planting in hilly ecosystems of north-east India, an experiment was carried out in kharif seasons of 2013 and 2014 in split plot design with three replications. The results revealed that SRI recorded significantly higher values for all growth parameters (plant height, dry matter accumulation, leaf area index, flag leaf length, tillers/m2, root volume and root dry weight), yield attributing characters (productive tillers/m2, panicle length, grains/panicle, filled grains/panicle and test weight), water productivity (kg grain/m3 of water), grain yield and economics over the CP. This caused 36.84 and 29.41, 34 and 28, 60.0 and 55.3% improvement in water productivity, grain yield and net returns over the CP during 2013 and 2014, respectively. Among the organic sources of nitrogen, application of 25% RDN through FYM+25% RDN through VC+25% RDN through PM+25% RDN through MC significantly enhanced the growth, yield attributing characters, water productivity (0.26 and 0.23 kg of grain/water m3), grain yield (3.53 and 3.41 t/ha), net returns (88 x 103 and 83 x 103 Rs./ha) and B: C ratio (1.84 and 1.74) in 2013 and 2014, respectively.