Dillip Kumar Swain

Variation in yield, N uptake and N use efficiency of medium and late duration rice varieties

Field experiments were conducted at the village Kasiadihi, Dhenkanal district, Orissa, India during wet seasons 2001, 2002 and 2003 under non water-stressed conditions (0–25 cm standing water) to assess variability in N uptake and utilization by medium and late duration rice varieties. The N rates were 0, 40, 80 and 120 kg N/ha applied as urea in four equal splits at transplanting, active tiller initiation, panicle initiation and flowering stages. The grain yield response was up to 80 kg N/ha. The optimum grain yield attainable by the efficient medium duration varieties was 4·5 t/ha. The N efficient late duration varieties produced optimum grain yield of 5·8 t/ha. The relationship for total dry matter and grain yield production between N fertilized (40, 80 and 120 kg N/ha) and non-fertilized treatments were all significant, suggesting cultivar selection under optimum N fertilized conditions. The difference in optimum yield of the medium and late duration varieties was due to the differences in the amount of N uptake and its use efficiency by the plant for grain production. There was a curvilinear relationship between grain yield and N use efficiency for grain production. The relationship between N use efficiency for grain production and N contents of leaf, stem and grain at maturity was quadratic. The optimum plant N use efficiency of medium duration varieties was 49 kg grain/kg N uptake, achieved with leaf, stem and grain N contents of 10, 8 and 14 g/kg, respectively, at maturity. For late duration varieties, the optimum plant N use efficiency was 68 kg grain/kg N uptake and it was maintained with leaf and stem N content of 4·0 g/kg each and grain N content of 9·0 g/kg at maturity. The N content in plant organs could be the selection guide used to obtain efficient rice varieties.

Evaluation of Field Level Adaptation Measures Under the Climate Change Scenarios in Rice Based Cropping System in India

With the rise in population, under future scenarios, global food demand is expected to increase. Biotic and abiotic factors such as climate change are threat to food security owing to its variability, occurrence, duration and magnitude of extreme events. Since, the climate change is unequivocal, the adaptations and mitigations for sustainable agricultural production can minimize its negative impact on agriculture and improve food grain productivity. The grain yield of rice and peanut was simulated for the base period (1969–1999) and future periods 2020 (2011–2040), 2050 (2041–2070) and 2080 (2071–2100) under A2 and B2 scenarios of HadCM3 Global Climate Model. Under the A2 and B2 scenarios, the yield of both rice and peanut declined from base period to the future periods 2011–2040, 2041–2070 and 2071–2100. The cultivar ‘IR 36’ was found to be more sensitive to rising temperature under future climate scenarios as compared to ‘Swarna.’ The yield decline for future climate scenarios increased with locations from higher (Kharagpur and Cuttack) to lower latitude (East Godavari and Vizianagaram). Earlier transplanting time of rice compared to normal (15 July) and sowing time of peanut from normal (9 February) increased the simulated yields of rice-peanut system at higher latitude and reduced the yield loss at lower latitude in future climate scenarios. Delayed planting caused maximum grain yield reduction of the cropping system in future climate scenarios at all the locations.

Alkaline coal fly ash amendments are recommended for improving rice-peanut crops

Abstract A field experiment investigating amendments of organic material including farmyard manure, paper factory sludge and crop residues combined with fly ash, lime and chemical fertilizer in a rice-peanut cropping system was conducted during 1997–98 and 1998–99 at the Indian Institute of Technology, Kharagpur, India. The soil was an acid lateritic (Halustaf) sandy loam. For rice, an N:P:K level of 90:26.2:33.3 kg ha−1 was supplied through the organic materials and chemical fertilizer to all the treatments except control and fly ash alone. The required quantities of organic materials were added to supply 30 kg N ha−1 and the balance amount of N, P and K was supplied through chemical fertilizer. Amendment materials as per fertilization treatments were incorporated to individual plots 15 days before planting of rice during the rainy season. The residual effects were studied on the following peanut crop with application of N:P:K at 30:26.2:33.3 kg ha−1 through chemical fertilizer alone in all treatments, apart from the control. An application of fly ash at 10 t ha−1 in combination with chemical fertilizer and organic materials increased the grain yield of rice by 11% compared to chemical fertilizer alone. The residual effect of both lime and fly ash applications combined with direct application of chemical fertilizer increased peanut yields by 30% and 24%, respectively, compared to chemical fertilizer alone. Treatments with fly ash or lime increased P and K uptake in both the crops and oil content in peanut kernel compared to those without the amendments. Alkaline coal fly ash proved to be a better amendment than lime for improving productivity of an acid lateritic soil and enriching the soil with P and K.

Organic rice: potential production strategies, challenges and prospects

Organic farming is rapidly gaining recognition worldwide as a promising means to offer healthier food and to ensure environmental sustainability. Currently, organic produce including organic rice is in huge demand owing to its potential to fetch premium price in the global market. Despite the fact that rice performs well under organic production system, a set of constraints including nitrogen stress at critical growth stages, unavailability of rapidly mineralizable organic amendments, lack of appropriate varieties and intense crop–weed competition pose major challenges to realize the potential yield. Use of diverse organic nutrient sources including the split application of fast mineralizable nutrient-rich manures (vermicompost, poultry manure), green manures and bio-fertilizers can supply optimum nutrients in organic rice system. In parallel, development and deployment of rice varieties having response to organic nutrient inputs, resistance to diseases/insects and ability to compete with weeds can help minimize the risk of crop failure. Further, higher emission of greenhouse gases (GHGs) in organic rice field deserves greater attention in view of environmental sustainability. Strategic water management and selection of appropriate organic amendments could help address this issue. However, a substantial research gap still exists demanding a deeper understanding of the organic rice system in order to register higher yield gains. This review article outlines the latest advances in organic rice production system with an emphasis on nutrient supply and ensuing dynamics, the outflow of GHGs, pest dynamics, produce quality and key attributes of rice cultivars for organic cultivation. We underscore the urgency for alignment of modern agricultural techniques with organic rice production to improve both the system productivity and the produce quality along with effectively avoiding the risks associated with in discriminate use of chemicals in agriculture.

Yield and quality of tomato grown under organic and conventional nutrient management

Nutrient management plays an important role in yield and quality of tomatoes. A field experiment was conducted during the years 2008–09 and 2009–10 to analyze the effect of organic and conventional sources of fertilizer on yield and quality of tomatoes in an acid lateritic soil of India. The organic sources of fertilizer were vermicompost (VC), crop residue (CR), vermiwash (VW) and biofertilizer (BF). The conventional input was chemical fertilizer (CF) applied at recommended dose of 100:80:60 kg ha−1 of N:P2O5:K2O for the tomato. The organic source VC was used to supply 100% N recommendation as single source or 50% N recommendation when combined with CF or organic sources. Maximum fruit yield was recorded when CF was applied at full dose, which was on a par with VC at full recommendation. A higher percentage of large-size fruits (>7 cm) was obtained in VC-based treatments compared with CF treatment. Vermicompost at full dose increased ascorbic acid, beta carotene, total soluble solids and color value compared with its half dose along with other organic sources (CR, BF). The potential exists to improve tomato fruit quality through a better nutrient management, whether it be conventional, organic or a combination of both.

Studies on Tea Quality Grown Through Conventional and Organic Management Practices: Its Impact on Antioxidant and Antidiarrhoeal Activity

Quality tea production is in demand for its better palatability and beneficial effects on human health, including controlling several diseases with its high antioxidant properties. So far, few studies have been made on the impact of fertilizer input on tea quality. To address the issue, tea was grown under conventional and organic practices to compare the production of biochemical compounds like crude fiber, starch, total phenolics, (-)-epigallocatechin gallate [(-)-EGCG], (-)-gallocatechin gallate [(-)-GCG], and (-)-epicatechin gallate [(-)-ECG], as well as the antioxidant and antidiarrhoeal properties of the tea leaves. Organically grown tea lowered the content of crude fiber and starch as compared to the no-fertilizer treatment (control). However, the content was further lowered by the inorganic fertilizer treatment. Organic fertilization produced higher polyphenol than inorganic fertilization, which has shown greater antioxidant properties when analyzed through the methods of dot-blot and DPPH staining, DPPH radical assay, and hydroxyl radical scavenging activities by electron paramagnetic resonance spectrometry. Animal experiments conducted using green tea extracts on rodents revealed better diarrhoea control with organically tea than with inorganically grown tea. This study reveals the importance of organic agricultural practices in tea for quality improvement and sustainability of the food chain system.

Effect of elevated [CO2] on yield, intra-plant nutrient dynamics, and grain quality of rice cultivars in eastern India: Elevated [CO2] effect on plant nutrient dynamics and quality of rice

BACKGROUND Climate models predict an increase in global temperature in response to a doubling of atmospheric [CO2 ]. This may affect future rice production and quality. In this study, the effect of elevated [CO2 ] on yield, nutrient acquisition and utilization, and grain quality of rice genotypes was investigated in the subtropical climate of eastern India (Kharagpur). Three environments (open field, ambient, and elevated [CO2 ]) were tested using four rice cultivars of eastern India. RESULTS Under elevated [CO2 ] (25% higher), the yield of high-yielding cultivars (HYCs) viz IR 36, Swarna, and Swarna sub1 was significantly reduced (by 11-13%), whereas the yield increased (by 6-9%) for Badshabhog, a low-yielding aromatic cultivar. Elevated [CO2 ] significantly enhanced K uptake (by 14-21%), but did not influence the uptake of total N and P. The nutrient harvest index and use efficiency values in HYCs were reduced under elevated [CO2 ] indicating that nutrient translocation from source to sink (grain) was significantly reduced. An increase in alkali spreading value (10%) and reduction in grain protein (2-3%) and iron (5-6%) was also observed upon [CO2 ] elevation. CONCLUSION The study highlights the importance of nutrient management (increasing N rate for HYCs) and selective breeding of tolerant cultivars in minimizing the adverse effects of elevated [CO2 ] on rice yield and quality.

CHLOROPHYLLMETER-BASED NITROGEN MANAGEMENT OF WHEAT IN EASTERN INDIA

Topdressing of N fertilizer, whenever leaf greenness, as measured by Chlorophyllmeter (SPAD), falls below the threshold value can be used for site-specific N management in wheat cultivation. Herein, a field experiment was conducted to analyse the effect of SPAD-based N management on wheat productivity and N use efficiency during the dry season of 2010/11 and 2011/12 on acid lateritic soil of eastern India. The experiment had 12 treatments, with nine treatments combining three SPAD thresholds (38, 40 and 42) and three N levels (15, 25 and 35 kg N ha⁻¹) as real time N management (RTNM), one fixed time N management (FTNM), one farmers’ fertilizer practise (FFP) and control (Zero N), with three replications. The grain yield of RTNM ranged from 90 to 113% as that of FTNM, but using considerably less N. Maintaining SPAD threshold of 40 up to heading stage by topdressing 25 kg N ha⁻¹ at each time (N₂₅S₄₀) caused the highest grain yield (4483 kg ha⁻¹). While saving 22.5 kg N ha⁻¹ (18.8%), N₂₅S₄₀ increased agronomic N use efficiency by 58.5%, nitrogen recovery efficiency by 15.1% and partial factor productivity of applied N by 26.4% when compared with conventional fertilizer recommendations (i.e. FTNM). The SPAD-based N management strategy was found very promising in efficiently managing N fertilizer in wheat for improving wheat productivity and N use efficiency.

Effect of Mineral and Organic Nutrient Management on Sweet Corn Production System in Acid Lateritic Soil of India

Introduction: Nutrient management plays a key role in improving crop yield with maintenance of soil fertility for sustainable production in intensive cropping. Aim: A field experiment was conducted to study the effect of organic and mineral sources of fertilizer on yield and quality of sweet corn grown in acid laterite soil of India during the years 2009 and 2010. Materials and Methods: The organic inputs were vermicompost (VC), vermiwash (VW), biofertilizer (BF), and crop residue (CR) and the inorganic input was mineral fertilizer. Results: Optimal application of N, P, and K (100% recommended dose) either through organic source or mineral source was significantly superior to their suboptimal dose in increasing the yield of sweet corn, wherein mineral fertilizer recorded maximum production. Between organic and mineral sources of fertilizer application, ascorbic acid and total phenolics content of sweet corm were higher in organic nutrient management. The ascorbic acid was higher by 133% in VC100 and 37% in VC50 + CF50 compared to mineral (CF100) treatment. But crude protein content was low by 13.5% in VC100 and 2.9% in VC50 + CF50, respectively, as compared to CF100 treatment. Organic carbon content and pH of the acid lateritic soil were improved in organic nutrient management as compared to mineral fertilizer. Conclusion: Organic fertilizer application, therefore, exhibited potential in improving sweet corn yield and quality and soil health in acid lateritic soil of the subtropical climate.

Nitrogen fertilizer optimization and cultivar selection for rice grown near mountainous slopes in Orissa, India

Degradation of the natural resource base has led to decline in crop yields or stagnation that caused food shortages at varying degrees among mountain families. Rice, the major staple food in Asia, is suffering from lack of suitable cultivar and N fertilizer management, when grown near mountainous slopes under rain-fed agro-ecosystem. An investigation through a field experiment and simulation study was conducted at United Nations University, Tokyo to select suitable rice cultivars and N fertilizer level for the rice grown near mountainous slopes in Orissa, India. The field experiment was conducted during wet season (June to November) of 2001 at Kasiadihi village of Dhenkanal district, Orissa, India with eight popular rice cultivars of medium (120–130 d) and long duration (135–150 d) group and four N levels (0, 40, 80 and 120 kg·ha−1). Highest grain yield of 5,680 kg·ha−1 was obtained from cultivar Ranjit of long duration group followed by 4,730 kg·ha−1 from cultivar Mahamaya of medium duration group, across N levels. CERES-Rice model was used to simulated grain yield of these two selected cultivars using historical weather data of the past 18 years (1983–2000). Long duration cultivar Ranjit registered higher yield with lower stability as compared medium duration cultivar Mahamaya over the past 18 years. An optimum N fertilizer level of 80 kg·ha−1 was recommended for rice grown under rain-fed ecosystem near mountainous slopes in Orissa, India to attain optimum yield potential of cultivar.