Priyanka Gautam

Bio: Priyanka Gautam is an academic researcher from Indian Council of Agricultural Research. The author has contributed to research in topics: Nutrient management & Soil health. The author has an hindex of 18, co-authored 72 publications receiving 1031 citations. Previous affiliations of Priyanka Gautam include Rice University & Central Rice Research Institute.

Management of direct seeded rice for enhanced resource - use efficiency

Abstract: Rice (Oryza sativa), the staple food of more than half of the population of the world, is an important target to provide food security and livelihoods for millions. Imminent water crisis, water-demanding nature of traditionally cultivated rice and climbing labour costs ramble the search for alternative management methods to increase water productivity, system sustainability and profitability. Direct seeded rice (DSR) technique is becoming popular nowadays because of its low-input demanding nature. It offers a very exciting opportunity to improve water and environmental sustainability. It involves sowing pre-germinated seeds into a puddled soil surface (wet seeding), standing water (water seeding) or dry seeding into a prepared seedbed (dry seeding). The development of short duration, early-maturing cultivars and efficient nutrient management techniques along with increased adoption of integrated weed management methods have encouraged many farmers to switch from transplanted to DSR culture. This technology is highly mechanized in some developed nations like U.S, Europe and Australia. This shift should substantially reduce crop water requirements and emission of greenhouse gases. The reduced emission of these gases helps in climate change adaptation and mitigation, enhanced nutrient relations, organic matter turnovers, carbon sequestration and also provides the opportunity of crop intensification. However, weed and nematode infestation are major problems, which can cause large yield losses in DSR. Other associated problems with DSR are increased incidences of blast disease crop lodging impaired kernel quality, increased panicle sterility and stagnant yields across the years. Based on the existing evidence, the present paper reviews the integrated package of technologies for DSR, potential advantages and problems associated with DSR, and suggest likely future patterns of changes in rice cultivation.

Delineation of soil management zones for a rice cultivated area in eastern India using fuzzy clustering

Abstract: Efficient, cost effective and easy to use tools are needed for site specific management of soils for increasing the crop productivity. Currently nutrient management recommendations for rice in the study are typically uniform without consideration of spatial heterogeneity of nutrient content in soil. This study has emphasized the use of management zones (MZs) as an efficient method for variable application of fertilizers. Rajnagar Block of Kendrapada District in India was selected as the study area for the present study and 225 soil samples were collected on 1.5 kilometer grids. Soil samples were analyzed for pH, electrical conductivity, soil organic carbon, available nitrogen, available phosphorous, available potassium DTPA extractable micronutrients i.e., iron, zinc, copper, and manganese. Spatial variability of these soil properties was analyzed and spatial distribution maps were generated using geostatistics and ordinary kriging technique. Further, principal component analysis and fuzzy c-means clustering algorithm were performed to delineate the management zones based on optimum clusters identified using fuzzy performance index (FPI) and normalized classification entropy (NCE). The results revealed that the optimum number of MZs for this study area was three and there was heterogeneity in soil nutrients in three MZs. The delineated MZs provide a basis of information for site-specific fertilizer management in the rice cultivated fields in the study area.

Carbon and nitrogen fractions and stocks under 41 years of chemical and organic fertilization in a sub-humid tropical rice soil

Abstract: Effects of different fertilizers and manure on dynamics of soil organic carbon (SOC) and nitrogen fractions and their stock changes remains unclear under intensively cultivated rice soil profile. Profile soil samples in six treatments viz. control, nitrogen (N), nitrogen-phosphorus-potassium (NPK), farm yard manure (FYM), N + FYM and NPK + FYM were collected from a long term fertilizer experiment continuing since 1969 at ICAR-NRRI, Cuttack, India to study the soil organic carbon and nitrogen fractions (particulate organic carbon, POC; microbial biomass carbon, MBC; particulate organic nitrogen, PON; and microbial biomass nitrogen, MBN) and SOC sequestration. Results from the study revealed that in the control treatment, where no manure or chemical fertilizer was applied,the bulk density was highest. Balanced fertilization and combined use of chemical fertilizers and manure for 41 years increased the SOC in all the plots except the unfertilized control as compared with the initial value (6.6 g/kg). Balanced fertilization (NPK) and integrated fertilization (NPK + FYM) resulted in similar increases in particulate organic carbon, carbon mineralization and microbial biomass carbon, whereas particulate organic nitrogen, nitrogen mineralization and microbial biomass nitrogen were more in integrated fertilization (NPK + FYM) compared with control treatment. Soil organic C and nitrogen stocks changed positively across the fertilizer and manure treatments over the control. In the control plot, at 0–15 cm depth the soil carbon and nitrogen stock was 15.1 and 1.77 Mg ha −1 , respectively which increased to the 19.5 Mg ha −1 in NPK + FYM for carbon and 2.25 Mg ha −1 in N + FYM for nitrogen. As compared to the initial (13.7 Mg ha −1 ), the SOC stock in 0–15 cm depth increased under all the fertilized treatments during 41 year period in the order: NPK + FYM > N + FYM > NPK > FYM > N > control. The rate of increase in SOC (carbon sequestration) due to fertilizer application alone varied between 57 and 89 kg ha −1 yr −1 , while for FYM addition the rate of increase was 61 to 138 kg ha −1 yr −1 , highest being in NPK + FYM. Correlation coefficients between different soil organic C and N fractions indicate differential accumulation pattern of organic C and nitrogen in different depths. Based on crop yield and C storage, integrated fertilization of chemical fertilizers and manure proved to be the best for improving crop productivity and SOC sequestration.

Soil enzymes: Kuprevich, V. F. & Shcherbakova, T. A.: Translated from the Russian edition (1966), published by the Indian National Scientific Documentation Centre, New Delhi 1971. 392 pp., offset printing from type script, paper cover. Obtainable from U.S. Department of Commerce, National Technical Information Service, Springfield, Va. 22151

Abstract: B6nassy, C., 1955. R6marques sur deux Aphelinid6s: Aphelinus mytilaspidis Le Baron et Aphytis proclia Walker. Annls l~piphyt. 6: 11-17. Lord, F. T. & MacPhee, A. W., 1953. The influence of spray programs on the fauna of apple orchards in Nova Scotia II. Oyster shell scale. Can. Ent. 79: 196-209. Pickett, A. D., 1946. A progress report on long term spray programs. Rep. Nova Scotia Fruit Grow. Ass. 83 : 27-31. Pickett, A. D., 1967. The influence of spray programs on the fauna of apple orchards in Nova Scotia XIV. Can. Ent. 97: 816-821. Tothill, J. D., 1918. The predacious mite Hemisarcoptes malus Shimer and its relation to the natural control of the oyster shell scale Lepidosaphes ulmi L. Agric. Gaz. Can. 5 : 234-239.

A Definitive Book on Seed Ecology@@@Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination

Abstract: Introduction. Ecologically Meaningful Germination Studies. Types of Seed Dormancy. Germination Ecology of Seeds with Nondeep Physiological Dormancy. Germination Ecology of Seeds with Morphophysiological Dormancy. Germination Ecology of Seeds with Physical Dormancy. Germination Ecology of Seeds in the Persistent Seed Bank. Causes of Within-Species Variations in Seed Dormancy and Germination Characteristics. A Geographical Perspective on Germination Ecology: Tropical and Subtropical Zones. A Geographical Perspective on Germination Ecology: Temperate and Arctic Zones. Germination Ecology of Plants with Specialized Life Cycles and/or Habitats. Biogeographical and Evolutionary Aspects of Seed Dormancy. Subject Index.

Heat and Drought Stresses in Crops and Approaches for Their Mitigation.

Abstract: Drought and heat are major abiotic stresses that reduce crop productivity and weaken global food security, especially given the current and growing impacts of climate change and increases in the occurrence and severity of both stress factors. Plants have developed dynamic responses at the morphological, physiological and biochemical levels allowing them to escape and/or adapt to unfavourable environmental conditions. Nevertheless, even the mildest heat and drought stress negatively affects crop yield. Further, several independent studies have shown that increased temperature and drought can reduce crop yields by as much as 50%. Response to stress is complex and involves several factors including signaling, transcription factors, hormones, and secondary metabolites. The reproductive phase of development, leading to the grain production is shown to be more sensitive to heat stress in several crops. Advances coming from biotechnology including progress in genomics and information technology may mitigate the detrimental effects of heat and drought through the use of agronomic management practices and the development of crop varieties with increased productivity under stress. This review presents recent progress in key areas relevant to plant drought and heat tolerance. Furthermore, an overview and implications of physiological, biochemical and genetic aspects in the context of heat and drought are presented. Potential strategies to improve crop productivity are discussed.