Dynamics of iron under long-term application of chemical fertilizers and amendments on maize-wheat cropping sequence

Iron (Fe) is one of the essential micronutrient plays a crucial role in redox systems in cells and in various enzyme. The Fe-deficient plants have lower redox reaction and enzymatic activity. Intensive chemical fertilizer resulted in depletions of micronutrients especially Fe from the soil. To understand the dynamics of Fe under long-term fertilizer experiment the present study was initiated during 1972 at experimental farm of College of Agriculture CSK HPKV, Palampur in randomized block design with eleven treatments replicated thrice. The soil of the experimental area was silty loam, acidic in reaction and taxonomically classified as “Typic Hapludalfs.” Surface (0–20 cm) and subsurface (20–40 cm) soil samples collected after the harvest of maize (Kharif, 2008). The continuous use of chemical fertilizers and amendments for the last 36 years in maize-wheat system in an acid Alfisol brought out marked depletion in the pools of Fe as compared to buffer plots. All the pools of Fe were noticeably higher in farmyard manure (FYM) amended plots compared to zero-fertilized plots. Although, residual fraction was found to be the most dominant fraction but organically bound and exchangeable forms were found to play major role in the nutrient supply and crop productivity and nutrients’ uptake. Highest productivity of maize (2008) and wheat (2008–2009) was recorded under 100% nitrogen, phosphorus and potassium (NPK) + FYM treatment. FYM and lime treatments resulted in significantly higher uptake of all the nutrients by both the crops compared to other treatments. Organically bound fraction was found to have highest significant and positive correlation with yield and nutrient uptake of maize and wheat crops. Further, regression analysis studies too revealed that organic form was the most important pool contributing towards the variation in the above parameters. While, exchangeable and organically bound forms contributed significantly towards diethylene triamine pentaacetic acid (DTPA)-extractable Fe.     

Carbon Stock, Afforestation and Acidic Deposition: An Analysis of Inter-Relation with Reference to Arid Areas

Recent advances in desert afforestation underlines its viability and importance in combating global warming and acidification. In this paper, the inter-relation between afforestation, global warming and acid rain has been analyzed. Numerical simulations indicate that afforestation of deserts has distinct advantage as carbon sink and as an important factor for changing microclimate of the region rather than a source of energy. Acidic deposition may well be utilised as fertiliser in nutrient deficit soil of tropical arid areas. However, past trends and projections of acidic deposition in arid areas adjacent to Thar deserts indicate an early efforts are required to cap the opportunity. Delays may contribute towards more incidences of failures.     

Characterization of LORF11, a unique gene common to the three Marek's disease virus serotypes

The unique open reading frame 11 (LORF11) of Marek's disease virus (MDV) is present in all three serotypes of MDV and is located in the unique long region of the MDV genome. In the serotype 1 Md5 genome, LORF11 comprises 2711 nucleotides and encodes a predicted protein of 903 amino acids. In order to study the biological function of LORF11 we deleted it from the MDV cosmid A6 by using the RecA-assisted restriction endonuclease cleavage method. The recombinant cosmid, A6DeltaLORF11, was transfected into duck embryo fibroblasts (DEF) in conjunction with parental SN5, P89, SN16, and B40 cosmid clones. Recombinant rMd5DeltaLORF11 plaques were evident at 12-13 days after transfection. Polymerase chain reaction amplification of DEF cells infected with rMd5DeltaLORF11 viruses confirmed the deletion of a 2.57-kb fragment resulting in a 296-bp fragment. Three rMd5DeltaLORF11 mutants were generated and their biological functions were studied in vitro and in vivo. In vitro growth characteristics of rMd5DeltaLORF11 viruses were similar to those of parental rMd5, indicating that LORF11 is not essential for replication in vitro. In vivo studies of rMd5DeltaLORF11 mutants showed that they were impaired in viral replication in the lymphoid organs and had 100x lower viremia than chickens infected with the parental rMd5 virus. Furthermore, rMd5-infected chickens horizontally transmitted the virus to contact controls whereas no horizontal transmission occurred in rMd5DeltaLORF11-infected chickens. Three independent deletion mutants were tested and showed the same phenotypes, so it is unlikely that the observed phenotype is because of any random mutation in the genome. Therefore the LORF11 gene of MDV is essential for normal virus replication in chickens and deletion of LORF11 renders an attenuated virus.     

Trait phenotyping and SSR markers characterization of wheat (Triticum aestivum L.) germplasm for breeding early maturing wheat’s for Western-Himalayas

Genetic Resources and Crop Evolution - The study involved evaluation of 96 wheat genotypes for early maturity and related traits and molecular characterization of trait specific candidate genotypes...     

Chloroplast derived SSRs reveals genetic relationships in domesticated alliums and wild relatives

Genetic Resources and Crop Evolution - Alliums comprise of popular spices and used for various culinary purposes and nutraceuticals. Poor genetic characterization and scarce information regarding...     

Prospects and challenges in utilization of indigenous rocks and minerals as source of potassium in farming

Potassium (K) is one of the essential nutrients required by crops in large quantities; however, its use in agriculture by farmers is less than required in developing countries. This neglect has led to excess mining of K in soils by crop plants and has resulted in a negative balance of K in soils. This loss necessitates the need of more use of potassium fertilizers in agriculture. Rocks and minerals offer a potential fertilizer to utilize in agriculture as source of K. The crop trials revealed that feldspar, mica, glauconite, nepheline and shoenite are good sources of K for crops, especially in highly weathered acid soils. However, some researchers have reported no agronomic benefit of feldspar or granite rock application to crops. Overall the size modification, acidulation, microbial inoculants and preparation of K-enriched compost are the effective techniques to utilize K-bearing rocks and minerals. Very limited information is available on these aspects. Thus, in this review, an attempt has been to consolidate up-to-date information of indigenous rocks and minerals as possibilities for alternate sources of K for crop plants. Moreover, this area of research needs attention to utilize indigenous K sources, which can aid to limit the import and cost, of the establishment of potash fertilizer-based industries in developing countries.     

Impact of Organic Amendments on Groundwater Nitrogen Concentrations for Sandy and Calcareous Soils

Experiments were conducted on calcareous and sandy soils to investigate the effects of organic amendments for vegetable production on groundwater nitrogen (N) concentration in south Florida. The treatments consisted of applying yard and food residuals compost, biosolids compost, a cocompost of the municipal solid waste and biosolids, and inorganic fertilizer. Nitrate nitrogen (NO₃-N), ammonium nitrogen (NH₄-N), and total N concentrations were collected for a period of two years for both soils. Statistical analysis results revealed that for the three species tested, there were no significant differences among treatments. NO₃-N concentrations for all treatments remained less than the maximum contamination level (10 mg/L). NO₃-N transport to groundwater was higher in calcareous soil (mean=5.3 mg/L) than in sandy soil (mean=0.6 mg/L). NH₄-N concentrations ranged from 0 to 13.6 mg/L throughout the experiment. Calcareous soil had lower NH₄-N concentrations (mean=0.1 mg/L) than sandy soils (mean=0.7 mg/L). Total N ranged from 0.4 to 21.7 mg/L for all treatments for both soils reflecting high adsorption of dissolved organic N in both soils. Overall, results indicated that all the compost treatments were comparable to inorganic fertilizer with regard to N leaching and N concentrations in the groundwater while producing similar or higher yields.     

Timber species grouping in Bangladesh: linking wood properties

Timber species grouping (TSG) is essential for meaningful and cost-optimal use of wood. Bangladesh forests are exceedingly diverse and comprise many woody species which are potentially suitable for versatile uses including structural materials. Traditionally, widely known tree species are used for structural timber because technological properties of most of the species are poorly known. In this study, a hierarchical agglomerative cluster analysis based on three selected wood properties [i.e., wood density, modulus of elasticity (MOE) and modulus of rupture (MOR)] of seventy-nine timber species was done. The clustering process led to the formation of four distinct species groups [i.e., very low (TSG1), low (TSG2), medium (TSG3) and high (TSG4)]. However, the species grouping patterns also varied from trait to trait. This might be due to moderate relationship between density and MOE (r ² = 0.46) or MOR (r ² = 0.52). Species of the TSG1 group are mainly characterized by extremely low trait values, while the TSG4 group consists of species having exceedingly high trait values. The TSG2 and TSG3 groups are characterized by low and medium trait values. Hence, it is suggested to select suitable species from these groups, particularly the lesser known high-quality species in afforestation and reforestation programs to meet future timber demand in Bangladesh.