Open Access Original Research Article

Greenhouse Gas Fluxes and Soil Carbon and Nitrogen Following Single Summer Tillage Event

Prakriti Bista, Urszula Norton, Rajan Ghimire, Jay B. Norton

International Journal of Plant & Soil Science, Page 183-193
DOI: 10.9734/IJPSS/2015/16234

No-till farming results in gradual buildup of soil organic matter (SOM) and re-introduction of tillage can often reverse it. However, tillage in low precipitation regions may be needed to manage weeds and disperse accumulation of immobile soil nutrients. The main objective of this study was to assess the effects of a single summer tillage on carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), soil water filled pore space (WFPS), dissolved organic carbon (DOC) and nitrate (NO3) in winter wheat - summer fallow systems that were either tilled for the first time after nine years of no-till (NTT), not-tilled (no-till, NT) or were frequently tilled (conventional, CT; and organic, CF). The study was established in the US Central High Plains region where annual precipitation averaged 332±39 mm. Soil and gas samples were collected before the tillage event (time zero) and at 1hr, 5 hrs, 25 hrs and 50 hrs after. Immediate increases in CO2 and N2O fluxes were observed in all tilled treatments within the first 1 to 5 hours but 50-hr cumulative N2O and CO2 in NTT did not differ from the values observed in NT. Tillage however, resulted in a 22% greater 50-hr cumulative CH4 assimilation in NTT compared with NT and was comparable with CH4 in CT suggesting enhanced soil aeration. Soil NO3 did not change in NTT unlike in CT and CF and soil DOC did not increase in NTT until 25 hrs after when, it returned to levels comparable with time zero. In contrast, DOC in CT and CF continued to stay elevated after 50 hrs. In conclusion, single tillage event of a long-term no-till performed on dry soil during summer did not negate benefits associated with SOM accrual and may be a viable alternative for farmers to address some of the management-related problems.

Open Access Original Research Article

Ultraviolet-visible and Infrared Spectroscopic Studies of Soil Humic Acids

Minakhi Kachari, Punam Belwar, Krishna Dutta, Annapurna Sarmah, Partha P. Saikia, Mrinal K. Baruah

International Journal of Plant & Soil Science, Page 194-202
DOI: 10.9734/IJPSS/2015/16032

Structural characterization of humic acids extracted from surface, below 15 cm depth and 30 cm depth tea garden soils have been studied here. Instrumental analysis of the organic substances were carried out using UV-Visible and IR spectroscopies. The results reveal low level of humification of the humic acids occurring in the soil samples and low condensation of these molecules. The predominant aliphatic characters of the humic acid molecules are evident from this study. The occurrence of hydrogen bonded oxygen containing groups, e.g., hydroxyl, carboxyl, etc., have been observed. The presence of nitrogen containing organic compounds as well as unleachable (in acid and alkali treatments) metal-bonded oxygen and nitrogen species are also indicated. The results obtained in this study would be quite helpful for structural understanding of soil organic matters.

Open Access Original Research Article

Effect of Soil Zinc and Boron on the Yield and Uptake of Wheat in an Acid Soil of West Bengal, India

Amiya Biswas, D. Mukhopadhyay, Asim Biswas

International Journal of Plant & Soil Science, Page 203-217
DOI: 10.9734/IJPSS/2015/15921

The production of wheat (Triticum aestivum L.), an important staple food in the world, is often restricted due to micronutrients status in soil. Micronutrient deficiency in soil including boron (B) and zinc (Zn) is quite widespread in Asian countries including India due to prevalent soil and environmental conditions. A field experiment was conducted following randomized complete block design over a two-year period in an acid soil of Terai region of West Bengal to study the effect of Zn and Bon the yield and uptake of nutrients by wheat. The highest grain yield (4.4 tha-1) was obtained after the combined application of Zn and B over that of other treatment combinations (variable rates of B and Zn application with nitrogen (N), phosphorus (P) and potassium (K)) or control (no NPK, B and Zn). Application of one micronutrient might have accelerated the uptake of other micro- and macro-nutrients (such as B, Zn, N, P and K) resulting in higher yield. A positive correlation was observed between the grain yield and the uptake of different nutrients with the weakest with Zn. An enhancement of the nutrients in soils was also observed at the harvest. High response from a combined application of B and Zn clearly demonstrated the necessity of micronutrients for improving production in the studied regions with acid soils. Therefore, an application of a mixture of micronutrients is recommended over a single micronutrient for the acid soil regions of West Bengal in order to get a better response from the applied nutrient sources and thus the production.

Open Access Original Research Article

Evaluation of pKa Values of Soil Humic Acids and their Complexation Properties

Sumitra Paul, Trishnamoni Sharma, Debajit Saikia, Partha P. Saikia, Dhrubajit Borah, Mrinal K. Baruah

International Journal of Plant & Soil Science, Page 218-228
DOI: 10.9734/IJPSS/2015/16033

A study has been undertaken to determine the acidic, and metal complexing properties of humic acid extracted from tea garden soils of different depths. The dissociation constant of humic acid has been evaluated from the pH titration curves. The pKa values obtained in this study almost agree well with the data reported for humic acids from natural sources. The presence of carboxylic and/or hydroxyl groups in the humic acids, under study, have been confirmed. Metal complexation properties of the extracted humic acids have been studied with three metal ions (Zn2+, Ni2+, and Cu2+). The stability constants of the metal humic acid complexes have also been determined. One pKa value for humic acid extracted from the surface soil (pKa = 2.50 and the 30 cm depth soil (pKa = 5.2) has been obtained whereas two pKa values (3.1 and 7.5) for humic acid from the 15 cm depth soil have been found. These acids contain carboxylic and/or hydroxylic acid groups. Stability constants of metal-humic acid complexes (log K) do not differ much for humic acids from the surface soil (1.92, 2.09 and 2.07) and the 15 cm depth soil (2.01, 2.31 and 1.72) for Zn2+, Cu2+ and Ni2+ respectively. This work will contribute some knowledge to the nature of organic matter in tea garden soil.

Open Access Original Research Article

Charophyte Community in the Lowermost Locality in the World Near the Dead Sea, Israel

Sophia Barinova, Roman Romanov

International Journal of Plant & Soil Science, Page 229-243
DOI: 10.9734/IJPSS/2015/16063

Aims: First study of the lowermost locality the Neot HaKikar with charophytes in the Dead Sea region of Israel has been implemented showing the algal diversity and ecological assessment of the water object environment.

Study Design:  We implemented diverse bio-indication methods.

Place and Duration of Study: Institute of Evolution, University of Haifa, Israel, Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences, Russia, between January 2012 and December 2014.

Methodology: Material for this study comes from 26 samples including 9 living and 9 fixed periphyton samples, 4 fixed samples of charophytes and 4 samples of water. We used bio-indication methods for the purpose of characterizing pool water quality and ecosystem sustainability. Index saprobity S and Index of aquatic ecosystem sustainability WESI were calculated.

Results: Altogether 39 species of algae, including macro-algae Chara contraria A. Braun ex Kützing (Charales, Charophyceae), were revealed in the Neot HaKikar pool. Chara was found in significant growth in the bottom and coastal part of the studied pool. Bio-indication and chemical variables characterized the charophyte site environment as mesotrophic to eutrophic with prevailing  benthic types of organisms with an autotrophic type of nutrition, which are mostly attached to the substrate and preferred standing water, medium-enriched by oxygen, with temperate temperature, medium salinity, low alkalinity, and low-to-middle organic pollution, representing the Class III of water quality. Seasonality of the algal community and water quality showed organic and other contaminants of pollution during the winter period as a result of evaporation and an atmospheric dust impact. The Charophyte community is sharply limited in its development as a result of periodical anthropogenic desiccation of the pool. We found unique properties of Chara contraria in the renewed population after two years of desiccation.

Conclusion: We can recommend the Neot HaKikar pool for the monitoring of unique natural aquatic objects in the Dead Sea area, and Chara contraria as a climatic indicator of surviving under future climate warming.

Open Access Original Research Article

Effects of Fertilization Patterns Using Mineral and Organic Fertilizers on Growth and Yield of Cucumber under Greenhouse

Mahmoud Rahil, Alia Qanadillo

International Journal of Plant & Soil Science, Page 244-253
DOI: 10.9734/IJPSS/2015/16249

This study was conducted to investigate the effects of four fertilization patterns on growth parameters, and yield of cucumber crop under greenhouse cultivation. A field experiment was carried out at the experimental farm of Palestine Technical University Kadoorie located at Tulakrm, Palestine. Cucumber seedlings were planted on 14 February 2012 in greenhouse at a rate of 1500 seedlings per 1000 m2. Four fertilization patterns were examined during the growing period of cucumber crop as follows: traditional fertilization (TF), mineral fertilization (MF), mineral fertilization plus humic acids (MFHA), and liquid organic fertilization (LOF).

Samples were collected from different sites at soil depths of 0-15 and 15-30 cm for evaluating the physical and chemical properties of the soil. The soil of the experimental plot can be classified as clay texture with bulk density in the upper 30 cm of 1.22 g cm-3. The soil had no salinity problem with saturation extract ECe of 0.9–1 dS/m. Plant data were collected during the growing period of cucumber crop for evaluating the total yield, plant height, number of harvested fruits per plant, weight of harvested fruits per plant and dry matter of above and underground parts.

Results of this study indicated that the average yield of investigated treatments indicated that the MFHA treatment obtained the highest crop yield of 72.30 t ha-1, followed by 67.36, 61.73 and 58.07 t ha-1, for MF, TF and LOF treatments, respectively. The MFHA treatment obtained the highest fruit number per plant followed by MF, TF and LOF, respectively. At the end of the growing period, the MFHA obtained the highest dry matter, while the LOF treatment gave the smallest one compared to the other fertilization treatments. The MFHA treatment obtained the highest water use efficiency followed by MF, LOF and TF treatments, respectively.