Open Access Original Research Article

Changes in the Microbial Properties of Olive Cultivated Soils under Short, Medium and Long-term Irrigation with Treated Wastewater

Yassine Hidri, Khaled Hibar, Amani Bchir, Rim Werheni, Naceur Jedidi, Abdennaceur Hassen

Asian Soil Research Journal, Page 1-20
DOI: 10.9734/asrj/2021/v5i130097

Aims: In Tunisia, Climatic changes and water shortage has led to the reuse of treated municipal wastewater (TMWW) in the agricultural sector since the sixties. This work was intended to study the short, medium, and long-term impacts of this practice on soil microbial properties.

Study Design: Five different experimental fields were chosen which had been irrigated with TMWW for 10, 20, 25, and 28 years, respectively. A pluvial irrigated field was selected as a control.

Place and Duration of Study: The study was conducted in Zaouit Sousse (Tunisian Sahel region) located in the south of Sousse City (longitude: 35°47′, latitude: 10°38′ and of altitudes: 20 m N.G.T.). The soil sampling campaign was carried out at the end of the dry season (September 2014). This study was undertaken in a semi-arid area that is facing a water crisis (water shortage and irreversible seawater intrusion).

Methodology: Soil fecal pollution indicators were determined with the most probable number MPN method. Bacterial and fungal enumeration was done by the plate count agar method. Pathogenic bacteria was determined using the conventional bacteria identification methods.

Results: Irrigation with TMWW (for more than ten years) induced a significant increase in soil microbial biomass (heterotrophic bacteria and filamentous fungi). Soil microbial contamination was assessed by measuring Total and Fecal Coliforms, E. coli, and Faecal Streptococci at three studied soil layers (0-20; 20-40 and 40-60 cm) show’s a significant increase in TMWW irrigated plots compared to the control. Salmonella spp. and Shigella spp. screening revealed the absence of those pathogens in all studied soils. This result is true for the three soil horizons (0-20; 20-40 and 40-60 cm). This result seems to be due to the short survival period of these pathogens in the soil.

Conclusion: TMWW irrigation had positive effects on soil fertility. However, this practice has led to a deterioration of the soil sanitary quality. The quality of the wastewater treated in Sousse Sud plant must be improved to ensure the reduction of emerging bacterial pathogens to non-detectable levels or to levels that have not been associated with human health risk.

Open Access Original Research Article

Influence of Arbuscular Mycorrhizae on Callusing and root colonization of Tea (Camellia sinensis) Clones in Kenya

Awa Chelangat, Joseph P. Gweyi-Onyango, Nicholas K. Korir, Maina Mwangi

Asian Soil Research Journal, Page 21-26
DOI: 10.9734/asrj/2021/v5i130098

Mycorrhizal fungi are a major component of the soil micro flora in many ecosystems, but usually have limited saprophytic abilities. Arbuscular mycorrhizal fungi (AMF) are an important component of soil life and soil chemistry. In soil, phosphorus may be present in relatively large amounts, but much of it is poorly available because of the very low solubility of phosphates by formation of complexes with iron, aluminum, and calcium, leading to soil solution concentrations of 10μm or less and very low mobility. Tea is a major income earner in the country, but yields are declining since high yielding tea varieties have a major problem with rooting and take so long in the nursery. The current study was initiated to investigate the role between Mycorrhizae and plants to explain rooting and growth rates during early stages of tea establishment. It was conducted at James Finlay in Kericho County, Kenya. The experiment was laid out in a Randomized Complete Block Design (RCBD) with factorial arrangements. Phosphorus treatments consisted of a standard rate of 107.66kg ha -1, two clones of the tea (S15/10 and SC 12/28) and two mycorrhizal strains (Glomus mosseae and Glomus intraradices) plus one control without mycorrhizae. Data was collected on rate of callusing, chlorophyll content and rate of root infection by mycorrhizal fungus. Application of 50kg Mycorrhizae ha-1 exhibited the highest callusing rate on clone SC 15/10 with significant differences (P≤0.05) observed on the chlorophyll content from week 1 to week 30 where the standard application of phosphorus plus 50kg Mycorrhizae ha-1 on clone S 15/10 had the highest content consistently throughout the trial. The highest frequency of mycorrhizae colonization in the rhizosphere was observed when 70kg ha-1 was added under clone SC 12/28. AMF strains are recommended for use on tea propagation in improving callusing rate and the chlorophyll content at a rate of 50kg Mycorrhizae ha-1.

Open Access Original Research Article

The Impact of Potassium Sources and Bio Fertilizer on Corn Plant and Potassium Availability in Calcareous Soil

Basma R. A. Rashwan, Alaa Eldeen A. Shaheen

Asian Soil Research Journal, Page 27-37
DOI: 10.9734/asrj/2021/v5i130099

Two field experiments were conducted in a calcareous soil during summer seasons of 2019 and 2020 at the experimental in a private farm Mallawi, El- Minia Governorate, Egypt to evaluate application of K fertilization at different rates of K2SO4 and non-classic products, i.e. K feldspar, mixture with or without inoculation with the K dissolving bacteria (Bacillus circulans.) soil chemical properties, plant growth, yield and nutritional value of corn (Zea-maize hybrid third 310). Our results proved that inoculation of maize seeds with Bacillus circulans at rate of 36% K2O improved soil pH, EC, soil organic matter content and enhanced the soil available N, P and K concentrations. Also, the growth parameters, yield and nutritional status of the plants were significantly increased by using non-traditional potassium fertilizers particularly in the case of seed inoculated with potassium dissolving bacteria (Bacillus circulans).

Open Access Original Research Article

Assessment of Heavy Metal Contents in Three Different Land used Soils in Ohaji/Egbema Imo State, Nigeria

L. C. Okoro, M. O. Nwachukwu, S. G. I. Ikeh

Asian Soil Research Journal, Page 38-47
DOI: 10.9734/asrj/2021/v5i130100

This assessment of some heavy metal contents in different land used soils in Ohaji/Egbema, Imo State was conducted between June, 2019 and May, 2020. Three land used soils namely; the grass land, continuously cropped and forest land were studied. Soil profile representations were established in each of the physiographic units and soil samples collected from the pedogenetic horizons for the analysis of some heavy metals like Lead (Pb), Copper (Cu), Manganese (Mn), Zinc (Zn), and Iron (Fe). The heavy metals observed in this study were Cu, Mn, Zn and Fe while Pb was not detected in this study. The results of this study showed that the grass land, continuously cropped and forest land had no Pb detected. The heavy metal contents(Cu, Mn, Zn and Fe) detected decreases with depth from 0.15cm depth to 60-90 cm depth in grass land and continuously cropped and forested land respectively. The occurrence of Fe was high in forested land which ranges from 7.8-6.3Mg/Kg with mean value of 7.0Mg/Kg than continuous cropped land and grass land with lower values. The forest land had high sodium content with mean value of 0.74 and high electrical conductivity with a mean 4.91 dsm-1. The results showed low to moderate heavy metal load in forest land and high to moderate load of heavy metals in the grass land and continuously cropped land.

Open Access Original Research Article

Minor Cereal Crops Production and their Future Prospects in Bangladesh

Jatish C. Biswas, M. R. Islam, M. M. Haque, A. Hamid

Asian Soil Research Journal, Page 48-56
DOI: 10.9734/asrj/2021/v5i130101

Different kinds of cereals are the dominant carbohydrate source for the global population of which minor cereals, a group of neglected crops, play an important role in proving substitute of rice or wheat in the harsh environment of the globe. These crops have been replaced in many areas with the advent of irrigation facilities, availability of modern crop varieties and improvement of fertilizer management systems. In the present investigation, we have delineated production zones and established relationships of minor cereal cultivation with selected social character and future climatic conditions based on existing literature and survey data. In most cases, six minor cereals are cultivated in Bangladesh. Panicum miliaceum and Setaria italic cover larger areas and are mainly grown in north, north-west, central parts and hilly regions of the country and provide 400-1500 kg ha-1 grain yield. Although low grain yields, farmers having 0.2-0.8 ha land holdings mostly cultivate minor cereals because of its high profit within a short period of time, can be grown in poor soil and does not require special care. Besides, the product can be utilized in different ways, such as food and feed with social aristocracy. Because of climate change impacts, the optimum temperature windows for studying minor cereals will be narrowed down to 15 November through 15 February by 2050 although the critical maximum temperature range might not be a problem for growing minor cereals in Bangladesh. If high-yielding varieties of minor cereals are available, it would be a climate-smart technology in the future.