Asian Journal of Soil Science and Plant Nutrition

Chemical properties of soil of an area control the type of crops to be grown. Chemical characteristics of soil represent the nature of genetic process, its development and nutrient status. Crop production in the saline soil is constrained by salt accumulation in the root zone. Soil salinity has adverse effects on the physical and chemical properties of soil as well as on plant growth and yield. This research showed that the pH of soil in the Rice Fields of south western part of Bangladesh was slightly acidic to neutral (6.38 to 6.68), soil salinity (EC) contents were in the range of slight to moderately saline (2.31 to 4.52 dS m^-1). Though, the concentration of total N (0.08 to 0.117%), K⁺ (1354.05 to 2206.6 ppm), SO₄^2- (0.005 to 0.009 ppm), Mg²⁺(0.006 to 0.016%), Ca²⁺  (0.035 to 0.122%) and Fe²⁺ (13.31 to 33.5 ppm) had been observed low but available PO₄^3- (142.9 to 373.5 ppm) and Na⁺ content (643 to 1802.3 ppm) were high. To get high yield from these Fields, the constraints should be minimised by supplying or preserving the nutrients by integrated soil fertility management using organic and inorganic fertilisers followed by salinity control through proper drainage, use of salt free water and fertilisers (eg. Chloride).

Aims: To put all selected species in their proper place as in the phytogeographical affinities for each region.

Study Design: Field and jazan herbarium design was used in this study.

Place and Duration of Study: A total of 201 plant species were selected from Jazan of Saudi Arabia.

Methodology: About 201 plant species (seven species of Pteridophytes, one species of Gymnosperms and 193 species of Angiosperms) related to 59 families were recorded from a total of 524 species previously recorded in 2013 from Jazan region of Saudi Arabia. The selected plant species were revealed a distribution relationships between the three African paleotropical floristic regions and showed 9 African paleotropical floristic elements.

Results: The chorological analysis revealed the highest percentages of 51.24% was inhabiting in Afromontane archipelago-like regional center of endemism (AF) of the total recorded species. The distribution relationships among the African paleotropical floristic elements was subjected to numerical analysis which showed the similarity and dissimilarity between the elements based on the UPGMA dendrogram software.

Conclusion: The program  was constructed two main groups, the first group (I) were included with Afromontane archipelago-like regional center of endemism (AF) flowed by the Guineo-Congolian regional center of endemism (GC). The second group (II) in which Sahara Regional Subzone (SS1) was recognized in a separated in a single level.

The main target of sustainable agriculture including organic farming is to use natural compounds such as plant aqueous extracts to elevate plant growth and productivity. The subject of the present study is to determine the plant growth and inflorescences production, some biochemical constituents of shoot and inflorescences and antioxidative activities of essential oil obtained from chamomile plants exogenously sprayed with aqueous extracts of dried roselle calyces, turmeric rhizomes, safflower flowers and red beet roots. A pot experiment was conducted during the two successive seasons of 2016/2017 and 2017/2018 in the open field of Experimental Farm of Agricultural Botany Department, Faculty of Agriculture, Ain Shams university, Qalyubia, Egypt. Transplants of chamomile, 45 days old, were separately sprayed after 15 days from transplanting by the four different aqueous extracts and distilled water was used as a control. Generally, spraying with tested plant aqueous extracts on chamomile plants caused high efficiency in growth promotion, inflorescences and essential oil production. Red beet and safflower extracts gave the highest number of branches and inflorescences per plant. Chlorophyll a, b, carotenoids, reducing sugars and amino acids were increased in chamomile shoots when red beet and safflower extracts were sprayed while flavonoids and phenolic compounds were significantly decreased in comparing with roselle and turmeric extract treatments. Different concentrations of essential oil and inflorescences ethanolic extracts obtained from chamomile plants treated with safflower and red beet extracts showed the highest scavenging activities on DPPH radical and lowest IC₅₀ values_. Finally, it could be concluded that application of plant aqueous extracts considered as alternative method to chemical compounds which achieved sustainability of organic farming.

Most of new reclaimed soils in Egypt are light to medium in texture. They are mainly poor in physical and hydro-physical soil quality such as porosity, water retention capacity and available water content. The objective is to assess some bio-polymers and synthetic polymers to test their effects on the soil physical and hydro-physical properties and on Lettuce plant production.

Seven treatments were applied using bio-polymers (2%dextran, 3%alginate and 3% xanthan) and two synthetic polymers (2 and 3% polyacrylamide and 2 and 3% diaper). These polymers were cheeked for their efficiency in enhancing soil properties of Toshka soil and the growth performance of Lettuce plant (Lactuca sativa) grown in soil for 55 days under open field conditions was considered.

Fresh and dry weights of plant and nutrient contents were increased significantly with all bio-treatments amendment. Whereas, synthetic polymers caused negative effects on the previously mentioned parameters.

Concerning the effects on soil properties, dextran treatment recorded the lowest values of total drainable pores (TDP %), the highest values of porosity (%), and available water. Whereas, the synthetic polymers amended soil attained negative effect with all these measured parameters compared with control treatment.

The study declared beneficial order of enhancement of soil physical and hydro-physical properties and plant production as obtained with Dextran, followed by Alginate, and Xanthan bio-polymers, while synthetic polymers did not show such effects. Hence, the study recommend using bio- polymers instead of synthetic polymers.

The present study aimed to investigate physiological and biochemical responses of wheat plantlets to application of concentrations of vitamins. In general, the data point out that addition of low concentrations of vitamins to MS media greatly improved most vegetative growth criteria concerned of wheat plantlets culture in vitro via plant tissue culture technique. In the current study root length (7.53 cm), shoots fresh weight (0.480 g), total chlorophyll content (380 μg g^-1 FW), soluble sugars (6.88 mg glucose g^-1 DW), and soluble proteins (4.9 mg protein g^-1 FW) enhancement in in vitro of wheat plantlets with application low concentrations of vitamins on the contrast, the highest concentration of the same vitamins, decreased their physiological and biochemical characteristics compared to control.