Evaluation and screening of low phosphorus stress tolerance of common bean (Phaseolus vulgaris L.)

A field experiment was carried out to screen low phosphorus tolerance indexes in common bean. Analysis and comparison of the coefficient of variation of the relative values of phosphorus efficiency-related indexes in 30 common bean varieties subjected to different phosphorus treatments were identified. Plant dry matter weight, phosphorus accumulation, and acid phosphatase activity are important indexes for determining low-phosphorus tolerance. A comprehensive evaluation system for low-phosphorus tolerance in common bean was established using the fuzzy membership function method. Varieties with a composite index ≥ 0.49 were identified as low phosphorus tolerant varieties, including “Longyun 13,” “Longyun 6,” and “Long17- 3525,” while varieties with a composite index ≤ 0.27 were identified as varieties sensitive to low phosphorus, including “Long12-2752,” “NR,” and “Long15-1554.” Bangladesh J. Bot. 50(3): 903-909, 2021 (September) Special

Identification of effective Rhizobium isolate(s) for efficient symbiosis with soybean under moisture stress conditions

The objective of the paper is to observe the effectiveness of Bradyrhizobial species on symbiosis with soybean under moisture stress conditions. In physiological tests, treatment T3: B. daqingense (under irrigated condition) showed significant amount of leghaemoglobin content (1.82 mg). Proline content was recorded highest (2.8 mg g-1 seed) in T8 B. liaoningense in stress. Highest chlorophyll content (1.84 mg/LFW) was recorded in T4 B. liaoningense under irrigated condition. The highest N-uptake in plant shoot, root and grain was obtained in B. daqingense under irrigated condition. Similarly, highest was obtained in in treatment T3 B. daqingense under irrigated condition. At R8 stage, grain yield was significantly highest (6.48 g) in treatment T3 (B. daqingense under irrigated condition). In both irrigated and moisture stress conditions bradyrhizobial strains B. daqingense (treatment T3 and Treatment T7) were most effective in terms of nitrogen fixation, nitrogen accumulation, phosphorus accumulation, shoot dry weight, root dry weight and grain yield as compared to the other treatments.

Nitrogen and Phosphorus Accumulation in Horizontal Subsurface Flow Constructed Wetland

The article presents the results of studies aimed at determining the level of accumulation of total nitrogen and total phosphorus in parts of reeds (Phragmites australis (Cav.) Trin. ex Steud.), as well as in a constructed wetland bed. The influence of the vegetative phase and dormancy of plants on the level of accumulation of biogenes in plant parts and in the bed of constructed wetland was investigated. Young plants at the stage of intensive growth were found to contain the most total nitrogen and total phosphorus. The leaves of the common reed, on the other hand, revealed the highest ability for the phytoaccumulation of nitrogen (32.21 gN/kg d.m.). Accumulation of total phosphorus in the leaves of reeds was, on average 1.54 gP/kg d.m. The results of studies on the filtration material filling the beds showed that the surface layer of up to 20 cm in depth was characterized by the highest total nitrogen content and total phosphorus content (average: 12.53 gN/kg d.m. and 3.01 gP/kg d.m.). The accumulation of these compounds decreased along with the depth of the deposit as well as in the direction of the outflow of sewage from the constructed wetland.

Field Scale Demonstration of Fly Ash Amended Bioretention Cells for Stormwater Phosphorus Removal: A Review of 12 Years of Work

In 2007, ten bioretention cells were constructed in Oklahoma as part of a full-scale technology project to demonstrate stormwater phosphorus reduction. The filter media used was amended with 5%, Class C fly ash by weight to increase phosphorus and heavy metal retention. In 2014, core samples were collected from four of the cells, and three were instrumented for continuous water monitoring for the following year. This paper will review the design, construction, computer modeling of phosphorus retention, and measured phosphorus removal after seven years of operation. Total phosphorus retained in the sampled cells showed reductions in effluent water concentrations of 68 to 75%, while total effluent mass reductions of 51 to 93% were achieved. Total phosphorus accumulation in the cells measured in cores ranged from 0.33 to 0.60 kg/year, which was somewhat greater than the annual calculated effluent reduction of 0.27 to 0.41 kg/year. While good, phosphorus retention was not as high as computer modeling predicted. Other research on the cells, including hydraulics, heavy metal adsorption, and microbial transport, is summarized. Experimental challenges with phosphorus extraction from samples are also discussed. All experience and results suggest that fly ash amendments are an effective option for phosphorus removal in bioretention cells.