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Okra is a well-known and economically important vegetable grown in Bangladesh for consumption and seed production. The yield of okra is low compared to developed countries that can be increased using irrigation water efficiently. Traditional irrigation methods are used for okra cultivation in the developing countries, resulting in significant water loss. One of the options that appears to be promising for reducing this water loss is drip irrigation since it applies water directly to the plant’s root zone. However, farmers frequently complain about manual inspection and water wastage from the overhead tanks in small-scale microirrigation systems. An automated microirrigation system can help to solve this problem. This approach was developed at Bangabandhu Sheikh Mujibur Rahman Agricultural University to evaluate the performance of okra in terms of plant growth, seasonal water usage, and yield factors. For a better understanding of specialist crop irrigation management, the effectiveness of water utilization was also investigated. The experimental field was set up in a Randomized Complete Block Design (RCBD) from March to May 2021, with three different treatments such as T1 (Conventional irrigation), T2 (Drip irrigation) and T3 (Timer drip irrigation), for comparing the treatments with four replications. To construct an automated microirrigation system, a pump controller with sensing probes to regulate the water level in the irrigation tank and irrigation timers for watering the okra field depending on scheduling were used. According to the data, only the length of the pod varied significantly, whereas the other factors were non-significant. The yield components, such as the weight of pod per plant and yield, did not varied significantly among the treatments. The highest (12.95 kg/m3) and the lowest (10.47 kg/m3) water use efficiency were obtained in T3 (Timer drip irrigation) and T1 (Conventional irrigation) respectively. The study reveals that automated microirrigation technology can save 11% more irrigation water than conventional irrigation.

Concentrations of heavy metals in irrigation water and soil were examined to determine the level of contamination in a particular irrigation channel in Gazipur, Bangladesh. In this conduit, effluent from households, industries, and municipalities was combined with irrigation water. The study was carried out in order to estimate pollutant loads along a wastewater irrigation channel and to conceptualize seasonal changes in composite wastewaters. A total of six wastewater and nine contaminated soil samples were collected directly from the study area and analyzed for this project. From February to March, before the monsoon, the pH of the water is too low for this channel to be used for irrigation. At the end of the monsoon season, from April through May, all wastewater tests were within these parameters, making them suitable for irrigation. Considering the standard limits, Pb, Cr, and Cu concentrations in all wastewater samples were found unsuitable for irrigation and thus problematic for soils and crops. The concentration of Cd in the wastewater samples ranged from 27.82 to 88.36 mg/L, whereas the tolerance limit for Cd in irrigation water is 0.01 mg/L. In soil samples from the three places chosen, the levels of Pb were below the safe limit and the levels of Cr were above the safe limit. The heavy metal pollution index of all the sites crossed the safe limit. On the basis of the geo-accumulation index and the pollution index, Pb indicates no pollution and Cd indicates very high levels of pollution in all locations. The maximum enrichment factor was found for Cd, Pb, and Cu, which have minor enrichment, Ni, which has no enrichment, and Cr, which has moderate enrichment. The study also tried to link heavy metals in wastewater to their deposition in soil and seasonal and temporal variations. The study revealed that industrial effluent utilized for irrigation was closely related to the accumulation of heavy metals in soils. Since irrigated agricultural soils are likely to be exposed to harmful wastes, it is crucial that the effluents from the industrial region of Gazipur are appropriately controlled.

Using potential microbes in biodegradable solid waste management is an emerging science. Microbes play a significant role in recycling of organic solid wastes. Therefore, the present project was carried out to isolate indigenous potential non-phytopathogenic fungi from local relevant decomposed substrates for the purpose of organic waste recycling as bio-organic fertilizer (BOF). A total of thirteen fungal strains were isolated. Seven of them were identified as Trichoderma spp., and the rest were Penicillium spp. Germination of mung bean (Vigna radiata), mustard (Brassica campestris), and wheat (Triticum aestivum) seeds were assessed by application of 13 fungal isolate suspensions. Significant increase of germination percent was achieved in mung bean (98.35%), mustard (96.65%), and wheat (93.35%) by fungal treatments RW-T02, PL-P01, and CD-T01/MSW-T05, respectively, compared to the controls. But radicle and plumule lengths were not promoted by fungal treatments in the majority of cases. Significantly, the longest radicle and plumule lengths of mung bean and mustard were found in control treatments. Conversely, in wheat the longest radicle and plumule length were achieved in treatments MSW-T05 and RW-T03, respectively. Based on superior performances of percent germination and radicle/plumule length, six fungal isolates were selected for compatibility performance in mixed cultures. In the compatibility tests, two fungal combinations (ABF and BCE) presented superior mutual intermingle appearances. Perhaps these combinations may play significant roles in biodegradation of organic wastes.

Recycled wastewater is considered as a sustainable source of irrigation water. Despite commendable safety records, viral contamination of agricultural products has occurred the past causing disease outbreaks. This review examines the apprehension that the novel coronavirus (SARS-CoV-2) may also spread through recycled wastewater irrigation (RWI) industry. The novel SARS-CoV-2 is now perceived as an enteric pathogen, and has been found to remain stable in the wastewater for days. Mounting evidences also suggest that viral particles shed by infected individuals through sewage, and greywater is much higher (up to 10 Log10) than the amount typically removed (6-7 Log10) through the recycled water disinfection processes. Such gap indicated an increased risk of infection through fecal-oral transmission route. This study also identified greywater irrigation schemes posing a higher risk of transmission of SARS-CoV-2. It was recommended that countries putting greywater in the ‘low risk’ category may rewrite the safety guidelines in post COVID-19 times. This review also suggest that the choice of irrigation method could be critical in protecting the farmers, and the consumers from possible infections during the pandemic. In this regard, irrigation methods (i.e. sprinkler) that generate airborne droplet (leading to aerosols) may be operated with caution when public spaces are in the vicinity. The study also indicated that the developing countries should regulate surface irrigation practice that pump water from polluted rivers during the pandemic.

Adequate supply of micronutrients is important for the proper growth and yield of lentil, particularly in poorly fertile soil. This study was carried out to understand the effects of zinc (Zn), boron (B), and molybdenum (Mo) on the growth and yield of lentil, and how these elements can help manage soil fertility issues. In this regard, the morpho-physiological traits of lentils (BARI Masur-7) were collected from two experiments receiving the same treatments carried out during consecutive rabi seasons of 2015&ndash, 2016 and 2016&ndash, 2017. The experiments were laid out with a randomized complete block design having eight treatments, and was replicated thrice. The treatments were T1 (Control), T2 (Zn2.0 kg ha&minus, 1), T3 (B1.5 kg ha&minus, 1), T4 (Mo1.0 kg ha&minus, 1), T5 (Zn2.0B1.5 kg ha&minus, 1), T6 (Zn2.0Mo1.0 kg ha&minus, 1), T7 (B1.5Mo1.0 kg ha&minus, 1), and T8 (Zn2.0B1.5Mo1.0 kg ha&minus, 1). The results revealed that the application of micronutrients either singly or in combination had significant effects on the plant height, number of branches per plant, number of pods per plant, number of seeds per pod, thousand seed weight, and the seed yield of lentil. The maximum seed production was, however, observed in plots receiving treatment T8, i.e., the combined application of Zn, B, and Mo. Agronomic biofortification also had significantly increased protein content of lentil seeds while affecting the macro and micronutrient content of lentil seed. These results suggest that any micronutrient deficiencies might lead to a yield loss of lentil, and such a scenario could be avoided by a combined application of micronutrients at a proportionate level.