Free and Immobilized Microbial Culture–Mediated Crude Oil Degradation and Microbial Diversity Changes Through Taxonomic and Functional Markers in a Sandy Loam Soil

Crude oil contamination of soil and water resources is a widespread issue. The present study evaluated the degradation of aliphatic hydrocarbons (C11–C36) in crude oil by 17 bacteria isolated from a crude oil–contaminated soil. The results suggested that Pseudomonas sp. and Bacillus amyloliquefaciens were the best hydrocarbon-degrading bacteria in the presence of surfactant Tween-80 (0.1% w/v). Based on the present investigation and a previous study, Pseudomonas sp. + B. amyloliquefaciens and fungus Aspergillus sydowii were identified as best oil degraders and were immobilized in alginate–bentonite beads, guargum–nanobenonite water dispersible granules (WDGs), and carboxy methyl cellulose (CMC)–bentonite composite. Sandy loam soil was fortified with 1, 2, and 5% crude oil, and total petroleum hydrocarbon (TPH) degradation efficiency of free cultures and bio-formulations was evaluated in sandy loam soils. Compared to a half-life (t1/2) of 69.7 days in the control soil (1% oil), free cultures of Pseudomonas sp. + B. amyloliquefaciens and A. sydowii degraded TPH with t1/2 of 10.8 and 19.4 days, respectively. Increasing the oil content slowed down degradation, and the t1/2 in the control and soils inoculated with Pseudomonas sp. + B. amyloliquefaciens and A. sydowii was 72.9, 14.7, and 22.2 days (2%) and 87.0, 23.4, and 30.8 days (5%), respectively. Supplementing soil with ammonium sulfate (1%) enhanced TPH degradation by Pseudomonas sp. + B. amyloliquefaciens (t1/2–10 days) and A. sydowii (t1/2–12.7 days). All three bio-formulations were effective in degrading TPH (1%), and the t1/2 was 10.7–11.9 days (Pseudomonas sp. + B. amyloliquefaciens and 14–20.2 days (A. sydowii) and were at par with free cultures. Microbial diversity analysis based on taxonomic markers and functional markers suggested that the bioaugmentation process helped keep soil in the active stage and restored the original microbial population to some extent. The present study concluded that bio-formulations of crude oil–degrading microbes can be exploited for its degradation in the contaminated environment.

Agrotechnological passport of the potato variety Azart

Цель исследований: изучить реакцию нового среднераннего сорта картофеля Азарт селекции ФГБНУ «ФИЦ картофеля имени А.Г. Лорха» на густоту, сроки посадки и способы внесения минеральных удобрений, по комплексу хозяйственно ценных признаков (морфологические и биологические особенности, потребительские и столовые качества клубней, урожайность, показатели качества клубней, устойчивость к болезням, лежкость при хранении). Опыты проводили на экспериментальной базе «Коренево» ФГБНУ «ФИЦ картофеля имени А.Г. Лорха» (Московская область) в 2018–2020 годах на дерново-подзолистой супесчаной почве с низким содержанием гумуса (1,8–1,9%), высоким – подвижного фосфора (269–278 мг/кг почвы) и ниже среднего – обменного калия (128–130 мг/кг почвы). Минеральные удобрения (азофоска с добавлением калимагнезии) вносили локально двумя лентами при нарезке гребней культиватором КРН-4,2 с туковысевающими аппаратами в середине апреля. Изучали три приема внесения: 1. Единовременное N90P90K135(контроль); 2. Дробно-локальное (стартовое N60P60K90+ подкормка N30P30K45) через 7–10 дней после всходов; 3. Дробное (стартовое N30P30K45 + подкормка N30P30K45) через 7–10 дней после всходов + подкормка N30P30K45 в фазе бутонизации. Посадку картофеля проводили в два срока: ранний (третья декада апреля при температуре почвы не ниже 5–7 °C) и базовый (контроль) – через 7–10 дней после первого срока. Клубни массой 50–80 г высаживали клоновой сажалкой СН-4Б-К на глубину 8–10 см. Исследовали три густоты посадки: 44 (контроль), 50 и 56 тыс. клубней/га по схеме 75×30, 75×27, 75×24 см. Определен наиболее эффективный агрокомплекс приемов, включающий раннюю посадку (третья декада апреля при температуре почвы не ниже 5–7 °C) с густотой 44 тыс. клубней/га на фоне дробно-локального внесения удобрений (стартовое N60P60K90при нарезке гребней + подкормка N30P30K45) при междурядной обработке через 7–10 дней после всходов. В условиях дерново-подзолистой супесчаной почвы Центрального региона Нечерноземной зоны сорт дает прибавку урожая в размере 3,9 т/га, или 10,3%. При этом условный доход составил 39,0 тыс. р/га. The purpose of the research: to study the reaction of a new medium-early potato variety Azart selection of the Russian Potato Research Centre on the density, planting dates and methods of applying mineral fertilizers, according to a complex of economically valuable characteristics (morphological and biological features, consumer and table qualities of tubers, yield, quality indicators of tubers, resistance to diseases, storage shelf life). The experiments were carried out at the experimental base Korenevo Russian Potato Research Centre (Moscow region) in 2018–2020 on sod-podzolic sandy loam soil with low humus content (1.8–1.9%), high – mobile phosphorus (269–278 mg/kg of soil) and below average – exchangeable potassium (128–130 mg/kg of soil). Mineral fertilizers (azofoska with the addition of kalimagnesia) were applied locally with two ribbons when cutting the ridges with a KRN-4,2 cultivator with tow-raising devices in mid-April. We studied three methods of making: 1. One-time N90P90K135 (control); 2. Fractional-local (starting N60P60K90 + top dressing N30P30K45) 7–10 days after germination; 3. Fractional (starting N30P30K45+ top dressing N30P30K45) 7–10 days after germination + top dressing N30P30K45 in the budding phase. Potato planting was carried out in two terms: early (the third decade of April at a soil temperature of at least 5–7 °C) and basic (control) – 7–10 days after the first term. Tubers weighing 50–80 g were planted with a clone planter CH-4B-K to a depth of 8–10 cm. Three planting densities were studied: 44 (control), 50 and 56 thousand tubers/ha according to the scheme 75×30, 75×27, 75×24 cm. The most effective agrocomplex of techniques has been determined, including early planting (the third decade of April at a soil temperature of at least 5–7 °C) with a density of 44 thousand tubers/ha against the background of fractional-local fertilization (starting N60P60K90when cutting ridges + top dressing N30P30K45) with row-to-row processing 7–10 days after germination. In the conditions of sod-podzolic sandy loam soil of the Central region of the Non-Chernozem zone, the variety gives an increase in yield of 3.9 t/ha or 10.3%. At the same time, the conditional income amounted to 39.0 thousand rubles/ha.

THE RESULTS OF THE STUDY OF THE AFTEREFFECT OF THE USE OF BIOMELIORANTS TO INCREASE THE PRODUCTIVITY AND BIOLOGICAL ACTIVITY OF DEGRADED SOD - PODZOLIC SOIL

The paper evaluates the effectiveness of the aftereffect of the use of biomeliorants (effluent and biocompost) to increase the productivity of soils in degraded reclaimed lands, carried out under the conditions of a lysimetric experiment on a stationary site, when growing annual grasses (vetch-oat mixture). It was experimentally established that effluent and biocompost based on sewage sludge and manure had a positive effect (in the first year of aftereffect) on the productivity and biological activity of soddy-podzolic sandy loam soil of fallow reclaimed agricultural lands.

Differential Variation in Non-structural Carbohydrates in Root Branch Orders of Fraxinus mandshurica Rupr. Seedlings Across Different Drought Intensities and Soil Substrates

Non-structural carbohydrates (NSCs) facilitate plant adaptation to drought stress, characterize tree growth and survival ability, and buffer against external disturbances. Previous studies have focused on the distribution and dynamics of NSCs among different plant organs under drought conditions. However, discussion about the NSC levels of fine roots in different root branch orders is limited, especially the relationship between fine root trait variation and NSC content. The objective of the study was to shed light on the synergistic variation in fine root traits and NSC content in different root branch orders under different drought and soil substrate conditions. The 2-year-old Fraxinus mandshurica Rupr. potted seedlings were planted in three different soil substrates (humus, loam, and sandy–loam soil) and subjected to four drought intensities (CK, mild drought, moderate drought, and severe drought) for 2 months. With increasing drought intensity, the biomass of fine roots decreased significantly. Under the same drought intensity, seedlings in sandy–loam soil had higher root biomass, and the coefficient of variation of 5th-order roots (37.4, 44.5, and 53% in humus, loam, and sandy–loam soil, respectively) was higher than that of lower-order roots. All branch order roots of seedlings in humus soil had the largest specific root length (SRL) and specific root surface area (SRA), in addition to the lowest diameter. With increasing drought intensity, the SRL and average diameter (AD) of all root branch orders increased and decreased, respectively. The fine roots in humus soil had a higher soluble sugar (SS) content and lower starch (ST) content compared to the loam and sandy–loam soil. Additionally, the SS and ST contents of fine roots showed decreasing and increasing tendencies with increasing drought intensities, respectively. SS and ST explained the highest degree of the total variation in fine root traits, which were 32 and 32.1%, respectively. With increasing root order, the explanation of the variation in root traits by ST decreased (only 6.8% for 5th-order roots). The observed response in terms of morphological traits of different fine root branch orders of F. mandshurica seedlings to resource fluctuations ensures the maintenance of a low cost-benefit ratio in the root system development.

Pre-emergence herbicidal activity and persistence of 2,4-di-tertbutylphenol in relation to soil types

Although 2,4-di-tert-butylphenol (2,4-DTBP) has demonstrated strong phytotoxic effect on various weedy plants in previous findings, research on its pre-emergence herbicidal activity in the soil is still scanty. The aim of this study was to investigate the effects of two soil types on pre-emergence herbicidal activity and persistence of 2,4-DTBP. The bioassay was carried out in a growth chamber where goosegrass [Eleusine indica (L.) Gaertn.] seeds were sown in different rates of 2,4-DTBP in two soil series under sterilized and non-sterilized soil conditions. Bioassays of each treatment were conducted in four replicates and arranged in completely randomized design. 2,4-DTBP exhibited potent pre-emergence activity as a root inhibitor where it completely inhibited (100% inhibition) of the root growth of E. indica in sandy loam soil at an application rate of 6.14 kg ai/ha. 2,4-DTBP was rapidly detoxified in silt loam soil as a result of high microbial activity where it completely lost its phytotoxicity by giving 100% emergence within 10 weeks even it was applied at an application as high as 20.4 kg ai/ha. However, 2,4-DTBP remained highly phytotoxic in sandy loam soil where it reduced the root and shoot growth by 47 and 36%, respectively, throughout 10 weeks duration of the investigation. The presence of microbes in non-sterilized soil further suggest that soil microbes may modify the chemical structure of the 2,4-DTBP, which in turn decreased its toxicity. The high level of pre-emergence herbicidal activity in conjunction with its biodegradation in silt loam soil imply that 2,4-DTBP may have potential for development as a natural-soil applied herbicide

Optimizing N Fertilization for Increasing Yield and Profits of Rainfed Maize Grown under Sandy Loam Soil

The optimum dose of fertilizers for crops varies with soil, agro-ecology, and crop management practices. Optimizing application dose is critical to reduce nutrient loss to the environment and increase nitrogen use efficiency (NUE), crop yields, and economic return to farmers. An experiment was conducted to determine the optimum N dose for increasing maize (Zea mays L. cv, Manakamana-3) yield, NUE, and farm profits under rainfed conditions. Five levels of N (0, 60, 120, 180, and 240 kg ha−1), and a non-fertilized treatment were tested in a randomized complete block design with three replications. Effects of each treatment on yield and yield attributing traits, plant lodging and Sterility (plants with no cob or grain formation), NUE, and stay green trait of maize were recorded. Application of N above 120 kg ha−1 (N120) did not have any significant effects on yield and yield components. Nitrogen, at N120 and above, produced highly fertile plants (though sterility slightly increased at N180 and N240), higher N uptake, and lower dead leaf area (18–27%). N120 produced the highest agronomic; yield increase per unit of N application (AEN—26.89 kg grain kg−1 N) and physiological efficiency of N (PEN—42.67 kg grain kg−1 N uptake), and net benefit (USD 500.43). Considering agronomic, economic, and NUE factors, an N dose of 120 kg ha−1 was found optimum for the cultivation of rainfed maize (Manakamana-3) under sandy loam soil.

Biochar, Compost, and Biochar–Compost Blend Applications Modulate Growth, Photosynthesis, Osmolytes, and Antioxidant System of Medicinal Plant Alpinia zerumbet

Alpinia zerumbet (Zingiberaceae) is a unique ornamental and medicinal plant primarily used in food ingredients and traditional medicine. While organic amendments such as biochar (BC) and compost (Co) have been demonstrated to improve plant productivity, no studies have examined their effects on the growth, physiology, and secondary metabolites of A. zerumbet. This study evaluated the impact of the amendment of BC, Co, or a biochar and compost mixture (BC+Co) on modifying and improving the growth, photosynthesis, antioxidant status, and secondary metabolism of A. zerumbet grown on sandy loam soil. The morpho-physiological and biochemical investigation revealed variation in the response of A. zerumbet to organic amendments. The amendment of BC and BC+Co significantly increased net photosynthetic rates of plants by more than 28%, chlorophyll a and b contents by 92 and 78%, respectively, and carboxylation efficiency by 50% compared with those grown in the sandy loam soil without amendment. Furthermore, the amendment significantly decreased plant oxidative stress, measured as leaf free proline and glycine betaine. Enzymatic antioxidant activity, total phenols, and flavonoids also varied in their response to the organic amendments. In conclusion, this study shows that BC and/or Co amendments are an efficient and sustainable method for improving the metabolite contents and reducing oxidative stress in A. zerumbet.

Pattern of N Mineralization and Nutrient Uptake of Tithonia diversifolia and Saccharum officinarum Leaves in Sandy Loam Soil

Background: This study aimed to determine the pattern of N mineralization of tithonia (Tithonia diversifolia) and sugarcane (Saccharum officinarum) leaves and assess the uptake of N nutrients in maize by giving T. diversifolia and S. officinarum leaves with different qualities on sandy loam soil. Methods: The research used a completely randomized design (CRD) with following treatment: T1 (100% T. diversifolia), T2 (100% S. officinarum), T3 (75% T. diversifolia: 25% S. officinarum), T4 (50% S. officinarum: 50% T. diversifolia), T5 (25% T. diversifolia leaves: 75% S. officinarum), T6 (without T. diversifolia and S. officinarum or control). Result: The results showed that the N mineralization pattern of the organic matter combination was significantly higher than the control for all observations. The amount of N mineral released in each treatment was T1 (54.58-529.7 mg/kg), T2 (41.80-381 mg/kg), T3 (47.69-473.6 mg/kg), T4 (46.70-424.0 mg/kg), T5 (70.69-378.9 mg/kg) and T6 (47.14-303.6 9 mg/kg). The sequence of cumulative N release during 12 weeks of incubation was T1 (529 mg/kg) greater than T3 (573.6 mg/kg) greater than T4 (424.0 mg/kg) greater than T2 (381 mg/kg) greater than T5 (378.9 mg/kg) greater than T6 (303.6 mg/kg). These results suggested that T. diversifolia and S. officinarum leaves significantly increased N nutrient uptake in maize by 125% to 144.54%.

Sulfamethoxazole Leaching from Manure-Amended Sandy Loam Soil as Affected by the Application of Jujube Wood Waste-Derived Biochar

Vertical translocation/leaching of sulfamethoxazole (SMZ) through manure-amended sandy loam soil and significance of biochar application on SMZ retention were investigated in this study. Soil was filled in columns and amended with manure spiked with 13.75 mg kg−1 (S1), 27.5 mg kg−1 (S2), and 55 mg kg−1 (S3) of SMZ. Jujube (Ziziphus jujube L.) wood waste was transformed into biochar and mixed with S3 at 0.5% (S3-B1), 1.0% (S3-B2), and 2.0% (S3-B3) ratio. Cumulative SMZ leaching was lowest at pH 3.0, which increased by 16% and 34% at pH 5.0 and 7.0, respectively. A quicker release and translocation of SMZ from manure occurred during the initial 40 h, which gradually reduced over time. Intraparticle diffusion and Elovich kinetic models were the best fitted to leaching data. S3 exhibited the highest release and vertical translocation of SMZ, followed by S2, and S1; however, SMZ leaching was reduced by more than twofold in S3-B3. At pH 3.0, 2.0% biochar resulted in 99% reduction in SMZ leaching within 72 h, while 1.0% and 0.5% biochar applications reduced SMZ leaching to 99% within 120 and 144 h, respectively, in S3. The higher SMZ retention onto biochar could be due to electrostatic interactions, H-bonding, and π-π electron donor acceptor interactions.