Fluorescein Diacetate Activity Research Articles

Metagenomic Analysis to Assess the Impact of Plant Growth-Promoting Rhizobacteria on Peanut (Arachis hypogaea L.) Crop Production and Soil Enzymes and Microbial Diversity.

Peanut production could be increased through plant growth-promoting rhizobacteria (PGPR). In this regard, the present field research aimed at elucidating the impact of PGPR on peanut yield, soil enzyme activity, microbial diversity, and structure. Three PGPR strains (Bacillus velezensis, RI3; Bacillus velezensis, SC6; Pseudomonas psychrophila, P10) were evaluated, along with Bradyrhizobium japonicum (BJ), taken as a control. PGPR increased seed yield by 8%, improving the radiation use efficiency (4-14%). PGPR modified soil enzymes (fluorescein diacetate activity by 17% and dehydrogenase activity by 28%) and microbial abundance (12%). However, PGPR did not significantly alter microbial diversity; nonetheless, it modified the relative abundance of key phyla (Actinobacteria > Proteobacteria > Firmicutes) and genera (Bacillus > Arthrobacter > Pseudomonas). PGPRs modified the relative abundance of genes associated with N-fixation and nitrification while increasing genes related to N-assimilation and N-availability. PGPR improved agronomic traits without altering rhizosphere diversity.

Dose Effect of Polyethylene Microplastics Derived from Commercial Resins on Soil Properties, Bacterial Communities, and Enzymatic Activity.

Soils are the largest reservoir of microplastics (MPs) on earth. Since MPs can remain in soils for a very long time, their effects are magnified. In this study, different concentrations of polyethylene (PE) MPs derived from commercial resins (0%, 1%, 7%, and 14%, represented as MP_0, MP_1, MP_7, and MP_14) were added to soils to assess the changes in the soils' chemical properties, enzyme activities, and bacterial communities during a 70-day incubation period. The results show that PE MP treatments with low concentrations differed from other treatments in terms of exchangeable Ca and Mg, whereas at high concentrations, the pH and availability of phosphate ions differed. Fluorescein diacetate (FDA), acid phosphatase (ACP), and N-acetyl-β-d-glucosaminidase (NAG) enzyme activities exhibited a dose-related trend with the addition of the PE MPs; however, the average FDA and ACP activities were significantly affected only by MP_14. Changes in the microbial communities were observed at both the phylum and family levels with all PE MP treatments. It was revealed that even a low dosage of PE MPs in soils can affect the functional microbes, and a greater impact is observed on those that can survive in polluted environments with limited resources.

Termite mound soil based potting media: a better approach towards sustainable agriculture.

Termite mound soils are known to possess unique physico-chemical and biochemical properties, making them highly fertile. Considering their rich nutrient content, the objective of the current experiment is to assess the physico-chemical properties and enzyme activities of termite mound based potting media and evaluate theirperformance for further exploration in floriculture. Potting media consisting of termite mound soil (TS) of a subterranean termite, Odontotermes obesus were prepared in 7 different combinations with garden soil (GS), sand (S) and farmyard manure (FYM) and a control (without termite mound soil), i.e., T1 (TS, GS, S, FYM (v:v:v:v /1:2:1:1)), T2 (TS, GS, S, FYM (v:v:v:v / 2:1:1:1)), T3 (TS, S, FYM (v:v:v / 2:1:1)), T4 (TS, GS, FYM (v:v:v / 2:1:1)), T5 (TS, GS, S (v:v:v / 2:1:1)), T6 (TS, S, FYM (v:v:v / 3:1:1)), T7 (TS, S, FYM (v:v:v / 1:1:2)) and control (GS, S, FYM (v:v:v / 2:1:1)). The samples were then analysed in laboratory. Experimental analysis on physico-chemical and biological parameters revealed superiority of T7 (TS, S, FYM (v:v:v / 1:1:2)) in terms of pH (7.15), organic carbon (2.13%), available nitrogen (526.02 kg ha-1), available phosphorus (56.60 kg ha-1), available potassium (708.19 kg ha-1), dehydrogenase activity (18.21 μg TTF g-1 soil day-1), Phosphomonoesterase (PME) activity (46.68 54 μg p-nitrophenol/gsoil/h) and urease activity (3.39 μg NH4-N g-1 soil h-1). Whereas T4 (TS, GS, FYM (v:v:v /2:1:1)) registered superiority in terms of PME activity (50.54 μg p-nitrophenol/gsoil/h), Fluorescein diacetate (FDA) activity (11.01 μgfluorescein/gsoil/h) and Soil Microbial Biomass Carbon (SMBC) (262.25 μg/g). Subsequent to the laboratory analysis, two best potting mixtures (T7 & T4) were selected and their performance was assessed by growing a test crop, Tagetes erecta cv. Inca Orange. Considering the growth parameters, the potting media: T7 was found to be significantly superior in terms of plant spread (39.64 cm), leaf area index (4.07), fresh weight (37.72 g), yield (317.81 g/plant), and diameter (9.38 cm) of flower over T4 & control. The Benefit:Cost (B:C) ratio meaning the ratio of net returns to total cost of cultivation was determined. The B:C ratio of raising marigold flower as potted plant in T7 was 1.10 whereas the B:C ratio of the potting mixture of T7 was 2.52. This shows that T7 potting media is also economically viable choice for commercial purposes.

Rhizophagus intraradices and Azospirillum brasilense improve growth of herbaceous plants and soil biological activity in revegetation of a recovering coal-mining area.

We assessed, in a field experiment, the effects of arbuscular mycorrhizal fungi (Rhizophagus intraradices) and plant growth-promoting bacteria (Azospirillum brasilense) on the soil biological activity and the growth of key pioneer species used in the revegetation of coal-mining areas undergoing recovery. We applied four inoculation treatments to the pioneer plant species (Lablab purpureus, Paspalum notatum, Crotalaria juncea, Neonotonia wightii, Stylosanthes guianensis, Andropogon gayanus and Trifolium repens) used in the recovery process: NI (Control - Non-inoculated), AZO (A. brasilense), AMF (R. intraradices), and co-inoculation of AZO and AMF. On the 75th and 180th days, we measured plant dry mass, mycorrhizal colonization, N and P concentration, and accumulation in plant tissue. We collected soil to quantify glomalin content and soil enzyme activity. After 180 days, we did a phytosociological characterization of the remaining spontaneous plants.The both microorganisms, singly or co-inoculated, promoted increases in different fractions of soil glomalin, acid phosphatase activity, and fluorescein diacetate activity at 75 and 180 days. The inoculation was linked to higher plant biomass production (62-89%) and increased plant P and N accumulation by 34-75% and 70-85% at 180 days, compared with the non-inoculated treatment. Among the pioneer species sown Crotalaria juncea produced the highest biomass at the 75th and 180th days (67% and 76% of all biomass), followed by Lablab purpureus (3% and 0.5%), while the other species failed to establish. At 180 days, we observed twenty spontaneous plant species growing in the area, primarily from the Poaceae family (74%). That suggests that the pioneer species present in the area do not hinder the ecological succession process. Inoculation of R. intraradices and A. brasilense, isolated or combined, increases soil biological activity, growth, and nutrient accumulation in key pioneer plant species, indicating the potential of that technique for the recovery of lands degraded by coal mining.

Strigolactone GR24-mediated mitigation of phosphorus deficiency through mycorrhization in aerobic rice

Strigolactones (SLs) are a new class of plant hormones that play a significant role in regulating various aspects of plant growth promotion, stress tolerance and influence the rhizospheric microbiome. GR24 is a synthetic SL analog used in scientific research to understand the effects of SL on plants and to act as a plant growth promoter. This study aimed to conduct hormonal seed priming at different concentrations of GR24 (0.1, 0.5, 1.0, 5.0 and 10.0 µM with and without arbuscular mycorrhizal fungi (AMF) inoculation in selected aerobic rice varieties (CR Dhan 201, CR Dhan 204, CR Dhan 205, and CR Dhan 207), Kasalath-IC459373 (P-tolerant check), and IR-36 (P-susceptible check) under phosphorus (P)-deficient conditions to understand the enhancement of growth and priming effects in mycorrhization. Our findings showed that seed priming with 5.0 µM SL GR24 enhanced the performance of mycorrhization in CR Dhan 205 (88.91 %), followed by CR Dhan 204 and 207, and AMF sporulation in CR Dhan 201 (31.98 spores / 10 gm soil) and CR Dhan 207 (30.29 spores / 10 g soil), as well as rice growth. The study showed that the highly responsive variety CR Dhan 207 followed by CR Dhan 204, 205, 201, and Kasalath IC459373 showed higher P uptake than the control, and AMF treated with 5.0 µM SL GR24 varieties CR Dhan 205 followed by CR Dhan 207 and 204 showed the best performance in plant growth, chlorophyll content, and soil functional properties, such as acid and alkaline phosphatase activity, soil microbial biomass carbon (MBC), dehydrogenase activity (DHA), and fluorescein diacetate activity (FDA). Overall, AMF intervention with SL GR24 significantly increased plant growth, soil enzyme activity, and uptake of P compared to the control. Under P-deficient conditions, seed priming with 5.0 µM strigolactone GR24 and AMF inoculum significantly increased selected aerobic rice growth, P uptake, and soil enzyme activities. Application of SLs formulations with AMF inoculum in selected aerobic rice varieties, CR Dhan 207, CR Dhan 204, and CR Dhan 205, will play an important role in mycorrhization, growth, and enhancement of P utilization under P- nutrient deficient conditions.

Impact of PVC microplastics on soil chemical and microbiological parameters

Microplastics (MPs) are emerging pollutants whose occurrence is a global problem in natural ecosystems including soil. Among MPs, polyvinyl chloride (PVC) is a well-known polymer with remarkable resistance to degradation, and because its recalcitrant nature serious environmental concerns are created during manufacturing and waste disposal.The effect of PVC (0.021% w/w) on chemical and microbial parameters of an agricultural soil was tested by a microcosm experiment at different incubation times (from 3 to 360 days). Among chemical parameters, soil CO2 emission, fluorescein diacetate (FDA) activity, total organic C (TOC), total N, water extractable organic C (WEOC), water extractable N (WEN) and SUVA254 were considered, while the structure of soil microbial communities was studied at different taxonomic levels (phylum and genus) by sequencing bacterial 16S and fungal ITS2 rDNA (Illumina MiSeq).Although some fluctuations were found, chemical and microbiological parameters exhibited some significant trends. Significant (p < 0.05) variations of soil CO2 emission, FDA hydrolysis, TOC, WEOC and WEN were found in PVC-treated soils over different incubation times. Considering the structure of soil microbial communities, the presence of PVC significantly (p < 0.05) affected the abundances of specific bacterial and fungal taxa: Candidatus_Saccharibacteria, Proteobacteria, Actinobacteria, Acidobacteria and Bacteroides among bacteria, and Basidiomycota, Mortierellomycota and Ascomycota among fungi.After one year of experiment, a reduction of the number and the dimensions of PVC was detected supposing a possible role of microorganisms on PVC degradation. The abundance of both bacterial and fungal taxa at phylum and genus level was also affected by PVC, suggesting that the impact of this polymer could be taxa-dependent.

Soil Enzyme Activity Behavior after Urea Nitrogen Application.

Understanding how fertilizer application (particularly N, the most used chemical fertilizer worldwide) interacts with soil microbes is important for the development of best management practices that target improved microbial activity to enhance sustainable food production. This study was conducted to determine whether urea N rate and time of application to maize (Zea mays) influenced soil enzyme activity. Enzyme activity was determined by monitoring fluorescein diacetate (FDA) hydrolysis, ß-glucosidase, acid-phosphomonoesterase, and arylsulfatase activities. Experiments were conducted from 2014 through 2016 to compare single (fall or spring applications) and split applications of N at varying N rates under irrigation (Becker) and rainfed conditions (Lamberton and Waseca) in MN, USA. Nitrogen rates varied by location and were based on University of Minnesota guidelines. Soil samples were collected seven times each season. Nitrogen application split into two applications increased FDA activity by 10% compared with fall and spring applied N at Waseca. Fall or spring N application decreased arylsulfatase activity by 19% at Becker and by between 13% and 16% at Lamberton. ß-Glucosidase and acid-phosphomonoesterase activities were unaffected by N application. Sampling time and year had the greatest impact on enzyme activity, but the results varied by location. A negative linear relationship occurred between FDA and ß-glucosidase activity at all three sites. In summary, urea N application had small effects on enzyme activity at the sites studied, suggesting that some form of organic N could be more important than the ammonium provided by urea.

Range grasses to improve soil properties, carbon sustainability, and fodder security in degraded lands of semi-arid regions

Tropical grasses are the primary source of forage for livestock and a valuable resource for improving soil health and environmental sustainability in semi-arid regions. A study was carried out in a semi-arid region of central India to determine the short-term (6-year) impact of nine range grasses on soil physio-chemical and biological properties, carbon stock, and forage security. The experiment was carried out in a randomized block design with three replications. Results show that the majority of the grass roots were distributed in the upper soil layer (0–10 cm, 63.5–76.5 %), and then in the middle (10–20 cm, 21.3–25 %) and lower (20–30 cm, 2.2–11.5 %) layers. Perennial tussock grass (Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult) had a higher root volume (2219 mm3), followed by Guinea grass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs] (1860 mm3). A lower soil bulk density (BD, 1.11–1.23 g cm−3), higher gravimetric water content (GMW, 14.0–17.8 %), and soil organic carbon (0.38–0.73 %) were recorded for grass-cultivated plots compared to the barren land (1.38 g cm−3, 13.0 %, and 0.28 %, respectively). The perennial tussock grass and Guinea grass resulted in the highest soil microbial biomass carbon (SMBC, 70.1 mg kg−1 soil) and enzyme activities (dehydrogenase, 17.09 μg TPF g−1 day−1 and fluorescein diacetate activity 4.94 μg fluorescein g−1 h−1). The considerable improvement in soil properties with minimal inputs resulted in a higher sustainable yield index and carbon sustainability index in plots planted with Guinea grass (0.9 and 89.29) and perennial tussock grass (0.89 and 71.61). Therefore, the cultivation of either Guinea grass or perennial tussock grass as an intercrop or sole crop in the semi-arid environment can be an ecologically sound strategy to improve soil health, C sequestration, and fodder supply.

Impact of symbiotic mycorrhiza interrelation in some soil biological parameters and growth of five cover crops

Cover crops serve as an essential source of nutrients in the soil and generally improve the soil’s properties. Cover crops’ production is considered a benefit of the soil quality; by protecting the soil from erosion, reducing the weeds and the so-called soil-borne plant pathogens. Different varieties of cover crops can be cultivated such as legumes, non-legumes, brassica, and grass-type of plants with a variability of the symbiosis. A pot experiment was carried out with five cover crops, as non-symbiont (Brassica carinata B.c.), single-symbiont with arbuscular mycorrhiza fungi (AMF) (Phacelia tanacetifolia P.t., Avena strigosa A.s.) and double symbiont with AMF and nitrogen-fixing bacteria (Vicia benghalensis V.b., Vicia faba V.f.) crops; and a mixture of the five species, placed in sandy soil (arenosol) in plastic pots (5000 g soil) in 4 repetitions. One of the pots with mixed cover crops was inoculated by AM fungi industrial product. We measured soil biological activity of dehydrogenase (DHA) and fluorescein-diacetate (FDA) enzymes, the frequency of AM fungi (F%), the all protein, glomalin content and electrical conductivity (EC) of the soils. Mixture of all the cover crops resulted maximum EC and significantly enhanced the enzymatic, DHA, FDA activities in comparison with single plants. Mycorrhiza colonization frequency was high in all cover crops except the mustard (B.c.), as nonsymbiont. Vetch (V.b.), as double symbiont was responding very positively to AMF inoculation, and enhanced the performance of its growth. It was found in the pot experiment, that vetch, has the highest capacity to retain soil-protein, glomalin concentration, as well. The mixture of five cover crops could be suggested to use, due to the synergistic positive performance of the individual crops, and the better functioning of beneficial fungal / bacterial symbiosis.

Impact of crop establishment and residue management on soil properties and productivity in rice‐fallow ecosystems in India

AbstractThe degradation of agricultural land, both chemical and biological, is a big concern all over the world. Crop cultivation practices that are distinctive to each location have negative consequences for agricultural production. Therefore, there is an urgent need for better crop and soil management techniques. This experiment was conducted for 5 years (2016–2020) to identify the best crop establishment‐cum‐residue management (CERM) practices and suitable crops for succession after the rice harvest in rice‐fallow ecosystems of India. Experimentation was conducted in the split‐plot design and each treatment was replicated thrice, having CERM in main‐plot and post‐rainy season/winter crops in sub‐plot. All the CERM treatments had two variants, with crop residue (R+) and without crop residue (R−). Rice yields were markedly higher (19.1%–32.2%) in transplanted puddled rice with residue (TPR‐R+) over conventional‐till direct seeded rice (CTDSR) and zero‐till DSR (ZTDSR) treatments. However, TPR adversely impacted the performance of all the post‐rainy pulses/oilseed crops. Post‐rainy season crop yields under ZTDSR/CTDSR were 14.9%–45.8% higher leading to higher system productivity as compared to TPR. ZTDSR with residue retention showed higher soil aggregation. The practice of ZTDSR increased the soil dehydrogenase activity (46.2%), urease activity (29.8%), soil microbial biomass carbon (65.4), and fluorescein diacetate activity (9.0%) in the crop root zone with 3.3‐ and 4.47‐times higher earthworm population and earthworm biomass, respectively. The rice‐pulse system showed 1.74‐times more earthworm population over rice‐oilseed sequences. Total soil organic carbon (SOC) stock in ZTDSR was 21.8% higher over TPR in 0–45 cm soil profile. Thus, the adoption of ZTDSR practices and diversification of rice‐fallows with pulses crops is recommended for enhancing the crop productivity, increasing SOC stock, and improving soil biological properties in the rice‐fallow ecosystems of India.

Biochar alters chemical and microbial properties of microplastic-contaminated soil

The occurrence of microplastics (MPs) in soils can negatively affect soil biodiversity and function. Soil amendments applied to MP-contaminated soil can alter the overall soil properties and enhance its functions and processes. However, little is known about how soil amendments improve the quality of MP-contaminated soils. Thus, the present study used a microcosm experiment to explore the potential effects of four types of biochar on the chemical and microbial properties of low-density polyethylene (LDPE) MP-contaminated soil under both drought and well-watered conditions. The results show that the biochars altered soil pH, electrical conductivity (EC), available phosphorous, and total exchangeable cations (TEC) with some variability depending on the biochar type. Oilseed rape straw (OSR)-derived biochars increased soil pH, EC, and TEC under both water conditions with the highest values of 7.94, 0.54 dS m−1 and 22.0 cmol(+) kg−1, respectively. Soil enzyme activities varied under all treatments; in particular, under drought conditions, the fluorescein diacetate activity increased in soils with high temperature (700 °C) biochar. The application of soft wood pellet biochar (700 °C) to MP-contaminated soil increased urease activity by 146% under well-watered conditions. OSR-derived biochars significantly reduced soil acid phosphatase activity under both water conditions. With biochar supplementation, the diversity indices of the bacterial community increased in well-watered soil but not in soil under drought conditions. The abundance of bacterial phyla, such as Firmicutes, Proteobacteria, Actinobacteria, Dictyoglomi, and Gemmatimonadetes, was relatively high in all treatments. Biochar application resulted in negligible variations in bacterial communities under drought conditions but significant variations under well-watered conditions. The findings of this study imply that biochar can be used as a soil amendment to improve the overall soil quality of MP-contaminated soil, but its impact varies depending on the pyrolysis feedstock and temperature. Thus, selecting a suitable biochar is important for improving the soil quality in MP-contaminated soils.

Biochar Effects on Soil–Plant Properties after Six Month Adaptation in Soil

ABSTRACT Biochar (BCH) is one of the most promising amendments to improve soil quality and store carbon in soils. Vast majority of the studies utilized freshly produced materials and assess BCH effects immediately after soil amendment. The aim of this study was to investigate the influence of biochars aged six months with two soil types on soil physicochemical and biological properties along with plant growth. Soils from a protection zone of water sources and from an agricultural area were mixed with three different types of BCH. After six months of aging, lettuce (Lactuca sativa var. capitata) plants were grown on these soils in greenhouse. Plant aboveground and root biomass, soil physicochemical properties [pH, cation exchange capacity (CEC), total nitrogen (TN), soil organic carbon (SOC), and total phosphorus (TP)], and biological activities [fluorescein diacetate activity (FDA) and urease activities, soil respiration, and` humic and nitrogen index] were determined. Studied BCHs had slight influence on soil physicochemical parameters. pH was significantly increased by all BCH amendments: in Luvisol by 12.7% and in Fluvisol by 11.25% (by 1.1 times). SOC was augmented in both soil types with the addition of the third BCH type that corresponded to the initial BCH input. BCH aging in soil had no influence on CEC, TN, TP and soil microbial activities (FDA, urease, and soil respiration). Moreover, two BCHs did not influence plant growth, whereas the third BCH type had a negative impact, decreasing lettuce development by 62% in Luvisol and by 41% in Fluvisol relative to untreated control soils.

Resistance and resilience of soil fluorescein diacetate activity against abiotic stress

Present study was under taken to evaluate the impact of long-term application of fertilizers and lime on fluorescein diacetate (FDA) activity, and their resistance and resilience against heat stress (48°C for 24 h) in acidic Alfisol. To accomplish this, soil samples (0-15 cm depth) were collected from seven treatments (control, 100% N, 100% NP, 100% NPK, 100% NPK+ handweeding, 100% NPK+FYM and 100% NPK+lime) from soybean crop under long-term fertiliser experiment (LTFE) at Birsa Agricultural University, Ranchi (2018). Resistance and resilience capacity of FDA were analyzed at 1, 15, 30 and 60 days after heat stress (DAS). FDA in soil was significantly higher in NPK+FYM (747 μg fluorescein g/soil/h) followed by100% NPK+hand weeding, 100% NPK+lime, 100% NPK, 100% NP, 100% N and control treatment. At 1 DAS, maximum reduction (69%) of FDA was noticed under 100% NP alone plots followed by 100% N (64%) treatments over initial value. Treatment 100% NPK+FYM had highest resistance index (0.33) with lowest resistance (0.19) was noticed in 100% NP alone treatment. Recovery rate of most of the treatments was higher during 15 to 30 DAS and almost 100 % recovery at 60 DAS. In nutshell, FDA emerged as a good indicator to assess resistance, resilience and functional behavior of soil against abiotic stress.

Topramezone: A selective post-emergence herbicide in chickpea for higher weed control efficiency and crop productivity

Chickpea (Cicer arietinum L.) is a dominant pulse crop in the world for its climate resilience and nutritional values. Weed infestation causes a significant yield loss in chickpea and jeopardize in realizing the potential yield across regions. Pendimethalin as pre-emergence (PRE) is the ruling herbicide, however, post-emergence (POST) herbicides are limited in this crop particularly for managing broad-leaved weeds and higher yield gain. We assessed the impact of POST herbicides available in different crops on weed phytotoxicity, crop selectivity and yield performance in chickpea on sandy-loam soil of Kanpur, India. The experiment was undertaken for two consecutive years (2016-17 and 2017-18) comprising nine herbicides, besides unweeded control (UWC) and weed-free check (WFC). Among the herbicides tested, halosulfuron-methyl 70 g a.i. ha−1 and tembotrione 100 g a.i. ha−1 showed the maximum phytotoxicity scale of 5-10 on chickpea. Clodinafop-propargyl + sodium-acifluorfen 122.5 g a.i. ha−1 and imazethapyr + imazamox 70 g a.i. ha−1 had a recoverable phytotoxicity (scale 3–5) on chickpea. Topramezone 20.6 g a.i. ha−1 at 25 days after sowing (DAS) resulted in higher phytotoxicity on weeds (toxicity scale of 7–10) without any phytotoxicity on chickpea. It significantly controlled the dominant broad-leaved weeds: Chenopodium album L., Lepidium didymum L., Spergula arvensis L., Medicago polymorpha L. and Fumaria parviflora Lam. compared to the remaining herbicides. Topramezone reduced total weed density by 68-70% and 48–51% (P ≤ 0.05) at 45 and 95 DAS compared with UWC, respectively. Therefore, this herbicide had higher (P ≤ 0.05) weed control efficiency in both years (89.8% in 2016-17 and 76.5% in 2017-18) than remaining treatments. Topramezone increased 15.3-19.6% chickpea seed yield than the recommended herbicide pendimethalin 1000 g a.i. ha−1 - quizalofop-p-ethyl 100 g a.i. ha−1 without affecting the nodulation and fluorescein diacetate activity. The UWC resulted in 64% (mean of two years) yield loss compared to the WFC in chickpea. Importantly, topramezone gave comparable yield with WFC. Hence, topramezone can be safely used in chickpea for managing broad-leaved weeds and realizing higher productivity.

Evaluating ash and biochar mixed biomixtures for atrazine and fipronil degradation

Composition of biomixtures is crucial for the success of the bio-purification system. Therefore, compost in a rice straw-compost biomixture (BM) was partially replaced with rice husk ash (RHA, 5 & 10%), sugarcane bagasse ash (SBA, 5 & 10%) and wheat straw biochar (WBC, 1 & 5%). Degradation of atrazine and fipronil was studied in these biomixtures and effects of pesticide concentration (50 and 100 μ g g −1 ) and bio-augmentation with pesticide-degrading microbial cultures were evaluated. Ashes and biochar had varied effects on atrazine and fipronil degradation that followed first order kinetics, but, was biphasic for atrazine degradation. Atrazine degradation during the II nd phase was faster than the I st phase. Compared to control (BM), RHA decreased the half-life ( t 1∕2 ) of atrazine at lower concentration (50 μ g g −1 ) while no significant effect of SBA and WBC (1%) was observed. However, WBC (5%) increased atrazine t 1∕2 by 200% (50 μ g g −1 ) and 300% (100 μ g g −1 ). No significant effect of RHA, SBA and WBC (1%) was evident on fipronil degradation and the t 1∕2 varied between 11.63–15.42 days, while, WBC (5%) slightly increased the t 1∕2 by 35%–40%. These results suggested that atrazine degradation in WBC-mixed biomixtures was limited by its availability due to higher adsorption, while higher fipronil adsorption in WBC-mixed biomixtures did not affect its degradation. Bio-augmentation of biomixtures with pesticide degrading cultures increased degradation of atrazine and fipronil and their metabolites, hydroxyatrazine and fipronil sulfone, respectively and the effect was significant on atrazine/hydroxyatrazine degradation. No significant effect of ashes/biochar was evident on microbial biomass carbon, dehydrogenase and fluorescein diacetate activity. This study suggested that bio-augmentation of ashes/biochar-mixed rice straw-compost biomixtures can be exploited for detoxification of these pesticides in bio-purification systems. • Rice husk and sugarcane bagasse ashes (10%) mixed biomixtures did not inhibit atrazine concentration. • Wheat straw biochar at 5% levels inhibited degradation of atrazine. • No effect of amendments was evident on fipronil degradation. • Bio-augmentation significantly increased atrazine degradation.

Microbiological Effectivity Evaluation of New Poultry Farming Organic Waste Recycling

Due to the intensification of the poultry sector, poultry manure is being produced in increasing quantities, and its on-site management is becoming a critical problem. Animal health problems can be solved by stricter the veterinary and environmental standards. The off-site coupled industrial chicken manure recycling technology (Hosoya compost tea) fundamentally affects the agricultural value of new organic-based products. Due to the limited information available on manure recycling technology-related microbiological changes, this was examined in this study. A pot experiment with a pepper test plant was set up, using two different soils (Arenosol, slightly humous Arenosol) and two different doses (irrigation once a week with 40 mL of compost tea: dose 1, D1; irrigation twice a week with 40 mL of compost tea: dose 2, D2) of compost tea. Compost tea raw materials, compost tea, and compost tea treated soils were tested. The products (granulated manure, compost tea) and their effects were characterized by the following parameters: aerobic bacterial count (log CFU/g), fluorescein diacetate activity (3′,6′-diacetylfluorescein, FDA, µg Fl/g soil), glucosidase enzyme activity (GlA; PNP/µmol/g), and identification of microorganisms in compost tea with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Furthermore, we aimed to investigate how the microbiological indicators tested, and the effect of compost tea on the tested plant, could be interpreted. Based on our results, the microbiological characteristics of the treated soils showed an increase in enzyme activity, in the case of FDA an increase +0.26 μg Fl/g soil at D1, while the GlA increased +1.28 PNP/µmol/g with slightly humous Arenosol soil and increased +2.44 PNP/µmol/g at D1; and the aerobic bacterial count increased +0.15 log CFU/g at D2, +0.35 log CFU/g with slightly humous Arenosol and +0.85 log CFU/g at W8. MALDI-TOF MS results showed that the dominant bacterial genera analyzed were Bacillus sp., Lysinibacillus sp., and Pseudomonas sp. Overall, the microbial inducers we investigated could be a good alternative for evaluating the effects of compost solutions in soil–plant systems. In both soil types, the total chlorophyll content of compost tea-treated pepper (Capsicum annuum L.) had increased as a result of compost tea. D1 is recommended for Arenosol and, D2 for slightly humous Arenosol soil.

Impact of variable tillage based residue management and legume based cropping for seven years on enzymes activity, soil quality index and crop productivity in rice ecology

Conventional tillage (CT) with excessive soil disturbance and crop residue removal in rice ( Oryza sativa L.) – wheat ( Triticum aestivum L.) sequence has been witnessed as an unsustainable practice in rice based cropping system. Climate resilient agro-techniques consisting with principles of risk mitigation and adaptation for sustainable agriculture such as zero tillage (ZT) is being adopted in south Asian countries. However, long–term impact of sequential ZT ​+ ​residues addition in crop rotation after puddled rice (CT–ZT ​+ ​R) on soil enzymes activity and soil quality index (SQI) are not adequately addressed. Experiment was conducted in split-plot design having four crop establishment techniques: (i) CT in each crop of rotation without residue (CT–CT), (ii) CT in each crop with incorporated residue (CT–CT ​+ ​R), (iii) CT rice – ZT in post–rainy season crops without residue (CT–ZT), (iv) CT rice – ZT in post–rainy season crops with surface residue mulch (CT–ZT ​+ ​R) each with three levels of crop rotations: (i) rice–wheat (R–W), (ii) rice–chickpea ( Cicer arietinum L.) (R–C) and (iii) rice–chickpea–mungbean ( Vigna radiata L.) (R–C–Mb). CT–ZT ​+ ​R enhanced 25% soil organic carbon (SOC) and 45% microbial biomass carbon (SMBC) over CT–CT ( P ​< ​0.05). Further, CT–ZT ​+ ​R increased SMBC/SOC ratio by 31.4 and 16.7% ( P ​< ​0.05) over CT–CT, respectively. For SOC, SMBC and SMBC/SOC ratio, an order of R–C–Mb ​> ​R–C ​> ​R–W ( P ​< ​0.05) was observed. CT–ZT ​+ ​R increased ( P ​< ​0.05) fluorescein diacetate activity by 17–31%, alkaline phosphatase by 4–25% and acid phosphatase by 16–31% over CT–CT ​+ ​R and CT–CT. ZT in post–rainy season (CT–ZT ​+ ​R) resulted in 21–37% higher β-glucosidase and 25–31% protease activity than those of continuous CT. The interaction revealed that CT–ZT ​+ ​R under R–C–Mb and R–C rotations increased ( P ​< ​0.05) 26% and 10% rice grain yield compared with CT–CT x R–W system, respectively. The SMBC had higher share (86–90%) towards SQI values followed by fluorescein diacetate (10–14%) and emerged as soil quality indicators in long–run. CT–ZT ​+ ​R and CT–ZT increased 40% SQI values compared with CT–CT. Besides, R–C–Mb and R–C rotations had 13–35% higher SQI over R–W ( P ​< ​0.05). Thus, elimination of intensive tillage at least in post–rainy seasons after puddled rice with crop residues retention and cropping intensification with grain legumes can bring about higher rice productivity and soil quality in rice based ecologies.

Unveiling the Efficiency of Psychrophillic Aporrectodea caliginosa in Deciphering the Nutrients from Dalweed and Cow Manure with Bio-Optimization of Coprolites

There is an immense demand for vermicomposting employing psychrophilic vermiculture (Aporrectodea caliginosa) for management of wastes under the Himalayan ecosystem. Dalweed (weeds from the world-famous urban Dal Lake) and cow manure (CM) are cheaply and abundantly available bio resources in Kashmir valley. Dalweed (DW), disposed of in the heart of the city, ascribes unpleasant effects on tourism and the natural ecosystem. Initial substrate mixtures of DW and CM with different ratios (CM100, DW100, CM80:DW20, CM60:DW40, CM40:DW60 and CM20:DW80) and castings harvested were analyzed for the following parameters: pH, TOC, TN, NO3- P, K, Fe, Zn, C:N, C:P, and C:S ratio. The results of a 56day study revealed in consistency and disparity towards the bio-optimization of coprolites depending upon the type of waste residue and mixture ratio used. Treatments with medium to low dalweed residues (CM60:DW40 followed by CM80:DW20) were found to be optimum and significantly primed chemical properties of castings using A. caligenosa. C:N, C:P, and C:S ratios showed a non-linear response with maximum decrease in C:N ratio by 35%, C:P ratio by 38% in CM100, and C:S ratio by 67% in DW100. Humification ratio, humification index, and percent humic acids were changed across all the treatments with the highest respective values of 21.33 ± 1.05, 11.33 ± 0.76, and 47.83 ± 0.76 for CM60:DW40. Results also showed that the earthworm population and biomass significantly increased with the highest respective increments of 57.53% and 74.88% in CM60:DW40 over initial values. Moreover, the highest number of cocoons (95.67 ± 1.17) were recorded within CM60:DW40 and the lowest in the control (43.33 ± 1.53). Dehydrogenase and fluorescein diacetate activities were inconsistent with the highest in CM40:DW60 (64.64%) and CM20:DW80 (63.54%) respectively over the initial substrates, while highest urease activity (74.40%) was observed from CM100. The results highlight the role of A. caliginosa in sustainable transformation of CM and DW with insightful, beneficial, and priming impacts on castings for its agronomic value.

On-farm assessment of cover cropping effects on soil C and N pools, enzyme activities, and microbial community structure

AbstractIntroducing cover crops (CC) in annual cropping systems can promote nutrient cycling and improve soil health. However, impacts of CC on soil health indicators vary and depend on the duration of CC, cropping systems, and other environmental conditions. We performed an on-farm assessment of cover cropping impacts on soil health indicators including C and N pools, enzyme activities, and microbial community structure under different no-till maize-based cropping systems (maize (Zea mays L.)–soybean (Glycine max L.) [CS], CS-winter wheat (Triticum aestivum L.) [CSWw], and maize-oats (Avena sativa L.) [CO]). At five farms, fields with different durations of CC were compared to adjacent no CC (NCC) fields. In general, long-term CC enhanced the soil health parameters compared to NCC. Long-term (20-year) winter rye CC had higher water-extractable C and N content, enzyme activities (β-glucosidase (1.2 times greater), urease (5.5 times greater), acid (1.5 times greater) and alkaline (4 times greater) phosphatase, arylsulfatase (0.8 times greater) and fluorescein diacetate (FDA) (0.7 times greater)) and soil bacterial community abundance (1.2 times greater). Short-term (3–6 years) legume and grass CC mixtures increased β-glucosidase (0.9 times), acid (0.7 times) and alkaline (1.5 times) phosphatase, arylsulfatase (3 times), FDA (0.8 times) activities and total phospholipid fatty acid (1.6 times) concentration. However, short-term (3–6 years) winter rye, legume and brassica mixtures did not significantly alter soil microbial community structure. This study showed that implementation of CC for &gt;6 years promoted C, N, S, and P cycling that are beneficial to soil health in maize-based cropping systems.

Effect of improved land and water management strategies on crop productivity and soil fertility in wastewater irrigated eggplant (Solanum melongena)

Wastewater irrigation with efficient land and water management strategies improve the marketable yield as well as reduce the pollutant threat posed by the irrigation. A field experiment was conducted for two years (2014- 2016) at ICAR- IARI farm, New Delhi to study the effect of municipal wastewater irrigation along with two land configurations (ridge and furrow and basin) and two methods of irrigation (drip and flood) on the yield of eggplant (Solanum melongena cv. Supriya) and soil health. Wastewater irrigated eggplants resulted significantly higher yield (37.1 t/ha), fruit weight (325 g) and fruit diameter (10.02 cm) in the tune of 38, 26 and 7% higher respectively over groundwater irrigated plot. Among irrigation methods, drip irrigation increased yield, fruit weight and fruit diameter of eggplant by 10, 9 and 1% higher over flood irrigation. Significantly higher fruit weight (294 g) of eggplant was recorded with the flat bed system compared to a raised bed system (288 g) and higher yield (4%) was also recorded under a flat bed system over a raised bed system. Wastewater irrigated plots recorded higher plant height, number of branches per plant as compared to groundwater irrigated plants at 120 and 180 days after transplanting. Application of wastewater significantly enhanced available N and P content and DTPA-Pb and Fe in the soil as compared to groundwater irrigated soil. Flood irrigation led to the accumulation of DTPA-Pb and Ni in soil, compared to drip irrigation. Significantly higher dehydrogenase activity, fluorescein diacetate activity and soil microbial biomass carbon were noticed in wastewater irrigated soil as compared to groundwater plots at upper depth (0-5cm). The findings of the present investigation illustrate that wastewater applied through drip irrigation resulted in yield increment as well as reduced metal concentrations in soil.