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Papers by Aabid Lone

SKUAST Journal of Research, Dec 31, 2022

Advances in Weed Science, 2024

Sustainability Sciences in Asia and Africa, 2023

Agronomy

Soil quality assessment serves as an index for appraising soil sustainability under varied soil m... more Soil quality assessment serves as an index for appraising soil sustainability under varied soil management approaches. Our current investigation was oriented to establish a minimum data set (MDS) of soil quality indicators through the selection of apt scoring functions for each indicator, thus evaluating soil quality in the Himalayan foothills. The experiment was conducted during two consecutive years, viz. 2016 and 2017, and comprised of 13 treatments encompassing different combinations of chemical fertilizers, organic manure, and biofertilizers, viz. (i) the control, (ii) 20 kg P + PSB (Phosphorus solubilizing bacteria), (iii) 20 kg P + PSB + Rhizobium, (iv) 20 kg P + PSB + Rhizobium+ FYM, (v) 20 kg P + 0.5 kg Mo + PSB, (vi) 20 kg P + 0.5 kg Mo + PSB + Rhizobium, (vii) 20 kg P + 0.5 kg Mo + PSB + Rhizobium + FYM, (viii) 40 kg@ P + PSB, (ix) 40 kg P + PSB + Rhizobium, (x) 40 kg P + PSB + Rhizobium+ FYM, (xi) 40 kg P + 0.5 kg Mo + PSB, (xii) 40 kg P + 0.5 kg Mo + PSB + Rhizobium, an...

Indian Journal of Agronomy, 2018

A field experiment was undertaken during rainy (kharif) season of 2015 and 2016 to assess the eff... more A field experiment was undertaken during rainy (kharif) season of 2015 and 2016 to assess the effect of crop establishment methods, viz. system of rice intensification (SRI), direct seeded rice (DSR), recommended method (RM) and farmers’ practice (FP) on the performance of 4 newly released high yielding rice (Oryza sativa L.) variet-ies, viz. ‘SR-1’, ‘SR-2’, ‘SR-3’ and ‘Jhelum’. SRI method significantly improved growth parameters (plant height, tiller-number, leaf-area index, light interception, root dry weight and root volume), physiological parameters (photosynthetic rate and transpiration rate) and nutrient (NPK) uptake of all the varieties. The average increase in grain yield in SRI, DSR and RM was 22%, 14% and 6.0% over FP, respectively. Among the varieties, ‘SR-1’ and ‘SR-2’ produced 9.5% and 16.8% higher grain yield over ‘Jhelum’, which was at par with ‘SR-3’. However, the highest net returns and benefit: cost ratio was recorded in DSR and ‘SR-2’ rice variety.

International Journal of Current Microbiology and Applied Sciences, 2018

International Journal of Engineering Research and, 2017

Large field to field variability restricts efficient fertilizer management when broad based blank... more Large field to field variability restricts efficient fertilizer management when broad based blanket recommendations are used in rice. Hence, the nutrient management for rice requires an approach that enables adjustments in nutrient applications to accommodate the sitespecific needs of the crop for supplemental nutrients. This study was conducted to establish and evaluate the threshold leaf colour value to guide in-season need based fertilizer N top dressing in Pusa Sugandh-3. For this purpose various growth parameters, yield parameters, grain and straw yield were measured in both years. Almost all the measured parameters in LCC 4 @ 20 kg N ha-1 were significantly higher than remaining LCC and fixed time N management treatments as well as control. Following the principle that threshold value is the one which simultaneously optimizes grain yield and NUE, LCC 4 @ 20 kg N ha-1 was adjudged as the threshold value for real time nitrogen management in Pusa Sugandh-3.

Applied Biological Research, 2016

Field experiments were conducted in 2013 and 2014 with the aim to develop optimal nitrogen manage... more Field experiments were conducted in 2013 and 2014 with the aim to develop optimal nitrogen management for Basmati rice cv. ‘Pusa Sugandh-3’ using leaf colour chart (LCC). The treatments included no nitrogen (N0) treatment, three fixed time (60, 90 and 120 kg N ha−1) and four real time nitrogen management treatments. Grain and straw yield, total N uptake and various indices of N use efficiency were measured in both the years. The best response in all the parameters assessed was achieved with LCC treatments maintained at 20 kg N ha−1 (LCC 420) and 30 kg N ha−1 (LCC 430). However, LCC 420 treatment had significantly higher nitrogen use efficiency (NUE) as compared to LCC 430 treatment because the nitrogen applied in former treatment was 20 kg ha−1 lesser than the later, while as yield in both the treatments was same. Based on the principle that threshold value is the one which simultaneously optimizes grain yield and NUE, LCC 420 treatment was adjudged as threshold value for real time N management in Basmati rice variety ‘Pusa Sugandh-3’ under temperate conditions of Kashmir.

Applied Biological Research, 2016

Soil analysis for boron is vital as the range between its deficiency and toxicity is quite narrow... more Soil analysis for boron is vital as the range between its deficiency and toxicity is quite narrow and its application slightly above the optimum level may prove toxic to plants. In present study, the extractability of various extractants was assessed in relation to the physicochemical properties of soils. Soil sampling was carried out in 30 orchards in district Kulgam, Kashmir. Four extractants widely used to determine plant-available boron from either acidic or alkaline soils were used. The hot-water-soluble boron (HWSB) extraction procedure was used as a benchmark to observe relative variation in available boron in alternate extractants like calcium chloride-mannitol (CaCl2-mannitol), ammonium acetate and diethylene-triaminepenta-acetic acid-sorbitol (DTP Asorbitol). A significant correlation was found for available B among all the extractants tested, the strongest correlation (r = 0.975** at P≤0.01) was observed between HWSB and DTPA-sorbitol and hence it may substitute the hot water extraction method for estimating plant-available B.

Applied Biological Research, 2016

A field experiment was conducted in kharif 2012 and 2013 at MRCFC, SKUAST, Khudwani (Kashmir) on ... more A field experiment was conducted in kharif 2012 and 2013 at MRCFC, SKUAST, Khudwani (Kashmir) on a silty clay loam soil to evaluate the impact of water regimes and weed management practices on nutrient uptake in rice and weeds under SRI. The soil at experimental site was neutral in reaction, medium in available P, K and organic carbon and low in available N. The treatments comprised of 3 irrigations schedules [alternate wetting and drying (AWD), continuous saturated condition and continuous flooding] and 7 weed management practices viz., 4 herbicidal treatments [pyrazosulfuron ethyl @ 20 g a.i. ha−1 (3 DAT); cyhalofop butyl @ 80 g a.i. ha−1 (15 DAT); pyrazosulfuron ethyl 20 g a.i. followed by cyhalofop butyl 80 g a.i. ha−1 (3 and 15 DAT), and butachlor @ 1.5 kg a.i. ha−1 (3 DAT)]; cono weeding, weedy check and weed-free control. The results revealed that saturated water regime treatment had highest uptake of macronutrients by grain and straw, while highest uptake of macro-nutrients by weeds was in AWD and lowest in continuous flooding. Among weed control measures, the lowest macronutrients uptake by crop was associated with post-emergence application of cyhalofop-butyl and highest amount of NPK depletion by weeds was observed in unweeded control. Minimum NPK uptake by weeds was noticed in sequential application of pyrazosulfuron-ethyl @ 20 g a.i. ha−1 and cyhalofop-butyl @ 60 g a.i. ha−1 treatment.

Pedosphere, 2016

Microbial activities are affected by a myriad of factors with end points involved in nutrient cyc... more Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues. Because of their prominent role in the global carbon balance and their possible role in carbon sequestration, soil microbes are very important organisms in relation to global climate changes. This review focuses mainly on the responses of soil microbes to climate changes and subsequent effects on soil carbon dynamics. An overview table regarding extracellular enzyme activities (EAA) with all relevant literature data summarizes the effects of different ecosystems under various experimental treatments on EAA. Increasing temperature, altered soil moisture regimes, and elevated carbon dioxide significantly affect directly or indirectly soil microbial activities. High temperature regimes can increase the microbial activities which can provide positive feedback to climate change, whereas lower moisture condition in pedosystem can negate the increase, although the interactive effects still remain unanswered. Shifts in soil microbial community in response to climate change have been determined by gene probing, phospholipid fatty acid analysis (PLFA), terminal restriction length polymorphism (TRFLP), and denaturing gradient gel electrophoresis (DGGE), but in a recent investigations, omic technological interventions have enabled determination of the shift in soil microbe community at a taxa level, which can provide very important inputs for modeling C sequestration process. The intricacy and diversity of the soil microbial population and how it responds to climate change are big challenges, but new molecular and stable isotope probing tools are being developed for linking fluctuations in microbial diversity to ecosystem function.

Environmental Monitoring and Assessment, 2016

Soil quality assessment provides a tool for evaluating the sustainability of soils under differen... more Soil quality assessment provides a tool for evaluating the sustainability of soils under different crop cafeterias. Our objective was to develop the soil quality index for evaluating the soil quality indicators under different cropping systems in northwest Himalaya-India. Composite soil samples were taken from the study area from different cropping systems which include T 1 (forest soil control), T 2 (rice-oilseed, lower belts), T 3 (rice-oilseed, higher belts), T 4 (rice-oats), T 5 (rice-fallow), T 6 (maize-oats), T 7 (maize-peas), T 8 (apple), T 9 (applebeans), and T 10 (apple-maize). Physical, chemical, and biological soil indicators were determined, and it was found that soil enzyme activities involved in nutrient cycling were significantly higher in forest soils, which were reflected in higher levels of available pool of nutrients. Carbon stocks were found significantly higher in forest soil which was translated in improved soil physical condition. Principal component analysis (PCA) was performed to reduce multidimensionality of data followed by scoring by homothetic transformation of the selected indicators. Pearson's interclass correlation was performed to avoid redundancy, and highly correlated variables were not retained. Inclusion of legumes in the apple orchard floor recorded highest soil quality rating across the treatments. Cereal-based cropping systems were found in lower soil quality rating; however, the incorporation of peas in the system improved soil health.

ABSTRACT The impact of six different herbicides representing several chemical families on soil mi... more ABSTRACT The impact of six different herbicides representing several chemical families on soil microbial community was investigated using laboratory microcosm approach. The herbicides consisted of isoproturon, metribuzin, clodinafop propargyl, atlantis (mesosulfuron methyl + idosulfuron methyl sodium) and sulfosulfuron applied at normal agricultural rates. The sixth herbicide namely UPH-110 (Clodinafop propargyl 12% + Metribuzin 42% WG) was tested at four different application rates. The impact was assessed on various soil biological health indicators viz, microbial biomass carbon, soil respiration, dehydrogenase and phosphatase activities. The response of microbial community was mixed. Overall among the various methodological approaches adopted, dehydrogenase activity was most sensitive and microbial biomass carbon the least under the existing conditions. Interestingly, the sensitivity of acid phosphatase towards the applied herbicides was more than alkaline phosphatase. Influence whether positive or negative was however only transitory except UPH-110 @ 1000 g ha-1 in case of soil respiration. The influence of UPH-110 was dose dependent. Significant toxic impact was mostly observed at higher concentrations (600 and 1000 g ha-1 ). The magnitude of hazard and duration of toxicity increased as the dose increased.

ABSTRACT Effect of six different herbicides representing four chemical families on soil microbial... more ABSTRACT Effect of six different herbicides representing four chemical families on soil microbial communities was studied using laboratory microcosm approach. The herbicides tested were isoproturon, metribuzin, clodinafop propargyl, atlantis (Mesosulfuron methyl 3% + Idosulfuron Methyl Sodium 0.6% WG) and sulfosulfuron applied at normal agricultural rates, and UPH-110 (Clodinafop propargyl 12% + Metribuzin 42% WG) tested at four different application rates. Microbial response to the applied herbicides was studied following cultivation dependent approach. The microbial community showed a mixed response towards applied herbicides. With a few exceptions, metribuzin displayed a negative, clodinafop a positive and sulphonylurea herbicides a neutral effect while as the effect of isoproturon was variable. Significant toxic impact of UPH-110 was mostly observed at higher concentrations (@ 600 and 1000 g ha-1). The magnitude of hazard and duration of toxicity increased as the dose of UPH-110 increased. The influence whether positive or negative, was only transitory in nature and recovered to the level of untreated microcosms by or before 30th day of application. Among the microbial groups studied, fungal population was least affected at field rate, bacteria, ctinomycetes and Azotobacter showed mixed response while as the phosphorus solubilizers population showed a tendency to increase in response to the applied herbicides.The herbicidal impact on soil microbial population was found to depend on the nature and dose of herbicide used and also the type of microbial group.

Pedosphere, 2015

Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as ... more Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly based on short-term studies has been encouraging and the trend obtained so far has raised many hopes. Biochar has been reported to positively impact an array of soil processes ranging from benefiting soil biology, controlling soil-borne pathogens, enhancing nitrogen fixation, improving soil physical and chemical properties, decreasing nitrate (NO − 3) leaching and nitrous oxide (N 2 O) emission to remediation of contaminated soils. However, very little biochar is still utilized as soil amendment mainly because these benefits are yet to be quantified, and also the mechanisms by which the soil health is improved are poorly understood. Due to the infancy of research regarding this subject, there are still more questions than answers. The future research efforts must focus on carrying out long-term experiments and uncover the mechanisms underlying these processes so that key concerns surrounding the use of biochar are addressed before its large scale application is recommended.

SKUAST Journal of Research, Dec 31, 2022

Advances in Weed Science, 2024

Sustainability Sciences in Asia and Africa, 2023

Agronomy

Soil quality assessment serves as an index for appraising soil sustainability under varied soil m... more Soil quality assessment serves as an index for appraising soil sustainability under varied soil management approaches. Our current investigation was oriented to establish a minimum data set (MDS) of soil quality indicators through the selection of apt scoring functions for each indicator, thus evaluating soil quality in the Himalayan foothills. The experiment was conducted during two consecutive years, viz. 2016 and 2017, and comprised of 13 treatments encompassing different combinations of chemical fertilizers, organic manure, and biofertilizers, viz. (i) the control, (ii) 20 kg P + PSB (Phosphorus solubilizing bacteria), (iii) 20 kg P + PSB + Rhizobium, (iv) 20 kg P + PSB + Rhizobium+ FYM, (v) 20 kg P + 0.5 kg Mo + PSB, (vi) 20 kg P + 0.5 kg Mo + PSB + Rhizobium, (vii) 20 kg P + 0.5 kg Mo + PSB + Rhizobium + FYM, (viii) 40 kg@ P + PSB, (ix) 40 kg P + PSB + Rhizobium, (x) 40 kg P + PSB + Rhizobium+ FYM, (xi) 40 kg P + 0.5 kg Mo + PSB, (xii) 40 kg P + 0.5 kg Mo + PSB + Rhizobium, an...

Indian Journal of Agronomy, 2018

A field experiment was undertaken during rainy (kharif) season of 2015 and 2016 to assess the eff... more A field experiment was undertaken during rainy (kharif) season of 2015 and 2016 to assess the effect of crop establishment methods, viz. system of rice intensification (SRI), direct seeded rice (DSR), recommended method (RM) and farmers’ practice (FP) on the performance of 4 newly released high yielding rice (Oryza sativa L.) variet-ies, viz. ‘SR-1’, ‘SR-2’, ‘SR-3’ and ‘Jhelum’. SRI method significantly improved growth parameters (plant height, tiller-number, leaf-area index, light interception, root dry weight and root volume), physiological parameters (photosynthetic rate and transpiration rate) and nutrient (NPK) uptake of all the varieties. The average increase in grain yield in SRI, DSR and RM was 22%, 14% and 6.0% over FP, respectively. Among the varieties, ‘SR-1’ and ‘SR-2’ produced 9.5% and 16.8% higher grain yield over ‘Jhelum’, which was at par with ‘SR-3’. However, the highest net returns and benefit: cost ratio was recorded in DSR and ‘SR-2’ rice variety.

International Journal of Current Microbiology and Applied Sciences, 2018

International Journal of Engineering Research and, 2017

Large field to field variability restricts efficient fertilizer management when broad based blank... more Large field to field variability restricts efficient fertilizer management when broad based blanket recommendations are used in rice. Hence, the nutrient management for rice requires an approach that enables adjustments in nutrient applications to accommodate the sitespecific needs of the crop for supplemental nutrients. This study was conducted to establish and evaluate the threshold leaf colour value to guide in-season need based fertilizer N top dressing in Pusa Sugandh-3. For this purpose various growth parameters, yield parameters, grain and straw yield were measured in both years. Almost all the measured parameters in LCC 4 @ 20 kg N ha-1 were significantly higher than remaining LCC and fixed time N management treatments as well as control. Following the principle that threshold value is the one which simultaneously optimizes grain yield and NUE, LCC 4 @ 20 kg N ha-1 was adjudged as the threshold value for real time nitrogen management in Pusa Sugandh-3.

Applied Biological Research, 2016

Field experiments were conducted in 2013 and 2014 with the aim to develop optimal nitrogen manage... more Field experiments were conducted in 2013 and 2014 with the aim to develop optimal nitrogen management for Basmati rice cv. ‘Pusa Sugandh-3’ using leaf colour chart (LCC). The treatments included no nitrogen (N0) treatment, three fixed time (60, 90 and 120 kg N ha−1) and four real time nitrogen management treatments. Grain and straw yield, total N uptake and various indices of N use efficiency were measured in both the years. The best response in all the parameters assessed was achieved with LCC treatments maintained at 20 kg N ha−1 (LCC 420) and 30 kg N ha−1 (LCC 430). However, LCC 420 treatment had significantly higher nitrogen use efficiency (NUE) as compared to LCC 430 treatment because the nitrogen applied in former treatment was 20 kg ha−1 lesser than the later, while as yield in both the treatments was same. Based on the principle that threshold value is the one which simultaneously optimizes grain yield and NUE, LCC 420 treatment was adjudged as threshold value for real time N management in Basmati rice variety ‘Pusa Sugandh-3’ under temperate conditions of Kashmir.

Applied Biological Research, 2016

Soil analysis for boron is vital as the range between its deficiency and toxicity is quite narrow... more Soil analysis for boron is vital as the range between its deficiency and toxicity is quite narrow and its application slightly above the optimum level may prove toxic to plants. In present study, the extractability of various extractants was assessed in relation to the physicochemical properties of soils. Soil sampling was carried out in 30 orchards in district Kulgam, Kashmir. Four extractants widely used to determine plant-available boron from either acidic or alkaline soils were used. The hot-water-soluble boron (HWSB) extraction procedure was used as a benchmark to observe relative variation in available boron in alternate extractants like calcium chloride-mannitol (CaCl2-mannitol), ammonium acetate and diethylene-triaminepenta-acetic acid-sorbitol (DTP Asorbitol). A significant correlation was found for available B among all the extractants tested, the strongest correlation (r = 0.975** at P≤0.01) was observed between HWSB and DTPA-sorbitol and hence it may substitute the hot water extraction method for estimating plant-available B.

Applied Biological Research, 2016

A field experiment was conducted in kharif 2012 and 2013 at MRCFC, SKUAST, Khudwani (Kashmir) on ... more A field experiment was conducted in kharif 2012 and 2013 at MRCFC, SKUAST, Khudwani (Kashmir) on a silty clay loam soil to evaluate the impact of water regimes and weed management practices on nutrient uptake in rice and weeds under SRI. The soil at experimental site was neutral in reaction, medium in available P, K and organic carbon and low in available N. The treatments comprised of 3 irrigations schedules [alternate wetting and drying (AWD), continuous saturated condition and continuous flooding] and 7 weed management practices viz., 4 herbicidal treatments [pyrazosulfuron ethyl @ 20 g a.i. ha−1 (3 DAT); cyhalofop butyl @ 80 g a.i. ha−1 (15 DAT); pyrazosulfuron ethyl 20 g a.i. followed by cyhalofop butyl 80 g a.i. ha−1 (3 and 15 DAT), and butachlor @ 1.5 kg a.i. ha−1 (3 DAT)]; cono weeding, weedy check and weed-free control. The results revealed that saturated water regime treatment had highest uptake of macronutrients by grain and straw, while highest uptake of macro-nutrients by weeds was in AWD and lowest in continuous flooding. Among weed control measures, the lowest macronutrients uptake by crop was associated with post-emergence application of cyhalofop-butyl and highest amount of NPK depletion by weeds was observed in unweeded control. Minimum NPK uptake by weeds was noticed in sequential application of pyrazosulfuron-ethyl @ 20 g a.i. ha−1 and cyhalofop-butyl @ 60 g a.i. ha−1 treatment.

Pedosphere, 2016

Microbial activities are affected by a myriad of factors with end points involved in nutrient cyc... more Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues. Because of their prominent role in the global carbon balance and their possible role in carbon sequestration, soil microbes are very important organisms in relation to global climate changes. This review focuses mainly on the responses of soil microbes to climate changes and subsequent effects on soil carbon dynamics. An overview table regarding extracellular enzyme activities (EAA) with all relevant literature data summarizes the effects of different ecosystems under various experimental treatments on EAA. Increasing temperature, altered soil moisture regimes, and elevated carbon dioxide significantly affect directly or indirectly soil microbial activities. High temperature regimes can increase the microbial activities which can provide positive feedback to climate change, whereas lower moisture condition in pedosystem can negate the increase, although the interactive effects still remain unanswered. Shifts in soil microbial community in response to climate change have been determined by gene probing, phospholipid fatty acid analysis (PLFA), terminal restriction length polymorphism (TRFLP), and denaturing gradient gel electrophoresis (DGGE), but in a recent investigations, omic technological interventions have enabled determination of the shift in soil microbe community at a taxa level, which can provide very important inputs for modeling C sequestration process. The intricacy and diversity of the soil microbial population and how it responds to climate change are big challenges, but new molecular and stable isotope probing tools are being developed for linking fluctuations in microbial diversity to ecosystem function.

Environmental Monitoring and Assessment, 2016

Soil quality assessment provides a tool for evaluating the sustainability of soils under differen... more Soil quality assessment provides a tool for evaluating the sustainability of soils under different crop cafeterias. Our objective was to develop the soil quality index for evaluating the soil quality indicators under different cropping systems in northwest Himalaya-India. Composite soil samples were taken from the study area from different cropping systems which include T 1 (forest soil control), T 2 (rice-oilseed, lower belts), T 3 (rice-oilseed, higher belts), T 4 (rice-oats), T 5 (rice-fallow), T 6 (maize-oats), T 7 (maize-peas), T 8 (apple), T 9 (applebeans), and T 10 (apple-maize). Physical, chemical, and biological soil indicators were determined, and it was found that soil enzyme activities involved in nutrient cycling were significantly higher in forest soils, which were reflected in higher levels of available pool of nutrients. Carbon stocks were found significantly higher in forest soil which was translated in improved soil physical condition. Principal component analysis (PCA) was performed to reduce multidimensionality of data followed by scoring by homothetic transformation of the selected indicators. Pearson's interclass correlation was performed to avoid redundancy, and highly correlated variables were not retained. Inclusion of legumes in the apple orchard floor recorded highest soil quality rating across the treatments. Cereal-based cropping systems were found in lower soil quality rating; however, the incorporation of peas in the system improved soil health.

ABSTRACT The impact of six different herbicides representing several chemical families on soil mi... more ABSTRACT The impact of six different herbicides representing several chemical families on soil microbial community was investigated using laboratory microcosm approach. The herbicides consisted of isoproturon, metribuzin, clodinafop propargyl, atlantis (mesosulfuron methyl + idosulfuron methyl sodium) and sulfosulfuron applied at normal agricultural rates. The sixth herbicide namely UPH-110 (Clodinafop propargyl 12% + Metribuzin 42% WG) was tested at four different application rates. The impact was assessed on various soil biological health indicators viz, microbial biomass carbon, soil respiration, dehydrogenase and phosphatase activities. The response of microbial community was mixed. Overall among the various methodological approaches adopted, dehydrogenase activity was most sensitive and microbial biomass carbon the least under the existing conditions. Interestingly, the sensitivity of acid phosphatase towards the applied herbicides was more than alkaline phosphatase. Influence whether positive or negative was however only transitory except UPH-110 @ 1000 g ha-1 in case of soil respiration. The influence of UPH-110 was dose dependent. Significant toxic impact was mostly observed at higher concentrations (600 and 1000 g ha-1 ). The magnitude of hazard and duration of toxicity increased as the dose increased.

ABSTRACT Effect of six different herbicides representing four chemical families on soil microbial... more ABSTRACT Effect of six different herbicides representing four chemical families on soil microbial communities was studied using laboratory microcosm approach. The herbicides tested were isoproturon, metribuzin, clodinafop propargyl, atlantis (Mesosulfuron methyl 3% + Idosulfuron Methyl Sodium 0.6% WG) and sulfosulfuron applied at normal agricultural rates, and UPH-110 (Clodinafop propargyl 12% + Metribuzin 42% WG) tested at four different application rates. Microbial response to the applied herbicides was studied following cultivation dependent approach. The microbial community showed a mixed response towards applied herbicides. With a few exceptions, metribuzin displayed a negative, clodinafop a positive and sulphonylurea herbicides a neutral effect while as the effect of isoproturon was variable. Significant toxic impact of UPH-110 was mostly observed at higher concentrations (@ 600 and 1000 g ha-1). The magnitude of hazard and duration of toxicity increased as the dose of UPH-110 increased. The influence whether positive or negative, was only transitory in nature and recovered to the level of untreated microcosms by or before 30th day of application. Among the microbial groups studied, fungal population was least affected at field rate, bacteria, ctinomycetes and Azotobacter showed mixed response while as the phosphorus solubilizers population showed a tendency to increase in response to the applied herbicides.The herbicidal impact on soil microbial population was found to depend on the nature and dose of herbicide used and also the type of microbial group.

Pedosphere, 2015

Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as ... more Biochar as a soil amendment is confronted with the challenge that it must benefit soil health as it can be by no means separated from soils once it is added. The available literature even though sparse and mostly based on short-term studies has been encouraging and the trend obtained so far has raised many hopes. Biochar has been reported to positively impact an array of soil processes ranging from benefiting soil biology, controlling soil-borne pathogens, enhancing nitrogen fixation, improving soil physical and chemical properties, decreasing nitrate (NO − 3) leaching and nitrous oxide (N 2 O) emission to remediation of contaminated soils. However, very little biochar is still utilized as soil amendment mainly because these benefits are yet to be quantified, and also the mechanisms by which the soil health is improved are poorly understood. Due to the infancy of research regarding this subject, there are still more questions than answers. The future research efforts must focus on carrying out long-term experiments and uncover the mechanisms underlying these processes so that key concerns surrounding the use of biochar are addressed before its large scale application is recommended.