Response of Inorganic Fertilizers Organic Manure and Biofertilizer on Soil Health and Yield Attributes of Chick Pea (Cicer aretinum L.) Cv. Aruna

An experimental trial carried out on topic for the two repeated year 2021-22, start from rabi seasons at research farm of soil science and agricultural chemistry prayagraj. The geographical co-ordinates of the university campus are approximately 25.47690 N latitude and 81.85740 E longitude and 98 meters (322 feet) the area of prayagraj district comes under subtropical belt in the south east of uttar pradesh, which experience extremely hot summer and fairly cold winter. The maximum temperature of the location reaches up to 460C - 480C and minimum temperature is 40C - 50C. The relative humidity ranged between 20 to 94 percent. The average rainfall in this area is around 1100 mm annually. the designed lay out 48 total soil was sandy loam and samples were taken from different depths 0-15 cm and 15-30 cm the conjunctive use of N, P, & K and different vermicompost and rhizobium the treatment T16 [RDF @ 100 % + VC @ 100 % + Rhizobium @ 100 %] plant height (cm), number of branches, number of pods plant-1, number of seeds pod plant-1, grain yield, seed weight, gave best results. The maximum B:C ratio was achieved in treatment T16 [RDF @ 100 % + VC @ 100 % + Rhizobium @ 100 %], i. e. 1.95 and 2.18, for chick pea cv. aruna during respectively years and was found at par than any other treatment.

Aboveground and Soil Carbon Stock of Teak Plantations under Varied Rainfall Regimes

Aims: Forest plantations are considered to be the most effective approach to reducing the atmosphere's rising carbon dioxide levels. The variation in the carbon stock under important plantation species and the heterogeneity across climatic regimes, however, are urgently needed.Place and Methodology: Research was conducted on seven-year-old teak plantations in Karnataka, India, to determine the above-ground and soil carbon sequestration potential of teak plantations under various rainfall regimes.Results: The teak plantations under high rainfall zone (RFZ) accumulated maximum above-ground biomass revealing the positive effect of rainfall the productivity. This was reflected in the total above-ground carbon sequestration of the plantations leading to maximum carbon storage under the high RFZ followed by medium and low RFZ. Further, the variation of the SOC along the soil depth was evident in the present study.Conclusion: According to the findings, rainfall significantly impacted above-ground carbon sequestration and SOC, with high rainfall leading to the greatest sequestration. The climate sensitivity of carbon sequestration demands elaborate studies to improve carbon storage in the plantations in future climate change scenarios.

Physico-Chemical Properties of Surface Soil in Ashoknagar District of Madhya Pradesh for Agricultural Production

Looking at the crop production and soil related constraints in different village of Ashoknagar District of Madhya Pradesh we found it important to characterize the soils of the village. For this purpose, one hundred twenty-five GPS-based surface soil samples (0-15 cm) were collected from five blocks (Mungaoli, Chanderi, Ishagarh, Ashoknagar and Sadora) of Ashoknagar district from April to May 2017-2018. Soils were studied for their physical and chemical characteristics - status of sand,silt,clay percent varied from 36.6-56.7%, 3.9-38% and 25.2-42.4%, with the mean value of 47.5%, 17.2% or 35.1%, respectively and soil pH, EC, OC, Calcium carbonate, total Nitrogen or available sulphur were observed in the range of 7.2– 8.6, 0.32 - 0.62dSm?1, 2.14 - 7.06 gkg-1, 0.5 –3.5 % 0.01-0.24 % and 4.36 – 40.25 mg kg-1under different villages of the investigated area with the average value of 8.0, 0.45dSm?1, 4.35gkg-1, 1.7% and 0.11 %,14.68 mg kg-1 respectively. The availability of sulphur increased with an increase in organic carbon and clay content in the soil.

Impact of Cropping Systems on Soil Organic Carbon Levels and Enzyme Activity

Monocropping makes agriculture more susceptible to the adverse effects of climate change. Resilient agriculture systems that can buffer crops against various agricultural vulnerabilities is the need of the hour. In this context, a study was conducted to assess the impact of various rice based cropping systems on soil health.Aims: To study the effect of different rice based cropping systems on soil enzyme activity and organic carbon.Study Design: Randomized block design, Replications – 3.Place and Duration of Study: Integrated Farming System Research Station (IFSRS) of Kerala Agricultural University located at Karamana, Thiruvananthapuram, during kharif, rabi and summer seasons of 2019-2020.Methodology: The experiment consists of eleven cropping systems (T1 : rice - fallow - fallow, T2 : rice - rice - fallow, T3 : rice - daincha - cowpea, T4 : (rice + daincha) - rice - green gram, T5 : rice - cassava - amaranthus, T6 : rice - cassava - cowpea, T7 : rice - para grass - fodder cowpea, T8 : rice - fodder cowpea - fodder maize, T9 : rice - okra - culinary melon, T10 : rice - okra - yard long bean and T11 : rice - rice – amaranthus).Results: Soil organic carbon and enzyme activities were found highest in the cropping system (rice+daincha) – rice – green gram during kharif. During rabi, soil organic carbon and activity of urease and acid phosphatase were highest in rice- daincha- cowpea while dehydrogenase activity was highest in rice- fodder cowpea – fodder maize. During summer, rice- okra – yard long bean, rice- cassava- amaranthus and rice- cassava – cowpea recorded the highest urease, acid phosphatase and dehydrogenase activity, respectively. The organic carbon was highest for the sequence rice – okra –culinary melon. The soil organic carbon and enzyme activities were least in rice- fallow-fallow cropping sequence during all the three cropping seasons.Conclusion: Brown manuring, use of leguminous crops and cover crops in the crop sequence instead of leaving the land fallow and addition of organic sources of nutrition increase the soil organic carbon and enzymatic activity of microbes. The increase in soil organic carbon and activity of enzymes in soil owing to crop rotation of rice with arable crops relies on the crop species which are cultivated.

Long Term Effect of Organic and Inorganic Manures on Rice Productivity and Major Nutrient Dynamics in 33 Years Old Rice-Rice Cropping System of Godavari Delta

Aim: To study the “Long Term Effect of Organic and Inorganic Manures on Rice Productivity and Major nutrient dynamics in 33 years old Rice- Rice Cropping System of Godavari Delta”.Place and Duration of Study: A field experiment was carried out during kharif 2022 at Regional Agricultural Research Station, Maruteru, West Godavari district in the ongoing All India Coordinated Rice Improvement Project (AICRIP) on Long term soil fertility management in low land rice soils of Godavari delta under rice-rice cropping system.Study Design and Methodology: Treatments imposed in this study were T1: Control, T2: 50 % NPK, T3: 50% NPK + 50 % N-FYM, T4: 50 % NPK + 50% N-Green Manure, T5: 50 % NPK + 50 % N-Azospirillum, T6: FYM @ 10t/ha, T7: 100 % NPK+Zn+S, T8: 100 % NPK +Zn+S+FYM @ 5 t ha-1. All together 8 treatments laid out in RBD with three Replications. The application of fertiliser was carried out in accordance with the treatments. The prescribed fertiliser dose (90:60:60) was administered in the following forms: urea (46% N), single superphosphate (16% P2O5), muriate of potash (60% K2O), and zinc sulphate (ZnSO4.7H2O) @ 50 kg ha-1. The total dosage of phosphorus, potassium, and zinc were applied as basal. Three equally divided applications of nitrogen were made: one at the basal, one at the tillering stage, and one at the panicle initiation stage. Well decomposed farmyard manure (FYM) manure and Pheltophorum (green leaf manure) were applied one week before transplanting. Popular cultivar of Kharif rice MTU 1064 (Amara) was used for the study.Results: Long-term application of organic and inorganic fertilizers and their combination didn’t show any marked difference on physico-chemical properties of soil (pH and EC). Bulk density was recorded lowest in FYM @ 10 t ha-1 and it was on par with (T8, T3, T4, T5). Organic carbon was observed highest in FYM @ 10 t ha-1 and it was on par with (T8 and T3). There was a significant impact of long-term application of organic and inorganic fertilizers and their combination on soil chemical properties, highest available N, P, K, S and Zn was observed highest in conjunctive treatment (T8) 100 % NPK + Zn + S + FYM @ 5 t ha-1 whereas, lowest was recorded in control. There was a significant impact on grain and straw yields. Highest grain and straw yields were recorded in (T8) 100 % NPK + Zn + S +FYM @ 5 t ha-1 and it was on par with (T7) 100 % NPK + Zn + S.Conclusions: After the investigation, present study concludes that conjunctive and combined application of organics with inorganics improve soil physical, physico-chemical and chemical properties of the soil.

Organic Carbon and Biological Properties of Soils in Various Agro-Ecological Units of Kerala, India

A study was carried out in four agro-ecological units (AEUs), viz., southern laterites (AEU 8), south central laterites (AEU 9), north central laterites (AEU 10), and the northern laterites (AEU 11) of Kerala, with the objective of detailing the soil fertility status of the study area and unveiling the relationship between organic carbon (OC) and various biological properties of soils, like population of phosphorus solubilizers and acid phosphatase activity, by following one-way analysis of variance (ANOVA). The findings of the study revealed that the average values of OC among the four AEUs varied from 0.63 to 0.82%, and remarkably, 98% of the collected soils displayed OC content ranging from 0.5 to 1.5%. The mean values for the population of phosphorus solubilizers ranged from 3.12 to 3.34 log cfu g-1 soil. The acid phosphatase activity also varied across the study area, with mean values ranging from 24.84 to 30.70 µg p-nitrophenol produced g-1 soil h-1, and most of the collected soils showed activity between 25 and 50 µg p-nitrophenol produced g-1 soil h-1. Implementation of effective soil management practices, in accordance with soil test results, is imperative for the preservation and enhancement of organic carbon levels through the incorporation of organic matter, such as compost and cover crops, while minimizing the excessive use of chemical fertilizers. This approach not only augments organic carbon content but also enhances the biological properties of soils, thereby improving soil fertility and overall soil health.

Impact of Herbicides on Soil Fertility and Nutrient Uptake by Transplanted Rice (Oryza sativa L.) in Eastern U.P, India

A field experiment was carried out at Agricultural Research Farm, Institute of Agricultural Sciences, Varanasi during kharif 2017 and 2018 to evaluate the nitrogen intake by transplanted rice (Oryza sativa L.) and the available nutrient status of soil under ten weed control treatments. The treatment bispyribac-Na 9.1% (24.57 g/ha) + metsulfuron-methyl 1.2% (3.24 g/ha) + chlorimuron ethyl 1.2% (3.24 g/ha) recorded higher Organic carbon (0.47%), pH (7.38), EC(0.18 dS m-1), available N193.48 kg/ha, P22.46 kg/ha, and K 221.56 kg/ha in soil, higher nutrient (N, P and K) content in grain 1.14, 0.33, 0.38%, and straw 0.74, 0.12, 1.74% and protein content 6.81 & 4.42% in grain and straw, respectively. improved N, P, K uptake in grain 58.57, 17.06, 19.23 kg/ha and straw 71.00, 11.36, 166 kg/ha, respectively over weedy check (grain 46.09, 13.35, 15.10 kg/ha and straw 58.58, 9.38 and 137.65 N, P and K respectively). This treatment exhibited positive performance of soil fertility and N, P and K uptake by transplanted rice.

Assessment of Soil Fertility Status under the Barren Land Soil of the Central Plain Zone of Uttar Pradesh, India

Soil fertility evaluation of barren land is the most basic decision-making tool for an effective sustainable plan for a particular area. Thus, the present study was carried out to evaluate the soil fertility status in session variation of the two blocks of Kanpur Dehat (Akabrpur and Maitha). The soil samples were randomly collected based on the variability of land at a depth of 0-15 cm, 15-30 cm, and 30-60 cm in 5-5 sites in the both blocks. A GPS device was used to identify the location of the soil sampling points. Soil samples were analyzed for texture, pH, OC, EC, N, P, K, S, Fe, Zn, Cu, Mn, and exchangeable cations status following standard analytic methods in the laboratory of Soil Science and Agricultural Chemistry, C.S.A. University of Agriculture and Technology, Kanpur, UP. The soil organic carbon ranged from 0.18 to 0.34% of both blocks. Available nitrogen ranged from 102.78 to 138.39 kg ha-1, available phosphorous ranged from 9.89 to 16.47 kg ha-1 and available potassium ranged from 230.65 to 276.38 kg ha-1 in the surface soil of Maitha, all of which showed a decrease in value with increase in depth. Exchangeable calcium ranged from 4.58 to 6.34 (cmol (p+) kg-1), exchangeable magnesium ranged from 2.20 to 4.40 (cmol (p+) kg-1), and the pH of the soil in both blocks was highly alkaline in nature, all of which varied significantly with site and depth. The results indicated that soils are not good for the cultivation of various crops. Farmers are required to maintain Soil Health Card which helps them to adopt suitable management practices and provide proper nutrition to soil.

Influence on Crop Health and Yields as Affected by Soil Organic Matter and Crop Residue Management: An Overview

For growth of plants and crop productivity, soil is a crucial component. However, just a very small portion of the soil is genuinely fertile for farming these days, and if we managed it incorrectly, it could be depleted. It has been demonstrated that organic nutrients increase crop production, quality, and yield, which in turn improves the quality as well as richness of the soil's characteristics and creates a more favorable environment for the soil's beneficial microorganisms. According to reports, organic carbon in the soil and soil matter are the most significant indicators of soil quality and soil health. They are also advantageous for the sustainability of agriculture. Crop residue can be used effectively to improve soil quality and increase or maintain SOM's physical and chemical qualities.

Assessing Soil Fertility Dynamics and Carbon Sequestration Potential in Groundnut (Arachis hypogaea L.) Cultivation Areas of Sri Satya Sai District, Andhra Pradesh, India

In 2021-2022, a study was conducted at the Agricultural Research Station in Anantapur, Andhra Pradesh, India, focusing on soil fertility changes and carbon storage potential in Sri Satya Sai district. A total of 300 soil samples were collected, 150 before and 150 after groundnut (Arachis hypogaea L.) cultivation in three blocks (i.e., Chennekothapalle, Ramagiri, and Roddam) of Sri Satya Sai District, Andhra Pradesh, India. Chennekothapalle exhibited a decline in pH from 6.83 to 6.53 after groundnut (Arachis hypogaea L.) cultivation, accompanied by a decrease in electrical conductivity (EC) levels from 0.22 to 0.18. Similarly, Ramagiri displayed a similar trend with a drop in pH from 7.03 to 6.63 and a decrease in EC from 0.22 to 0.20 dS/m. Roddam experienced a slight reduction in pH from 6.52 to 6.48 and a decrease in EC from 0.18 to 0.16 dS/m. Organic carbon (OC) content showed varying trends, with notable increases in Chennekothapalle (from 0.44% to 0.94%), Ramagiri (from 0.43% to 1.13%), and Roddam (from 0.3054% to 0.4454%) after cultivation. Nitrogen levels witnessed an increase in all three blocks, Chennekothapalle rising from 141.3 to 171.3 kgs/ha, Ramagiri from 162.11 to 192.11 kgs/ha, and Roddam from 129.44 to 154.44 kgs/ha. Additionally, Posphorus levels increased in Chennekothapalle (from 16.76 to 19.76 kgs/ha), Ramagiri (from 13.62 to 18.62 kgs/ha), and Roddam (from 30.24 to 35.24 kgs/ha) after cultivation. Similarly, Potassium levels showed increases in Chennekothapalle (from 159.07 to 184.07 kgs/ha), Ramagiri (from 161.04 to 195.04 kgs/ha), and Roddam (from 154.49 to 174.49 kgs/ha), indicating distinct patterns of soil fertility dynamics across these regions. In Chennekothapalle, the soil organic carbon content (TOC) increased from 0.004% to 0.009%, and there was a substantial rise in soil carbon stock (SCS) from 18.11 to 39.37 kgs/m². Carbon turnover, measured through mean CO2 levels, increased from 160.45 gms to 343.7 gms, and the Carbon Sequestration Potential (CSP) was 6900 Kgs. In Ramagiri, TOC saw an increase from 0.004% to 0.011%, with SCS improving from 30.92 to 37.38 kgs/m², indicating greater soil carbon storage. A significant rise in CO2 levels from 158.69 gms to 415.3 gms was observed, and CSP was 7700 Kgs. In Roddam, TOC increased from 0.003% to 0.004%, and SCS rose from 20.24 to 30.06 kgs/m², signaling improved soil carbon stocks. CO2 levels increased from 111.98 gms to 163.3 gms, reflecting enhanced carbon turnover, and remarkably, CSP was 3150 Kg. In comparing the three blocks, it's evident that Ramagiri exhibited the most substantial increase in soil fertility and carbon sequestration potential. While Chennekothapalle is showing significant improvements, Roddam experienced relatively modest changes in all parameters.

Unveiling the Impact of Integrated Nutrient Management on Soil Health and Microbial Dynamics in Mustard Cultivation

During the Rabi season of 2020-21, an investigation was carried out at College Farm, Agricultural College, Polasa, Jagtial, under the supervision of Professor Jayashankar Telangana State Agricultural University. The primary aim of the research was to assess the influence of integrated nutrient management on the organic carbon content, enzyme activity and microbial population in the mustard (Brassica juncea L.) crop. The experiment was conducted in soil with a sandy clay loam texture and followed a randomized block design, consisting of nine distinct treatments, each of which was replicated three times. These treatments includes: T1: 100% Recommended Dose of Fertilizer (RDF), T2: 100% RDF + FYM, T3: 100% RDF + FYM + Biofertilizer consortium, T4: 75% RDF, T5: 75% RDF + FYM, T6: 75% RDF + FYM + Biofertilizer consortium, T7: Soil Test Based NPK, T8: 75% STB NPK + FYM and T9: 75% STB NPK + FYM + Biofertilizer consortium. The results revealed that the organic carbon, dehydrogenase activity and microbial population of soil were significantly enhanced by the application of combined use of organic, inorganic fertilizers and biofertilizers. All the parameters were recorded higher with the integrated application of 75% STB NPK+ FYM + Biofertilizer consortium which was on par with 100 % RDF + FYM + Biofertilizer consortium, 75 % RDF + FYM + Biofertilizer consortium, 75 % STB NPK + FYM, 100 % RDF + FYM, 75 % RDF + FYM. The population of bacteria and fungi, organic carbon content and dehydrogenase were recorded lower in the treatments receiving sole application of inorganic fertilizers.

INM-A Potential Way of Farming in Reduction of CH4 and CO2 Emission in Rice-sunflower Sequential Cropping System

Aim: To find out the CH4 and CO2 emission pattern and the considerable amount of SOC sequestered by using different organic sources in sandy clay loam soil. Study Design: Randomized Block Design. Place and Duration of the Study: The study was conducted in a farmer's field at Ayanathur, which is geographically located at 11°23’N latitude, 79°29'E longitude, and an altitude of +26 m MSL. Duration of the study confined to 2 years cycle from September 2016 to January 2018 I and II crops respectively. Methodology: Different sources of organic manures viz., Farm Yard Manure @ 12.5 t ha-1, vermicompost, pressmud, poultry manure, and composted coirpith are each @ 5 t ha-1 were applied as basally and incorporated along with Azospirillum and phosphobacteria @ 2 kg ha-1 as a soil application at the time of last ploughing. Fertilizers were applied as per the treatment schedule of 150:50:50 kg N, P, and K ha-1 was followed throughout the period of study through urea, Di Ammonium phosphate and muriate of potash for rice crops. An open path LICOR analyzer 7700 and 7500 for CH4 and CO2 to find the CH4 and CO2 fluxes during the period of study through calibration of eddy covariance fluxes emissions were calculated. Results: Combined application of a Recommended dose of fertilizers along with Farmyard manure @ 12.5 t ha-1 reduced the CH4 emission by 13.6 and 15 % over other organic sources in rice whereas, the CO2 emission by 54.4 and 53.8% and 61.5 and 53.9 % over other organic sources in rice and sunflower respectively. Concomitantly, the SOC increased by 6.8 and 7.5% in rice and 4,7 and 4.4% in sunflower over other organic sources.

Effect of Different Organic Manures and Their Levels on Nutrient Status and Soil Microbial Activity under Rose (Rosa bourboniana Desportes) Cultivation

A field experiment was conducted to study the effect of different organic manures and their levels on nutrient status and soil microbial activity in rose at Hisar during 2020-21. The treatments comprised of 3 different types of organic manures viz., farm yard manures, vermicompost and poultry manure and 4 levels control, 4 kg/m2, 5 kg/m2 and 6 kg/m2. The experiment was carried out in the split plot design with three replications. Observation on organic carbon, dehydrogenase activity and alkaline phosphatase activity, N, P and K content in rose leaves and available N, P and K content in soil at the time of harvest were recorded. Organic carbon in soil was maximum (0.93%) with the application of vermicompost while dehydrogenase and alkaline phosphatase activity were highest with the application of farmyard manure and poultry manure, respectively. Nitrogen (2.17%) and phosphorus (0.27%) content were maximum in rose leaves at harvest stage with the application of poultry manure while Potassium (1.41%) content was maximum vermicompost. Same trend was observed in the nutrient status of soil with the application of different organic manures. It is concluded that the application of poultry manures had pronounced effect on microbial activity and nutrient status in rose.

Influencia del cambio de uso del suelo sobre las reservas de carbono orgánico en el Parque Natural Regional Cortadera, Boyacá (Colombia)

Los páramos almacenan grandes reservas de carbono orgánico en el suelo (COS), influenciados por las condiciones climáticas y biogeoquímicas, propias del ecosistema; sin embargo, su progresiva conversión hacia cultivos, ganadería o minería incide directamente en las reservas de COS. Con el fin de determinar el efecto que ejerce el cambio de uso de suelo sobre la variabilidad de las reservas de COS, se realizó un monitoreo de COS entre 2013, 2018 y 2020, en el Parque Natural Regional Cortadera. Se estudiaron parcelas permanentes de muestreo (PPM), ubicadas bajo tres diferentes usos del suelo: conservado, en recuperación e intervenido. Se analizaron muestras de carbono orgánico y densidad aparente, a dos profundidades (0-15 cm y 15-30 cm). Se encontró que la PPM en escenario conservado presentó los contenidos más altos de COS, con valores de 290,37; 199,22 y 257,5 tC ha-1, para cada uno de los años en estudio; seguido por la PPM en recuperación, que evidenció valores de COS 215,3 tC ha-1, en el 2020, en contraste con la PPM intervenida, que presentó contenidos mínimos de 15,50; 34,01 y 88,06 tC ha-1. Se observó que los mayores contenidos de COS se encuentran a la profundidad de 15 a 30 cm. Dichos aspectos, resaltan la importancia de avanzar en acciones enfocadas a la protección de ecosistemas estratégicos, considerando las constantes amenazas relacionadas con la transformación del paisaje y, con ello, la posibilidad de proveer funciones y servicios asociados a la captura de carbono y la regulación climática.

The paramos accumulate high stocks of soil organic carbon (SOC), influenced by the climatic and biogeochemical conditions of the ecosystem. However, their progressive conversion to crops, livestock, or mining has a direct impact on the SOC stocks. To determine the effect of land use change on the variability of SOC stocks, monitoring of SOC content was conducted between the years 2013, 2018, and 2020 in the Parque Natural Regional Cortadera. Permanent sampling plots (PPS) located under three different land uses were studied: conserved, recovering, and intervened. To do so, samples of soil organic carbon and bulk density at two depths were analyzed (0-15 cm and 15-30 cm). The conserved PPS showed the highest SOC contents, with maximum values of 290.37; 199.22, and 257.5 tC ha-1 for each of the years under study; follow by the recovery PPM that presented COS values of 215.3 tC ha-1 in 2020, in contrast to the intervened PSP that showed minimum contents of 15.50; 34.01 and 88.06 tC ha-1. Furthermore, the highest SOC contents were found at 15-30 cm depth. These factors emphasize the importance of carrying out actions focused on protecting strategic ecosystems such as paramos, taking into account the continuous threats related to the transformation of the landscape and, consequently, the possibility of providing ecosystem functions and services related to carbon capture and climate regulation.

Effect of poplar and eucalyptus based agroforestry system on soil biochemistry

The field experiment was conducted during the winter season of 2016-17 at the experimental site of Agroforestry Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. Poplar and eucalyptus were intercropped with different wheat varieties (UP-2526, UP-2565, UP-2628, and DPW-621-50). After harvesting the wheat crop, the soil sampling was performed to determine the soil parameters like electrical conductivity (EC), organic carbon and the minerals content. Nitrogen, phosphorus and potassiumcontent and other biochemical constituents were higher in the agroforestry system as compared to the open farming system. A high soil pH (7. 53) was found in an open farming system and lower pH in an agroforestry system. Soil EC in the agroforestry system was slightly higher than the open farming system. Organic carbon was maximum (1. 33%) under the poplar agroforestry system compared to the eucalyptus based agroforestry system. Overall, this study determines the effect of poplar and eucalyptus based agroforestry systems on soil biochemistry.

Remoção de carbono orgânico dissolvido de águas filtradas com tratamento complementar por pré-oxidação com ozônio e adsorção em carvão ativado / Removal of dissolved organic carbon in filtered water complemented with treatment by pre-oxidation with ozone and adsorption on activated carbon

Resumo Este trabalho teve como objetivo avaliar as remoções de carbono orgânico dissolvido presente em águas filtradas de estação de tratamento de água com tratamento complementar por pré-oxidação com ozônio e adsorção em carvão ativado granular. Para o estudo de adsorção foi utilizado o método de ensaio rápido em coluna de escala reduzida, com carvão ativado produzido de cascas de coco. Realizou-se a comparação entre as curvas de ruptura para os ensaios com e sem aplicação de ozônio. Os resultados mostraram reduções nas concentrações de carbono orgânico dissolvido no início dos ensaios e após a passagem da água com e sem pré-ozonização pelas colunas ensaio rápido em coluna de escala reduzida seguida de incrementos progressivos das concentrações à medida que se aumentou o volume de leitos tratados. Na fase final dos ensaios, os aumentos de volume de leitos tratados não causaram mudanças significativas nas concentrações efluentes de carbono orgânico dissolvido. O mesmo comportamento foi observado com relação à absorção em radiação ultravioleta a 254 nm. O uso de ozônio previamente à adsorção em carvão ativado granular, usando o método ensaio rápido em coluna de escala reduzida, resultou em maiores reduções na absorbância da luz ultravioleta em 254 nm do que nas concentrações de carbono orgânico dissolvido. As absorbâncias específicas à radiação ultravioleta das amostras ozonizadas foram menores do que as que não receberam ozônio.

Abstract The objective of this study was to evaluate the removal of dissolved organic carbon in filtered water followed by pre-oxidation with ozone and adsorption on granular activated carbon. The rapid small-scale column test was used for the adsorption essays with activated carbon produced from coconut shells. A comparison was made between the breakthrough curves for tests performed with and without pre-oxidation with ozone. The results showed reductions in dissolved organic carbon concentrations after initial passage of water with and without ozone through the rapid small-scale column test column, followed by progressive increases in concentrations along with the number of the bed volumes. In the final phase of the tests, increases in bed volumes did not cause significative changes in effluent dissolved organic carbon concentrations. The same behavior was also observed with respect to ultra-violet absorbance at 254 nm. The use of ozone prior to adsorption on GAC, using the ERCER method, caused greater reductions on UV254 absorbance than in concentrations of dissolved organic carbon. The specific ultraviolet absorbance values of samples that received ozone were lower than those that were not ozonized.

Long-term Use of Balanced and Integrated Nutrient Management Improved Soil Aggregation and Carbon Stabilization in a Maize-wheat Cropping Sequence

Sustainable nutrient management practices have the potential to enhance carbon (C) storage capacity of agricultural soils that may help offset increasing atmospheric CO2 concentration. Nutrient management practices on long-term basis differentially influence aggregates and distribution of soil organic C (SOC) present within aggregates, which in time may affect C stabilization. The present study assessed the impact of long-term application of fertilizers for 44 years either alone or integration with farmyard manure (FYM) on bulk density, SOC and C pools, potassium permanganate oxidizable C (KMnO4), aggregate stability and distribution of C fractions within different size aggregate under maize-wheat cropping sequence. The application of 100%NPK+FYM significantly (P< 0.05) improved soil aggregation and mean weight diameter (MWD). The percent of macro-aggregates (MacroA) and meso-aggregates (MesoA) was maximum in 100%NPK+FYM followed by NPK and the minimum in the control treatment. Irrespective of aggregate classes, TOC (g kg-1 aggregate) was maximum in 100%NPK+FYM treatment with an average of 8.42 g kg-1 aggregate as compared to control (5.05 g kg-1 aggregate). If averaged across the treatments, TOC concentration in aggregates followed the order MacroA> MesoA>MicroA. Correspondingly, results for KMnO4-C were similar in different treatments and aggregate classes. Application of FYM with inorganic fertilizers (NPK) or NPK showed a significant increase in all oxidizable organic C fractions particularly recalcitrant C fraction, which reflects the stable nature of OC as compared to very labile and labile C fractions. In general, C present in mineral fraction and large-sized aggregates (MacroA) has higher recalcitrant fractions of SOC as compared to small-sized aggregates (MesoF and MicroF). The study concluded that long-term balanced and integrated nutrient management improved soil aggregation, C distribution within aggregates, and C storage capacity of soils under maize-wheat. Carbon associated with macro aggregate and a mineral fraction has more recalcitrant C fraction compared to meso and micro aggregate fractions.

Vertical Distribution of TOC, TN and Other Important Soil Attributes and Their Relationship in Alfisol and Entisol of West Bengal

A study to assess the profile distribution of important soil attributes in Alfisols and Entisols of West Bengal was conducted during 2016-17. Purposefully selected random sampling was carried out to collect the soils from different locations of two study sites, viz., Kalinagar (25º27'33.9"N, 88º19'10.2"E) from Malda district and Durganagar (26º09'62.7"N, 89º53'51.7"E) from Cooch Behar district of West Bengal at 0-15, 15-30, 30-45 and 45-60 cm depths. Understanding of vertical distribution of soil fertility indicators like soil organic carbon (SOC), total nitrogen (TN) and other important properties in two different soil and climatic conditions will provide an insight regarding the behaviour of soil with the change in environmental conditions. Soil bulk density (BD), porosity, pH, SOC, TN, C:N ratio and texture were determined using standard laboratory procedures and computations. Obtained results were subjected to statistical analyses. Soils of Kalinagar sites were slightly acidic in nature while soils of Durganagar were neutral in nature. Kalinagar soils were silt clay loam in texture where Durganagar soils classified as loam to sandy loam. Soil BD values increased with depth in both Kalinagar (Alfisol) and Durganagar (Entisol). The porosity percentage progressively decreased with an increase in depth. Soils of Durganagar reported higher soil porosity at all the depths studied. An increase in soil pH with increasing depth was observed in both the sites. The mean total organic carbon (TOC) content recorded maximum in surface soil and its concentration decreased with the depth. Kalinagar soils observed 7.63% higher TOC (17.94 g kg-1) content than Durganagar (16.57 g kg-1) at surface depth (0-15 cm) and its accumulation at the lower depths was also maximum in former soil. Mean TN values were also found to decrease by increasing the depth. The accumulation of total nitrogen at the subsequent depths was relatively higher in Kalinagar than Durganagar. Increase in C:N ratio with increasing depth was noticed in Kalinagar site but the opposite trend was accorded in case of Durganagar. Accumulation of SOC and TN throughout the soil depth was found to be greater in Alfisol (Kalingar) due to higher clay and silt fractions as compared to Entisol (Durganagar). There was a significant positive relation of TOC with clay and silt (r = 0.285, p<0.05, r = 0.314, p<0.01, respectively) and of TN with clay and silt (r = 0.328, p<0.01, r = 0.262, p<0.05, respectively) irrespective of soil orders. Alfisols with high bulk density have a greater capacity to accumulate SOC and TN throughout the soil profile due to higher clay and silt fractions in comparison to Entisols with loose textural properties.

Microbiological attributes of yellow oxissol under different monocultures in the savanna region of Piauí state / Atributos microbiológicos de um latossolos amarelo sob diferentes monoculturas no cerrado piauiense

Microbial biomass is an important component in maintaining soil quality and plant productivity. The aim of this paper was to evaluate alterations in microbiological attributes and organic carbon in accordance with seasonal change in different monocultures in the Savanna region of Piauí state. Soil samples were collected in areas of soy, eucalyptus, pasture, and in an area of native savanna, at depths of 0-0.20 m, during the rainy and dry periods. Using these samples microbial biomass carbon (MBC), basal respiration (BR), metabolic quotient (qCO2), microbial quotient (qMIC), and total organic carbon in the soil (TOC) were evaluated. MBC differed significantly between the systems evaluated, with higher values in the soil under native vegetation in the two sampling periods. TOC presented a significant difference between the systems, with higher values in the native savanna and soybean in the rainy period. For the qMIC, the soybean area presented lower values in the two periods compared with the other areas. Basal respiration as well as qCO2 values differed between the systems only in the dry period. The results reveal that the type of vegetation cover, management system, and seasonality influence the behavior of biological properties in the soil.

A biomassa microbiana é um componente importante para manter a qualidade do solo e a produtividade das plantas. O objetivo deste trabalho foi avaliar as alterações nos atributos microbiológicas e carbono orgânico, em função da variação sazonal em diferentes monoculturas no Cerrado piauiense. Amostras de solo foram coletadas em áreas de soja, eucalipto, pastagem e em uma área de mata nativa de Cerrado na profundidade de 0-0,20 m, durante o período chuvoso e seco. A partir dessas amostras avaliaram-se o carbono da biomassa microbiana (CBM), respiração basal (RB), quociente metabólico (qCO2), quociente microbiano (qMIC) e o carbono orgânico total do solo (COT). O CBM diferiu significativamente entre os sistemas avaliados, com maiores valores no solo sob mata nativa nos dois períodos de amostragem. O COT apresentou diferença significativa entre os sistemas, com maiores valores na mata nativa e soja no período chuvoso. Para o qMIC, a área com soja apresentou menores valores nos dois períodos em comparação às demais áreas. A RB assim como valores de qCO2 diferiram entre os sistemas apenas no período seco. Os resultados demonstram que o tipo de cobertura vegetal, o sistema de manejo e a sazonalidade influenciam o comportamento das propriedades biológicas do solo.

Chemical and physical properties of an anthropogenic dark earth soil from Bragança, Para, Eastern Amazon / Propriedades físicas e químicas de Terra Preta Antropogênica em Bragança, Pará, Amazônia Oriental

Although anthropogenic dark earth (ADE) is generally found in non-floodable land, it also occurs on floodplains but, there is no information about the chemical and physical characteristics of ADE in this environment. In this study, we propose to check the hypothesis that a Gleysol, classified as ADE, presents improved chemical and physical conditions than an adjacent soil, no anthropogenic. Thus, the objective of this study was to characterize the chemical and physical properties of the top layer of two ADE profiles in a Gleysol and compare them with an adjacent soil. Samples were taken from two areas classified as ADE in Bragança, Pará State, Brazil, at the "Jabuti" archaeological site, and from an adjacent non-anthropogenic site. Disturbed and undisturbed soil samples were collected at the soil depth of 0.05-0.10 m for chemical (pH, potential acidity, exchangeable cations, and soil organic carbon) and physical (soil particle size distribution, particles density, water retention curve, total porosity, microporosity, macroporosity, and bulk density) analysis. The two areas of ADE in a Gleysol, showed improved soil chemical properties compared to the adjacent soil, particularly in relation to phosphorus and calcium levels that contributed to higher cation exchange capacity which, in turn, was positively related to organic carbon content. Changes in soil physical properties were less noticeable but both areas of ADE presented higher water retention capacity, particularly at low tension. The improved conditions of the ADE soil under Gleysols shows that these areas are adequate for soil cultivation, especially with plants adapted to floodplain.

Embora as terras pretas antropogênicas (TPA) geralmente são encontradas em áreas de terra firme, elas também ocorrem em áreas e várzeas, mas, não há informações sobre as características químicas e físicas de TPA neste ambiente. Neste estudo, nós propomos verificar a hipótese de que um Gleissolo, classificado como TPA, apresenta melhores condições químicas e físicas do que o solo adjacente, não antropogênico. Assim, o objetivo do estudo foi caracterizar as propriedades químicas e físicas da camada superficial de dois perfis de TPA em um Gleissolo e compará-los com um solo adjacente. Amostras de solo foram coletadas em duas áreas classificadas como TPA em Bragança, Estado do Pará, Brasil, no sítio arqueológico "Jabuti" e em uma área adjacente não antropogênica. Amostras de solo com estrutura deformada e indeformada foram coletadas na profundidade de 0,05-0,10 m para análises químicas (pH, acidez potencial, cátions trocáveis, e carbono orgânico do solo) e físicas (distribuição do tamanho das partículas do solo, densidade de partículas, curva de retenção de água, porosidade total, microporosidade, macroporosidade e densidade do solo). As duas áreas de TPA em Gleissolo, apresentaram melhores propriedades químicas comparadas com o solo adjacente, principalmente em relação aos níveis de fósforo e cálcio que contribuíram para a maior capacidade de troca catiônica que, por sua vez, foi positivamente relacionada com o conteúdo de carbono orgânico. Mudanças nas propriedades físicas do solo foram menos pronunciadas, mas as duas áreas de TPA exibiram maior capacidade de retenção de água, sobretudo em baixa tensão.