Agroecosystems Research Articles

Microbial Community Composition and Activity in Saline Soils of Coastal Agro-Ecosystems.

Soil salinity is a serious problem for agriculture in coastal regions. Nevertheless, the effects of soil salinity on microbial community composition and their metabolic activities are far from clear. To improve such understanding, we studied microbial diversity, community composition, and potential metabolic activity of agricultural soils covering non–, mild–, and severe–salinity. The results showed that salinity had no significant effect on bacterial richness; however, it was the major driver of a shift in bacterial community composition and it significantly reduced microbial activity. Abundant and diverse of microbial communities were detected in the severe–salinity soils with an enriched population of salt–tolerant species. Co–occurrence network analysis revealed stronger dependencies between species associated with severe salinity soils. Results of microcalorimetric technology indicated that, after glucose amendment, there was no significant difference in microbial potential activity among soils with the three salinity levels. Although the salt prolonged the lag time of microbial communities, the activated microorganisms had a higher growth rate. In conclusion, salinity shapes soil microbial community composition and reduces microbial activity. An addition of labile organic amendments can greatly alleviate salt restrictions on microbial activity, which provides new insight for enhancing microbial ecological functions in salt–affected soils.

Amphibian diversity in different habitat of Agro ecosystem in Aurangabad district (Bihar)

Amphibians are one of the key components of various ecosystems viz. freshwater, grassland as well as forest ecosystem. Present study for assessment of amphibian diversity was conducted in different agro ecosystem habitat types of Aurangabad district of Bihar province. Different habitat types selected for assessment of amphibian diversity of this area as: - (1) agricultural and non-agricultural land (2) pond (3) grassland. The data was collected by visual encounter survey and call count survey using line transect method. Species identification was confirmed with pictorial guide and various identification keys available. Collected data was analysed descriptively as well as statistically to find out different diversity indices. A total of 13 species of amphibians belonging to 4 families and 9genera were recorded. This study reveals that the Aurangabad district of Bihar province is rich in amphibian fauna. The district lies between 24°45’ and 24°75’ North Longitude and 84°22’ and 84°37’ East latitude. Further studies may explore the population structure, microhabitat, habitat, and use by amphibians for better understanding and also impose of several conservation strategies in Bihar state.

A Scale to Measure the Attitude of Organic Farmers towards Paramparagrat Krishi Vikas Yojana

Organic farming is considers as the medium and long term effect of agricultural interventions on the agro ecosystem. A scale has been developed for the study of attitude of organic famers towards PKVY. Attitude is a behavioural construct that cannot be measured by a single variable, hence there arise a need for developing a standardized instrument for its measurement. A method of Equal-Appearing Intervals was used to construct the attitude scale. A total of 60 attitude statements about PKVY scheme expressing varied degree of favourableness were collected and modified based on the Edward’s criteria. These statements were subjected to judge’s opinion by agricultural extension scientists of State Agricultural Universities and ICAR Research Institutes and field level extension workers. Based on expert’s response a standardized scale has been developed with 10 statements which are having universe of content, uniform distribution of scale values along the psychological continuum and high scale “S” values and lower Interquartile range “Q” values and more or less equal number of favourable and unfavourable attitude items. The selected statements were tested with validity and reliability.

Phosphorus transformation in root zone environment under semi tropical agro ecosystem in sandy clay loam soil

Phosphorus transformation in root zone environment under semi tropical agro ecosystem in sandy clay loam soil

First report of a ‘Candidatus Phytoplasma australasia’ strain in witches’ broom diseased Crotalaria retusa in India

Crotalaria retusa, commonly known as rattle weed in India, it is commonly used as a source of various organic residues for soil nutrition enrichment and nitrogen fixation under various agro ecosystems. During May 2020, C. retusa plants exhibiting symptoms related to phytoplasma presence was observed at the College of Horticulture in Bengaluru, Karnataka, India. The plants showed shoot proliferation, reduced leaf size and stunted growth leading witches’ broom symptoms with incidence of 2 to 5%. Phytoplasma presence in symptomatic C. retusa plants was confirmed by polymerase chain reaction assays on 16Sr RNA and secY genes with specific primers. Amplified products were eluted, cloned and sequenced. The 16S rRNA sequence analysis showed that the detected phytoplasma shared 99.61% to 100% nucleotide identity on 16S rDNA with a number of ‘Candidatus Phytoplasma australasia’ strains reported from different countries across the world, and from 99.41 to 99.77% identity on the secY gene to phytoplasma strains infecting mainly horticultural crops. This result is well supported by the clustering of C. retusa phytoplasma with ‘Ca. P. australasia’ in the phylogenetic analysis on both genes. Further, the virtual RFLP pattern showed a similarity coefficient of 1.0 with ‘Ca. P. australasia’, enclosed in the 16SrII-D subgroup. This is first report of 16SrII-D phytoplasmas in C. retusa showing witches’ broom symptoms in India.

Carbon Sequestration for Sustaining Soil Health and Improving Crop Productivity in Sugarcane Based System

Soil management practices such as no tillage and residue mulching have been reported to promote the storage of carbon from atmospheric origin, and to constitute potential carbon sinks. Their assess remains of major importance now a days (i) for mitigating the increased atmospheric concentrations in greenhouse gases (especially CO2) and (ii) for addressing the problem of agro ecosystem transformation and sustained land productivity. The C fixed in plants by photosynthesis and added to the soil is the primary source of C in ecosystems. Recent concerns with rising atmospheric levels of CO2 and global warming have once again focused attention on soil organic matter and C-sequestration. Carbon sequestration taken as C-storage, can be achieved by various management practices and the capacity of different management practices to promote storage of soil C and provide a major sink for atmospheric CO2, can be evaluated most convincingly from long-term studies that contributes unique information on soil C addition, losses and storage. But any predictions for change in C stock in soils depend on reliable estimates of net above ground biomass and the proportion of which is returned back to the soil.

Urban to Agro Ecosystems: Effects of Land Use on Pollinators and Ecosystem Services

Urban to Agro Ecosystems: Effects of Land Use on Pollinators and Ecosystem Services

Bioefficacy of novel molecules against painted bug on mustard agro-ecosystem in Bundelkhand region

Bioefficacy of different novel molecules were tested for the management of painted bug in mustard agro ecosystem during Rabi- 2020–21 at Rani Lakshmi Bai Central Agricultural University, Jhansi. Data were recorded for the incidence of painted bug. It was observed that different individual of newer molecules was significantly reduced painted bug population in mustard agro-ecosystem and enhanced the yield over control plot. The result revealed that among all the individual of newer molecules and combination of newer molecules after first spray Acetamiprid 25 SP @ 25 gm a.i./ha and was found to be the most effective in both spray with maximum reduction painted bug population and it was significantly superior over the rest of treatment followed by Fipronil 5SC @ 75g a.i./ha, NSKE 5% + Lantana leaf extract 1.5%, Verticillium lecanii @ 2.5 Kg/ha + Kunap Jal and control. All the treatments were significantly superior as compared to untreated control.

Pelatihan Agro Eco-System Analysis Petani Ketela Pohon dalam Teknik Pengelolaan Organisme Pengganggu Tanaman

<em><strong>Training on Agro Eco-System Analysis for Cassava Farmers in Plant Pest Organism Management Techniques</strong>. </em>Pest population fluctuations in cassava plants tend to increase and spread rapidly in drought fields and a monoculture cropping pattern with close spacing therefore the presence of pests planted is highly dependent on agro-ecosystem conditions. Therefore ecological-based pest control is very necessary. To maintain the stability of the plant ecosystem, basic skills are needed in conducting agroecosystem analysis (AESA). Based on the analysis results obtained recommendations for appropriate ecosystem management for each growing season and facilitate farmers in determining good cultivation techniques regarding pest control, cropping patterns, soil and water conservation as well as natural enemies that are appropriate for their plants. AESA activities are carried out so that farmers understand and are skilled in managing their cassava plantations because Randotonda Village is a producer of "Nuabosi" cassava which is known as a regional superior product. The activity is carried out in a participatory manner by directly involving the participating farmers as observers, fact seekers and decision-makers for the management of their agroecosystems through discussion and manifesting current real conditions with the hope that in the future they can manage their cropping agroecosystems properly. The highest increase in farmer understanding occurred in natural enemy components of 91.67% while the average increase in farmer understanding for all agro-ecosystem components was 57.14%. All participants were able to perform AESA very well which was indicated by the ability of farmers to make recommendations for managing cassava agroecosystems for the next planting season.

Mathematical Investigation and Computers Simulation of Plant Protection Process Taking into Account the Temporary Age Structure and Arbitrary Tropic Functions

The problem of describing the process of protecting agricultural crops in mathematical modeling is relevant. Today, the problem of plant protection attracts the attention of a large circle of scientists in connection with its promising use in priority areas of development of science, technology and agriculture. Mathematical modeling of the process of protecting the planned crop is one of the main tools in predicting the state of natural systems and managing them. One of the most important national economic, social and environmental problems at present is the improvement of systems for protecting agricultural crops from pests. Mathematical modeling of the process of protecting the planned harvest obliges to improve regional systems for protecting cotton on the basis of a targeted ecological and biological study, revealing the specifics of the formation and development of agro ecosystems in intensive crop production. The main task of the integrated method of combating agricultural pests of the plant protection process is the management of agrocenoses of “harmful insects” and “beneficial insects” of species based on the use of biological, chemical methods as a means or a management tool.The use of mathematical methods and computer software products to solve the problem of protecting the planned crop significantly increases the efficiency of planned and economic work and ensure optimal results. In this paper, we consider a mathematical model of the plant protection process, taking into account the temporal age structure and arbitrary trophic functions, formulate the task of plant protection. Necessary and sufficient conditions for the solvability of the plant protection problem with arbitrary trophic functions are found

English

Soil fertility status evolution is a decision making tool for the sustainable soil nutrient management. To evaluate its status, about 29 research data were collected and meta data analysis were made using SPSS for the selected soil chemical parameters. The soil was moderately acidic and salt free, 93.2% of Zinc (Zn), 100% of Manganese (Mn), 100% of Iron (Fe) and 79.3% of Copper (Cu) status were in sufficient range respectively. However, 44.7% of Phosphorus (P) and 72.3% exchangeable Potassium (K) status were found in a low range, 54.7% of organic carbon (OC) and 34.5% of total nitrogen were respectively found in a medium range, while 93.2% CEC was found in high range. The fertilizer recommendation can be done based on soil fertility status to economize crop production. Land use practices in agro ecosystems and plant species significantly influence the nutrient balance in the soil. According to this review, full nutrient balances of N, P and K in southern Ethiopia, across cropping types were (-31, +71 and -169) respectively. Accordingly, for the better crop production applying recommended fertilizers might be an option to replace the lost nutrients. Major crops (wheat, maize, teff, barley and sorghum) have reveled increased grain yield which were economically positive, indicating the potential of soil in the areas were in deficient levels, hence crops showed responses for fertilizer inputs. Therefore, balanced fertilizer use increase crop production and reduce environmental pollution. Key words: Crop response, land use, nutrient flow balance, soil fertility status

Analysis of agriculturally relevant rainfall characteristics in a tropical highland region: An agroecosystem perspective

Analysis of Rainfall onset date (OD), cessation date (CD), and length of growing period (LGP) for specific sites in highly dissected topography and highly variable climate may not provide actionable information for crop production planning. In tropical highland regions information on these parameters is scant at a resolution relevant for targeted management. This study examined recent (1981-2016) OD, CD, and LGP variability and trends for the main rainy season in different agroecosystems (AESs) in the northwestern Ethiopian Highlands. Onset criteria were derived from surveys, rainfall data, and previous literature whereas cessation criteria were set from the soil water holding capacity (WHC), daily reference evapotranspiration (ETo), and daily rainfall in each site. Dry spells (DS) were analyzed for the small rainy season in higher elevation AESs where the season is relevant for potato production. All analyses were performed using site specific data grouped by agroecosystem (AES), a unit that has similar climate, soil, crop, and farm management for better agricultural decisions. Results show high inter-annual variability of OD and CD, and LGP exhibited a significant trend in some AES and greater variability in higher elevation AES. Generally, trend analysis results showed early onset and cessation of rainfall. Significant increasing trends and variabilities in DS and OD may significantly affect crop production and thus AES specific crop production calendar should be revised to minimize crop failure. The analysis also confirmed that farmers perception is consistent with meteorological analysis. The results emphasize the importance of AES-based improved seasonal weather forecasts and tailored climate information services to guide farm decisions and improve management of climate variability by smallholder farmers. It also concluded that AES level analysis can better provide actionable information for decision makers and growers than site specific and scattered studies as mosaic results are reported between sites grouped in the same agroecosystem.

Fruit fly species diversity, population dynamics and infestation rate during fruiting season of snake gourd

A monitoring survey was conducted in snake gourd agro ecosystem during the fruiting season at Gangnapur, West Bengal, India to generate extensive data on fruit fly diversity, population dynamics, infestation rates and evaluate the effect of trapping on fruit fly infestation rates vis-à-vis benefit cost ratio of snake gourd cultivation. Methyl Eugenol and Cue Lure traps were used to assess the fruit fly species diversity. The number of adult male flies trapped was used to calculate fruit fly per trap per day and assess the population dynamics. Bactrocera dorsalis, Zeugodacus cucurbitae and Zeugodacus tau were the predominant fruit fly species during the fruiting season. Maximum species diversity and evenness estimates were registered by Methyl Eugenol traps. Species richness estimates for Cue Lure and Methyl Eugenol traps during the entire experiment are analogous due to the trapping of two different types of fruit fly species. Zeugodacus cucurbitae is the most abundant species in the snake gourd ecosystem and dominated the community of fruit flies throughout the study. Fruit fly per trap per day values indicated that the Gangnapur area is at infestation level, for Zeugodacus cucurbitae and Bactrocera dorsalis, while, for Zeugodacus tau the area is at suppression level. The rate of infestation varied from 6.93 % to 44.09 %. Farmers with traps in their fields reported a benefit cost ratio of 0.73 to 4.63, while the no-trap group reported 0.34 to 1.56. This study at Gangnapur has proven the beneficial effect of trapping on the benefit cost ratio of snake gourd cultivation.

Allelopathic potential of croton bonplandianus bail

An extensive survey of floristic of native and invasive weed species was carried out during 2016 to 2019 in the semiarid agro ecosystem of Baramati Tahsil, Dist- Pune (M.S.). About 18 dominant invasive weeds such as Ageratum, Alternanthera, Croton., Xanthium, Parthenium and Tridax were encroaching the natives, becoming a serious threat to the major crops of this area such as wheat, sorghum, pearl millet, mung bean, pigeon pea, chillies and tomato. Amongst these Croton bonplandianus was highly dominant and wide spreading. Hence, its allelopathic potential was investigated. The allelopathic influence of leaf and root leachates as well as extracts of Croton bonplandianus Bail. was examined on seed germination of mung bean (Vigna radiata L.). The germination assay revealed that allelopathic potential and other factors are responsible for its dominance and successful invasion. The allelopathic influence of rhizosphere soil and its aqueous leachates indicated that both are responsible for inhibiting the seed germination and seedling growth of mungbean. Both the experiments have clearly confirmed the allelopathic potential of Croton bonplandianus. The HPTLC analyses confirmed the existence of a broad groups of allelochemicals like terpenoides, steroids, flavonoids, pungent and bitter essential oils and phenolics in its leaves and roots, which confirmed its allelopathic potential. Further characterization of above mentioned allelochemicals is in progress.

Agro–ecosystem sensitivity to climate change over the Ethiopian highlands in a watershed of Lake Tana sub–basin

The study analyzed the level of agro–ecosystem sensitivity to climate change among the agro–climatic zones (ACZs) that are situated in the highlands of Lake Tana sub–basin. The analyses considered the actual land capability class (LCC in % considering soil texture, slope and elevation zone), crop diversity (count), length of growing period (LGP, month), and inter–annual variability of climate (mean annual rainfall–MARF in mm, mean monthly minimum temperature–MMMinT in ºC, and mean monthly maximum temperature–MMMaxT in ºC). For comparison purpose, it was essential to index/standardize the values of specified indicators. The proportion of arable land varied from 13.30% (in the Sub-Alpine) to 93.00% (in the Moist–Cold). The value of coefficient of variation showed the presence of variations of 7.85–11.21 (%), 7.21–10.34 (%), 16.37–39.61 (%) for MARF (mm), MMMaxT (ºC), and MMMinT (ºC), respectively across the ACZs. The inter–annual variability of both onset and offset time of rainy season was found to be in the range of 0.3–1.25 months. The LGP (month) was in the range of 3.25–6.25 across the ACZs; whereas crop diversity (count) ranged from 2–7. The production of red onion (allium cepa), oat (Avena sativa), local wheat (Triticum), and pea (Pisum sativum) was abandoned in the Sub–Alpine; whereas the production of linseed (Linmu usitatisimum), barley (Hordeum vulgare), and niger (Guizotia abyssinica) in the Moist–Cool. Yet, crops like maize and tef became the common crops in the Cold, possibly because of global warming. The indexed value of agro–ecosystem sensitivity to climate change ranged from 0.14–0.71. The level of agro–ecosystem sensitivity was higher towards the Sub–Alpine. The local development interventions to be made in the various ACZs need to be determined/prioritized considering the level of agro–ecosystem sensitivity.

Soil properties among Indian Central Himalayan agroecosystems as affected by altitude and size variations

The present study has been performed among Central Himalayan agroecosystems (AGEs) to analyze the changes in some physico- chemical properties of soils along four altitudes viz. very low (VLA), low (LA), mid (MA) and high altitude (HA). The AGEs were categorized into three size classes i.e. small, medium, and large based on the regional availability of landholding sizes. Results revealed that the size of the AGEs significantly affected only physical parameters of the soil while chemical parameters remain unaffected, this may be due to the regional similarity in management practices of AGEs which governed by the identical seasonal cropping patterns, local food selectivity and economic status of the peasant. The soil bulk density was recorded maximum at VLA (1.00 g cm-3) and decreased with increasing altitude and sizes of agroecosystem thus the correlations were significant. Water holding capacity depicted positive relation with porosity (r= 0.229, P<0.01) and OC (r= 0.273) while negative relation with silt (r= -0.172), bD (r= -0.221,) and pH (r= -0.081). Soil nitrogen was reported highest at MA in medium sized agroecosystems, during the rainy season (0.287 %) followed by winter (0.257 %) and summer season (0.243 %). Overall maximum soil carbon stock was observed at MA (41.41 t ha-1) > HA (37.85 t ha-1) > LA (33.00 t ha-1) > VLA (30.16 t ha-1). Suitable management practices of higher altitudes reflected as the high fertility of the soil in those regions (SQI= HA> MA> LA> VLA) which must be followed by the farm managers of lower altitudes.

The study on diversity of macromoth community in two different forest types from agro and forest ecosystems

The study on diversity of macromoth community in two different forest types from agro and forest ecosystems

A REVIEW ON USE OF BIOACOUSTICS FOR DETECTION, MONITORING AND MANAGEMENT OF INSECT PESTS

Forest and agro-ecosystems are the main natural bioresources which provides support to human livelihoods. ‘Indian False Vampire bats’ are the important components of these ecosystems as primary consumers of large sized nocturnal insects and small vertebrates, there by fulfill key ecosystem services as bio-control agents. Flight has enabled them to exploit a variety of foraging niches inaccessible to other mammals. Ecomorphological and the dietary selection study on false vampire bats suggest they are the carnivorous bats and perform crucial role as pest managers in the ecosystem. The nocturnal foraging behaviour, echolocation capability, dentition and flight manoeuvrability of these bat species are the adaptations that enhance their ability to capture nocturnal prey items. Undoubtedly, they are the most gregarious and successful group of beneficial animals to the ecosystem. Their population should be preserved for the benefit to conserve sustainable development of the ecosystem. The Indian false vampire bat conservation will not only replenish the ecosystem but also aid the forest floral health management and reduce the usage of pesticides in the agro ecosystem. Key words: Ecosystems, Bio-control agents, Foraging niches, False vampire, Health management

Hayman’s graphical analysis of yield, quality and their components traits in rice (Oryza sativa L.) under coastal agro ecosystem

Six × six full diallel mating involving six parents viz., (P1) ADT 37, (P2) ADT 43, (P3) ADT 45, (P4) ASD 16, (P5) CO51 and (P6) CO47 was effected to evolve 30 hybrids in rice crop. The six parents along with their 30 F1 hybrids were evaluated for ten agronomic traits viz days to 50 per cent flowering, plant height at maturity, the number of productive tillers per plant, panicle length, the number of filled seeds per panicle, seed length, seed breadth, seed L/B ratio, hundred seed weight and seed yield per plant. The traits viz., seed length and seed L/B ratio were controlled by complete dominance. Incomplete dominance was found to operating in the expression of the traits viz., the number of filled seeds per panicle and seed yield per plant. Partial dominance can be had as semi additivity. On the other hand, the traits viz., days to 50 per cent flowering, plant height at maturity, panicle length, seed breadth and hundred seed weight were controlled by over dominance. Apart from this amphi directional dominance was well evidenced from the correlation coefficient of Yr and Wr – Vr as well as Vr – Wr graph. It is earnestly advised to inter-cross among the parents to evolve high heterotic lines and/or improved populations. Key wordsRice, Vr-Wr graphical analysis, Coastal salinity.

Phytotoxic evaluation of neonicotinoid imidacloprid and cadmium alone and in combination on tomato (Solanum lycopersicum L.).

Neonicotinoids and heavy metals pollution exist simultaneously in agro ecosystem. However, little is known about their combined ecotoxicological effects on non-target crop plants. We have selected imidacloprid (IMI) and cadmium (Cd), applied alone and in combination, to evaluate their effect on growth, physiological and biochemical parameters of tomato. Results showed that the single application of contaminants (IMI and/or Cd) adversely affected both the growth and chlorophyll pigment, and Cd alone application was more phytotoxic than IMI. However, their combined action aggravated the inhibitory effect and indicate a synergistic effect, but it exerted antagonistic effects on chlorophyll pigment inhibition compared with IMI and Cd alone treatments. Both chemicals increased hydrogen peroxide level and generated lipid peroxidation, and the co-contamination exacerbates oxidative stress by their synergistic effect. Those results implicate that disturbance of cellular redox status is the plausible mechanism for IMI and Cd induced toxicity. In conclusion, the single or combined IMI and Cd cause negative effects on tomatoes.