Dry Zone Research Articles

Niche partitioning association of fungal genera correlated with lower Fusarium and fumonisin-B1 levels in maize

AbstractThrough partitioning of ecological niches, several fungi are able to coexist on the same host crop. In (partial) absence of niche partitioning, competitive exclusion among fungi can occur. Competitive exclusion is one of the bases for biocontrol. We investigated fungal correlations, in terms of relative abundance of the fungi, in pre-harvest maize, as a natural ecosystem model. Internal mycobiome fungal relative abundance of maize was used to establish correlations. The maize had been harvested from dry and wet agro-ecological zones of Zambia. The relative abundances of the fungal genera were determined using DNA amplicon sequencing. For this study, positive or absence of correlations between fungal genera signified good niche partitioning (co-existence), whereas negative correlations signified poor niche partitioning and potential for competitive exclusion. When species compete within one niche (competitive exclusion), we may expect to detect higher levels of mycotoxins—since mycotoxins are considered antagonistic agents aimed at defending or invading an ecological niche. To estimate the importance of mycotoxins in competitive exclusion, we measured the influence of the fungal correlations on levels of fumonisin-B1 (FB1) in the maize. FB1 data were derived from a previous study on the maize, determined by HPLC. Results showed that Sarocladium and Stenocarpella had the strongest significant negative correlation with Fusarium, suggesting poor niche partitioning and potential for antagonism of these genera with Fusarium. Furthermore, higher levels of Stenocarpella resonated with lower levels of FB1 and vice versa. It was also observed that, when Sarocladium was in low abundance (< 10%), the frequency of detection of higher levels of FB1 (> 100 µg kg−1) in the pre-harvest maize was highest.

Effect of Socio-Economic and Institutional Factors on Different Choices of Food Production System Practiced in Home Gardens: A Case Study in Mahakanumulla Village Tank Cascade System

The global existence of small-scale food production at the household level has a wide range in terms of physical appearance and utilization. Household, market, and field gardens can be identified as three types of home food producti on systems in a village tank cascade system (VTCS) in the dry zone of Sri Lanka. The variation in food producti on systems adapted in VTCS serves differently for the community either by providing nutrient requirements or ensuri ng financial or food security. It is important to understand the determinants of this variation to support the comm unity to adapt the most suitable food production system for their well-being. Based on random utility theory, this study analyzes the socio-economic and institutional factors affecting the choice of food production system practiced in home gardens in Mahakanumulla VTCS. A revealed preference approach was employed to identify the current home garden choice of households. The decision to have a ho usehold garden is more driven by socio-economic and institutional factors rather than market gardens and field gard ens. The effect of these factors on the decision to have a field garden is comparatively less. Using these results policymakers can predict farm management decisions of households and plan evidence-based strategic governm ent intervention to meet the daily nutrient requirement, ensure food security, and mitigate food scarcity.

Land Use Planning by Using GIS Techniques for Land Resource Inventory (LRI)- Northern Dry Zone of Karnataka, India

A study was conducted to determine land capability and to develop suitability map based on soil characteristics and climatic factors of watershed area. Detailed soil survey was carried out for Donur-2 micro watershed which comes under Basavana Bagewadi taluka of Vijayapura district, Karnataka to acquire the comprehensive data related land resources. From the study area, it was observed that based on soil-site characteristics four soil series were identified such as Dadamatti, Karjol, Nidoni and Rampur series and mapped into eight mapping units using GIS techniques. Donur-2 watershed area has been grouped into three land capability classes (LCC) viz., II, III and IV with four subclasses IIes, IIIs, IIIse and IVe. Subclass ‘e’ is due to major limitation of soil property group ‘e’ i.e erosion and slope, subclass ‘s’ is due to major limitations group ‘s’ having parameters like texture, depth and gravelliness. Subclass ‘se’ and ‘es’ are due to limitations of both soil parameters group above mentioned, however se and es are different classes which are based major limitation one of the group and followed by other group. Land capability map was developed using GIS techniques which indicates that out of 324.3 ha study area, LCC class IIIs covering major area i.e. 179 ha (55.12%), followed by class IIs i.e. 109 ha (33.51%), class IVe i.e. 23 ha (7.15%) and minor area of 7 ha (2.15%) area is covered by class IIIse. Soil suitability assessment indicates that majority of land is moderately suitable for agriculture. Class III soils are designated as moderately fertile agricultural land with significant constraints. However, with special conservation practices soils under class III can be used for cultivation of different crops. Class IV soils are categorized as reasonably fertile for intermittent cultivation, characterized by significant restrictions that limit crop options but with careful management practices these can be used for cultivation of arable crops. Therefore, the utilization of a land use planning approach (LUP) is instrumental in formulating tailored land resource management strategies to enhance land productivity, mitigate land degradation and attain sustainability goals.

Thermal performance analysis of hollow brick walls in hot and dry climatic zones

Thermal performance analysis of hollow brick walls in hot and dry climatic zones

Agro-climatic zone-wise drought hazards in Karnataka under historical and future climate scenarios

This study performed the spatio-temporal analysis of drought hazards across the agro-climatic zones (ACZs) of Karnataka under historical and future climate scenarios. The India Meteorological Department’s high-resolution gridded data for1989-2019 was used for historical drought occurrence analysis. Coordinated Regional Climate Downscaling Experiment ensemble data of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios were used for analysing future drought hazards in the near (2031-2060) and end term (2061-2099) periods. The standardised precipitation index (SPI) was used to calculate the frequency of droughts at different accumulation periods of 1, 3, 6, 9, and 12 months. Subsequently, the ACZ-wise drought hazard index (DHI) was calculated and mapped geospatially using ArcGIS. The results indicated that moderate drought events have the highest frequencies of occurrence, followed by severe and extreme drought events for all accumulation periods. During 1989-2019, 54.8%, 28.3% and 16.7% of droughts were moderate, severe, and extreme, respectively. An increase of 2.6% and 2.4% in the frequency of moderate droughts is projected under the RCP4.5 and 8.5 scenarios, respectively, in the end term. Under both historical and future climate scenarios, a high frequency of extreme droughts was observed in the long accumulation periods (SPI-9 and SPI-12), whereas the frequency of moderate droughts was observed to be high in the short accumulation periods (SPI-1 and          SPI-3). Under the historical scenario, the frequency of droughts in the extreme category was high in the southern transition, central dry, and north eastern dry zones, severe category in the northern dry, southern transition, and coastal zones, and moderate category in the north transition, hill, and southern dry zones. Among the 30 districts of Karnataka, Chitradurga, Udupi, Tumakuru, Ballari, Koppala, Raichuruand Gadaga districts have very high DHI. This study sheds light on the potential consequences of climate change on drought scenarios in the Karnataka state’s agro-climate zones and urges for zone specific drought adaptation and mitigation strategies to strengthen the State resilience.

Study on Sheep Flock Composition and Employment Generation of Kenguri Sheep Farmers in Yadgir, Karnataka

The valuable factors regarding Kenguri sheep flock composition and farmers employment generation were computed during the study. From both intensive and extensive rearing systems 20 farms were chosen randomly on accessibility basis from- Northern Eastern dry agro-climatic zone i.e., Yadgir district of Karnataka, India. The analysis was performed from January to February in the year 2022, for a period of 2 months. The main components of this work were tabulated by structured proforma by calculating mean, standard deviation and P-value. The total flock size was more intensive rearing system (270.46) when compared to extensive rearing system (122.15) and the other constituents of sheep flock were better seen in intensive rearing system than that of extensive rearing system. The sheep farmers have spent more time for feeding and watering of adults (1.75 and 1.60) hrs and lambs (1.55 and 1.45) hrs, followed by health care (1.17 and 1.10) hrs in intensive and extensive rearing systems, respectively, than other activities. As the flock size and employment play a major role in socio-economic profile of marginal farmers, so this type of evaluation uplifts the sheep farmers for more such rearing and breeding ventures in coming days.

Clouds and plant ecophysiology: missing links for understanding climate change impacts

Observations and models indicate that human activity is altering cloud patterns on a global scale. Clouds impact incident visible and infrared radiation during both day and night, driving daily and seasonal variability in plant temperatures—a fundamental driver of all physiological processes. To understand the impacts of changing cloud patterns on essential plant-based processes such as carbon sequestration and food production, changes in local cloud regimes must be linked, via ecophysiology, with affected plant systems. This review provides a comprehensive treatment of cloud effects (apart from precipitation) on fundamental ecophysiological processes that serve as the basis of plant growth and reproduction. The radiative effects of major cloud types (cumulus, stratus, cirrus) are differentiated, as well as their relative impacts on plant microclimate and physiology. Cloud regimes of major climate zones (tropical, subtropical, temperate, polar) are superimposed over recent changes in cloud cover and primary productivity. The most robust trends in changing global cloud patterns include: (i) the tropical rain belt (comprised mostly of deep convective clouds) is narrowing, shifting latitudinally, and strengthening, corresponding with shorter but more intense rainy seasons, increased clouds and precipitation in some parts of the tropics, and decreases in others; (ii) tropical cyclones are increasing in intensity and migrating poleward; (iii) subtropical dry zones are expanding, resulting in fewer clouds and drier conditions at these latitudes; (iv) summer mid-latitude storm tracks are weakening and migrating poleward, and clouds in temperate regions are decreasing; and (v) clouds over the Arctic are increasing. A reduction in coastal fog and low clouds (including those associated with montane cloud forests) have also been observed, although these trends can be partially attributed to local patterns of deforestation, urbanization, and/or reductions in aerosols associated with clean air initiatives. We conclude by highlighting gaps in the cloud-ecophysiology literature in order to encourage future research in this under-studied area.

Assessment and Mapping of Soils Erosion and Crop Loss by Impact of Heavy Rainfall in Northern Dry Zone of Karnataka, India

Assessment and Mapping of Soils Erosion and Crop Loss by Impact of Heavy Rainfall in Northern Dry Zone of Karnataka, India

Studies on the Sex Ratio of Different Mango Varieties under the Northern Dry Zone of Karnataka

An investigation was carried out to evaluate different cultivars of mango for their performance, growth, and flowering under the northern dry zone of Karnataka. Tree height, canopy volume and trunk girth were maximum in Baneshan, while Kadar recorded maximum tree spread. Baneshan were the first to come into full bloom, and Dashehari were recorded maximum panicles per plant. The maximum number of fruits per panicle at harvest was found in Kesar. The maximum fruit set per cent was observed in Totapuri

Characteristics and Estimation of Dew in the Loess Hilly Region of Northern Shaanxi Province, China

As a non-precipitation water source, dew is important for plant and animal survival and crop production in arid and water-scarce areas. This study assessed the amount of dew in a dry zone in a long-term (2016 to 2022) field observation experiment at the Ansai Experimental Station, a typical loess hilly area in China. Dew primarily occurred in summer and autumn, with a frequency of >50%. The average annual dew amount was 29.20 mm, with an average annual rainfall of 641.8 mm. The average annual dew-to-rain ratio was 4.58%, and the average annual number of dew days was 143.6 d/a. The surface soil moisture content increased by approximately 1.02% with increasing dew amounts. The change in the soil moisture at a 5 cm depth was 0.14% on average and lagged substantially by 1 h. Using the Beysens model, the annual estimated and measured dew amounts in 2022 were 25.27 and 29.84 mm, respectively, and the annual normalized root mean square deviation (NRMSD) was 0.17. Thus, the Beysens model evaluated the dew amount in the study area well at the monthly and annual scales. The quantification of dew resources can provide support for the development, utilization, and management of limited water resources in arid areas, promoting more accurate decision-making for the sustainable development of water resources in the future.

Collective Study on Housing Management Practices of Kenguri Sheep Farmers under Intensive and Extensive Rearing Systems in Yadgir District of Karnataka, India

The main domains of housing management practices followed by Kenguri sheep farmers were analyzed during the research. Twenty sheep farms in intensive and extensive were pointed out based on the accessibility in the respective study location Yadgir (Northern Eastern dry agro-climatic zone) district of Karnataka, India. The examination was carried out during the months of January to February in the year 2022. The objectives of housing practices were assessed by computing frequency percentage values and average descriptive values. The majority of intensive sheep farmers had wooden type of flooring (60.00%) and whereas, mud flooring (100.00%) is the only option for extensive sheep farmers. All intensive sheep farms had galvanized roofing (100.00%), in contrast all extensive sheep farms were with no roofing. Sheep in intensive rearing had trough water sources (45.00%) majorly and in extensive rearing they had natural water source (70.00%) accessibility. Most of the intensive sheep farmers maintained proper commercial feed (60.00%) access for the sheep, but fodder (65.00%) was the key food type for sheep reared under an extensive system. The advantage of fans for better ventilation (40.00%) was seen in intensive rearing systems, whereas, only natural ventilation (100.00%) was observed in extensive rearing system. The good space availability and pen dimensions are the only concerns with an intensive rearing system. The outcomes of this work will help the sheep farmers become accustomed to the better housing management practices in the near times.

Evaluation of the drought resilience of indigenous irrigation water systems: a case study of dry zone Sri Lanka

The wave of modernization and globalization in the last century has rapidly involved a technological paradigm shift from indigenous irrigation water systems to modern systems in arid regions. Despite interest in the drought resilience of indigenous water systems, the impact of this paradigm shift on drought resilience remains poorly understood because previous studies have focused on fixed irrigation water systems. To fill this gap, we investigated the drought resilience of an indigenous and modern irrigation water system that coexists in the drought-prone Mahaweli H region of the Sri Lankan dry zone. To explain drought resilience, we quantified the historical irrigation system performance (1985–2021) of both water systems using the water duty indicator (i.e., the volume of water required to cultivate a unit land area). The statistical Pettitt test was used to detect significant change points in the time series of water duty, and we divided the time line into few periods based on the change points. Furthermore, a quantitative trend analysis of several socio-hydrological variables and a qualitative analysis of their socio-hydrological backgrounds with triggers of water duty were conducted to explain drought resilience path dependency in modern and indigenous water systems. The results indicated a higher drought resilience is embedded in the indigenous system as the mean water duty increment in drought years compared to non-drought years is 16.4% for the indigenous system and 58.3% for the modern system. In addition, drought resilience pathways that elucidated by water duty change points also demonstrated that indigenous water system features a higher drought resilience compared to the modern water system. The findings of this comparative study can contribute to the design of drought resilience improvement strategies in arid region irrigation water systems in a more comprehensive manner.

Evaluation of chrysanthemum (Dendranthema grandiflora Tzvelve) varieties for growth, quality and yield under eastern dry zones of Karnataka

Evaluation of chrysanthemum (Dendranthema grandiflora Tzvelve) varieties for growth, quality and yield under eastern dry zones of Karnataka

Growth, yield, yield indices and system productivity of Pigeonpea as influenced by pigeonpea-based intercropping system in eastern dry zone of Karnataka

Growth, yield, yield indices and system productivity of Pigeonpea as influenced by pigeonpea-based intercropping system in eastern dry zone of Karnataka

Demonstration of Dicoccum wheat variety DDK-1029 under Northern dry zone of Karnataka

Demonstration of Dicoccum wheat variety DDK-1029 under Northern dry zone of Karnataka

Impact of manuring and fertilization over long term on soil available plant nutrients in eastern dry zone of Karnataka

Impact of manuring and fertilization over long term on soil available plant nutrients in eastern dry zone of Karnataka

Rubroscirus karnatakaensis sp. nov. and redescription of R. sinensis Fan (Acari: Cunaxidae) from plants in India

Two species of Rubroscirus (Acari: Cunaxidae) were collected from the Eastern dry zone of Karnataka, India. Females and males of Rubroscirus sinensis Fan, 1992, collected from five different species of plants, are recorded for the first time from India and redescribed. The female of Rubroscirus karnatakaensis sp. nov. collected on three species of plants is described. This bring the total number of Rubroscirus species from India to three.

Effects of agro-climatic zone, soil orders, and irrigation types on the exchangeable cadmium in paddy soils

Even though the concentrations of the total cadmium (Cd) in paddy soils from different countries have been reported, the exchangeable Cd (Ex-Cd) concentration in these soils are unknown despite its importance in agriculture. This study was conducted with a total of 5,460 soil samples collected in Sri Lanka, representing six agro-climatic zones (ACZ), six soil orders, and three irrigation types. The exchangeable Cd concentration in soil samples was extracted using 0.01 M CaCl2 and analyzed using an inductively coupled plasma-mass spectrophotometry (ICP-MS). The Ex-Cd ranged between <0.31-163 μg kg−1 with mean and median concentrations of 14.05 and 8.98 μg kg−1, respectively, and was affected by both agro-climatic and soil conditions. Samples collected from the Wet zone, particularly the Wet zone Low country, had higher Ex-Cd (24.1±1.0 μg kg−1) than that those from the Dry zone Low country (11.6±0.2 μg kg−1) (p<0.05). Among the soil orders, Histosols (21.3±3.0 μg kg−1) and Inceptisols (19.5±0.9 μg kg−1) had the highest Cd concentration while Vertisols had the lowest (6.3±0.4 μg kg−1) (p<0.05). The irrigation types only affected Ex-Cd in Dry zone Low country (p<0.05), but not in other agro-climatic zones. Overall, the consideration of agro-climatic zones, soil orders, and irrigation types is needed when implementing agronomic strategies to mitigate the risk associated with Cd accumulation in paddy fields.

Studies on Nano DAP on Growth, Yield and Quality of Chickpeas under Rainfed Conditions of Northeastern Dry Zone of Karnataka

A field experiment was conducted at Zonal Agricultural Research Station, Kalaburagi, during rabi season of 2022-23 to study the growth and yield of chickpea as influenced by fertilizers and foliar application of nano DAP. The experiment included four levels of RDF in main plots viz., 0% RDF (M1), 50% RDF (M2), 75% RDF (M3) and 100% RDF (M3) and three levels of nano DAP sprays in subplots viz., 2 ml litre-1 of water (S1), 4 ml litre-1 of water (S2), and Seed treatment with Nano DAP @ 5ml kg-1 seeds (S3) laid out in split plot design. The results revealed that among all the treatment combinations,100% RDF + nano DAP @ 4 ml litre-1 of water recorded significantly higher growth, parameters viz., plant height (37.56 cm), number of primary branches plant-1 (6.86), leaf area plant-1 (2.58 dm2 plant-1), LAI (0.86) and total dry matter accumulation in plant (20.24 g plant-1) at harvest.; yield parameters viz., number of pods plant-1 (23.52), seed weight per plant (9.16 g), 100 seed weight (22.30 g), haulm yield (3550kg ha-1), seed yield (1868 kg ha-1), quality parameters viz., protein content (19.31%) and protein yield (361.15 kg ha-1). This treatment was however found on par with 75 per cent RDF + foliar spray of nano  DAP @ 4 ml litre-1 of water which recorded on par growth parameters viz., plant height (36.56 cm), number of primary branches plant-1 (6.59), leaf area plant-1 (2.51 dm2 plant-1), LAI (0.84), chlorophyll content  (57.47) and total dry matter accumulation by plant (19.80 g plant-1) at harvest.; yield parameters viz., number of pods plant-1 (23.25), seed weight per plant (9.04 g), 100 seed weight (21.16 g), haulm yield (3504kg ha-1), seed yield (1796 kg ha-1), protein content (19.04%) and protein yield (342.52 kg ha-1).

Agricultural drought assessment in dry zones of Tolima, Colombia, using an approach based on water balance and vegetation water stress

Soil water balance is an essential element to consider for the management of droughts and agricultural land use. It is important to evaluate the water consumption of a crop in each of its phenological phases and the status of water reserves during critical hydrologic periods. This study developed an agricultural drought index (Standardized Soil Moisture Deficit Index - SMODI) conceptualized with a water balance model considering the vegetation stress caused by soil moisture deficit. This contribution was based on meteorological information, soil moisture from satellite images, hydrophysical properties of the soil and crop evapotranspiration. Information from 61 weather stations located in the dry zone of Tolima was used for estimating the water balance. SMODI was compared with the most common drought indexes: Standardized Precipitation - Evapotranspiration Index (SPEI), the Palmer Self-Calibrated Drought Index (scPDSI), and other eleven macroclimatic indexes. Pearson's correlation coefficients (r), Tukey's test, and analysis of variance were applied to analyze the degree of association between SMODI and the contrasting indexes on a quarterly basis. SMODI considers factors influencing soil moisture distribution and retention and the water stress thresholds that plants have evolved to withstand during drought periods. Consequently, this integrated approach enhances the assessment of agricultural drought by relying on pertinent physical processes. SMODI identified extremely dry, severe, moderate and normal drought 5 %, 3 %, 20 % and 72 % respectively conditions in areas characterized by Entisols, Inceptisols, and Andisols, where rice and fruit crops and pasturelands are cultivated. The SMODI has a good correlation with macroclimatic indexes (0.70 < r < 0.74).