The canopy storage of CO2, latent heat, and sensible heat within agricultural crops has not yet been fully examined, particularly on small farms situated in complex terrain. Reported canopy storage terms are consistently smaller than those found in forest ecosystems, such that they are often neglected. Our multiport profile system has been developed to examine these storage terms. The system sequentially samples air from four heights to a single non-dispersive Infrared Gas Analyzer (IRGA). Following laboratory testing, the system has been field proven in an east Tennessee maize crop in 2023. The new system enables quantifications of CO2, latent and sensible heat atmospheric storage terms and, with supporting temperature measurements, allows improved examination of the surface heat energy budget and the net air-surface exchange of CO2. It offers a valuable tool for a better understanding of gas-energy fluxes on small farms on topographically varied landscapes.

Two complete years of surface boundary layer observations above an agricultural field in Eastern Tennessee are used to quantify soil carbon dioxide (CO2) efflux rates without the use of chambers. The period of study includes two complete growing seasons of maize. Nighttime observations of the accumulation of CO2 in the layer of the atmosphere closest to the ground are employed, from which periods are selected to avoid sporadic incursions of air and turbulence from aloft. Observations reveal that the vertical extent of the atmospheric pools of CO2 increased through the night and reached heights estimated to sometimes exceed 10 m, particularly when the maize crops were fully grown. The time sequence of measurements indicates an effective soil microbial activation temperature of 12 to 15 degrees C, with efflux rates (measured over 10-min periods) exceeding 10 mu mol m(-2) s(-1) in the peak of the summer and dropping to below 0.5 mu mol m(-2) s(-1) in midwinter. When the crop was most rapidly growing, the efflux rates increased by a factor of about 2.5 for a 10 degrees C soil temperature increase (i.e. Q10 approximate to 2.5. The analysis assumes the relevance of classical stable boundary layer theory supported by recent field studies such that concentrations of CO2 decrease linearly with height in strongly stable stratification when CO2 accumulation is observed. The analysis also depends on the availability of CO2 measurements made close to the top of the vegetative canopy (in the present case, often native weeds outside the maize growing seasons). The measurements show that the accumulation of CO2 can be confined within the layer of air below the height at which conventional eddy covariance sensors are deployed.

While the use of three-dimensional sonic anemometers for eddy covariance is well established, there remain questions about its deployment and consequent data analysis. Convention has largely accepted that coordinates must be rotated so that the corrected transverse and vertical mean velocities become zero. In non -ideal terrain, a planar fit coordinate rotation is widely accepted. However, if the coordinate system changes through time, such as in a rapidly growing maize canopy, or is affected by the local topography, finding temporally and directionally stable regions for a reference point is crucial for flux estimation. A model -based recursive partitioning (MOB) algorithm is proposed to answer this problem. The algorithm creates individual wind sectors and accounts for temporal or spatially dependent variables that may affect planar fits. A cross -validation fitting procedure of the MOB algorithm has proved crucial in identifying variables that influence the choice among different parametric models, such as day of year, solar altitude, and wind direction. Momentum exchange is the most sensitive to alternative coordinate rotation systems, especially in stable conditions. The MOB methodology would be most useful during these conditions. The analyses presented here show that in quantifying scalar fluxes during the day, especially in the case of sensible heat flux and by extension to evapotranspiration and carbon dioxide exchange, there is little need for coordinate rotation if the sensors were aligned with the vertical parallel to gravity.

Intensive cultivation is a threat to soil health. Holistic management strategies are necessary to rejuvenate soil health. Farmyard manure (FYM) application is an alternative option to rejuvenate soil health and crop productivity. A short-term field study was conducted at UAF-Pakistan to evaluate the co-application of FYM and inorganic fertilizer (Di-ammonium Phosphate; DAP) for rejuvenation of soil health and maize productivity. Treatments included four levels of phosphorus (P) at a rate of 0, 90, 120, and 150 Kg ha-1 alone and in combination with two levels of FYM with the rate of 0 and 10 tons ha-1 in two-factor randomized complete block design with three replicates. Total eight treatments were maintained as T1 (control), T2 (90 Kg ha-1 P), T3 (120 Kg ha-1 P), T4 (150 Kg ha-1 P), T5 (10 tons ha-1 FYM), T6 (90 Kg ha-1 P and 10 tons ha-1 FYM), T7 (120 Kg ha-1 and 10 tons ha-1 FYM), and T8 (150 Kg ha-1 P and 10 tons ha-1 FYM). Data analysis showed that treatment T8 significantly (P <= .005) improved the plant height (15.31%), cob length (21.33%), cob weight (36.92%), 1000 grains weight (4.89%), grain yield (31.21%), PUE (39%), and soil physical properties over control. Overall, we concluded integrated application of FYM and DAP increases nutrient use efficiency and maize productivity.

Download This Paper Open PDF in Browser Add Paper to My Library Share: Permalink Using these links will ensure access to this page indefinitely Copy URL Copy DOI

Globally, rejuvenation of soil health is a major concern due to the continuous loss of soil fertility and productivity. Soil degradation decreases crop yields and threatens global food security. Improper use of chemical fertilizers coupled with intensive cultivation further reduces both soil health and crop yields. Plants require several nutrients in varying ratios that are essential for the plant to complete a healthy growth and development cycle. Soil, water, and air are the sources of these essential macro- and micro-nutrients needed to complete plant vegetative and reproductive cycles. Among the essential macro-nutrients, nitrogen (N) plays a significant in non-legume species and without sufficient plant access to N lower yields result. While silicon (Si) is the 2nd most abundant element in the Earth’s crust and is the backbone of soil silicate minerals, it is an essential micro-nutrient for some plants. Silicon is just beginning to be recognized as an important micronutrient to some plant species and, while it is quite abundant, Si is often not readily available for plant uptake. The manufacturing cost of synthetic silica-based fertilizers is high, while absorption of silica is quite slow in soil for many plants. Rhizosphere biological weathering processes includes microbial solubilization processes that increase the dissolution of minerals and increases Si availability for plant uptake. Therefore, an important strategy to improve plant silicon uptake could be field application of Si-solubilizing bacteria. In this review, we evaluate the role of Si in seed germination, growth, and morphological development and crop yield under various biotic and abiotic stresses, different pools and fluxes of silicon (Si) in soil, and the bacterial genera of the silicon solubilizing microorganisms. We also elaborate on the detailed mechanisms of Si-solubilizing/mobilizing bacteria involved in silicate dissolution and uptake by a plant in soil. Last, we discuss the potential of silicon and silicon solubilizing/mobilizing to achieve environmentally friendly and sustainable crop production.

The need to anticipate high risk of exposure following the generation of a cloud of cold and dense gas beneath a forest canopy introduces a need to examine the processes facilitating exchange with the air above the canopy. It is the concentrations in this above-canopy air that are used to initialize many dispersion models and these concentrations are lower than would be expected if no canopy were present. In the lack of direct experimental studies of trans-canopy dilution in a forested environment, results from a variety of related experiments are used here to illustrate the complexity of the problem and to derive a first-order assessment of the extent of expected dilution. The focus is on the dense gas clouds following accidents involving liquid chlorine, ammonia and carbon dioxide. It is concluded that the dilution would result in above-canopy concentrations between 2% and 50% of average sub-canopy levels, depending on site-specific circumstances. It is also concluded that the relative importance of the various contributing processes is such that detailed incorporation of them in dispersion models would constitute an unjustified complexity unless definitive experimental observations are available. Instead, the consequences of the issues now considered might best be accommodated by reducing predicted downwind concentrations by a factor of about ten with a corresponding extension of the duration of the dispersion event.

In Tunisia, climate change impacts that lead to the degradation of soil resources are considered to be a major limiting factor on socio-economic development. These impacts are exacerbated by the intensive plowing and cultivation practices used by Tunisian farmers, which expedite the depletion of soil organic matter (SOM), leading to changes in the physio-chemical properties of soil and consequently promoting soil erosion. In fact, the decrease in soil organic carbon (SOC) stocks affects soil’s fertility and the ability to regulate climate change. The objective of this study, which was conducted in Le Krib in the Siliana region of northwestern Tunisia, was to evaluate the effects of two cropping systems, consisting of durum wheat (Triticum aestivum) and oats (Avena sativa), and two types of tillage, no-till (NT) and mouldboard plowing (MP), on different soil aggregate classes (>2000 µm, 2000–250 µm, 250–180 µm, 180–53 µm and <53 µm) and soil physio-chemical properties, as well as the resulting effects on the carbon and nitrogen concentrations in these aggregates. The results showed that the carbon content of all soil aggregate classes was influenced by interactions between the previous crop and tillage regime. The clay-silt fraction had higher carbon concentrations under no-till and mouldboard plowing management. Furthermore, the previous crop and tillage type and their interactions had significant effects on nitrogen concentrations in micro-aggregates. The highest nitrogen concentrations (2846.6 ppm) were found in micro-aggregates in soils where the previous crop was durum wheat and mouldboard plowing was used, while the lowest concentrations (1297 ppm) were obtained in soils where the previous crop was oats and mouldboard plowing was used.

Organic matter decomposition is a biochemical process with consequences affecting climate change and ecosystem productivity. Once decomposition begins, C is lost as CO2 or sequestered into more recalcitrant carbon difficult to further degradation. As microbial respiration releases carbon dioxide into the atmosphere, microbes act as gatekeepers in the whole process. Microbial activities were found to be the second largest CO2 emission source in the environment after human activities (industrialization), and research investigations suggest that this may have affected climate change over the past few decades. It is crucial to note that microbes are major contributors in the whole C cycle (decomposition, transformation, and stabilization). Therefore, imbalances in the C cycle might be causing changes in the entire carbon content of the ecosystem. The significance of microbes, especially soil bacteria in the terrestrial carbon cycle requires more attention. This review focuses on the factors that affect microorganism behavior during the breakdown of organic materials. The key factors affecting the microbial degradation processes are the quality of the input material, nitrogen, temperature, and moisture content. In this review, we suggest that to address global climate change and its effects on agricultural systems and vice versa, there is a need to double-up on efforts and conduct new research studies to further evaluate the potential of microbial communities to reduce their contribution to terrestrial carbon emission.

Citrus production is affected globally by several environmental stresses. Some citrus-producing regions suffer from severe ecological abiotic stresses, including cold, soil salinity and sodicity, extreme temperature, and drought. These abiotic stresses can alleviate the growth, fruit yield, and quality of citrus. Strategies that attempt to sustain and increase tolerance of citrus against the negative effect of abiotic stresses are the use of antiperspirant compounds, phytohormones, synthetic and natural growth regulators, soil and plant moisture retaining tools and structures, nutrition management, application of organic fertilizers, rootstocks breeding in citriculture, and others. These strategies increase the yield and growth of the plant along with the relative improvement of the fruit quality during the growth and fruiting period, increasing the absorption of water and nutrients, the extensive accumulation of osmolytes and the increase of antioxidant enzymes, changes in the amount of signaling substances, and the expression of genes under stress, increase tolerance to abiotic stresses in citrus fruits. In this review, we tried to provide a summary of the abiotic stress management in citrus by literature.

One of the most significant threats to global health since the Second World War is the COVID-19 pandemic. Due to COVID-19 widespread social, environmental, economic, and health concerns. Other unfavourable factors also emerged, including increased trash brought on by high consumption of packaged foods, takeout meals, packaging from online shopping, and the one-time use of plastic products. Due to labour shortages and residents staying at home during mandatory lockdowns, city municipal administrations' collection and recycling capacities have decreased, frequently damaging the environment (air, water, and soil) and ecological and human systems. The COVID-19 challenges are more pronounced in unofficial settlements of developing nations, particularly for developing nations of the world, as their fundamental necessities, such as air quality, water quality, trash collection, sanitation, and home security, are either non-existent or difficult to obtain. According to reports, during the pandemic's peak days (20 August 2021 (741 K cases), 8 million tonnes of plastic garbage were created globally, and 25 thousand tonnes of this waste found its way into the ocean. This thorough analysis attempts to assess the indirect effects of COVID-19 on the environment, human systems, and water quality that pose dangers to people and potential remedies. Strong national initiatives could facilitate international efforts to attain environmental sustainability goals. Significant policies should be formulated like good quality air, pollution reduction, waste management, better sanitation system, and personal hygiene. This review paper also elaborated that further investigations are needed to investigate the magnitude of impact and other related factors for enhancement of human understanding of ecosystem to manage the water, environment and human encounter problems during epidemics/pandemics in near future.

An experiment conducted over a field of maize in Ohio during the growing season of 2015 provided measurements sufficient to compare among three methods for quantifying net ecosystem exchange of sensible heat, latent heat and carbon dioxide: eddy covariance (EC), the familiar Bowen ratio energy balance (BREB) method and a statistical procedure making use of surface temperature measurements by downward-looking infrared thermometry (the augmented Bowen ratio analysis - ABRA). EC and BREB yield run-by-run estimates of fluxes. The third method (ABRA) gives average values over prescribed ensembles of data. The Ohio observations support the conventional understanding that EC is the preferred methodology provided the site is large enough. Both BREB and ABRA can make use of measurements closer to the surface than EC, and hence are more suited for studies of small test plots. The ABRA method provides results agreeing with conventional BREB and EC in daytime except for periods near dawn and dusk when heat storage can be a substantial contributor in the surface heat energy budget. The unattributed heat storage in the morning found in analysis of observations made elsewhere is substantiated. It is concluded that the apparent heat storage term in the surface heat budget is most influenced by heating of crop biomass and the energy demands of photosynthesis. The comparisons provide clear evidence of the difficulties associated with application of all gradient-based methodologies at night (affecting both BREB and ABRA) when atmospheric stability often prohibits reliable association of fluxes with gradients. CO2 measurements reveal substantial differences among the three different methodologies (ABRA, BREB and EC), with EC appearing to be more robust and therefore preferred if the test area is large enough.

Excessive use of chemical fertilizers causing a serious threat to the agro-ecological system, developing resistance to pest and declining food safety.Under current scenario, the application of bio-organic nutrients sources become imperative to sustain the productivity of arable farming.Thus to study the possible use of bioorganic sources of nutrients in soil fertility, crop quality and saving the application cost of chemical fertilizer, a pot experiment was conducted in green-house at Land Resources Research Institute, NARC Islamabad.Integrated effects of bio-organic fertilizers such as phosphate solubilizing bacteria (PSB), vermicompost (VC) along with chemical fertilizer was investigated on soil-plant nutrients contents, growth and yield of tomato.Post-harvest results showed that the integrated use of bio-organic fertilizers with chemical fertilizer significantly increased the agronomic yield (Plant height and chlorophyll content) and fruit yield (Number of fruits, fruit weight, fruit diameter and yield) in tomato.The maximum plant height (161.24cm),chlorophyll contents (61.2), number of fruits ( 19), fruit weight (55g), fruit diameter (45.6a) and fruit yield (1.39 Kg/plant) were recorded in the treatment T5 where VC+PSB+75%RD were applied and minimum in treatment T1 (control).Treatment T5 has increased 117% fruit yield over control.The highest N (2.05% and 2.89%), P (0.33% and 0.50%) and K (2.32% and 6.67%) concentration in shoot and fruit of tomato respectively were found in treatment T5 (VC+PSB+75%RD).Similarly, in soil the highest N (4 mg Kg -1 ), P (0.66mg Kg -1 ) and K (3.53mg Kg -1 ) was recorded in treatment T6 (VC+PSB+100RD).Thus, study results recommend that the integrated use of bio-organic sources with appropriate proportion of chemical/synthetic fertilizers is best option of fertilizer savings and to achieve maximum benefits regarding quality and yield.

Conservation agriculture (CA) is an important technology in many developing countries for increasing smallholder agricultural productivity and conserving arable soils. This study focuses on the effect of CA on smallholder household wellbeing including productive assets, livestock and housing material quality. The study uses a survey of CA adopters and non-adopters in the Tete and Barue districts of Mozambique. Propensity score matching was used to develop two counterfactual groups; (1) non-adopters in the communities that had received technical assistance on implementing CA, and (2) non-adopting households in communities that had not received CA instruction. Results suggest that CA adopters realized higher levels of farm production assets and better quality housing materials. CA adoption had no association with livestock ownership. The findings are encouraging with respect to demonstrating the relationship between CA adoption and improvements in smallholder household wellbeing.

Sixty percent of the population of Pakistan is directly or indirectly reliant upon rain-fed agriculture that depends on predictable weather patterns. Global climatic change affects our agriculture and its impacts seem to increase daily. Pakistan produces wheat, rice, cotton, sugarcane, and maize and these crops are affected by climate change. Incessant escalation in earth temperatures globally is changing precipitation patterns including a shift in our monsoon season. These conditions affect agricultural production, farm livelihoods and agribusiness infrastructure that is leading to food insecurity and malnutrition among the farming communities. The aim of this review is to highlight the climate change impacts on Pakistan's agricultural sector, current risks, and mitigation potential to insure resilient agricultural practices that provide household food security.