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Soil moisture has continued to occupy the forefront of several interdisciplinary debates globally, particularly in agriculture, climatology, hydrology and civil engineering for several decades. Climate smart and precision farming depend extensively on knowledge of the volumetric pattern and trend in water content of the soil particularly at the root zone. This study evaluated the temporal and spatial variation of soil moisture (0–40 cm depth) in Etsako West Local Government Area, Edo State, Nigeria. It used time series soil moisture data (1982–2019) sourced from the Famine Early Warning Systems Network (FEWS NET) and Land Data Assimilation System (FLDAS). Descriptive and inferential statistics as well as geographical information system (GIS) were used in data analysis. Results showed that Nitisols (Iyuku) had mean soil moisture of 9.0285 m3/m3, Lixisols (Ugieda) recorded 9.0574 m3/m3 whereas Acrisols (Idegun) was 9.1307 m3/m3. September emerged as month with peak soil moisture of 0.9 m3/m3 in Lixisols and Acrisols while January and February were the months with the lowest value of 0.5 m3/m3 across the three soil classes. Soil moisture in all the soil classes also exhibited a rising trend in the climatic period with annual increase of 0.002 m3/m3 in Nitisols, 0.002 m3/m3 in Lixisols and 0.001 m3/m3 in Acrisols. Temporal pattern of soil moisture was not statistically significance while spatial variation was statistical significant across the soil classes. In a spatial data-driven society, this study has therefore unlocks the potentials of GIS and remote sensing resources in assessing global environmental change indicators in data sparse regions.

Stomatal conductance (SC) and chlorophyll concentration (CC) are sensitive to soil matric suction (ψ). The relationship between these two plant parameters and ψ in the root zone can help understand the water uptake efficiency and photosynthetic capacity of a plant. This paper aims to quantify the relationships between SC and CC with ψ, for Schefflera arboricola grown in compacted bare silty sand and biochar amended soil (BAS). Plant parameters (SC, CC, leaf area (LA), root length (RL)) and ψ were regularly monitored in an atmospheric controlled room. The maximum recorded SC was greater in BAS than that in bare soil due to the higher water demand of LA. Based on measured data upon evapotranspiration, two equations are proposed to interpret the effects of ψ on plant water uptake and photosynthesis. A fitting equation is established to relate normalized SC with ψ to identify a threshold suction ([Formula: see text]; indicator of drought stress resistance). The magnitude of [Formula: see text] is found to be mainly dependent on LA/RL ratio and root ends. Furthermore, a new relationship between CC and ψ is observed and developed. A decrease in CC at higher ψ is attributed to leaf senescence and stomatal closure, restricting plant to produce more chlorophyll.

Increasing winter temperature in lower Gangetic Plain of India has put a threat to the cultivation of summer rice along with decreasing fresh water availability. Increasing ambient temperature also increase the soil temperature in the root zone of the crop. Thus, the effect of soil temperature over an optimum value may be detrimental for the root growth which turns into reduction of grain yield. Keeping in mind this situation, an experiment was carried out during 2014 and 2015 on summer rice in University Research Farm. Three transplanting dates and four irrigation regimes were chosen so that the crop experiences extreme weather as well as water stress condition. It is found that the mean soil temperature has a gradual increasing trend with advancement of crop growth. A significant and exponential increase in root weight was recorded with the increase in soil temperature. It is found that root growth was reduced when soil temperature increased beyond a critical value of 34 °C due to delayed transplanting and reduction of grain yield was noticed. So the summer-rice farmers are advised to complete transplanting within first fortnight of February to avoid yield reduction due to delay.

Dahlia (Dahlia ×hybrida) is an important floriculture crop that has gained popularity in recent years. Greenhouse growers have recently reported a phenomenon known as “dahlia decline,” that can affect potted dahlias in greenhouse production. The crop exhibits graying foliage, root decline, and plant death, and the phenomenon has reportedly caused partial or total crop loss and has no known initiating factor. We hypothesized that plant exposure to supraoptimal root-zone temperatures (RZTs) during production may decrease dahlia root quality, especially above 40 °C and could initiate dahlia decline. Because there is a lack of understanding on how supraoptimal RZT may impact dahlia growth and development, experiments were conducted to evaluate the effects of supraoptimal RZTs on seven dahlia cultivars in Spring 2019 and 2020. Dahlias were grown for 4 to 5 weeks in the greenhouse and then root zones were exposed to ≈22 (control), 35, 40, 45, or 50 °C using a water bath. Root quality was rated before treatment and rated weekly after the hot water bath treatment, along with vegetative growth parameters for 4 weeks. In both years, significant decline in root ratings were observed. ‘XXL Veracruz’ and ‘XXL Sunset’ average root ratings decreased after a 45 and 50 °C treatments in year 2 and both cultivars demonstrated increased root rating averages by 3 weeks after treatment. Cultivars exhibited a significant increase in root rating in the final observations when compared with root ratings taken 1 week posttreatment even if the initial decline after treatment was not significant. Overall plant height was significantly impacted, resulting in shorter heights in both years for all cultivars as treatment temperatures increased to 50 °C in comparison with the control and 35 °C, and a few cultivars exhibited significantly shorter height at 40 and 45 °C. Ultimately, our research did not show typical plant responses that were consistent with reported dahlia decline, but we were better able to characterize dahlia response to supraoptimal RZT.

Mine tailings expose the earth crust to environmental contamination necessitating to fix the metal and metalloid contaminants in the over burden soil, and rehabilitation of spoil dumps. The use of plants to stabilize and inactivate the potentially toxic compounds in such soil could be an effective low cost green technology. However, for its sustainable implementation necessary prerequisites are required that address collateral components of contamination of native environment, including contamination per se, physical soil degradation onsite and dispersal of particulate matter in the surrounding environment. A plant type that phytostabilizes the contaminants in the root zone with least translocation to shoot to avoid their recycling in the atmosphere, and morphological characteristics to physically stabilize the degraded soil to combat dispersion of its particulate matter, coupled with utilization of shoot zone for economic harvest, could help facilitate sustainability of such phyto-technology. Based on a case study of iron ore mine spoil dumps, it is suggested that selection of suitable genotypes of vetiver grass would not only minimize the toxicity level of iron in such soil, but also stabilize the degraded soil owing to high soil binding property of web forming roots. Utilization of aboveground biomass as safe fodder would ensure renewability and sustainability of such eco-plantations. The absorbed metal does not incur any genetic damage to shoots.

The sustainable development and utilization of saline-alkali land are closely related to holding fast the minimum cultivated land area of China. The change of soil salt in cotton field under long-term mulched drip irrigation (MDI) is connected with the development of the national cotton industry. From 2015 to 2019, five cotton fields with different applying years of MDI, which were reclaimed in 2004, 2008, 2010, 2012 and 2015 respectively and were saline-alkali wasteland before, were monitored continuously in the Manas River irrigation area of Xinjiang. By means of continuous location monitoring and spatial–temporal variability (For example, the monitoring data of cotton fields under MDI in 2004, 2008, 2010, 2012 and 2015, and in the year of 2015 were counted as 12, 8, 6, 4 and 1 years, respectively), the spatial–temporal variations of soil salt and ions in cotton field with 1-16a MDI technology were presented. The cotton growth characteristics and its main influencing factors were also analyzed in the study. The results showed that saline-alkali cotton field experienced changed from intensive saline soil to moderate saline soil and finally to non-saline soil under long-term MDI. The change of soil salt and the response of cotton growth to soil salt were divided into three typical stages. Firstly, soil desalinated rapidly in 1-4a MDI cotton field, which the annual average desalination rate was 24.93% in 0–100 cm soil layer (root zone). Additionally, the survival rate of cotton rocketed from 1.48% to 42.04%, and yield increased sharply from 72.43 kg ha−1 to 3075.90 kg ha−1. Soil desalination was lower in 5-11a MDI cotton field, which the annual average desalination rate was 10.92% at the root zone. The annual survival rate and yield of cotton increased by 6.26% and 5.18%, respectively. After 12a MDI, the soil salt in cotton field tended to be generally constant, which the average salt content in root zone was less than 2.49 g kg−1. The survival rate of cotton was stable above 90.39%, and the yield per unit area exceeded 5401.32 kg ha−1. Ions, sodium absorption ratio and Cl− and SO42− equivalent ratio (CSER) in cotton soil also decreased with the extension of MDI. Salt composition changed year by year, but the type of intensive saline soil had always been chloride-sulphate solonchak (0.2

Poor soil aeration can be the result of poor soil drainage, soil compaction, or flooding of the root zone, and tolerance to root hypoxia is determined by rootstock characteristics. Based on this assumption, we aimed to verify whether cherry rootstocks can be classified according to their tolerance to poorly aerated soils based on their root growth traits. Six cherry rootstocks, ‘Mazzard F12/1’, ‘Gisela 6’, ‘Colt’, ‘Maxma 14’, ‘Maxma 60’ and ‘Cab 6P’, were established in 300L containers under field conditions and they were evaluated. Three soils with different textures were selected to generate different air-filled porosities by controlling the volumetric water content: 21% (Ɛα21%), 16% (Ɛα16%) and 9% (Ɛα9%). Vegetative growth, photosynthetic parameters and fine root growth were measured during the 2013-2014 season. In soils with a low air content, Ɛα9%, ‘Colt’ and ‘Maxma 60’ rootstocks increased total fine root production by increasing root growth rates in the last phase. ‘Colt’ and ‘Maxma 60’ can be classified as tolerant rootstocks. In contrast, ‘Mazzard F12/1’ and ‘Gisela 6’ reduced shoot growth by 51.5% and 42.4% and reduced the maximum rate of photosynthesis (Amax) by 69% and 78%, respectively, compared with contrasting soil aeration, resulting in a reduction in total fine root output in poorly aerated soil. They were classified as sensitive rootstocks. Higher fine root production and lower root mortality were the major root traits of tolerance that improved photosynthetic performance and were associated with high photosynthetic capacity under a prolonged low oxygen content in the soil.

The controlled groundwater depth (CD) is a technique for increasing the yield and reducing water body's pollution. This research was conducted to investigate the effect of controlled groundwater depths and nitrogen levels on wheat yield, sub-irrigation, water productivity and aquatic environment. The treatments were three nitrogen fertilizer levels including 27, 227 and 327 kgN/ha and three groundwater depths including 60 cm (CD60), 90 cm (CD90) and 120 cm (CD120). The results showed that the wheat yield in CD60 was 10% lower than that in CD120 and in CD90 that it was 18% higher than that in CD120. The water productivity in CD60 and CD90 was 52.6% and 57.9% higher than that in CD120, respectively. Also, by increasing the nitrogen fertilizer level to 227 kgN/ha, the wheat yield and water productivity were increased. The drainage water in CD60 and CD90 was 59.2% and 35.7% lower than that in CD120, respectively. The nitrate leaching in CD60 and CD90 were 72.1% and 43.8% lower than that in CD120, respectively. In general, the optimum groundwater depth was 90 cm (CD90) with 227 kgN/ha. The groundwater depth higher than or less than 90 cm decreased the yield and water productivity and increased drainage water and nitrate leaching. The yield reduction in groundwater depth lower than 90 cm is due to lack of soil aeration (water logging) in root zone and in groundwater depth higher than 90 cm is due to lower groundwater contribution for supplying water requirement of wheat crop.

Problems of the rational use of water resources are of particular relevance now due to frequent use of resource-saving technologies in nursery gardens. Drip irrigation is considered one of the most promising methods to create favorable conditions for plant growth. The aim of this study is to develop a scientifically substantiated regime of drip irrigation of plum seedlings on soddy-podzolic soils to obtain high-quality planting material. A two-factor field experiment was performed in spring 2018. The factors analyzed included: (1) the drip irrigation regime (maintaining of the moisture content in the root zone in the ranges of 60–80, 70–90, and 80–100% of the field capacity) and (2) plum variety (Mashen’ka and Utro) engrafted on cherry plum stock. Drip irrigation resulted in uniform moistening of the root zone and saved irrigation water to two to three times as compared to sprinkling. The main portion of the total water amount consumed by seedlings in irrigated variants of the experiment consisted of irrigation water (from 55 to 67%) and atmospheric precipitation (from 14 to 29%). Biometric parameters (stem diameter, height, and leaf area) of 3-year-old seedlings grown under drip irrigation were 1.2–1.5 times greater as compared to seedlings in the control variant without watering. It is recommended to use the irrigation regime with maintaining soil moisture in the range of 80–100% of the field capacity for the rational use of irrigation water and for cultivation of high-quality plum planting material in the nursery. In the variant with maintaining soil moisture in the range of 70–90% of the field capacity, the amount of standard seedlings was by 1–2% smaller as compared to the variant with moisture content of 80–100% of the field capacity, and the irrigation rate is decreased by 59–206 m3/ha depending on conditions of the year.

The objective of this study was to investigate the capability of modifying the irrigation and nitrogen application rates as an adaptation to climate change, especially, increasing air temperature, using the Root Zone Water Quality Model (RZWQM2). Field experiments were conducted in the winter wheat season of 2015-2016 and 2019-2020 at the Rasheed County, south of Baghdad, Iraq. The effect of increasing air temperature on the water use efficiency, nitrogen use efficiency, and grain yield of wheat was assessed under different irrigation deficits and nitrogen application rates. Three levels of water depletion: 30, 50, and 70 of available water and four N application rates (0, 140, 200, and 260 kg N ha−1) were applied for winter wheat. Two temperature scenarios in the RZWQM2 were created for the study purpose. The first scenario was to add 2Co to the normal temperature, and the second scenario was to add 4Co to the normal temperature. Results showed that high irrigation levels presented better results than the low levels under projected temperature scenarios. However, all applied nitrogen rates presented similar results under projected temperature (2Co and 4Co scenarios). Therefore, modifying irrigation requirements is a workable adaption strategy to the increased temperature.

Soil moisture capacity improvement could be a solution to increase the water productivity under drought condition. In this study, a try has been made to evaluate the influence of the superabsorbent polymer as a soil humidifier to increase root zone moisture content for maize cultivation. Field experiments were established in the Gotvand region of Khuzestan province, Iran. Three treatments of Aquasorb 3005 application (0, 300, and 600 kg/ha) and four irrigation strategies were considered in three replications for two growing seasons of 2019 and 2020 (from March to July). Irrigation planning, cultivation costs, biomass, harvest index and canopy cover were measured at different time steps of the growing seasons to provide growth simulation models using AquaCrop software. Minimum error test showed that the use of Aquasorb 3005 increased the yield of the product at 1% confidence level. Moreover, the depth and timing of irrigation were optimized by whale optimization algorithm with the objective of maximization of biomass under the water resources and economic constraints. Results illustrated the influence of superabsorbent application and irrigation planning on the improvement of water productivity.

In this study, two models are computed which are modified penman's monteith and Hargreaves – Samani model. The essence is to provide qualitative information related to the antagonistic effect of climate change on sustainable crop production through qualitative understanding of evaporation and transpiration processes in simple term evapotranspiration (ETo). This is computed using climatic parameters obtained from Abubakar Tafawa Balewa University; Agro weather station, Bauchi for the period of three years. This describes the two processes of water loss on plants, at first, through transpiration and on another note, on the soil surface by evaporation. The study deduced a comparative analysis on aforementioned Methods to determine the evaporating power of the atmosphere in improving crops yield and production through estimating the amount of water needed at the root zone of the plant and also, the seasonal variation during the study. The result of this study shows a little deviation in the two models. The model based on Modified Penman's Monteith displays optimal evapotranspiration. This makes the model satisfy its creation for estimation of reference evapotranspiration. In May, June, September, and October for 2013-2015, high trends are recorded. While In July and August low trend was recorded between climatic parameter and the estimated evapotranspiration. The statistical analyses also show that there is a linear relationship between the two estimated models. In the above months, it shows that application of water is needed for the healthy growth of crops and improved crops yield

Goal. Based on the results to substantiate the need for a significant increase in legume crops in Ukraine on the basis of analysis of food and feed indicators of their seeds, the impact on soil quality and the environment. Material and methods. Field – determination of features of growth and development of plants, elements of seed productivity; biometric and measuring-weight – accounting of yield and total biomass; biochemical – determination of protein, fat and other components of seeds; statistical – variation, regression and analysis of variance. Results and discussion. The significant nutritional value of legume seeds, which is rich in high-quality protein with a high content of essential amino acids, isoflavones, essential micronutrients, is substantiated. It is distinguished by high taste, quickly swells and boils, has a pleasant aroma. This group of crops is able to fix nitrogen from the air, provide for their own needs and leave a significant amount of it in the soil for subsequent crop rotations. Legumes should be considered in the crop rotation system together with winter wheat as fallow crops. Their synergistic effect on subsequent crop rotations is explained by the peculiarity of the microflora of the root zone, where symbiotic and free-living bacteria are concentrated. Observations indicate the need to increase crops of pea, chickpea and lentil in Ukraine, as there are all the necessary conditions - adapted to insufficient moisture varieties, developed technology for their cultivation, accumulated positive experience for obtaining high yields. Conclusions. Based on our own results and analysis of the experience of many countries around the world revealed the importance of legumes for our country. Their role in providing high-quality food, improving soil quality, increasing the country’s export potential is noted

Plastic film mulch (PFM) was an important agricultural measure to promote crop production. It is important to reveal the patterns of root-associated microbiomes under PFM to enhance the basic knowledge in the agroecosystem. The microbial composition, assembly, and co-occurrence in four compartments (bulk soil, root zone, rhizosphere, and rhizoplane) under maize field adopting PFM and flat planting were analyzed at the V12 stage. The root phenotypic traits were measured to explore their interaction mechanisms with microbes. The compartment was the dominant factor shaping the bacterial communities, while fungal communities were recruited by treatment. With a variety of plant growth-promoting abilities, bacteria order SBR1013, S085, genera Aquicella, and fungi family Aspergillaceae, Laslosphaeriaceae, Hypocreaceae were identified significantly enriched by PFM across all compartments. PFM harbored a more stable and complex co-occurrence network than that of flat planting, and the Chitinophagales with the ability to utilize recalcitrant carbon was the keystone taxa while they were Sphingomonadales under flat planting. Root traits were found closely related to root-associated microbiomes, and interkingdom networks further revealed that the relationships between rhizoplane microbes and root weight/root length density were greatly enhanced by PFM compared to flat planting. PFM changed maize root traits and assembly, composition, and co-occurrence patterns of root-associated microbiomes, recruited specific taxa potentially benefit to plant growth. The interactions of root traits and microbes were strengthened by PFM. These findings enhanced understanding of root-soil interactions in the agroecosystem.

Nitrogen (N) is normally applied twice during sugarcane cultivation on Negros Island in the Philippines. As the first application is carried out during the early growth stage, there is a high possibility that N is not absorbed sufficiently by the sugarcane and a large amount of N may be leached with percolating water. To investigate this leaching, we monitored the vertical movement of soil water and soil solutes using GS3 dielectric moisture and electrical conductivity (EC) sensors in a sugarcane field on Negros Island. The monitoring was conducted after the first N application at different application rates (50% or 100% of the recommended rate) and timings (immediately or 30 days after planting [DAP]). The EC values increased when 100%-N was applied immediately after planting, indicating that N leached into the deeper soil layer. The monitoring results suggest that the applied N did not remain in the root zone (due to leaching) and was not replenished until the second application, when the absorption ability of the sugarcane was high. Conversely, when 100%-N was applied at 30 DAP, the applied N remained in the root zone until the second application. When 50%-N was applied at 30 DAP, the increase in EC was small compared to the 100%-N application. These results indicate that applying N immediately after planting at the recommended rate led to an insufficient nutrient supply for the sugarcane, as well as the loss of N fertiliser via leaching.

The salinity of soil is a crucial challenge for growers irrigating in semi-arid zones. To accomplish salinity, growers require information about salt's basis and processes of the salt mobility through the root zone. Soil salinity can be managed by exceptional irrigating farming practices including irrigation scheduling to leach down salts through the root zone. This study aimed at examining the salts movement in saline soil in a semi-arid region in Sindh, Pakistan. This field experiment was conducted during the summer of 2017 on a salt-affected land by using three irrigation treatments of canal water including T1 (7 day irrigation interval), T2 (14 day irrigation interval) and T3 (21 days irrigation interval) under 10, 9 and 8 cm depths of irrigation water, respectively. The texture of soil was silty clay loam having an electrical conductivity (EC) ranging from 7.73 to 20.69 dS/m. However, the pH of the soil ranged from 7.89 to 8.04. The findings of a two-way analysis of variance were consistent with the statistical examination of EC and pH data day- wise (7, 14 and 21 days) and depths-wise (10, 9 and 8 cm). Average reductions in the EC and pH of the soil were observed at 7 days interval and 10cm depth at P

The article describes a new modelling approach and module for soil salinity management. The two major objectives of the module are to simulate the seasonal course of the salinity of the soil solution in the active root zone of drip-irrigated crops to assist irrigators to optimise irrigation and salt leaching, and to help evaluate the salt fluxes in the deep percolating water for assessing the longer-term salt load of the irrigated crops on the regional ground and surface water resources. The module is based on the solutions of the DIDAS program for quasi-steady water flow and uptake for various drip irrigation scenarios, and on differentiating the applied water to evaporation from the soil surface, uptake by the plant roots, deep percolation through the root zone that leaches salt out of it, and deep percolation outside of the root zone that does not leach salts. After laying out the rationale behind the suggested approach and outlining the expressions used in the module for evaluating the salinity of the root zone, several sample computations, in silico experiments, are performed to illustrate the module functionality and its potential application, and to serve for sensitivity analysis of the system parameters. Additional investigation is needed into the adequacy of the suggested modelling approach and the developed module to simulate soil salinity in the active root zone.

This study was carried out in a private farm located in Gharbiya Governorate, the Nile Delta, Egypt. The study aimed to assess how far the alternative furrow application and deficit irrigation may improve irrigation indices and water productivity of Soybean. Two techniques of alternation were applied. The first is Standing Alternate furrow Irrigation (SAI), the second is Reciprocal Alternate furrow Irrigation (RAI). The two techniques were compared with Conventional furrow Irrigation (CI), at which, all furrows are conventionally irrigated per each irrigation (Control). Results revealed that irrigation requirements under both of (SAI) and (RAI) techniques s are significantly less than that with (CI). Surface runoff increased as the level of application increased. The significant difference was found only between (RAI) with the level of 50 % Etc. and the treatment of (CI) with the level of 100% Etc. The highest value of (Ea) was achieved with (RAI) and 75% ETc irrigation level while the lowest value was found with (CI) and 100% ETc irrigation level. The lowest values of actual ET were found (RAI) and 50% ETc irrigation level. Also, results indicated that produced yield of soybean varied significantly (P

Reducing nitrate leaching from agricultural land to aquifers has been a high priority concern for more than a half century. This study presents theory and observations of a threshold concentration of nitrate in the root zone (Cmax), which the leachate concentration increases at higher rates with increasing root-zone nitrate concentration. The value of Cmax is derived both by direct results from container experiments with varying nitrogen (N) fertigation and as a calibration parameter in N-transport models beneath commercial agricultural plots. For five different crops, Cmax ranged between 20 and 45 mg L-1 of NO3 -N derived from experiments and models. However, for lettuce (Lactuca sativa L.), which was irrigated with a large leaching fraction, Cmax could not be defined. In crops irrigated and fertilized in the warm/dry season (corn [Zea mays L.] and citrus), the experiments show a dramatic change in leachate-concentration slope, and simulations reveal a wide range of sensitivity of leachate NO3 -N concentration to Cmax. In annual crops irrigated and fertilized in the cool/wet season (e.g., potato [Solanum tuberosum L.] in a Mediterranean climate), the experiments show a distinct Cmax that is less dramatic than that of the summer-irrigated crops in the container experiment and a smaller impact of Cmax in N-transport models. The simulations show that, for summer-irrigated crops, maintaining fertigation at C

A tremendous increase in municipal solid waste (MSW) generation and its poor management is observed in almost all the developing countries. Landfilling, though undesirable, is an unavoidable disposal option with leachate generation and landfill gas (LFG) emissions as its major inescapable consequences. To evade these dismal outcomes of waste contentment, plant-soil based cover options are being studied widely. In the present study, an attempt was made to employ locally available plants for the phytoremediation of landfills. The experimental set-up was designed using 100 kg of MSW which was laid over with a thin soil layer of 30 cm. The efficiency of the laboratory-scale experimental set-up of 1 m3 volume was assessed in terms of trace element remediation and LFG oxidation. The initial and final parameters were finally assessed and compared. Plant species were found to develop a strong root zone, thereby reducing the infiltration of water into the waste mass. The present study showed a reduction in LFG emissions of 11.12%, 54.38%, and 32.12% in the deep zone, root zone, and topsoil zone, respectively. Furthermore, the study of the microbes, influencing soil chemical characteristics, could be helpful for designing an appropriate phytocover under diverse climatic conditions of India.

The lack of water resource in these past decades encourages the implementation of the precision agriculture system towards the sustainability in palm oil plantation. Therefore, it requires a specific information about the palm oil performance regarding the water balance system that affect the water consumption through the plant root water uptake. However, the prediction of root water uptake distribution is still a challenge. Another method to investigate the soil water dynamics under the plant root system is through the numerical simulations that are widely use to assess the soil water flow of the plant. In alignment with the idea of promoting the sustainable palm oil plantation, the investigation of root water uptake and water content under oil palm tree is highly demanding. As an introduction, through this study, it is find of interest to simulate the root water uptake and water content pattern of oil palm tree using the 2D simulation soil-water flow. The study was performed by applying the 2D simulation soil-water flow model to 17th year old oil palm tree located in Siak, Riau with the loam soil type. The climate data was used as primary data to predict the rate of evapotranspiration. The soil properties and root dimension and distribution of oil palm was taken by the literature study. The simulation over 30 days illustrated the root water uptake distribution, water content change, pressure head and flow velocity. The most intensive root water uptake occurred in the upper root zone of oil palm tree as an impact of the higher root density. The significant root water uptake in the upper root zone lead to the decreasing of water content and increasing of pressure head in the soil. Consequently, there was a change of water flow direction from the wet area in the downward and sideward do dry root zone as the water supply to the oil palm tree.

Freshwater is recharged mainly by rainfall and stored inland for a period of time, which is directly affected by its storage capability. The storage capability of river basins has different spatiotemporal features that are important for the predictability of freshwater resources. However, the estimation of freshwater storage capability (FSC) remains a challenge due to the lack of observations and quantification indices. Here, we use a metric that characterizes hydrological “inertia” after rainfalls to analyze FSC over the 194 largest global major river basins based on satellite observations from the Gravity Recovery and Climate Experiment (GRACE) and simulations from the Community Land Model version 5 (CLM5). During 2003–16, the global land was observed to retain 28% of precipitation after one month based on GRACE observations, and the simulation depicts that the retained proportions decrease from 42% after one day to 26% after one month, with smaller FSC partly attributed to wetter conditions and higher vegetation densities. The root zone contributes about 40% to the global land FSC on daily to monthly time scales. As the time scale increases, the contribution from the surface soil decreases from 26% to 14%, while the contribution from the deep soil increases from 4% to 10%. Snow contributes over 20% of land FSC, especially over high latitudes. With six decades of CLM5 long-term simulations, it is revealed that the change of FSC in most basins is related to internal climate variability. The FSC of river basins which displays the proportion of precipitation retained on land is worthy of further attention regarding the predictability of water resources.

Agricultural and industrial activity generates high concentrations of organic and inorganic pollutants, many of which are incorporated into the trophic chain, affecting ecosystems. There are several strategies for the remediation of polluted areas; we discuss one of them in the present review that shows the successful evidence of the use of arbuscular mycorrhizal symbiosis in phytoextraction (the removal of contaminants from soil and water sources with mycorrhizal plants), and in the process of phytostabilization (the reduction of the mobility of heavy metals in soil by mycorrhizal roots, absorption onto roots, or precipitation within the root zone). Mechanisms of action of arbuscular mycorrhizal fungi (AMF) including, altered uptake and distribution of heavy metals, improvement in the mineral nutrition and water availability, protection against oxidative stress and increment in the physical stability of the soil by producing glomalin has been discussed with reference to heavy metals (HMs) and persistent oxidative pollutants (POPs). We report plant species associated with species of mycorrhizal fungi as strategy for phytostabilizing heavy metals and reducing biotranslocation to the aerial parts of plants.

The drought of 2018 in central and northern Europe showed once more the large impact that this natural hazard can have on the environment and society. Such droughts are often seen as slowly developing phenomena. However, root zone soil moisture deficits can rapidly develop during periods lacking precipitation and meteorological conditions that favor high evapotranspiration rates. These periods of soil moisture stress can persist for as long as the meteorological drought conditions last, thereby negatively affecting vegetation and crop health. In this study, we aim to characterize past soil moisture stress events over the croplands of southwestern Germany and, furthermore, to relate the characteristics of these past events to different soil and climate properties. We first simulated daily soil moisture over the period 1989–2018 on a 1 km resolution grid, using the physically based hydrological model TRAIN. We then derived various soil moisture stress characteristics, including probability, development time, and persistence, from the simulated time series of all agricultural grid cells (n≈15 000). Logistic regression and correlation were then applied to relate the derived characteristics to the plant-available storage capacity of the root zone and to the climatological setting. Finally, sensitivity analyses were carried out to investigate how results changed when using a different parameterization of the root zone, i.e., soil based or fixed, or when assessing soil moisture drought (anomaly) instead of stress. Results reveal that the majority of agricultural grid cells across the study region reached soil moisture stress during prominent drought years. The development time of these soil moisture stress events varied substantially, from as little as 10 d to over 4 months. The persistence of soil moisture stress varied as well and was especially high for the drought of 2018. A strong control on the probability and development time of soil moisture stress was found to be the storage capacity of the root zone, whereas the persistence was not strongly linearly related to any of the considered controls. On the other hand, the sensitivity analyses revealed the increased control of climate on soil moisture stress characteristics when using a fixed instead of a soil-based root zone storage. Thus, the strength of different controls depends on the assumptions made during modeling. Nonetheless, the storage capacity of the root zone, whether it is a characteristic of the soil or a difference between a shallow or deep rooting crop, remains an important control on soil moisture stress characteristics. This is different for SM drought characteristics, which have little or contrasting relation with the storage capacity of the root zone. Overall, the results give insight to the large spatial and temporal variability in soil moisture stress characteristics and suggest the importance of considering differences in root zone soil storage for agricultural drought assessments.

Water management simulation model DRAINMOD-S was calibrated (1995-96) and validated (1997) using 3-year experimental field data (1995-1997) from the installed subsurface drainage system at 1.8 m drain depth with 40, 60, and 80 m drain spacing at Golewala watershed, Faridkot, Punjab, India. Sensitivity analysis of the model parameters revealed that lateral saturated hydraulic conductivity, drain depth, and drain spacing are the most effective parameters in changing the model output. The root mean square error, efficiency, and coefficient of determination between observed and simulated soil salinity ranged from 0.01to 0.06 dS.m-1, 0.647 to 0.834 dS.m-1 and 0.957 to 0.999 dS.m-1 for three drain spacings (40, 60 and 80 m), respectively, during calibration and validation period. The calibrated and validated model was used to predict the soil salinity (EC) for five consecutive years (1998-2003). The average soil salinity of root zone (300-600 mm), (600-900 mm) and (900-1200 mm) decreased from January, 1998 to December, 2003. The predicted values of soil salinity were found to decrease from 2.23, 2.34, and 1.92 dS.m-1 to 1.68 dS.m-1, 1.70 and 1.42 dS.m-1 for 40 m drain spacing at root zone depth of 300-600 mm, 600-900 mm, and 900-1200 mm, respectively. Similarly, the salinity values for the same period and root zone depth were found to decrease from 2.20, 2.31, and 1.90 dS.m-1 to 1.75,1.78, and 1.74 dS.m-1 for 60 m drain spacing; and 2.21, 2.31, and 1.93 dS.m-1 to 1.80,1.82, and 1.48 dS.m-1 for 80 m drain spacing, respectively, at the end of five years. DRAINMOD-S model was reliably applicable for predicting soil salinity under sub-surface drainage system in arid and semi-arid region of Punjab, India.

Soil moisture in root zone soil layers is one of the most important indicators of agricultural drought. Thus, monitoring agricultural drought requires not only knowledge of rainfall anomaly but also quantification of soil moisture. In this study, the effects of various methods of quantifying the green vegetation fraction green vegetation fraction (GVF) on the land-surface-model (LSM)-based soil moisture drought index (SMDI) were assessed using the harvest area data of the World Meteorological Organization together with the widely used vegetation health index and drought severity index. GVF data used in this study include monthly climatological GVF, weekly advanced very high-resolution radiometer (AVHRR)-normalized difference vegetation index-based and 8-daily moderate-resolution imaging spectroradiometer (MODIS) leaf area index (LAI)-based GVF. The results show that SMDI is optimized when using the near-real-time GVF and that LAI-based GVF increases the accuracy of SMDI when monitoring early agricultural drought. The study shows that we can be confident in the accuracy of signals of emerging drought, particularly during the rapid onset of drought.

Water shortage is the main limitation for agricultural production in many parts of the world. Drought or unavailability of water may seriously limit plant growth as well as yield. A pot experiment ...

Heating greenhouses is essential to provide favorable climatic conditions for growing plants under cold periods. In this article, we have studied the performance of an Active Solar Heating System (ASHS) consisting of two solar water heaters equipped with flat solar collectors, two storage tanks and exchanger pipes. During the day, the water is heated in the thermosyphon solar collectors and stored in tanks before being placed into circulation in the exchanger pipes to distribute the heat to the aerial and root zones of plants. To assess the performance of the Active Solar Heating System, climatic and agronomic parameters were monitored in two identical canarian greenhouses, one equipped with ASHS heater and the second without. Experimental results show that the ASHS system improve the nocturnal climatic conditions under greenhouse. The thermal comfort created by the ASHS system in root zone, increases the absorption of nutrients, which improve the external quality (color, size, weight and firmness) and the internal quality (sugar content, acidity and taste) of tomato fruits. This improvement is also reflected by increasing total tomato yield by 55% in winter period. The results of economic analysis indicate that the ASHS system is a cost effective in terms of investment and energy saving.

The objective of this study was to investigate the effects of used-nutrient solution recirculation on nutrient efficiency improvement and reduction of environmental pollution of an ion-selective electrodes (ISEs)-based recycle-type aeroponic crop cultivation system. A recycle-type aeroponic crop cultivation test bench was fabricated, which consisted of K+, NO3-, and Ca2+ ISEs, pH, and EC sensor, and lettuce were cultivated for inspecting the nutrient solution recirculation process. The specific growth rate of lettuce was evaluated. Different percentages of the used-solution (20%, 40%, 60%, 80%, and 100% of the target volume) were recirculated to find a proper recirculation volume for maintaining the target nutrient level with the minimum supply of stock solutions. The nutrient saving percentage was determined by comparing the nutrient solution requirement with the open-type aeroponic system and open-field cultivation practices. Reduction of environmental pollution was assessed based on the possible environmental pollutions (i.e., surface water pollution, groundwater contamination, and contaminant deposition in the human body), which could be occurred by the direct discharge of the hydroponic nutrient solution. The minimum amount of stock solutions were required during the 60% used-solution recirculation. The nutrient solution requirement of the recycle-type aeroponic system was almost 3 to 5 times less than the open-type aeroponic system, and 3 to 6 times less than open-field cultivation based on nutrient consumption rates at different growth stages. An open-type aeroponic system might require more nutrient solution than the open-field cultivation practices based on the frequency of nutrient solution supply in the crop root zone. Although, the discharged nutrient solution increased the K+, NO3-, and Ca2+ ion levels a little in the considered surface water reservoir, groundwater, and human body, long-term discharge of the high concentrated hydroponic nutrient solution would be hazardous. The findings of this study showed that the nutrient saving efficiency of a recycle-type crop cultivation system is higher compared to the open-type and conventional cultivation practices, which can minimize the cultivation cost notably, and the environmental pollutions can be reduced significantly through the sensor-based nutrient management.

The paper concerns influence of water distribution on the bioelectric potential in the soil–plant system. Two methods for measuring bioelectric potentials (BEPs) of plants have been compared, namely an invasive installation of needle electrodes (a) and a noninvasive method of providing contact due to root intergrowth through a metal grid (b). It has been shown that needle electrode installation into plant tissue leads to a decrease in the biopotential difference from 70 mV to a noise level within ~ 30 minutes; in fact, this means measuring the potentials generated by the plant organism due to the stress caused by the damage. On the contrary, noninvasive electrode installation provides long-term measurements for months and even longer. A specific system is suggested for automated electrophytogram based on the noninvasive method. It allows one long-term measurement of the plant electrophysiological signal directly under normal living conditions for the rhizosphere; it indicates the current functional state of a plant. An equivalent BEP measurement scheme has been proposed accounting for both electrical properties of the plant and root–inhabited medium. BEPs have been measured under conditions of varying water content in the root zone and water movement along and against the root growth direction. The biopotential is constant on average and fluctuates stochastically in the range from 245 to 275 mV at 60–70% of the total water capacity of the soil substrate. The bioelectric potential decreases almost twice when the soil dries. It is restored after irrigation and the restoration delay time increases with increasing water-deficit period. A model is proposed describing the effects in the system during a water-deficiency regime and irrigation.

Information on soil hydrodynamic processes assists in explaining the soil-water-plant relationship and has practical applications to irrigation management, such as the definition of soil water sensor placement. The objective of this study was to detail the hydrodynamic process in the soil root zone and to define the location for placement of soil water sensor under different configurations of trickle irrigation in banana crops. Three micro-sprinkler emitters with flow rates of 70 (T1), 53 (T2), 35 L h-1 (T3), and two drip system, one with one drip line per row of plants (T4), and another with two drip lines per row of plants (T5) were evaluated. The experiment was conducted in a randomized block design with five repetitions. Higher water extraction was found for irrigation systems with higher flow rates for all configurations of trickle irrigation systems. Soil moisture sensors in drip systems should be placed at distances of 0.75 to 0.81 m from the pseudo stem and at depths of 0.33 to 0.44 m. Under micro-sprinkler systems, soil water sensors should be placed at 0.75, 0.77 and 0.83 m from the pseudo stem towards to the emitter and at depths of 0.33, 0.48 and 0.55 m for emitter flow rates of 35, 53 and 70 L h-1, respectively. RESUMO O conhecimento do processo hidrodinâmico no solo ajuda a explicar a relação entre solo-água-planta com efeitos práticos no manejo da irrigação assim como no posicionamento de sensores de umidade no solo. O estudo foi realizado com o objetivo de detalhar o processo hidrodinâmico na zona radicular e definir a localização para o posicionamento do sensor de umidade do solo sob diferentes configurações de irrigação localizada na cultura da bananeira. Foram avaliados três microaspersores com vazões de 70 (T1), 53 (T2), 35 L h-1 (T3) e dois sistemas de gotejamento, (T4) - uma linha de gotejamento por linha de plantas, (T5) - duas linhas de gotejamento por linha de plantas. O experimento seguiu um delineamento em blocos casualizados consistindo de cinco tratamentos com cinco repetições. A extração de água foi maior nos sistemas de irrigação com maiores taxas de vazão para todas as configurações de sistemas de irrigação localizada. Os sensores de umidade do solo em sistemas de gotejamento devem estar a distâncias de 0,75 a 0,81m do pseudocaule e em profundidades de 0,33 a 0,44 m. Em sistemas de microaspersão, os sensores de umidade do solo devem estar a 0,75, 0,77 e 0,83 m do pseudocaule para o emissor e a profundidades de 0,33, 0,48 e 0,55 m para vazões de 35, 53 e 70 L h-1, respectivamente.

It is necessary to develop methods to improve soil moisture capacity and agricultural productions in arid and semiarid areas. This study was conducted to evaluate the impact of optimal water allocation to improve the yield production in Gotvand Plain, Khuzestan Province, south-western Iran. A field-scale experiment with three scenarios of sugarcane bagasse compost application (0, 15 and 30 ton/ha) and four levels of water supply (50%, 75%, 100% and 125% of total allowable water) was performed in three replications (March–July 2019). Porous media texture, infiltration rate and irrigation demand were simulated at daily time steps to provide the root zone moisture content using real-time analysis of soil water balance. Furthermore, the maximization of readily available water based on the agricultural demand were considered using grey wolf optimization algorithm under deep percolation and runoff constraints. The results showed that the water allocation strategies and compost scenarios can improve water use efficiency and soil moisture.

Determination of actual evapotranspiration is an important step for simulating the crop growth models in agricultural decision-making process. In this study, actual evapotranspiration (ETa) values for the main crops cultivated in Shahrekord plain, Chaharmahal and Bakhtiari province, Iran, are estimated based on real-time modeling and compared with the results obtained from the remote sensing data. Soil moisture balance was simulated considering the variation rate of crop canopy cover and its effects on evaporation and transpiration parameters. Daily values of ETa were predicted in a repeatable cycle based on the available soil moisture in root zone. Moreover, remote sensing images were analyzed as a data source to achieve the crop water requirement in critical times. For this objective, surface energy balance algorithm for land (SEBAL) was used to characterize the evapotranspiration and then derived ETa. Preliminary results obtained by applying satellite information showed a good agreement between the SEBAL estimates of evapotranspiration fluxes and the corresponding values simulated by the soil moisture estimation technique.

Background A floating system is a suitable low-cost hydroponic method for growing baby leaf vegetables. Among other, an important characteristic of the system is the use of large volume of nutrient solution which is characterized by high heat capacity. The aim of this study was to evaluate the effect of different root-zone temperatures on baby leaves of lettuce and rocket plants grown in a floating system under mild (spring) or extreme environmental conditions (summer and winter). Results Root-zone temperature was recorded in two tanks, one powered by a photovoltaic system and one where root-zone temperature was not controlled - this was used as a control tank. Photosynthetic parameters, yield, nutritional quality, and mineral composition were determined. In both baby leaf vegetables, during extreme weather conditions, yield was higher in the tanks with controlled root-zone temperature conditions than the control (+18.9% for rocket, and + 31.4% for baby lettuce), while quality parameters and chemical composition were not significantly affected. Stomatal conductance and net photosynthesis values were positively affected only during summer. On the other hand, control of root-zone temperature under mild weather conditions had no significant effect on baby lettuce and rocket. Conclusion Control of the root-zone temperature could be a useful tool to improve productivity for baby lettuce and rocket crops cultivated in floating systems under extreme weather conditions. © 2020 Society of Chemical Industry.

Decreasing cultivated area and climate variability necessitates adoption of efficient irrigation methods for higher productivity of vegetables. Study was conducted in Kerala State of India on the vegetable crops, namely, chilli, okra and tomato to evaluate the physiological efficiency with mechanistic understanding of plants under wick irrigation method, comparing with conventional irrigation. The crops were evaluated for growth, pigment contents and gas exchange attributes under wick irrigation. Results revealed the efficiency of wick system over conventional irrigation in terms of enhanced growth, significantly (P

In the current review paper, the efforts are being made to explain the technical and non-technical aspects of micro irrigation system termed as Drip Irrigation system. It has huge ability for water and nutrient conservation. The main aim is to reduce water scarcity near root zone and reduce evaporation. The assessment of yield and water productivity of clementine trees, cotton, pomegranate cultivars etc. is discussed. Effect of Drip irrigation on economic factors, productivity, fertilization techniques and irrigation scheduling is studied. The drip irrigation on several cash crops like cotton, jute, groundnut, etc. in different parts of countries like China, India, Japan, North Xinjiang, European countries etc. are discussed. The Assessment with season, geography, environment, availability of resources is systematically highlighted. Improvement and future scope for sustainable development is discussed. Also the computational analysis of Drip irrigation methodology and technology is done in order to improve the productivity and minimize the efforts and use of resources. The modeling and monitoring of 3D flow of water under drip irrigation is also studied. The overall effort in the current review analysis is to develop an optimum methodology and technology to enhance the use of Drip irrigation in large scale cultivation and Production.

Inadequate natural drainage facilities and flat lands causes, some of the Cauvery river basin command are suffering waterlogging and alkalinity problems during the canal water supply and period of excess rainfall. Subsurface drainage system is the method to lower the depth to groundwater level below the root zone and creates a favorable environment for crop growth. A study aimed to evaluate the performance of the parallel pipe subsurface system installed in farmers’ field at Sembari village, Lalgudi Taluk, Trichy District, Tamil Nadu in a waterlogged paddy field from October 2020 to February 2021. The field experiment was conducted with the combination of three lateral drain spacing (7.5, 10.0 and 12.5 m) and two drain depths (60 and 80 cm). 63 mm PVC perforated pipes wrapped with coir envelope were laid as lateral drains at a grade 0.3%. Inspection chambers connected with collector drains laid at a grade of 0.6% were used to measure the drain water discharge, observation wells installed midway between lateral pipes drains were used for measuring the depth to groundwater level. Hydraulic properties of soil, depth to water level, discharge collected in drain pipe were used as evaluation parameters. This study revealed that soil hydraulic conductivity had been increased to 30%, pH, EC and ESP has been reduced to 12, 54 and 20%, respectively. The system has performed well to alleviate the waterlogged condition in 7.5 m lateral drain spacing and 80 cm drain depth treatment by observing the higher rate of decrease in depth to water of 0.3 to 0.4 m and a drainage coefficient of 0.069 to 0.29 cm/day.

HighlightsSubsurface drip irrigation (SDI) has continued to expand in irrigation area within the U.S. during the last 15 years.Research with SDI continues for multiple crop types (fiber, grain and oilseed, horticultural, forage, and turf).SDI usage on many crops has matured through research and development of appropriate strategies and technologiesDespite some persistent challenges to successful use of SDI, important opportunities exist for further adoption.Abstract. Subsurface drip irrigation (SDI) offers several advantages over alternative irrigation systems when it is designed and installed correctly and when best management practices are adopted. These advantages include the ability to apply water and nutrients directly and efficiently within the crop root zone. Disadvantages of SDI in commercial agriculture relative to alternative irrigation systems include greater capital cost per unit land area (except for small land parcels), unfamiliar management and maintenance protocols that can exacerbate the potential for emitter clogging, the visibility of system attributes (components and design characteristics) and performance, and the susceptibility to damage (i.e., rodents and tillage) of the subsurface driplines. Despite these disadvantages, SDI continues to be adopted in commercial agriculture in the U.S., and research efforts to evaluate and develop SDI systems continue as well. This article summarizes recent progress in research (2010 to 2020) and the status of commercial adoption of SDI, along with a discussion of current challenges and future opportunities. Keywords: Drip Irrigation, Irrigation, Irrigation systems, Microirrigation, SDI, Water management.

O. Siabruk, O. Naydenova, Ya. Get’man. Influence of biological products on СО₂ emission and microflora of the root zone of corn The article presents the results of observations of carbon dioxide emissions and other indicators of soil biological activity in order to determine the effectiveness of the introduction of elements of biologization of agriculture. It was found that the use of a set of agricultural measures (tillage destructor tillage, pre-sowing treatment of seeds with biological product and double foliar treatment with humic preparation) increased СО₂ emissions and increased the number of microflora in the root zone of corn compared to control. There was a significant increase in the yield of corn grain due to the use of a complex of biological products (up to 16%, depending on the option). Keywords: carbon dioxide emission, biologization of agriculture, agricultural activities, soil microflora, corn.