Field Capacity Moisture Research Articles

Enhancement of Tomato Fruit Quality Through Moderate Water Deficit

In arid areas, water shortage has become a major bottleneck limiting the sustainable development of agriculture, necessitating improved water use efficiency and the full development of innovative water-saving irrigation management technologies to improve quality. In the present study, tomato (Solanum lycopersicum cv. Micro Tom) fruits were used as materials, and different irrigation frequencies were set during the fruit expansion stage. The normal treatment (CK) was irrigated every three days, while the water deficit treatments were irrigated at varying frequencies: once every 4 days (T1), 5 days (T2), 6 days (T3), 7 days (T4), and 8 days (T5). These corresponded to 80%, 70%, 60%, 50%, and 40% of the maximum field moisture capacity (FMC), respectively, with CK maintaining full irrigation at 90% of the maximum FMC. The water deficit treatment T3, with less stress damage to plants and the most significant effect on fruit quality improvement, was selected based on plant growth indices, photosynthetic characteristics, chlorophyll fluorescence parameters, and fruit quality indices, and its effects on carotenoids, glycolic acid fractions, and volatile compounds during tomato fruit ripening were further investigated. The outcome indicated that moderate water deficit significantly increased the carotenoid components of the tomato fruits, and their lycopene, lutein, α-carotene, and β-carotene contents increased by 11.85%, 12.28%, 20.87%, and 63.89%, respectively, compared with the control fruits at the ripening stage. The contents of glucose and fructose increased with the development and ripening of the tomato fruits, and reached their maximum at the ripening stage. Compared to the control treatment, the moderate water deficit treatment significantly increased the glucose and fructose levels during ripening by 86.70% and 19.83%, respectively. Compared to the control conditions, water deficit conditions reduced the sucrose content in the tomato fruits by 27.14%, 18.03%, and 18.42% at the mature green, turning, and ripening stages, respectively. The moderate water deficit treatment significantly increased the contents of tartaric acid, malic acid, shikimic acid, alpha ketoglutaric acid, succinic acid, and ascorbic acid, and decreased the contents of oxalic acid and citric acid compared to the control. The contents of total soluble sugar and total organic acid and the sugar–acid ratio were significantly increased by 48.69%, 3.71%, and 43.09%, respectively, compared with the control at the ripening stage. The moderate water deficit treatment increased the fruit response values to each sensor of the electronic nose, especially W5S, which was increased by 28.40% compared to the control at the ripening stage. In conclusion, during the ripening process of tomato fruit, its nutritional quality and flavor quality contents can be significantly improved under moderate (MD) deficit irrigation treatment. The results of this experiment can lay the foundation for the research on the mechanism of water deficit aiming to promote the quality of tomato fruit, and, at the same time, provide a theoretical basis and reference for tomato water conservation and high-quality cultivation.

The influence of conditions on water holding capacity characteristics of triticale varieties planted in the Samarkand region

In this article, the possibilities of water holding capacity in the leaves of triticale varieties were studied in the conditions of LFMC-70% and arid LFMC-50% of grassland-gray soils of Samarkand region, and the drought resistance characteristics of the varieties were studied. LFMC (Limited Field Moisture Capacity) was maintained at 70% under normal conditions and LFMC at 50% under dry conditions. According to the results of the experimental analysis, drought conditions had a significant and negative effect on the productivity of all studied genotypes. It was found that triticale cultivars "Odessiy" and "Tikhon" grown under LFMC-50% conditions in drought conditions meet water deficit less in all development phases and at all times of the day and are drought resistant compared to other cultivars. Analysis of the physiological and biochemical bases of adaptation in the selection of drought-resistant triticale varieties and the research conducted on the selection and obtaining of fertile varieties suitable for this region are described.

Effects of Water, Fertilizer and Heat Coupling on Soil Hydrothermal Conditions and Yield and Quality of Annona squamosa

Seasonal drought and summer soil high-temperature stress in Southern China often lead to decreased yield and quality of Annona squamosa. It is important to explore reasonable and effective water and fertilizer management measures as well as cover measures to improve the soil hydrothermal conditions in orchards to realize the increase in yield and quality of Annona squamosa. This study involved a two-year (2022–2023) field experiment in Yun County, Lincang City, Yunnan Province, using three factors and a three-level orthogonal test, resulting in nine different experimental treatments for water, fertilizer and heat. The three irrigation levels were W1 (soil moisture content of 55% of field moisture capacity), W2 (soil moisture content of 75% of field moisture capacity) and W3 (soil moisture content of 85% of field moisture capacity). The three fertilizer levels were F1 (1666 kg·hm−2), F2 (2083 kg·hm−2) and F3 (2500 kg·hm−2), and the three cover methods were A1 (no cover), A2 (fresh grass cover) and A3 (straw cover). The effects of these treatments on soil hydrothermal conditions, growth indices and fruit yield and quality of Annona s1uamosa were systematically monitored and analyzed, and the relationships between these treatments and yield and quality was analyzed based on a Mantel test. The results showed that T5 (W2F2A3) had the highest average soil moisture content over two years, followed by T7 (W3F1A3). The T7 (W3F1A3) treatment effectively reduced soil temperature by 5 °C compared to T1 (W1F1A1). T5 (W2F2A3) had the highest average yield over two years, with an increase of 33.99% compared to T1 (W1F1A1). Additionally, T5 (W2F2A3) has the highest average soluble solids, soluble sugars and vitamin C content over two years, with increases of 28.13%, 13.36% and 4.86%, respectively, compared to T1 (W1F1A1). A Pearson correlation analysis showed that there was a significant correlation between Annona squamosa growth and soil moisture content and soil temperature, and the Mantel test showed that soil hydrothermal conditions had significant influence on the growth and yield. T5 (W2F2A3) has the highest comprehensive benefit in promoting growth, increasing yield and improving quality for the plant. The effects of different irrigation quantities, fertilizer amounts and different cover measures on the coupling interaction for soil hydrothermal status in the root zone, growth, yield and quality of Annona squamosa were investigated, providing reliable theoretical support for the scientific planting model of Annona squamosa in the low-heat river valley of Yunnan Province.

Laboratory evaluation of wicking geotextile for moisture reduction in silty sands at different fines contents

The effect of fines content on the performance of the wicking geotextile is not clear. This study developed a simple moisture reduction test method to quantify the effectiveness of the wicking geotextile in reducing moisture in silty sands at four different fines contents and four different waiting periods. The sand was prepared at an initial moist condition based on its average field moisture capacity. A wicking or non-wicking woven geotextile was placed in the middle of a soil column. The effect of a geotextile on the moisture content of the sand was evaluated by measuring their gravimetric moisture contents at different distances from the geotextile at different times. Test results show that the amount of moisture reduced by the wicking geotextile decreased with the content of fines in the silty sand. On the contrary, the non-wicking geotextile obstructed water flow, hence moisture accumulated on it. The moisture content profile in the soil column indicated the influence zone by the wicking geotextile in the silty sand, which depended on the fines content. The percent of soil moisture content reduction by the wicking geotextile identified the limit of the fines content for the effectiveness of the wicking geotextile.

Modeling soil water dynamics of an intensively cultivated histosol

AbstractUnderstanding soil–water dynamics in cultivated organic soils (histosols) is crucial for sustainable agriculture, ecosystem preservation, and climate change mitigation. Data on the soil water retention curves (SWRCs) of these histosols in Canada are not readily available in the literature. The Hydrus‐1D model was used to predict SWRCs for a cultivated organic soil in Quebec. The model was validated with matric potential measured in a soil column at 10, 26, and 48 cm. The optimized hydraulic parameters in the Hydrus model resulted in field capacity moisture contents of 0.6, 0.696, and 0.49 cm3 cm−3 at the three depths, respectively. Wilting point moisture contents of 0.165, 0.107, and 0.14 cm3 cm−3 were obtained at the same depths. Model accuracy was confirmed with a Nash–Sutcliffe efficiency of 0.76, 0.91, and 0.78 for the three depths, respectively. These findings can inform decisions regarding water management practices such as irrigation and drainage requirements for intensively cultivated organic soils.

Impact of alternate partial root-zone irrigation on the rhizosphere microbiota of alfalfa plants inoculated with rhizobia.

Water is an important constraint on alfalfa (Medicago sativa) production in arid and semiarid areas, and alternate irrigation in root areas has water-saving potential for alfalfa production. To investigate the impact of alternate partial root-zone irrigation (APRI) on the rhizosphere soil microorganisms of alfalfa, this study subjected alfalfa plants to different irrigation methods and irrigation levels. The growth status and rhizosphere soil microbial community diversity of alfalfa plants under alternate root-zone watering treatment were analyzed through laboratory experiments and high-throughput sequencing. The results showed that at soil moisture levels of 80% field moisture capacity (FMC) and 60% FMC, APRI had no significant impact on the biomass or nodule number of alfalfa. However, 40% FMC significantly reduced the individual plant dry weight, chlorophyll content, and nodule number of the alfalfa plants. APRI increased the relative abundance of Actinomycetes in the alfalfa rhizosphere soil. Moreover, at 60% FMC, the MBC and MBN of rhizosphere, relative abundance of Actinobacteria and unclassified K fungi and Chao 1 index of bacteria significantly increased under APRI treatment. While relative abundance of Ascomycetes and Proteobacteria in the alfalfa rhizosphere significantly reduced under 60% FMC + APRI treatment. In summary, under the same irrigation conditions, APRI did not significantly affect the growth of alfalfa in the short term. And 60%FMC + APRI treatment did significantly affect the groups, structure and diversity of the rhizosphere soil microbial communities.

Effects of light and water availability on the growth of Aglaia duperreana seedlings.

Aglaia duperreana, a species with a long cultivation history, is of high ornamental value. To understand the growth and photosynthetic changes of A. duperreana seedlings under variable environmental conditions, we conducted an experiment with light intensities adjusted at 70%, 50% and 30%, crossed with three moisture treatments at 70%, 50% and 30% of field capacity, and a control group which maintained 90% light intensity and 90% field capacity. The results showed that both drought stress and shading propensity significantly inhibited the growth of A. duperreana seedlings, with stronger impacts from drought stress. The increments in stem height and ground diameter, net photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll content were decreased with the maximum declines by 71.4%, 81.2%, 93.2%, 71.5%, 70.6% and 30.4%, respectively. Under severe drought stress (30% of field capacity), partial shading (50% of translucency) appeared to lessen the detrimental effects of drought. The combination of 70% translucency and 70% field capacity was optimal, resulting in higher increments in stem height, leaf area, net photosynthetic rate, transpiration rate, and stomatal conductance. The maximum fluorescence, variable fluorescence, PSⅡ potential activity, and PSⅡ maximum light energy conversion efficiency increased and then decreased with decreasing moisture. These findings suggested that A. duperreana could adapt to drought and shading stress by modulating growth, enhancing chlorophyll content, and adjusting photosynthetic system. Maintaining translucency at 70% and field moisture capacity at 70% could promote photosynthesis, with positive consequences on growth of A. duperreana.

Влияние предполивного порога влажности почвы на продуктивность и кормовую ценность сои на мелиорированных землях

The results of vegetation and field experiments on the influence of moisture conditions on the productivity and feed value of Mageva soybeans are presented. It is established that the conditions of moisture availability are an important factor in regulating the level of symbiotic nitrogen fixation and the production process in soybeans. Increasing the pre-irrigation soil moisture from 40 to 60% PPV (maximum field moisture capacity) can significantly increase crop productivity: yield from 4.11 to 7.64 g/vessel, protein harvesting with seed yield from 8.04 to 16.50 g/vessel, essential amino acids from 5.22 to 10.70 g/vessel or 1.81‑2.05 times; fat collection – from 2.34 to 4.37 g/vessel, or 1.68‑1.85 times, collection of feed units from 28.77 to 53.48 g/vessel or 1.69‑1.86 times. In the field experiment, with optimal heat and moisture availability, the yield is 2.71 t/ha, the level of symbiotic nitrogen fixation reaches 208 kg/ha, which covers 96% of the nitrogen needs of plants. Excessive and especially insufficient moisture supply significantly reduce productivity indicators: yield – by 1.08‑1.84 times, protein collection by 1.14‑1.62 times, collection of essential amino acids – by 1.13‑1.60 times, lysine – by 1.12‑1.61 times, fat collection – by 1.04‑1.42 times, and unsaturated fatty acids – by 1.03‑1.41, collection of feed units – 1.10‑1.80 times, the level of symbiotic nitrogen fixation up to 33‑79% or 1.29‑2.90 times.

Long‐term combined subsoiling and straw mulching conserves water and improves agricultural soil properties

AbstractSubsoiling and straw mulching are two techniques that conserve soil water and improve the sustainability of agricultural production. However, the benefits to soil sustainability of combining subsoiling with straw mulching under intensive rotation between wheat and maize remain uncertain. We conducted a field experiment to determine the long‐term impacts of conventional tillage with straw mulching (CS), and subsoiling with straw mulching (SS), on soil macropore characteristics (>160 μm), soil aggregate characteristics, and soil hydraulic parameters at 0–100 cm depths. Results indicate that SS increased the mean macropore number (66.9%), macroporosity (93.5%), pore circularity (3.5%), field moisture capacity (11.8%), saturated moisture content (21.4%), available soil moisture content (24.1%), and the saturated hydraulic conductivity (39.3%) in the shallowest 50 cm of soil, and total organic carbon content (34.5%) and soil labile organic carbon (20.2%) in the shallowest 30 cm of soil, compared to CS. Compared with CS, SS was more effective at increasing the proportion of aggregates larger than 0.25 mm in the top 20 cm of soil and decreasing the proportion of aggregates smaller than 0.25 mm in the top 30 cm of soil. Correlations between soil organic carbon and various soil physical properties under different practices suggest that SS has larger causative effects on soil physical properties than CS. Therefore, SS is recommended over CS.

Plant growth regulators affecting canola (Brasica Napus L.) biochemistry including oil yield under drought stress.

The objective was to test the effects of PGR on canola (Brassica napus L.) biochemistry including oil yield under drought stress. A two-year (Y1 and Y2) split plot field experiment on the basis of a randomized complete block design with three replications was conducted. The main factor was, drought stress levels, including irrigation after areduction of 40 (D1), 60 (D2) and 80% (D3) of field capacity (FC) moisture, and the sub-factor was PGR including control (S1), soil application of humic acid (S2), foliar applications of amino acid (S3), fulvic acid (S4) or seaweed extract (S5), and the combination of all PGR (S6). Although drought stress significantly decreased plant chlorophyll contents (a, b and total), oil percentage and oil yield, PGR significantly increased them. The D3 treatment, compared with control, decreased crop oil yield by 48.67 and 35.29% in the first and second year, respectively. However, treatment Y2D3S6 significantly increased oil percentage (43.10%) compared with control (40.97%). The PGR increased seed oil yield, in D3, by a maximum of 254kg ha-1. The PGR numerically (p ≤ 0.0886) increased proline to 6.14 mg g-1 LFW (Y1D3S6) compared with control (4.79 mg g-1 LFW). The PGR also significantly increased sugar content to 17.05 mg g-1 LFW, significantly different from thecontrol (12.95 mg g-1 LFW). In conclusion, the tested PGR can improve the biochemical properties (quality) including oil yield of canola in drought stress conditions, which is of economic and health significance.

Effects of artificial sweeteners on antioxidant enzymes and physiological parameters in Triticum aestivum (Poaceae)

Due to increased consumption, artificial sweeteners are often present in the environment but their effects on plants are largly unknown. In this research, the effects of four artificial sweeteners on plant stress markers in Triticum aestivum L. were investigated. Wheat seedlings were grown from seeds in soil containing artificial sweeteners (saccharin, sodium cyclamate, sucralose, aspartame) in different concentrations (0, 25, 50, 100 mg kg-1). Plants were irrigated at regular intervals to maintain field capacity moisture and harvested after 15 days of growth. Electrolyte leakage, chlorophyll and carotenoid content, and antioxidant enzyme (superoxide dismutase, peroxidase, catalase) activities were determined in harvested leaves. Comparisons between control samples and test samples were statistically evaluated at a 95% confidence interval to determine significant differences. Overall, significant increases in chlorophyll and carotenoid content, and some antioxidant enzyme activities were observed in wheat plants exposed to artificial sweeteners in the soil. A significant increase in electrolyte leakage was observed with saccharin and aspartame treatment, indicating that these sweeteners can cause membrane damage in wheat. Chlorophyll a nd POX activity were the most sensitive stress parameters in wheat. This study showed the importance of evaluating the potential impact of anthropogenic pollutants that may be present in treated wastewater and consequently affect plants.

New procedure to estimate soil field capacity based on double ring infiltration data

Many models have been proposed to explain the water infiltration curve in soil, but according to the studies we have done so far, no model can simultaneously estimate the field capacity (FC) and soil hydraulic conductivity (K). The aim of this research is to present a new model that is defined based on the dynamic balance of water-soil-time and is able to estimate FC and soil hydraulic conductivity using cumulative field infiltration data. The studies were carried out in Varamin region with an area of 1370 square kilometers. For the penetration test, first, seven sides (A, B, C, D, E, F and G) were selected in 7 areas of agricultural land and with a double ring with an outer diameter (70 cm) and an inner diameter (30 cm) became. Also, to determine the soil texture, apparent specific gravity, PWP and FC, soil sampling was done at the depths of 0–10 and 20–30 cm. To determine FC moisture, pressure (−10 kPa) was used in a pressurized membrane device, and to determine volumetric moisture in PWP, sieved samples were placed on ceramic plates. Using a spray, the samples were wetted, so that they reached the saturation level, and the pressure was set to 1500 kPa. Examining the FC values showed that the maximum value of FC in site F (clay loam texture) is equal to 14.73 cm and the lowest value in site G (sandy clay loam texture) is equal to 6.8 cm by the model estimated by the results obtained in Laboratory confirmed. Meanwhile, the minimum saturated hydraulic conductivity of soil at site A was estimated to be 0.06 cm/min and the maximum at sites D and F was 0.28 cm/min. Time constant (Ksh) has shown completely different water infiltration rate in the first term of the model (Rfksh) compared to the second term of it (K), and no obvious relation has detected between them. But, their summation (k+Rfksh) was always equal to the maximum infiltration instantaneous rate (T→0). The research results showed that using the new model, the FC value varies between 6.8 and 14.73 cm. Also, the minimum and maximum instantaneous speed of water infiltration occurred in the site. An equal to 0.621 and in site D equal to 1.735 cm/min. The results of fitting the penetration model on cumulative penetration data showed that R2 varies between 0.994 and 0.999 and RMSE between 0.116 and 1.197. Therefore, the model is able to describe the penetration data well.

Controlling water deficiency as an abiotic stress factor to improve tomato nutritional and flavour quality.

Water deficit (WD) irrigation techniques to improve water use efficiency have been rapidly developed. However, the effect of WD irrigation on tomato quality has not been sufficiently studied. Here, we investigated the effects of varying water irrigation levels [T1-T4: 80%, 65%, 55%, and 45% of maximum field moisture capacity (FMC)] and full irrigation (CK: 90% of maximum FMC) on tomato fruits from the mature-green to red-ripening stages, to compare the nutritional and flavour qualities of the resulting tomatoes. The proline, aspartic, malic, citric, and ascorbic acid contents increased, phenylalanine and glutamic acid contents decreased, and the total amino and organic acid contents increased by 18.91% and 26.12%, respectively, in T2-treated fruits. Furthermore, the T2-treated fruits exhibited higher K and P contents alongside improved characteristic aromas. These findings provide novel insights for further improvements in tomato quality while also developing water-saving irrigation techniques.

Characteristics of soil physical properties in different soil management of oxisols and inceptisols

Oil palm (Elaeis guineensis Jacq.) is a plantation crop that has a bright future. Soil management such as land clearing, burning, use of heavy equipment and fertilisation in oil palm plantations will affect changes in soil physical properties. This study aims to assess the physical properties of soil in various treatments (planting circle, dead interplant spacings and live interplant spacings) on Oxisol and Inceptisol soil types. This research was conducted in Rancabungur and Malingping Banbten in October 2021 - May 2022. The method used in this study was multistage random sampling. Soil samples were taken from the Malingping area of Banten for the Oxisol soil type (2005 and 2009 planting years), and the Rancabungur area for the 2005 Inceptisol soil type. Comparison of soil physical properties of Oxisol of 2005 planting year with Oxisol of 2009 planting year and the ratio of Oxisol soil type of 2005 planting year and Inceptisol of 2005 planting year in various treatments did not show significant differences in soil physical properties (organic matter, content weight, field capacity moisture content, permanent wilting point, and particle density) between planting circle, dead interplant spacings and live interplant spacings. However, there were significant differences in the physical properties of soil texture between each management and permeability.

Foliar-applied nano-cerium dioxide differentially affect morpho-physiological traits and essential oil profile of Salvia mirzayanii Rech. f. & Esfand under drought stress and post-stress recovery conditions

Drought stress is known to diminish the growth and yield of plants by altering the physiological, biochemical and molecular processes, thus threatening food security worldwide. Nanoparticles (NPs) have emerged as an effective strategy to raise plant productivity under current rapid environmental challenges. However, there is little literature on mechanisms underlying the beneficial role of re-watering in drought-stressed plants treated with NPs. In this study, the effects of cerium dioxide nanoparticles [(CeO2 NPs), 0 (control), 125, 250, 500, and 1000 mL L−1] were investigated on morpho-physiological and phytochemical traits of Salvia mirzayanii plants under different drought stress intensities [(25%, 50%, 75%, and 100% (control) of field capacity (FC) moisture] and post-stress re-watering (recovery) in a three-way factorial arrangement based on randomized complete block design. Uptake and accumulation of CeO2 NPs in the leaf tissue of plant samples were confirmed using SEM and EDX techniques. The results of ANOVA demonstrated that growth and physio-phytochemical traits were significantly (p < 0.05) affected by individual treatment and/or their double and triple interactions. Exposure to various levels of CeO2 NPs during drought stress mitigated the adverse effects of stress on growth parameters (e.g., plant height, shoot and root dry weights, and root length) and photosynthetic pigments (chlorophyll a and b) content compared to the respective controls in varying degrees. However, proline and essential oil content were increased in drought-stressed plants, and tended to decrease during the period of recovery. Before re-watering, the antioxidant enzymes, CAT, POD, and SOD, activity in leaf tissues was increased with the increase of drought stress intensity upon both treated and non-treated CeO2 NPs conditions. However, the three-way interaction results demonstrated that recovery after drought stress following CeO2 NPs application particularly 1000 mL L−1 decreased the activity of antioxidant enzymes compared to the controls. Based on GC and GC-MS analysis, all essential oil samples predominantly composed of oxygenated monoterpenes and sesquiterpenes including Decane, Spathulenol, Octane, α-Terpinyl acetate, Hexyl isovalerate, Dodecane, Butanoic acid, Linalool, δ-Cadinene, Muurolol, α-Cadinol, Eudesm-7(11)-en-4-ol, which significantly (p < 0.05) changed under different experimental treatments. The recovery after stress, however, increased only the content of δ-Cadinene in plants from severe drought stress upon foliar application of 1000 mL L−1 CeO2 NPs compared to the non-recovery period. Conclusively, integrative use of CeO2 NPs and re-watering after drought stress could be an encouraging and eco-friendly strategy to improve both drought tolerance, growth and pyhtochemical contents in S. mirzayanii plants.

Divergent shift of normal alpine meadow towards shrub and degraded meadows reduces soil water retention and storage capacity

Soil saturated hydraulic conductivity (Ks) is a critical ecohydrological parameter for assessing the capacity of soil layers in grassland ecosystems to respond to precipitation efficiency, recharge groundwater and supply freshwater to rivers, which is significantly impacted by shifts in vegetation composition. Nevertheless, few studies focused on the effects of the shifts in vegetation composition on Ks of alpine grassland ecosystems. This study examined the effects of normal alpine meadow transition into shrub and severely degraded meadow stages on Ks and further qualified the driving processes. The results showed that the divergent shift of normal alpine meadows altered the soil and meadow properties. Soil water retention and storage capacity of the topsoil was reduced due to the divergent shift of the normal meadow transition into shrub meadow or severely degraded meadow. Ks and field moisture capacity (FMC) reduced by 73.1% and 64.9% in the 0–10 cm soil layer during the transition from normal to degraded meadow, while their variation in the 0–10 cm soil layer were not significant but water consumption increased during the shift from normal to shrub meadow. At the state of normal alpine meadow shift toward severely degraded meadow, the dominant factors affecting Ks were meadow cover (MC), root mass density (RMD), clay content and total porosity, with total effect coefficients of 0.48, 0.42, 0.39 and 0.69, respectively. Meanwhile, when normal alpine meadow shift toward shrub meadow, dominant factors affecting Ks were MC, non-capillary porosity, clay and sand contents, with total effect coefficients of 0.47, −0.86, −0.54 and −0.50, respectively. This study helps understanding the impacts of the shifts in vegetation composition on the ecohydrological processes in alpine meadow ecosystems in response to climate change and overgrazing.

Effect of Added Phosphorous and Organic Matter on the Availability of Phosphorous Fractions in Normal Soil under Field Capacity Moisture Tension

An Incubation study was conducted from January 2020 – May 2020 under "Laboratory conditions" at the Department of Soil Science and Agricultural Chemistry, Chandra Shekhar Azad Kanpur University of Agriculture and Technology, (U.P.) to study the “Effect of added phosphorous and organic matter on the availability of phosphorous fractions in normal soil under field capacity moisture tension”. To obtain a different fraction of phosphorus under the field capacity regime all three experiments were conducted under kankar soil conditions to determine Ca-P, Al-P and Fe-P as influenced by six different treatments. The results showed that with advancement in time of incubation, the availability of Ca-P (308.2 ppm and 235.3 ppm at 0 days and 90 days of incubation period, respectively), Al-P (89.5 ppm and 44.9 ppm at 0 days and 90 days of incubation period, respectively), while Fe-P (13.8 ppm and 13.1 ppm at 0 days and 90 days of incubation period, respectively) increased marginally at field capacity in kankar soil condition. Sunhemp (T2) proved more beneficial than FYM (T3) in increasing Fe-P, Al-P, and Ca-P as also Olsen’s P content in the soil. Therefore, the application of organic matter either in the form of sun hemp with phosphorus proved very useful in improving the avoidable content of the soil.

Drought Stress Modulation by Biochar and Effects on Soil and Performance of Seedlings of Urban Forest Tree Species

Aims: This study was designed to examine the effects of watering regime and biochar on soil properties and performance of seedlings of urban forest tree species (UFTS) in the nursery. Study Design: The experiment was a 5 by 3 by 2 factorial scheme involving urban forest tree species, watering regimes and biochar amendment or not. Place and Duration of Study: seedlings of five UFTS were raised in the Nursery and Screenhouse of Wesley University, Ondo, a rainforest zone of Nigeria. Methodology: Seedlings of five Urban Forest Tree Species (UFTS) were subjected to watering at 80, 60 and 35% field capacity (FC) with or without biochar amendment. UFTS evaluated are: Bauhinia monandra, Delonix regia, Terminalia catappa, Dypsis lutescens and Veitchia merrillii. Results: Watering regime and biochar amendment exerted significant effects on soil physical and chemical properties, physiological attributes and biochemical constituents and performance o the UFTS evaluated. Watering at 60 and 35% FC increased bulk and particle densities but reduced significantly (P&lt;.05) soil moisture content at field capacity compare with watering at 80% FC. Further, the 60 and 35% FC watering exhibited low N, available K+, Ca2+ and Mg2+. Addition of biochar to the variously watered soil considerably reduced bulk density but remarkably increased porosity, field capacity moisture and plant available moisture. Biochar amendment increased soil pH, total and volatile organic matter contents, available K+ and Ca2+, extractable Mg2+ and dissolved phosphate (PO43+). The responses of growth traits and biochemical constituents of UFTS to watering regimes was species specific. Relative to 80 % FC watering, seedling growth attributes reduced significantly under deficit water application (60 and 35% FC) in addition to remarkable accumulation of osmolytes (osmoprotectants) and enzymatic activities. Biochar amendment enhanced accumulation of osmolytes and activities of superoxide dismutase, guaiacol peroxidase and catalase enzymes of UFTS seedlings. Conclusion: Differential watering and biochar amendment affected soil physical and chemical properties and growth of UFTS seedlings evaluated. Biochar amendment of the variously watered soil enhanced seedling growth, and appear as effective strategy for improving soil properties and UFTS performance, and for mitigation of adverse effects of suboptimal watering.

ANALISIS KEBUTUHAN AIR TANAMAN SELADA (Lactuca sativa L.) PADA INCEPTISOL DAN VERTISOL BERBASIS INTERNET OF THINGS (IoT)

Lactuca sativa L. has good economic prospects, but lettuce production often declines due to the unmet water requirement of lettuce. This study aimed to determine the water needs of lettuce on Inceptisol and Vertisol based on the Internet of Things (IoT). The location study was in the green house, Huluduotamo Village, Bone Bolango Regency, from September to October 2021, while the Vertisol and Inceptisol samples were from Sidomukti Village, Gorontalo Regency. This study used the Penman method with the Cropwat 8.0 application which was integrated with a smartphone through the Blynk (IoT) application. The water requirement yield of lettuce plants in September on Vertisol and Inceptisol in the early phase was 2.45 mm/day, the middle phase was 3.73 mm/day, and the final phase was 3.54 mm/day. Soil moisture detection device at field capacity moisture content produces 319 Analog Digital Converter (ADC) and soil in moist conditions reaches 534 ADC. The analog data value of the water content of the Inceptisol field capacity is 343 ADC and the soil in a moist state is 574 ADC. The performance of the device for detecting soil moisture in the water condition of the 15% field capacity of Vertisol and 22% Inceptisol is more effective than the gravimetric method.

Mitigation of drought disaster in sorghum (Sorghum bicolor l. Moench) in Ultisol soil with application of soil amendments and NPK for diversification and improvement of food security

Drought is a common obstacle in crop cultivation. One third of the world’s food land is experiencing drought, which is increasing from year to year. Mitigation measures are needed to maintain national food security. The use of compost and biochar on Ultisol soils can increase crop yields and productivity under drought stress. Research on Jantho Ultisol soil with low fertility using a soil amadement of 10 t. ha−1, compost can increase soil pH from 4.57 to 5.97 at 50% field capacity soil moisture, an increase in sorghum yield from 1.54 t.ha−1 to 3.37 t.ha−1. Application of biochar 10 t.ha−1 increased pH from 4.57 to 5.03 at 50% field capacity soil moisture, an increase in yield from 1.5 4 t.ha−1 to 2.65 t.ha−1 with 600 kg ha−1 NP K fertilization at 50% soil field capacity moisture. The application of compost and biochar was effective in increasing soil pH and sorghum yield on Ultisol soil. This has mitigated the impact of drought and is an opportunity to increase productivity, diversify of food to increase food security towards food sustainability.