Irrigation Cycle Research Articles

How much water am I using for my yard?

This publication provides context and motivation for reducing outdoor water use. This is done by providing the estimated gallons of water used per irrigation cycle in Florida and then comparing the water used for irrigation to the water used for common indoor activities like showering or washing dishes.

Effects of irrigation cycle and polymer and mineral superabsorbents on some characteristics of tall fescue (Festuca arundinacea Schreb.)

Effects of irrigation cycle and polymer and mineral superabsorbents on some characteristics of tall fescue (Festuca arundinacea Schreb.)

The physico-chemical and bacteriological effects of UV-treated wastewater irrigation on soil and turfgrass quality: A case study in a coastal golf course

<p>This research describes the bacteriological and physicochemical impact of two types of irrigation water on soil and turfgrass quality during 2018 and 2019. Wastewater treated by an activated sludge process coupled with UV disinfection UV-TW was compared to fresh water FW. The first cycle (2018) was devoted to monitoring soil and turfgrass irrigated by FW, and the second cycle (2019) for UV-TW. Our results showed that the mean concentration of fecal indicators of treated wastewater UV-TW is about 2.17, 1.74, 1.77, and 1.52 log10 CFU/100ml for total coliforms, fecal coliforms, E. coli and cecal enterococci, respectively. The physicochemical characteristics showed no significant difference between soil irrigated with UV-TW and soil irrigated with FW except for pH and electrical conductivity. No significant difference was recorded comparing the fecal contamination of soil and turfgrass between the two irrigation cycles, except for fecal coliforms. Overall, the outputs of this work reported that the irrigation with UV-TW presents advantages not only on the quality of the soil and the vegetation, but also on the management of water scarcity. Thus, a highly controlled process of treatment and irrigation must be conducted to assure a safe hydric resource and to avoid any potential risk to human health.</p>

A Hydraulic Evapotranspiration Multisensor

An exclusively mechanical stand-alone automatic device, self-adjusting to weather changes for controlled irrigation, that operates only on the energy of piped water, without electricity, is the described low-cost “Hydraulic Evapotranspiration Multisensor-HEM”. It is composed of an Evaporation Pan with water left to evaporate, a Floater with a Magnet floating in this water, a Hydraulic Device managing a Hydraulic Water Valve having means to adjust irrigation frequency, and a system that returns water to said Pan, through an Adjustable Dripper, to replace that lost by evaporation. During the Evaporation Phase, gradually the water level is lowered to a predetermined level, at which the floating Magnet acts on said Hydraulic Device to start irrigation. Water from the irrigation line is returned to the Evaporation Pan at the proper for the irrigation time rate. When the lost water is replaced irrigation is terminated and the system resets. On installation Irrigation Frequency and Irrigation Time are set with two graduated screws, for normal weather and the conditions of the particular plantation. HEM responding to weather changes modifies the irrigation schedule set, either by shortening, at a high evaporation rate, the time interval between consecutive irrigation cycles to protect plantations from water deficit stress or extending this time interval at a low evaporation rate to save water. Assessing the performance of HEM, by taking the estimations of evapotranspiration from the Penman–Monteith method shows high accuracy in the studied site. Considering the advantages of the product against the programmable irrigation controller devices, HEM provides optimum irrigation control in field crops and makes it a powerful “green tool” to be used in Mediterranean greenhouses.

Модернизация системы управления капельным поливом сельскохозяйственных культур

The study solves the problem of modernizing the control system for automatic watering of plants. There is pre-sented a modernization project based on a flowchart, the operation of which does not require constant monitoring, since it functions in a set automatic mode and, if necessary, can be programmed for a certain period (week, month), while the setting is performed remotely. The advantages of the proposed system are the regulation of irrigation cycles with the choice of water consumption rate, time and duration of irrigation; regulation of the irrigation sector (irrigation angle); the possibility of carrying out different watering cycles within one day; the ability to switch irrigation control to manual mode; no dependence on power failures; aesthetic design. Mechanical damage to the pipelines included in the system is not possible, since the components are made of moisture- and heat-resistant polymeric materials. The project implementation provides for the modernization of the automatic control system for watering plants through the introduction of a modernized soil moisture control device. A diagram of the developed soil moisture sensor on an autogenerator is presented. The principle of operation of the sand filter included in the automatic irrigation system is considered.

Adsorption and desorption characteristics of arsenic in calcareous soils as a function of time; equilibrium and thermodynamic study.

Irrigation of carbonate-rich agricultural soils with arsenic (As)-contaminated water leads to the accumulation of As in these soils. In this regard, there is an opportunity to adsorb and fix the As in soil and decrease the As transportation to the plants and subsequently the human food chain. So, the present study aimed to investigate the adsorption-desorption characteristics of As in calcareous soils and the potential of As fixation over time. First, to achieve this purpose, 53 soil samples were gathered from the study site and after the laboratory analysis, the soils were categorized into four groups based on their physicochemical properties. Then, four representative samples of these groups were selected, namely soil 1, soil 2, soil 3, and soil 4. Afterward, the As adsorption-desorption was investigated in a lab-scale batch experiment. Next, the effect of age was assessed by incubating the As-adsorbed soils for 60days, and to study the impact of temperature, the adsorption was performed at four temperature levels (10, 20, 30, and 40°C). Finally, the isotherm models were fitted to experimental data, and the amount of loosely and tightly held As was quantified. Results revealed that the As adsorption isotherms were L-type, in which As adsorption increased with the increase of As loading. The double-site Langmuir (DSL) estimated that a limited amount of As was adsorbed on high-energy surfaces and a large amount of As was adsorbed on low-energy surfaces. Desorption results showed that a significant amount of As desorbed immediately; however, the desorption significantly decreased with the increase of age, especially at low equilibrium concentrations. By aging the loosely held As transformed into non-labile forms so that in soils 1, 2, 3, and 4, the fraction of As adsorbed on high-energy surfaces increased from 72.5, 93.2, 63.2, and 123mg/kg to 167, 141, 70.6, and 196mg/kg, respectively, and the fraction of As adsorbed on low-energy surfaces decreased from 397, 256, 202, and 317mg/kg to 182, 238, 173, and 172mg/kg, respectively (after aging for 60days). Aging proved to be a promising solution for decreasing As transport into the human food chain and could be employed for crops with longer irrigation cycles. ΔHad values were positive and varied from 9.26 to 13.0kJ/mol, confirming the endothermic nature of adsorption. ΔGad values were negative and varied from - 18.8 to - 22.8kJ/mol at all temperatures, demonstrating the spontaneous nature of adsorption.

SOIL HYDRAULIC PROPERTIES OF A CHROMIC LUVISOL IN KATUMANI, KENYA

<p><strong>Background:</strong> Soil hydraulic parameters in non-saturated conditions are crucial for explaining soil water dynamics in the field. It is therefore necessary to understand the link between soil water potential and hydraulic conductivity in the soil in order to estimate plant available water and hence simulate its movement within the soils. However, measurement of such hydraulic properties in the field and laboratory is somehow difficult, laborious and costly. <strong>Objective</strong>: To determine soil hydraulic properties of Ferro-chromic Luvisols in Katumani using the RETC code based on pedo-transfer functions; % sand, silt, clay and soil bulk density. <strong>Methodology:</strong> Undisturbed soil samples were collected from a profile pit at 0-15, 16-30, 31-45 and 46-60 cm depths using core rings for bulk densities and texture determination. Soil water retention curves and saturated hydraulic conductivities (Ksat) were estimated for all the samples using standard suction apparatus and the constant head method, respectively. The air entry suction (α) and pore size distribution (n) were generated using the RETC code. <strong>Results:</strong> The permanent wilting point and field capacity were at 0.081, 0.102, 0.107 and 0.121 and 0.188, 0.225, 0.241, 0.262 m<sup>3</sup>m<sup>-3 </sup>H<sub>2</sub>O, whilst its soil water diffusivity ranged from a low of 6.39, 6.94, 9.03 to a high of 12.5 cm<sup>2</sup>min<sup>-1</sup> in the 0-15, 16-30, 31-45 and 46-60 cm depth, respectively. Ksat values from RETC code ranged from 29 - 48 cm day<sup>-1</sup>, while the total and readily available water within the soil profile were 330.4 and 214.7 mm H<sub>2</sub>O, respectively. <strong>Implication:</strong> The air entry value (α) and pore size distribution (n) implied an almost even distribution from the top and subsequent horizons. The soils ‘field capacity was achieved at pF 2.0 whilst PWP was arbitrary indicated at pF 4.2 reducing the time it takes to calculate irrigation cycles based on the amount of water available to the crops. <strong>Conclusion:</strong> The data indicates that pedo-transfer functions; especially high bulk densities negatively impact on soil hydraulics conductivity.</p>

Germination and Growth Characteristics of Quercus myrsinifolia Blume Seedlings According to Seed Coat Removal, Type of Potting Soil and Irrigation Cycle

The importance of evergreen oak species is increasing due to changes in the ecosystem caused by climate change and environmental changes such as fine dust and carbon dioxide. The Quercus myrsinifolia Blume seeds showed a recalcitrant seed property, where the germination rate decreased when the moisture content was decreased. For seedling propagation of evergreen oak, the effect of oak seed coat (pericarp and testa) removal on germination and seedling growth as well as the effect of potting soil and irrigation cycle on seedling quality were investigated. The germination rate and germination characteristics of Q. myrsinifolia evergreen oak seeds showed significant differences depending on the storage period and the presence or absence of seed coat. Seed coat removal significantly increased germination rate compared to intact seeds, accelerated mean germination time, and increased germination rate and germination value. There was no significant difference in germination rate according to the storage period. The growth of Q. myrsinifolia seedlings was much better in the seeds with the seed coat removed than the intact seeds. The root collar diameter of seedlings germinated from intact seeds was 2.44 mm, and the root collar diameter of seedlings from which the seed coat was removed was 3.38 mm. As a result of the growth characteristics according to the potting soil, 1- and 3-year-old Q. myrsinifolia seedlings showed excellent root growth in commercial potting soil and sand mixed potting soil. Consequently, seedling quality index was 0.124–0.257 according to irrigation and 0.149–0.262 according to potting soil. From observing the root growth of the seedlings according to the irrigation treatment, in the case of 3-year-old seedlings, the total root length was 432 cm when irrigated every 3 days, and the growth was the best. The above results are expected to contribute significantly to the mass propagation of Q. myrsinifolia, which is important for warming and urban greening.

Morphological and physiological responses of desert plants to drought stress in a man-made landscape of the Taklimakan desert shelter belt

Drought and desertification have become a worldwide ecological problems, which pose new challenges for plant survival and adaptation. Thus, it is of great significance to explore the adaptive strategies of plants to drought stress for the survival and sustainable development of man-made ecosystem in desert. In this study, two drought treatments of control (10-day irrigation cycle) and drought (no irrigation) respectively were used to study the physiological and morphological acclimation of Haloxylon ammodendron (C.A. Mey) Bunge and Calligonum arborescens Litv, in a man-made landscape of the Taklimakan desert shelter belt. The results showed that not only significant difference for stomatal conductance and water potential was presented in this research for two species, but also the morphological difference. In response to drought, C. arborescens produced significantly shorter and thicker leaves, while H. ammodendron produced significantly shorter and thinner leaves. Additionally, for C. arborescens, non-structural carbohydrates (NSC) were significantly aggregated in the roots (P < 0.05), while in H. ammodendron NSC exhibited no significant change in leaves, stems, or roots, but significantly accumulated in the whole plant. The different leaf water potential Ψl for two species leading to a different WUE. In all, the two species exhibited different acclimation responses to drought, C. arborescens with a great higher WUE in drought, but H. ammodendron was smaller. Morphological adjustment was the main mechanism by which C. arborescens acclimated to drought, and it can be used as a “pioneer”sand-fixation species in deserts if resources enough. In contrast, H. ammodendron acclimated to drought by physiological adjustment dominated by stomatal closure, suggesting it could be used in sustainable development of ecological restoration areas.

Effects of Timing in Irrigation and Fertilization on Soil NO3−-N Distribution, Grain Yield and Water–Nitrogen Use Efficiency of Drip-Fertigated Winter Wheat in the North China Plain

In the North China Plain, drip irrigation is gradually used in winter wheat production, and the improper management of water and fertilizer aggravates the risk of crop instability and groundwater pollution. A lysimeter experiment with three levels of fertilization timing (T1 = beginning; T2 = middle; and T3 = end of the irrigation cycle) and two irrigation rates (W1 of 30 mm and W2 of 20 mm) was carried out to investigate the effects of irrigation rate and fertilization timing on the soil NO3−-N distribution, crop development, yield, and water–nitrogen usage efficiency of winter wheat. The results indicated that, under the condition of delayed fertilization timing (T2 and T3), the trend of NO3−-N migration to the edge of moist soil became more apparent. The treatments of irrigation rate and fertilization timing significantly affected the plant height, water–nitrogen utilization efficiency, aboveground biomass, grain yield, and leaf area index. The maximum grain yield of 7688.67 kg ha−1 was found at W1T2, which had a nitrogen partial factor productivity (NPFP) of 32.04 kg kg−1. Moreover, W1T2 did not result in a significant reduction in irrigation water use efficiency (IWUE) (4.27 kg m−3) in comparison with other treatments (4.00–5.43 kg m−3). Based on crop growth, N uptake, yield, IWUE, and NPFP, the irrigation rate of 30 mm combined with fertilization in the middle of the irrigation duration could be considered as suitable irrigation and nitrogen timing for drip-irrigated wheat.

Green roof irrigation management based on substrate water potential assures water saving without affecting plant physiological performance

AbstractIrrigation management in extensive green roofs (EGRs) is crucial in Mediterranean and semi‐arid climates, as it should guarantee efficient water use while ensuring plant survival and vegetation cover. However, benefits of maintaining moderately low substrate water potential (Ψs) have not been adequately investigated to date. An irrigation control unit based on Ψs thresholds for irrigation (MediWater Safe [MWS]) was compared to a common irrigation timer maintaining Ψs ⁓ 0 MPa (CTR) in shrub‐vegetated Mediterranean EGR modules. The effect of the different irrigation regimes on substrate temperature, plant water relations (leaf conductance to water vapour, midday water potential and turgor loss point) and root vulnerability to heat stress via electrolyte leakage was tested in four shrub species. Decreasing Ψs thresholds to −0.4 MPa reduced irrigation volumes by 68% in 3 summer months. However, the MWS unit neither influenced plant water status and vegetation cover nor induced physiological acclimation responses. Brief irrigation cycles imposed by MWS in the warmest hours reduced substrate surface temperature by 3°C compared to CTR. Plant water status dynamics and root vulnerability to heat were species specific. Progressive stomatal closure and plant decline occurred only in Ceanothus thyrsiflorus and were associated to high root vulnerability to heat. Mortality occurred only in some Ceanothus plants in the CTR module, where higher Ψs favoured the expansion of Hyperucum x moserianum. The results suggest that selecting proper Ψs thresholds for irrigation could optimize EGR benefits, guaranteeing substantial water savings and proper plant establishment. Moreover, we claim root resistance to heat as a key parameter for plant selection in Mediterranean EGRs.

Evaluation of Patch Budding Success in Persian Walnut Affected by Different Treatments after Budding

ABSTRACT Vegetative propagation of Persian walnut (Juglans regia L.) is more difficult than many other fruit trees. Temperature, relative humidity, water status of the scion and rootstock, nutrient uptake, time of grafting, physiological condition of the rootstock, and scion type all can affect grafting success. An experiment was conducted to evaluate the effects of post-budding irrigation frequency (3, 7 and 10-days), budding date (14 June, 5 and 26 July), and rootstock heading methods. All treatments and evaluations of their effects were performed in field conditions, for two consecutive years. Irrigation cycle, budding date and rootstock heading procedure all had significant effects. Bud take was greatest on 26 July (49.3%). Irrigation frequency had no significant effect on bud take but the 3-day cycle resulted in the best scion growth. Bend the branches to create shade at the bud site, rather than cutting the rootstock above the bud site resulted in the best bud take (61.1%). The results obtained in this study show that budding at the right time “provides better climatic conditions,” adjusting the irrigation cycle and choosing the best rootstock heading methods after budding, produces satisfactory results

Essential Oil Composition and Bioactive Properties of Lemon Balm Aerial Parts as Affected by Cropping System and Irrigation Regime

The ongoing climate crisis necessitates the sustainable use of natural resources and the adoption of environmentally friendly agronomic practices. Deficit irrigation is an ecofriendly technique that allows for the improvement in the water use efficiency of crops. On the other hand, medicinal and aromatic crops, which usually have an innate tolerance to harsh conditions, are suitable candidates for cultivation under low-input cropping systems. In the present study, Melissa officinalis plants were cultivated under conventional and organic cropping systems, while in each system two irrigation regimes (full irrigation or deficit irrigation) were tested. The aerial parts of the plants were evaluated in terms of growth and physiological parameters, chemical composition, antioxidant activity, essential oil yield and essential oil composition. Our results indicate that prolonged water stress after two deficit irrigation cycles had detrimental effects on the plant growth and biomass production, whereas it significantly increased the essential oil yield, regardless of the cropping system (organic or conventional cultivation). The recorded physiological parameters are in agreement with morphological features, especially the stomatal conductance, which was significantly reduced under deficit irrigation for both cultivation systems, revealing that the growth inhibition was the result of stomatal closure and carbon dioxide deprivation. Deficit irrigation and organic cultivation also increased total phenol and total flavonoid content, especially in the second harvest, thus resulting in higher antioxidant activity assayed by the FRAP method. In contrast, DPPH and ABTS methods did not show any differences among the tested treatments in the second harvest, which suggests that other bioactive compounds are also involved in the overall antioxidant mechanism of lemon balm plants, as indicated by the increased ascorbic acid content. Regarding the essential oil composition, the major detected compounds were geranial and neral and, although they were both increased under the organic cropping in the first harvest, the same trend was not observed in the second harvest. Finally, a variable effect of cropping system and irrigation regime on minerals content was recorded. In conclusion, deficit irrigation is an ecofriendly practice that could be applied in conventional and organic cropping systems of lemon balm crops, aiming to reduce irrigation water consumption and compensate for reduced herb yields with increased essential oil yield and polyphenol content.

Irrigation and phosphorous fertilization management to minimize rice grain arsenic content

This research sought to minimize inorganic arsenic levels in polished rice grain by using different irrigation and phosphorous fertilization practices while also maintaining crop yield and water productivity. Two experiments were conducted during seasons 2018–2019 and 2019–2020 using a split-plot design with three blocks, five irrigation treatments (main-plots) and two phosphorous levels (sub-plots). Irrigation treatments consisted of a traditional continuous flood (CF) control and four alternatives irrigation techniques with one or two drying events during the irrigation cycle. The phosphorous fertilization levels investigated were an unfertilized control (0 kg P2O5 ha−1) and the recommended fertilization level of 50 kg P2O5 ha−1. Soil pH and redox potentials were measured in each treatment. Strategically-timed, low severity drying events were effective at achieving aerobic soil conditions, resulting in Eh values over 50 mV. The alternative irrigation treatment with two drying events, implemented at panicle initiation and full flowering, was the most effective in reducing inorganic arsenic in grain without affecting grain yield or the amount of irrigation water applied. This irrigation technique could be considered as an alternative management to the traditional continuous flooded to reach minimal inorganic arsenic accumulation in grain in order to attend special quality standards or specific market requirements. Accumulated inorganic arsenic in grain was below international maximum levels in all analyzed samples, with an average value of 0.084 mg kg−1.

Study the Effect of Irrigation Cycle and Size of Mother Corms on Flower Yield and Daughter Corms in Saffron

Study the Effect of Irrigation Cycle and Size of Mother Corms on Flower Yield and Daughter Corms in Saffron

Impact of Sodium Hypochlorite on Organic Tissue Dissolution in the Periapical Region of Immature Permanent Teeth: An Ex Vivo Study

IntroductionThe purpose of this study was to evaluate the impact of different sodium hypochlorite (NaOCl) irrigation protocols on organic tissue dissolution in the periapical region of simulated immature permanent teeth. MethodsEight single-rooted premolars and 48 samples of porcine palatal mucosa were used. Acrylic resin prototypes were constructed, placing the tissue in close contact with the dental apices. Specimens were then divided into 6 groups (n = 8): 2 control groups of normal saline irrigation with (NS/WA) or without (NS/NA) ultrasonic activation and 4 experimental groups of 1.5% and 2.5% NaOCl irrigation with (NaOCl 1.5%/WA and NaOCl 2.5%/WA) or without (NaOCl 1.5%/NA and NaOCl 2.5%/NA) activation. Root canals were irrigated with 20 mL of the solution for 5 minutes distributed over 4 irrigation cycles. In each cycle, after irrigation, the solution was either kept stagnant or activated for 30 seconds and then replaced. Specimens were weighed on a precision balance before and after the irrigation protocols. Tissue dissolution was measured by the difference between the initial and final weights. One-way analysis of variance was applied followed by the Tukey honestly significant difference test (α = 0.05). ResultsThe NS/NA and NS/WA groups had mean weight reductions similar to the 1.5% NaOCl/NA group (P > .05) and lower than the others (P < .05). The 2.5% NaOCl/NA and 2.5% NaOCl/WA groups had the highest mean weight loss (P < .05), whereas the 1.5% NaOCl/WA group had intermediate values (P < .05). ConclusionsPeriapical tissue dissolution occurred in all groups, with a greater impact observed with 2.5% NaOCl with or without ultrasonic activation.

Indigenous Technical Knowledge based Rainfall Prediction: A Review

Indigenous technical knowledge (ITK) is the actual knowledge of a given population that reflects the experiences based on tradition and includes more recent experiences with modern technologies. Traditionally, farmers have used traditional knowledge to understand weather and climate patterns in order to make decisions about crop and irrigation cycles. This knowledge has been gained through many decades of experience and has been passed on from previous generations. The present study was undertaken with the objective of collection and documenting the indigenous technical knowledge of farmers regarding rainfall prediction based on abiotic and biotic factors which is being practiced generation after generation. Here in this paper an effort has been made to collect the abiotic and biotic factors predicting rainfall, as a part of ICAR sponsored NASF ad-hoc research project entitled “Developing climate resilient adaptive strategies for empowerment of farmers” which has been implemented in University of Agricultural Sciences, Dharwad from 2019 to 2022. Various indigenous technical knowledge are collected by analyzing the journals and newsletters, deep interaction with the farmers of study area, contacting the local resource persons and documenting oral histories without scientific validation. The study found that traditional methods of rainfall forecasting can be utilized for the purpose of short-term and long-term seasonal rainfall predictions by local communities. All available abiotic and biotic indigenous rainfall forecasting techniques may serve as alternative to modern technologies.

РЕТРОСПЕКТИВНЫЙ ОБЗОР ТЕХНОЛОГИЙ ОЧИСТКИ И ПОДГОТОВКИ ДРЕНАЖНЫХ ВОД С ОРОСИТЕЛЬНЫХ СИСТЕМ

Purpose: the retrospective analysis of technological and technical solutions on purification and treatment of drainage water from irrigation systems. Discussions. Three technological complexes to ensure the safe reuse of drainage water are distinguished in world practice. The first complex is based on the removal of suspended and soluble organic pollutants from drainage waters. The second complex includes traditional methods of desalination – reverse osmosis, electromembrane methods, etc. The third technological complex allows removing toxic contaminants. When developing technologies for drainage water purification and treatment to irrigate agricultural crops, it was taken into account that they include organic and inorganic compounds and toxic compounds of salts. The technology based on the use of solar reservoirs is the most promising. This complex includes accumulators-evaporators of drainage waters, a brine evaporator, mineralization from 10–15 to 200–250 g/dm³ is acceptable. The technological schemes and methods of purification and treatment of drainage water from irrigation systems described in the article allow solving the issue of saline wastewater disposal by returning them to the irrigation cycle and preventing their discharge into surface water bodies. Conclusions. As the analysis of technological solutions for drainage water treatment shows, complex technical solutions based on physicochemical and biological treatment methods are promising. The most common approach to the drainage water treatment is preliminary mechanical cleaning with further adsorption on natural sorbents.

Effects of compost tea on the spatial distribution of soil nutrients and growth of cotton under different fertilization strategies

Compost tea comes from a wide range of sources and can provide nutrients for crops and improve soil quality. In order to explore the effects of fertilization frequencies of compost tea on the spatial distribution of nutrients and the uptake by cotton, a trial comprised no fertilization treatment (CK) and three fertilizer treatments, that is, the application of a fixed amount of fertilizer at four (F3), two (F5), or one (F9) irrigation cycle, and each irrigation cycle was 10 days. The total amount of nutrients (N, P2O5, K2O) in fertilization treatment were all 18 g, and their amount of fertilization each time was 1/3, 1/5 and 1/9 of the total fertilizer, respectively. The results showed that in 0–10 cm soil layers, high-frequency fertilization (F9) reduced the soil pH by 5.6% compared with F3, the soil nutrient content of F3 treatment at seedling stage was significantly higher than that of the other two treatments by 71.9%–272.3%, however, the 20–40 cm soil layer was hardly affected by fertilization; The nutrient accumulation of cotton in F3 treatment was 17.1%–32.4% higher than that in the other two treatments, and the highest dry matter and recovery efficiency were also obtained under the F3 treatment. In conclusion, increasing the proportion of fertilization in seedling stage (F3) can increase the uptake and utilization of nutrients by cotton; While high-frequency fertilization (F9) can reduce the pH of calcareous soil. This study provides a basis for fertilizer optimization and soil quality improvement of composted tea.

Reviewing Mini-lysimeter Controlled Irrigation in Container Crop Systems

This study reviews how mini-lysimeters have been used effectively to optimize irrigation control in container horticulture production. Lysimeters are devices that measure evapotranspiration (ET) from the water balance of a fixed soil volume. The primary components of lysimeter-controlled irrigation are load cell sensors, a multiplexer, a data logger, a controller, and solenoid valves. The two common mini-lysimeter systems are platform lysimeters and suspension lysimeters. In these systems, a bending-beam single-point load cell is fastened between two plates, and a container is placed directly on the top platform. Platform lysimeters are commonly used for smaller pot sizes, and suspension lysimeters have been used for large shade trees up to 2.8 m tall and weighing 225 kg. Mini-lysimeters have been used for decades to calibrate ET models and create on-demand irrigation control programs that replenish plant daily water use or maintain deficit conditions. Research has demonstrated that lysimeter-based irrigation can respond more effectively to seasonal and diurnal variations in water demand, increasing irrigation cycles when evaporative demand is high, and decreasing irrigation cycles when demand is low. A strength of these systems is that for containerized plants, such as nursery production systems, mini-lysimeters capture whole-plant water use, which presents a more holistic measure compared with soil moisture sensors or leaf moisture sensors.