Irrigation Frequency Research Articles

Enhancement of sandy soil water retention using superabsorbent carboxymethyl cellulose grafted with polyacrylamide and polyacrylamidomethyl propanesulfonic acid copolymer

To enhance the productivity of sandy soil, considerable efforts have been devoted to improving its water retention capacity, thereby reducing the frequency of irrigation and minimizing water loss through evaporation. The present study aimed to develop carboxymethyl cellulose (CMC)—grafted-(polyacrylamide (PAM)-co-2-acrylamido-2-methylpropanesulfonic acid (PAMPS) superabsorbent hydrogel (SAH) for effective water retentionin sandy soil. Characterization of the grafted copolymer hydrogel was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The synthesized CMC-g-(PAM-co-PAMPS) SAH exhibited improved thermal stability, demonstrating a half-weight loss at 391 °C compared to 331 °C for the pure CMC biopolymer. The consequence of various grafting conditions on the percentage add-on was systematically optimized. Additionally, factors influencing water uptake behavior, including contact time, pH and temperature of the medium, particle sizes, and total dissolved salts, were investigated. The results indicated that increasing the co-monomer ratio from 3 to 18% significantly raised the % add-on value from 81 to 97.4%. The developed SAH showed an exceptionalwater uptake capacity of 313 g/g within a short duration of 15 min. Furthermore, it demonstrated the ability to reabsorb water over five successive cycles, achieving an efficiency exceeding 70%. The incorporation of the SAH into sandy soil resulted in a reduction of water outflow, with a significant decrease in the flow rate from 0.96 to 0.32 cm/min. The fabricated superabsorbent hydrogel presents a promising approach for enhancing water retention in sandy soil.

Optimized Water Management Strategies: Evaluating Limited-Irrigation Effects on Spring Wheat Productivity and Grain Nutritional Composition in Arid Agroecosystems

The Hetao Plain Irrigation District of Inner Mongolia faces critical agricultural sustainability challenges due to its arid climate, exacerbated by tightening Yellow River water allocations and pervasive water inefficiencies in the current wheat cultivation practices. This study addresses water scarcity by evaluating the impact of regulated deficit irrigation strategies on spring wheat production, with the dual objectives of enhancing water conservation and optimizing yield–quality synergies. Through a two-year field experiment (2020~2021), four irrigation regimes were implemented: rain-fed control (W0), single irrigation at the tillering–jointing stage (W1), dual irrigation at the tillering–jointing and heading–flowering stages (W2), and triple irrigation incorporating the grain-filling stage (W3). A comprehensive analysis revealed that an incremental irrigation frequency progressively enhanced plant morphological traits (height, upper three-leaf area), population dynamics (leaf area index, dry matter accumulation), and physiological performance (flag leaf SPAD, net photosynthetic rate), all peaking under the W2 and W3 treatments. While yield components and total water consumption exhibited linear increases with irrigation inputs, grain yield demonstrated a parabolic response, reaching maxima under W2 (29.3% increase over W0) and W3 (29.1%), whereas water use efficiency (WUE) displayed a distinct inverse trend, with W2 achieving the optimal balance (4.6% reduction vs. W0). The grain quality parameters exhibited divergent responses: the starch content increased proportionally with irrigation, while protein-associated indices (wet gluten, sedimentation value) and dough rheological properties (stability time, extensibility) peaked under W2. Notably, protein content and its subcomponents followed a unimodal pattern, with the W0, W1, and W2 treatments surpassing W3 by 3.4, 11.6, and 11.3%, respectively. Strong correlations emerged between protein composition and processing quality, while regression modeling identified an optimal water consumption threshold (3250~3500 m3 ha−1) that concurrently maximized grain yield, protein output, and WUE. The W2 regime achieved the synchronization of water conservation, yield preservation, and quality enhancement through strategic irrigation timing during critical growth phases. These findings establish a scientifically validated framework for sustainable, intensive wheat production in arid irrigation districts, resolving the tripartite challenge of water scarcity mitigation, food security assurance, and processing quality optimization through precision water management.

Frequent Irrigation in Manure-fertilized Soil Reduces CO2 Emissions Per Unit Yield by Increasing Maize Silage Yield

In agricultural areas where manure is used as fertilizer, the rapid mineralization of soil carbon upon rewetting, along with increased microbial activity, results in a significant release of CO2 emissions. This process leads to substantial soil carbon depletion, which has negative environmental impacts. This study aims to examine which irrigation regime reduces soil carbon loss to optimize CO2 emissions per unit yield for sustainable production. Soil CO2 emissions were measured using an infrared gas analyzer in soils fertilized with mineral (F) and cattle manure (M) under three irrigation regimes in the research. Irrigations were conducted at different intervals based on the difference between estimated cumulative plant water consumption and precipitation (25, 50, and 75 mm, respectively) in the IR1, IR2, and IR3 regimes. The consistent emissions of CO2 during the growing season were due to the ongoing depletion of organic carbon in the soil. Increasing soil moisture and decreasing soil temperature contributed to emission increases. The application of manure increased CO2 emissions per unit area, water consumption, and yield by 2.7, 2.8, and 2.0 times, respectively, compared to mineral fertilization. This was attributed to the higher seasonal carbon emission, lower water consumption, and higher yield associated with manure application. The IR1 treatment, which enhanced the mineralization of organic matter, resulted in a 1.08 times increase in CO2 emissions per unit area and a 1.16 times increase in emissions per unit water consumption compared to the IR3 treatment. On the contrary, it caused a 1.41 times decrease in emissions per unit yield with the yield contribution. Although CO2 emissions per unit yield were 75.4% higher than in FIR1, the MIR1 treatment was the most successful in reducing emissions, showing a 1.57 times decrease compared to MIR3. In conclusion, frequent irrigation in soil fertilized with manure decreases CO2 emissions per unit yield in silage maize. Higher yields with frequent irrigation management can lead to a greater reduction in CO2 emissions per unit of yield.

Design and manufacturing of superabsorbent polymers (SAPs) for agriculture in arid areas

Innovative water-saving technologies aim to address the problem of water scarcity in agriculture, which faces significant challenges in solving the problem of agriculture in semi-arid and arid areas. This study specifically focuses on establishing a promising low-cost method to solve water scarcity and agriculture issues in semi-arid and arid areas. The objective of this study is to find an innovative engineering solution to design, manufacture, and produce an engineered product that has the potential to assist and change agriculture in semi-arid and arid areas. Design and manufacture of an innovative engineering product in the form of absorbent tiles (ATs), ATs can absorb and retain large volumes of water, helping to maintain moisture, and consistent moisture levels promote better root growth, and nutrient supply leading to healthier plants and increased crop yields, and reduce the need for frequent irrigation. The study objective was achieved by synthesis of two superabsorbent polymers (SAPs) materials, the synthesis of sodium polyacrylate (hydrogel#1) with five varying cross-linker content (wt.), synthesis of poly (sodium acrylate-co-glycidyl methacrylate) (hydrogel#2) with five varying cross-linker content (wt.), prepare the agriculture residual rice straw (RS) fiber length with three dimensions as a filler, prepare the natural adhesive (NA) solution as a biopolymer backbone, and design and manufacture hydraulic manual press ( test rig). These composites were mixed, compressed, and shaped to design and manufacture two tiles including AT1 (AT-NaPA) and AT2 (AT-AGMA) with different dimensions according to the effect root zone of the plant type to absorb and retain rainwater dew water and reduce irrigation frequency. Furthermore, ATs improve plant growth and nutrient supply under aridity condition and facilitate water conservation.

Long-Term Decision Regret and Associated Factors After Urinary Reconstruction in Underserved Patients With Spinal Cord Injury.

Long-Term Decision Regret and Associated Factors After Urinary Reconstruction in Underserved Patients With Spinal Cord Injury.

Effects of Water Application Frequency and Water Use Efficiency Under Deficit Irrigation on Maize Yield in Xinjiang

Water conservation is critical for global maize production, particularly in arid regions where water scarcity, exacerbated by climate change, threatens conventional irrigation sustainability. Optimizing irrigation strategies to reconcile water productivity and yield remains a key scientific challenge in water-limited agriculture. This four-year study (2018–2021) evaluated integrated irrigation management that combined frequency and volume adjustments. A field experiment compared three strategies: high-frequency limited irrigation (HL: 2400 m3·hm−2), low-frequency conventional irrigation (LC: 2400 m3·hm−2), and high-frequency conventional irrigation (HC: 4800 m3·hm−2). The four-year mean yield showed that HL (10,793.78 kg·hm−2) had a non-significant 18.2% numerical advantage over LC (9,129.11 kg·hm−2, p > 0.05). The WUE for HL reached 3.63 kg·m−3, representing an 18.6% numerical increase compared to LC (3.06 kg·m−3; p > 0.05). Physiological parameters (plant height + 2.6%, leaf area + 9.9%, SPAD + 1.5%) showed marginal improvements in HL, yet lacked both statistical significance (p > 0.05) and strong yield correlation. Multi-year analyses confirmed no statistically distinguishable differences between strategies (p > 0.05), demonstrating that irrigation frequency adjustments alone cannot reliably enhance drought resilience. These findings caution against advocating for HL as a superior practice, given the statistical equivalence between HL and LC despite water savings, and the non-significant yield gap between HL and HC. Future research must establish causality through models integrating real-time soil–crop–climate feedback prior to recommending altered irrigation regimes.

What Are the Optimal Irrigating Wound Vacuum Parameters When Using Bacteriophage Therapeutics?

Objective: Bacteriophages are promising adjuvant anti-biofilm agents. Yet novel ways to repeatedly administer bacteriophages invivo are needed. One technique utilizes irrigating wound vacuum systems. However, the proper parameters to use with bacteriophages are poorly defined. Therefore, the objective of this study was to elucidate proper bacteriophage irrigating vacuum parameters. Methods: Individual Pseudomonas aeruginosa and Staphylococcus aureus clinical isolates were allowed to form biofilms in microwell plates and then exposed to repeated irrigations with saline or with bacteriophages over 8 hours. The repeated irrigations corresponded to theoretical different dwell times of the irrigating vacuum system. Residual biofilm mass was compared among groups by staining with crystal violet and measuring optical density. Results: As the number of saline irrigations increased, there was less biofilm burden, and this was substantially less than growth controls (p < 0.05). When compared with saline, bacteriophages substantially reduced biofilms except for the P. aeruginosa bacteriophage at dwell times of 20 minutes. Furthermore, bacteriophages caused no observable colony forming units per milliliter for all dwell times except 20-minute dwell times, and this was statistically significant (p < 0.05) when compared with saline infusions. Conclusions: Frequent irrigation with shorter dwell times facilitates biofilm disruption and reduces bacterial burden. However, if dwell times are too short, bacteriophages may not have sufficient time to hydrolyze biofilm and to infect and kill bacteria. On the basis of our model, we propose a minimum of 1 hour dwell time but appreciate that more translational research is needed to refine these approaches.

Growth Trend Prediction and Intervention of Panax Notoginseng Growth Status Based on a Data-Driven Approach.

In crop growth, irrigation has to be adjusted according to developmental stages. Smart agriculture requires the accurate prediction of growth status and timely intervention to improve the quality of agricultural products, but this task faces significant challenges due to variable environmental factors. To address this issue, this study proposes a data-driven irrigation method to enhance crop yield. Our approach harvests extensive datasets to train and optimize an integrated deep-learning architecture combining Informer, Long Short-Term Memory (LSTM) networks, and Exponential Weighted Moving Average (EWMA) models. Controlled greenhouse experiments validated the reliability and practicality of the proposed prediction and intervention strategy. The results showed that the model accurately issued irrigation warnings 3-5 days in advance. Compared to traditional fixed irrigation, the model significantly reduced irrigation frequency while maintaining the same or even better growth conditions. In terms of plant quantity, the experimental group increased by 410.0%, while the control group grew by 50.0%. Additionally, the experimental group's average plant height was 21.8% higher than that of the control group. These results demonstrate the efficacy of the proposed irrigation prediction method in enhancing crop growth and yield, providing a novel strategy for future agricultural planning and management.

Effect of Irrigation Frequency and Weed Management on Growth and Yield of Sesame

Sesame (Sesamum indicum L.), a vital oilseed crop, faces productivity challenges due to irrigation and weed management issues. This study aimed to investigate the impact of irrigation frequency and weed management on the growth and yield of sesame, conducted at Sher-e-Bangla Agricultural University, Bangladesh, using a split-plot design with four levels of irrigation (I₀: no irrigation, I₁: one irrigation at 20 DAS, I₂: two irrigations at 20 and 40 DAS, I₃: three irrigations at 20, 40, and 60 DAS) and four weed management strategies (W₀: no weeding, W₁: one hand weeding at 20 DAS, W₂: two hand weedings at 20 and 40 DAS, W₃: post-emergent herbicide application at 20 and 40 DAS). Results showed that three irrigations (I₃) significantly increased plant height, branching, and seed yield (1.282 t ha⁻¹), while weed control using herbicides (W₃) or combined hand weeding (W₂) minimized competition, yielding the highest seed output (1.171 t ha⁻¹). Differences were statistically significant (p&lt;0.05). These findings emphasize that adopting efficient irrigation schedules and integrated weed management can sustainably boost sesame productivity, providing valuable insights for farmers and researchers targeting yield improvements in resource-limited settings.

A smartphone application for estimating irrigation frequency and runtime for Californiancrops based on the water balance approach

Optimizing irrigation ensures that plants receive the right amount of water without any loss from deep percolation or drainage. However, non-professional crop growers, such as gardeners and garden hobbyists, have limited access to data-driven solutions to optimize irrigation cycles. This app aims to fill this gap by providing Irrigation Frequency and Runtime for a range of selected crops in California. The evapotranspiration-based smartphone app uses locally calibrated crop coefficients, Maximum Allowed Depletion factors, and weather data to determine the average daily irrigation runtime. It is also the first smartphone application that calculates effective rainfall for any selected location in California. In the future, the app could be applied to other U.S. states.

Restoration Strategies for Drylands: Impact of Hydrogel and Watering Frequency on Oak, Hawthorn and Pine Seedlings Survival

This study investigates the effects of irrigation frequency and soil hydrogel addition on the drought response and survival of seedlings from three tree species—oak (Quercus robur), hawthorn (Crataegus monogyna), and pine (Pinus sylvestris)—in a greenhouse experiment. The objective is to assess these factors' implications for ecological restoration in arid and semi-arid regions. A total of 240 seedlings (80 per species) were subjected to four experimental treatments, varying in watering regimes and soil amendments. Experiments 1 and 3 featured daily irrigation for the first 20 days, while Experiments 2 and 4 involved irrigation five times over the same period, followed by 30 days of drought stress. Hydrogel was incorporated into the soil in Experiments 3 and 4 at a rate of 8-10 grams per 8-10 liters of soil. Seedlings were tracked using unique codes and monitored for wilting and survival. Results showed hawthorn seedlings exhibited the highest survival rates and lowest wilting scores, followed by oak and pine. Seedlings grown in hydrogel-amended soil with daily watering demonstrated reduced wilting. The findings suggest that hydrogel addition and increased irrigation frequency enhance drought resilience, indicating potential benefits for using these methods in ecological restoration efforts in water-limited environments.

Frequent Irrigation of Silage Maize in Soil Containing Sewage Sludge Reduces Co2 Emissions Per Unit Yield By Increasing Productivity

Although organic fertilization improves soil health and productivity, a sustainable food supply also requires reducing environmental carbon emissions. The aim of this field study was to reduce CO2 emissions from soil per unit biomass yield of silage maize. The experiment was conducted in a total of 36 plots with three replicates with three irrigation regimes (R1, R2, and R3) with varying wetting–drying durations in soil containing four doses of stabilized sewage sludge (0, 30, 60 and 90 Mg ha−1; D0, D1, D2 and D3). Irrigation was applied when the ∑ (estimated evapotranspiration – effective precipitation) value reached 25, 50 and 75 mm in R1, R2 and R3, respectively. A steady change in carbon emissions was also detected with a steady loss of organic carbon throughout the vegetation period. R1 and D3 led to the highest cumulative CO2 emissions per unit production area of 9821.4 kg CO2 ha−1 and 11514.9 kg CO2 ha−1, respectively; these values were also 11.5% and 40.8% higher than the R3 and D0 values, respectively. The changes in CO2 emissions per unit of water use were similar to the changes in cumulative emissions. However, while R1 provided the lowest CO2 emission per unit biomass yield with the highest yield, the highest values were determined in D0 with a lower yield and in D3 with a higher emission. Therefore, frequent irrigation with 30 and 60 Mg ha−1 doses of sewage sludge can decrease CO2 emissions per unit yield in silage maize.

Effects of Different Irrigation Regimes on Root Growth and Physiological Characteristics of Mulch-Free Cotton in Southern Xinjiang.

In order to explore the effects of different irrigation methods on the physiological characteristics of mulch-free cotton in southern Xinjiang, the following experiments were carried out: (1) Different irrigation amount test: 300, 375, 450, 525, and 600 mm (represented by W1, W2, W3, W4, and W5) and a control (450 mm for film-covered cotton, represented by WCK) were set. (2) Drip irrigation frequency test: drip irrigation 12, 10, 8, and 6 times during the growth period (expressed by P12, P10, P8, and P6). Soil water dynamics, root distribution dynamics, chlorophyll fluorescence, leaf area index (LAI), SPAD (chlorophyll density), stress enzyme activities, and MDA (malondialdehyde) content were observed. The results showed that the average maximum change range of soil water content in the cotton field without film mulching was ±17.7%, which was 1.35 times higher than that in the cotton field with film mulching. Compared with cotton with film mulching, the root distribution characteristics of mulch-free cotton in the surface soil (0-20 cm) and the periphery (30 cm from the main root) decreased by 33.55-74.48% and 14.07-102.18%, respectively, while the root distribution characteristics in the deep layer (40-60 cm) increased by 49.62-242.67%, its average leaf green fluorescence parameters decreased by 9.03-50.44%, the activities of protective enzymes (SOD: superoxide dismutase, POD: peroxidase) decreased by 3.36-3.58%, the SPAD value decreased by 5.55%, and the MDA content increased by 3.17%, indicating that mulch-free cotton reduced the physiological function of cotton leaves, and the yield decreased by 42.07%. In the mulch-free treatments, the average root growth indexes were W2 > W3 > W4 > W5 > W1 and P12 > P10 > P8 > P6, and there was little difference between W2 and W3 and P12 and P10. With the increase in irrigation water and irrigation frequency, the initial fluorescence (F0) of leaves in each period of mulch-free cotton showed a downward trend, and the maximum fluorescence (Fm), variable fluorescence (FV), maximum photochemical efficiency (FV/Fm), potential photochemical activity of PS II (FV/F0), electron transfer of PS II (Fm/F0), and photosynthetic performance index (PIABS) showed an upward trend. In all water treatments, W3 and P12 had the highest SPAD value, protective enzyme activity, and the lowest MDA content, which was significantly different from other treatments except W4 and P10. The yield order of different treatments was W3 > W4 > W5 > W2 > W1, and the difference between W3 and W4 was not significant, but significant with W2 and W1. The irrigation frequency test was P12 > P10 > P8 > P6, and there was no significant difference between P12 and P10. We find that in the mulch-free treatment, all indicators of W3, W2, P12, and P10 were relatively high. It can be concluded that no mulching has a certain impact on cotton root distribution and leaf physiological function. When the irrigation amount is 450-525 mm and irrigation times is 10-12, it is beneficial for promoting root growth and plays a role in leaf physiological function, and the water use efficiency (WUE) is high, which can provide reference for the scientific water management of mulch-free cotton in production practice.

Yield and Storability of Onion (Allium cepa L.) Ecotypes as Influenced by Irrigation Intervals in Sudan Savanna of Nigeria

Field trials were conducted simultaneously during the 2023/2024 dry seasons at the Kebbi State University of Science and Technology, Aliero University orchard located at Aliero and The second experiment were conducted at Usmanu Danfodio University Sokoto Teaching and research Fadama farm. The area is located at Sokoto State, both locations are in Sudan Savannah agro-ecological zone of Nigeria. The aim was to study the effects of irrigation interval on yield and the storability of twelve onion ecotypes (Allium cepa L.). Treatments consisted of three irrigation intervals (3, 6 and 9 days), and twelve onion ecotypes (Ex-Dikwa, Ex-Kaffe, Ex-Bama, Ex-Alieru, Ex-Gothege, Ex-Gada, Ex-Wurno, Ex-GHM, Ex-Gaya, Ex-Borno, Ex-Lahodu, and Ex-Goronyo). Factorial combinations of irrigation intervals were allocated to the main-plots, while ecotypes were assigned to the sub-plots in a randomized completely block design, replicated three times. The size of each sub-plot was 1x2m (4m2). Result revealed that plant height, number of leaves, above ground biomass, total biomass,fresh bulb weight, cured bulb diameter and bulb diameter were higher with 3 to 6 days irrigation interval, while weight loose and weight loose in (%) were higher in 3 days irrigation interval. Higher percentage of rotted bulbs and sprouting were recorded by frequent irrigation of 3 days interval. Plant height, number of leaves especially at early growth stages, and number of leaves throughout the crop cycle were higher at 3 days irrigation, eoctypes Ex-Kaffe and Ex-Dikwa has the highest plant height and leave number at 4, 8 and 12 WAT in the both locations, also total biomass, above ground biomass, fresh bulb weight recorded the highest weight value followed by Ex-Dikwa. Similarly, 3 days irrigated ecotypes has the highest weight value followed by 6 days irrigation interval while 9 days irrigation ecotypes recorded the least weight value. Ex-Borno, Ex-Dikwa and Ex-Kaffe recorded the highest weight value after undergoing curing period in the two locations, while ExGHM, Ex-Lohodu has the least weight value. Likewise in sokoto Ex-Dikwa and Ex-Kaffe has the highest weight value. In terms of bulb diameter (cm) Ex-Dikwa recorded the highest value in Aliero while the least was recorded in Ex-Goronyo, similarly in Sokoto Ex-Dikwa, Ex-Kaffe and Ex-Borno has the highest weight values after curing while Ex-Aliero, Ex-Gothege, Ex-Gada, Ex-GHM, Ex-Lohodu and Ex-Goronyo followed. In terms of weight loose, Ex-Borno loses weight drastically for the whole of the storage period followed by Ex-Gaya and Ex-Goronyo. Equally, Ex-Wurno and Ex-Kaffe recorded less weight loose during the storage period. Based on the result of this study, 3 days irrigation scheduling proved the best for more number of leaves plant height and fresh bulb yield in the study area, ecotypes Ex-Dikwa and Ex-Kaffe could be adopted due to its potential for higher yielding, while 9 days irrigation interval is the best for post-harvest storage and Ex-Goronyo were found superior.

Projected Bioclimatic Changes in Portugal: Assessing Maize Future Suitability

In Portugal, maize is a major crop, occupying about 40% of the cereals area. The present study aimed to assess future bioclimatic conditions that could affect maize production in Portugal. For this purpose, a set of indicators was selected including dry spells (DSs) and the aridity index (AI). Two additional indicators were included, one related to the soil water reservoir available for maize (RAW) and the other related to the maize thermal unit (MTU), which were designed to assess the suitability of land for growing different varieties of maize. The analysis focused on historical (1971–2000) and future (2011–2070; 2041–2070; 2071–2100) climate scenarios (RCP4.5 and RCP8.5) using a four-member ensemble of global climate models. The results for the more distant and severe scenario suggest that there will be an overall increasing tendency in the AI, i.e., higher aridity, namely in the southern part of Portugal compared to the north (0.65 vs. 0.45). The soils in the south are characterized by a lower average RAW (&lt;35 mm) than in the north (&gt;50 mm), which leads to a lower irrigation frequency requirement in the north. As a result of the increased MTU, maize production will shift, allowing for varieties with higher thermal requirements and the conversion of areas traditionally used for silage maize to grain maize production areas. Adaptation measures to improve the climate resilience of maize are discussed.

Irrigation frequency requirements for sufficient warm‐season species quality in Florida

AbstractPeriodic drought and shortage of potable water have led many municipalities in Florida to set limitations and restrictions on irrigation frequency for home lawns. These restrictions do not take into account turfgrass health and response and may be inappropriate across different species and cultivars; hence, there is a need to identify genotypes that could sustain quality and performance under reduced irrigation. A study was conducted at the University of Florida Plant Science Research and Education Unit in Citra, FL, to assess turfgrass response of 10 bermudagrass (Cynodon spp.), nine zoysiagrass (Zoysia spp.), and five seashore paspalum (Paspalum vaginatum Swartz) cultivars to different irrigation regimes, consisting of non‐irrigated control (Rainfed), soil moisture sensor (SENSOR)‐based (up to 152 mm mo−1), 8X per month (8XMO up to 152 mm mo−1), 4X per month (4XMO up to 76 mm mo−1), 2X per month (2XMO up to 38 mm mo−1), and 1X per month (1XMO up to 19 mm mo−1). Plots were evaluated for turfgrass quality and percent green cover using digital image analysis every 3 days over a 22‐month period. Bermudagrass was able to sustain acceptable turfgrass quality during one of the growing seasons when irrigated 4XMO, showing substantial water savings compared to the other two species. SENSOR irrigation significantly reduced water consumption for all the three species and produced turfgrass quality similar to 8XMO irrigation. Results indicate that selecting the right cultivar for the area could help sustain turfgrass aesthetic and functionality.

Production of pre-sprouted sugar cane seedlings under localized irrigation

The area destined for seedlings in the sugar and alcohol sector was 48 thousand hectares in the 2018/2019 harvest. The cultivation of sugarcane from seedlings has allowed a reduction in the spent stalk volume, as it results in a high multiplication rate. The present study aims to evaluate the quality characteristics of resprouted seedlings via irrigation frequency, verifying the age of the nursery with the best performance for seedling production and the interference of the stem parts from which the buds are extracted for production. For the pretest, 16 varieties were planted at the Federal Goiano-Campus Ceres-Goiás Institute. In the second stage, the experiments were installed in a protected environment on February 19, 2019, and evaluated in the initial phase for 21 days. Evaluations were performed at three-day intervals, and validation was performed on March 19, 2019. The variety determined was CTC 4. The experiment consisted of 3x2 subdivided plots with 4 replications, and the sources of variation were places for the removal of propagating material (basal, apical and median buds) and the frequency of irrigation (1x and 2x). All the data were analyzed via SISVAR software. The irrigation frequency influenced the initial germination assessments. The position of the buds in the stem was 28.34% greater than the median value and 64.17% greater than the basal value. With respect to Dickson's quality index (IQD), the seedlings of the youngest nurses and the apical parts of the stalk were superior to the others.

Effects of irrigation frequency on root growth, nutrients accumulation, yield, and water use efficiency of Panax notoginseng under micro-sprinkler irrigation.

Micro-sprinkler irrigation has been a promising irrigation method to promote Panax notoginseng (Burk) F. H. Chen production but their scientific irrigation frequency in improving yield and water use efficiency of P. notoginseng remains contradictory and inconclusive. The objective of this study was therefore to examine and propose a scientific irrigation frequency in water management of P. notoginseng cultivation considering their impact on soil water, soil available nutrients, root growth, yield, and water use efficiency (WUE). The micro-sprinkler irrigation experiment under shading and rain-shelter conditions was carried out in the growing season of P. notoginseng from 2017 to 2018.The treatments included four micro-sprinkler irrigation frequencies, such as IF1 (irrigation once every three days), IF2 (irrigation once every five days), IF3 (irrigation once every seven days), and IF4 (irrigation once every nine days) in 2017-2018. The results indicated that the IF3 treatment significantly increased the nitrogen accumulation of P. notoginseng (271.98 mg plant-1). In addition, the IF2 treatment enhanced the phosphorus accumulation (27.82 mg plant-1), potassium accumulation (408.38 mg plant-1), total root surface area (67.49 cm2 plant-1), total root volume (3.79 cm3 plant-1) and yield (702 kg ha-1). The IF2 treatment significantly increased WUE by 29.2%, 28.1%, and 37.7% compared with the IF1, IF3, and IF4 treatments, respectively. Our findings suggested that IF2 treatment increased the soil water content, reduced the soil nutrient content, increased the accumulation of phosphorus and potassium in P. notoginseng, promoted the root growth of P. notoginseng, and improved the quality and yield of P. notoginseng, providing a scientific theoretical basis for reasonable water control and green quality production in the cultivation of P. notoginseng under shade and rain shelter cultivation.

Water use and performance of Kentucky bluegrass influenced by cultivar, irrigation practices, and soil texture

AbstractThe use of drought‐resistant grasses and deficit irrigation practices can reduce irrigation volume without sacrificing lawn quality, but a specific lawn's irrigation requirement may vary by soil texture or irrigation frequency. Two Kentucky bluegrass (Poa pratensis L.) cultivars (Mallard and Geronimo), two soil textures (silt loam and loamy sand), two irrigation frequencies (1× and 3× week−1), and two irrigation volumes (40% and 80% reference evapotranspiration replacement) were evaluated in a lysimeter experiment. The experiment was replicated over three runs: late summer 2018 and early and late summer 2019. Turf quality was determined by evaluating green turfgrass coverage, and water use was determined by monitoring lysimeter weights. Mallard and Geronimo did not differ in water usage, but Mallard maintained greater coverage throughout the experiment. Lysimeters replacing 80% reference evapotranspiration averaged 1.4× greater water use and coverage than those replacing 40% reference evapotranspiration over the three experimental runs. Irrigation frequency and soil texture had minimal practical impact on water use and variable effect on turfgrass coverage. Turfgrass grown in lysimeters filled with silt loam and irrigated at 40% reference evapotranspiration demonstrated periods of greater coverage compared to turfgrass in lysimeters with loamy sand under the same irrigation regime. While soil texture may have minimal impact on water consumption during extended drought stress, these findings highlight the importance of adjusting irrigation practices to maintain turfgrass coverage. This refined understanding can allow end‐users to implement customized irrigation strategies that preserve turfgrass quality while minimizing water waste.

Estimation of water stress in maize hybrid PMH-13 from stress degree days measurements

A split-plot field experiment was performed to estimate water stress in maize cultivar PMH-13 which was grown using two different nitrogen levels: N1=150 kg ha-1 and N2=120 kg ha-1, each having four irrigation treatments based on IW/CPE ratios of 2.0 (I1), 1.5 (I2), 1.2 (I3) and 1.0 (I4), respectively. In the present study, three replications for each treatment have been employed to examine the impact of various irrigation treatments and nitrogen application on crop stress and yield. Among the four irrigation treatments, I4 exhibited the highest SDD, whereas I2 had the lowest value. Higher frequency of irrigation in I1 and I2 resulted in a reduction of crop stress due to the maintenance of higher soil moisture. Nitrogen application increased yield and reduced SDD. Thus, the irrigation strategy with IW/CPE ratio of 2.0 with nitrogen application of 150 kg ha-1 is observed to be most appropriate to reduce stress and maximize the yield of PMH-13.