Microsprinkler Irrigation Research Articles

Seasonal Variations in Water Use of Japanese Plum Orchards Under Micro-Sprinkler and Drip Irrigation Methods Using FruitLook Data

South Africa is considered one of the driest countries, and its water insecurity challenges are exacerbated by climate change and variability, depletion, and degradation, among other factors. The challenges of water insecurity are exacerbated by some of the introduced crops, like the Japanese plums (Prunus salicina Lindl.) grown in South Africa, as they consume a lot of water. The Japanese plums are grown under irrigation to supplement low and erratic rainfall in the country. There is little information on the water requirements of Japanese plums (particularly in water-scarce regions), a gap addressed by this study. Therefore, the study aims to quantify and compare the seasonal water use of high-performing, full-bearing Japanese plum orchards under drip and micro-sprinkler irrigation in the Western Cape Province, using readily available satellite data from the FruitLook platform. The seasonal water use volumes of selected plum orchards were compared at provincial and farm scales. At a provincial scale, micro-sprinkler-irrigated orchards consumed significantly more water (up to 19%) than drip-irrigated orchards, whilst drip-irrigated orchards experienced an average 38% greater water deficit. Results were more variable at the farm scale, which was attributed to the influence of site-specific soil, climate, and crop conditions on the performance of the irrigation methods. Therefore, a blanket approach cannot be used when selecting an irrigation method and design. Instead, a case-by-case approach is recommended, which takes into account the root distribution, soil texture, and planting density, among other factors. The generated knowledge facilitates allocating and licensing water resources, developing accurate irrigation scheduling, and promoting improved water use efficiency.

Optimizing Irrigation Regimes for Peanuts in Water-Scarce Regions: A Case Study in Western Liaoning, China

Scientific irrigation scheduling is crucial for conserving agricultural water resources, as excessive irrigation diminishes crop yield and imprecise water application can equally reduce water use efficiency (WUE). In Western Liaoning Province, China, where water scarcity is critical, traditional irrigation regimes are commonly used for peanut cultivation, with local farmers applying water without considering actual crop water demands, thereby reducing water efficiency and yield. In this study, field experiments on peanuts were conducted from May to October during 2021 and 2022 in Heishan County, Western Liaoning Province, China. Four irrigation regime treatments for micro-sprinkler irrigation, with different lower limits of soil water content, were applied: T1 (55% field capacity), T2 (65% field capacity), T3 (75% field capacity), and T4 (85% field capacity). The plant height, stem thickness, root length, dry matter weight, yield, WUE, and net return were measured. Different irrigation regimes had significant effects on peanut growth. The yield was highest in the T3 treatment in 2021 at 5574 kg·hm−2. Moderate irrigation could improve the yield, but it was difficult to simultaneously achieve a high WUE. The WUE of the T3 treatment was 5% lower than that of the T2 treatment in 2022, where the WUE was the highest at 1.62 kg·m−3. The highest net return was observed in the T3 treatment at 27,307 yuan·hm−2. The T3 treatment, with the highest similarity degree of 0.83 as determined with the entropy value and TOPSIS method, was evaluated as the optimal irrigation regime. This regime not only exhibited a favorable balance of water use efficiency and yield but also maximized economic benefits, making it a recommendable practice for local peanut irrigation.

Intelligent sprinkler irrigation system for citrus orchard in plateau of Yunnan, China

This study was designed to develop water-saving irrigation strategy for citrus cultivation at Xinping County, Yunnan, China. This county has a mountainous landscape with resources of natural rivers. Based on the local standard water quota (DB53/T168-2019) of Yunnan Province, Xinping County falls into the dry-hot valley VI -2 zone. We developed a Smart Sprinklers irrigation system to meet the actual irrigation requirements of citrus plants with multiple benefits starting from economic to social and environmental protection. We considered the specific situation of the project area, and then design an irrigation system for citrus orchard. Hydraulic calculations determined the suitable materials and sizes for pipes, valves, and irrigation equipment, based on the area’s water demand favoring micro-sprinkler irrigation. Following technical standards, we selected appropriate equipment for designing the pipe network, including the layout, positioning, and installation of the pumping station, moisture meters, weather station, and pest monitoring system. Further research could investigate the adoption of renewable energy to enhance system sustainability and examine the transferability of these systems to different crops and similar geographic regions. It is concluded that this technology and design is very useful for the cultivation of citrus plants in hilly areas.

Delayed application of water and fertilizer increased wheat yield but did not improve quality parameters

Context or problemWheat is an important food crop for mankind, simultaneous improvement of wheat yield and quality is human most important goal, but they often cannot increase at the same time. Objective or research questionThe effects of irrigation mode, nitrogen application rate and topdressing time on yield and quality of two wheat varieties were studied, and the possibility of synergistic improvement of yield and quality was also explored. MethodsTwo irrigation treatments (conventional border irrigation and micro-sprinkling irrigation) were set up, and three nitrogen application rate treatments (120, 210 and 300 kg N ha−1) were set up under each irrigation treatment. The yield formation and quality parameters of wheat were investigated. ResultsThe grain yield, key enzyme activities of protein synthesis, protein content and dough processing quality of the two cultivars increased with the increase of nitrogen application rate. However, when the nitrogen level was higher than 210 kg N ha−1, the grain yield and processing quality of winter wheat did not increase further. Under the same nitrogen application rate, compared with conventional border irrigation (CBI), micro-sprinkling irrigation (MSI) significantly increased the grain yield and total protein content, but did not improve the ratio of glutenin to gliadin and dough processing quality parameters. ConclusionsUnder the experimental conditions, the synergistic improvement of wheat yield and quality parameters could be achieved by optimizing nitrogen application rate, and the delayed application of water and fertilizer could further increase wheat grain yield, but did not improve grain quality parameters. Implications or significanceThis study provided theoretical guidance for further improving the grain yield and quality of winter wheat in the North China Plain.

Effects of nitrogen fertilization and micro-sprinkler irrigation on soil water and nitrogen contents, their productivities, bulb yield and economics of winter onion production

Abstract Onion is sensitive to soil water stress and nitrogen limitations, causing a marked reduction in yield and bulb quality. A field trial was set in the winter seasons of 2016–17 and 2017–18 to evaluate the effects of three micro-sprinkler irrigation levels at 0.6, 0.9 and 1.2 ratios of crop evapotranspiration (ETc) and four nitrogen levels at 0, 75, 100 and 120% of the recommended nitrogen dose (RDN), including surface irrigation at 40 mm cumulative pan evaporation (CPE) with 100% RDN (SN) using an augmented strip plot design on water and N distribution in soil, their productivities, onion yield and economics. Results indicated that the root zone water content increased by 5.2% for 1.2 ETc, and 1.4% for 0.9 ETc over the cropping period, but declined by 1.5% for 0.6 ETc with micro-sprinkler irrigation compared to surface irrigation with nitrogen fertilization (SN). The largest total root zone water depletion was in 1.2 ETc (16.7%), followed by SN (15.3%) and 0.9 ETc (15.0%). The high irrigation regime produced the maximum yield and nitrogen productivity, whereas deficit irrigation displayed the greatest water productivity. However, the coupling of micro-sprinkler irrigation at 1.2 ETc and 120% RDN led to an increase of onion bulb yield (22.6%), water productivity (42.7%), plant N uptake (29.0%) and net income (30.6%) with maximum benefit-cost ratio (3.19) compared to SN. However, as this study was only based on two seasons, more field trials will be needed to confirm the optimum amount of water and nitrogen for winter onion.

Estimating crop coefficients and water use of a full-bearing mango orchard in north-eastern South Africa using the fraction of vegetation cover and a dual source evapotranspiration model

In semi-arid countries like South Africa, commercially produced mango (Mangifera Indica L.) are grown entirely under irrigation. However, there is little accurate quantitative information on the water use of mango orchards, and few accurate water use models currently exist. In this study, we evaluated the performance of the FAO 56 method of estimating crop evapotranspiration (ETc) and a dual source water use model against measurements of actual consumptive water use of a commercial mango orchard. The FAO approach calculates ETc as the product of a crop coefficient (Kc) and the reference evapotranspiration (ETo). We derived Kc for well-watered orchards from readily available data including the fraction of vegetation cover, average tree height, and a stomatal control coefficient. The dual-source model calculated orchard evapotranspiration as the sum of tree transpiration and orchard floor evaporation derived from the modified Shuttleworth and Wallace model. Actual evapotranspiration was measured using an open path eddy covariance system, while tree transpiration was measured using the heat ratio method of monitoring sap flow. Data were collected in a mature ‘Tommy Atkins’ mango orchard grown with micro-sprinkler irrigation in north-eastern South Africa. Results show that the reference evapotranspiration explained most of the variation in orchard transpiration (R2 ∼ 0.78) compared to the solar radiation (R2 ∼ 0.66) and the vapour pressure deficit of the air (R2 ∼ 0.66). Compared with field measured water use data, the FAO method gave relatively accurate estimates of transpiration (R2 = 0.74, NRMSE = ±18.00 %, NMAE = ±15.00 %, NSE = 0.70) and evapotranspiration (R2 = 0.58, NRMSE = ±19.00 %, NMAE = ±16.00 %, NSE = 0.55). NSE is the Nash-Sutcliffe Efficiency. The dual-source model yielded slightly less accurate estimates of transpiration (R2 = 0.61, NRMSE = ±22.00 %, NMAE = ±20.00 %, NSE = 0.39) and evapotranspiration (R2 = 0.52, NRMSE = ±23.00 %, NMAE = ±25.00 %, NSE = 0.51). The basal crop coefficient (Kcb) showed small seasonal fluctuations, varying between 0.40 and 0.60 throughout the year. In contrast, Kc showed clear seasonality varying between 0.59–0.64 at flowering and fruit set and rising to 0.81–0.90 during the fruit growing phase. Estimates of the annual total transpiration (686 mm) from the FAO method were within 5 % of the actual measured values (677 mm) while the dual source model estimated 612 mm of transpiration, which was almost 10 % lower than the measured values. The results highlight that even though the FAO method requires fewer input parameters, it is potentially more accurate in estimating water use in mango orchards than the dual-source model.

The microsprinkler irrigation system influences the growth, yield, and water productivity and nutrient uptake of aerobic rice under humid subtropical climatic conditions

The microsprinkler irrigation system influences the growth, yield, and water productivity and nutrient uptake of aerobic rice under humid subtropical climatic conditions

Micro-sprinkling irrigation and topsoil compaction improve seedling quality of winter wheat in the Huaibei Plain of China

Micro-sprinkling irrigation and topsoil compaction improve seedling quality of winter wheat in the Huaibei Plain of China

Microsprinkler irrigation in combination with nutrient management influences crop and water productivity and water-nutrient dynamics in large cardamom-growing soils in the hilly sub-Himalayan region of India

ABSTRACT A field experiment designed with three tiers of irrigation viz., I0: rainfed, I1: 100% crop evapotranspiration (1.0 ETc) and I2: 0.75 ETc and four tiers of soil nutrition viz., N0: control (no farmyard manure and fertilizer), N1: 100% recommended dose of fertilizer (RDF) as FYM, N2: 50% RDF as FYM +50% RDF as chemical fertilizers and N3: 100% RDF as chemical fertilizers was conducted for four consecutive years (2015–2018) on large cardamom at the hilly terrain of Gitdubling lower beyong busty in Kalimpong Block II in Darjeeling district of WB India. The results showed that I1N3 treatment combination providing microsprinkler irrigation at 1.0 ETc and full RDF (20:40:40::N:P2O5:K2O kg ha−1) recorded highest growth, yield attributes, fresh yield (665.2 kg ha−1) and dry yield (282.0 kg ha−1) of capsules, greatest water productivity (1.8 × 100 kg m−3) and largest soil availability and leaf accumulation of N, P and K. The soil water distribution along the phenological stages was inconsistent and followed the trend according to the rainfall amounts; however, the contents increased with an increase in soil depth and irrigation regime. The predictive regressive models showed the linear relationships between the dry capsule yield and irrigation water and total water use by the plant.

Response of Triticum Vulgare Growth and Nitrogen Allocation to Irrigation Methods and Regimes under Subsoiling Tillage

Subsoiling tillage breaks up the shallow plow layer and thickened plow pan resulting from prolonged crop rotation, thus enhancing the soil tillage layer environment and fostering crop growth. However, these changes in tillage practices are not accompanied by corresponding advancements in irrigation technology. Therefore, this study compared drip irrigation (DI) and micro-sprinkler irrigation (MS) with three watering levels (H, M, L) based on soil water content (70%, 60%, 50% of field capacity) against traditional surface irrigation (CK, 70%FC) to find the most suitable irrigation approach for subsoiling wheat fields. This study found that adjusting irrigation methods and regimes significantly impacted wheat growth and yield. Drip irrigation boosts winter wheat grain yield, harvest index, biomass transfer amount, biomass transfer rate, nitrogen accumulation, nitrogen use efficiency, and nitrogen harvest index significantly compared to surface and micro-sprinkler methods. Drip irrigation, notably the DI-M treatment, significantly enhances winter wheat grain yield by 28.7% compared to CK. Drip irrigation produced optimal results when soil water levels decreased to 60% of the field capacity. This suggests adopting a combination of DI, with irrigation initiated at 60% of field capacity, for enhanced wheat production and resource efficiency.

The impacts of irrigation methods and regimes on the water and nitrogen utilization efficiency in subsoiling wheat fields

Long-term rotary tillage limit water infiltration and crop productivity in North China Plain (NCP). The practice of subsoiling to fracture plow pans has made beneficial impacts on soil surface structure and water infiltration. Further, appropriate irrigation method coupled with irrigation regime can improve crop productivity in subsoiling condition. A three-year field trial (2020–2023) was carried out to assess the effects of the irrigation regime and the method on winter wheat evapotranspiration (ET), grain yield (GY), water productivity (WP), partial factor productivity from applied nitrogen (PPFN), and economic analysis. The three irrigation regimes were irrigated when soil moisture levels decreased to 70%, 60% and 50% of the field capacity (referred as H, M and L) and two irrigation methods were the surface drip irrigation (SDI) and the micro-sprinkler irrigation (MSI). The traditional flood irrigation with 70% of the field capacity in subsoiling filed was CK. The results showed optimizing irrigation method and irrigation regime significantly influenced ET, GY, WP, PPFN, and net incomes. As the irrigation amount increased, the ET first increased while GY, WP, PPFN, and net incomes increased and then slightly decreased. Based on the three-year average, the maximum GY of 9454 kg ha−1 and the net income of 11089 yuan ha−1 was achieved in SDI-M, which had WP of 2.3 kg m−3 and PPFN of 39.4 kg kg−1. At the same time, SDI-M did not result in much increase of ET (average of 405.1 mm in three seasons). Considering comprehensively ET, GY, WP, PPFN, and net incomes, to irrigate when soil moisture decreases to 60% of the field capacity by surface drip irrigation was the optimal strategy in all aspects. These results will provide a scientific reference for irrigation management in subsoiling wheat field in NCP, as well as in similar production areas worldwide.

Combined effects of rain-shelter cultivation and deficit micro-sprinkler irrigation practice on yield, nutrient uptake, economic benefit and water productivity of Panax notoginseng in a semi-arid region of China

The excessive rainfall and irrigation amount in the facility herbal medicine production system (FHmPS) in China leading to a severe root rot disease of Panax notoginseng, which endangers root yield and quality, compromise economic profit and waste resources. Therefore, the objective of our research was to seek optimal irrigation and cultivation management strategy for FHmPS to improve Panax notoginseng production and economic benefit. A three-year (2019, 2020 and 2021) field experiment was conducted on Panax notoginseng under two shelter-cultivation [rain-shelter cultivation (Sr) and unrain-shelter cultivation (NSr)] at three deficit irrigation levels [I1= 65%W, I2= 75%W, I3= 85% W, where W was the irrigation quota when the upper and lower limits of irrigation are (100% ∼ 40%)θFC under shelter-cultivation] to explore the combined practices effects on yield, quality, economic benefit, water productivity (WP) and nutrients uptake of Panax notoginseng, and to obtain the optimal irrigation and cultivation supply practice by the technique for order preference by similarity to ideal solution (TOPSIS). The results showed that SrI2 obtained relatively high plant nutrient uptake, net profit, WP, and quality. SrI2 significantly decreased the root rot incidence by 6–17.5% in comparison to other treatments. However, compared with rain-shelter cultivation, unrain-shelter cultivation weaken these effects in Panax notoginseng. Deficit irrigation promoted Sr to obtain higher WP than NSr. According to the result of TOPSIS, the comprehensive ranking of SrI2 and SrI3 were first and second among the practices, regardless of growing seasons and planting years. The SrI2 significantly decreased the yield of Panax notoginseng by 5.4%− 20.8% in comparison to other treatments. SrI2 and SrI3 were highly recommended for facility herbal medicine production system (FHmPS) in the semi-arid area of Southwest China.

Гидравлические исследования поливного модуля системы комбинированного орошения

Purpose: to state hydraulic characteristics and determine priority directions for improving the irrigation module design for combined drip and micro-sprinkler irrigation. Materials and methods. The study is based on the joint use of theoretical methods – a well-known mathematical model for calculating the hydraulic characteristics of the irrigation module and experiment, which allows assessing the problem state and scale solutions in any necessary proportions. Results. According to calculations, the uniformity of watering is maintained at an acceptable level at a lower head level in the range of 1.56–1.68 atm when installing six microsprinklers on a drip line. When installing eight sprinklers, the water head along the length of the drip pipeline decreased to an unacceptable 1.39–1.40 atm. Experimental studies have shown that there is only an option with two sprinklers installed on the pipeline above the level of 1.5 atm. Already with the installation of four sprinklers, the water head along the length of the pipeline decreased to 1.45–1.47 atm. At the same time, the variation in the actual microsprinkler performance reached 16 % or more. The discrepancy between experimental and model data is explained by the fact that the calculation model does not fully take into account local resistances that arise when connecting sprinklers. Conclusions. Two main reasons of the increased uneven distribution of irrigation water over the irrigated area have been identified. The first reason is a significant increase in water flow in the irrigation pipeline when emitters and sprinklers work together. The solution to this problem is to develop structures that make it possible to separate the water flow through emitters and through sprinklers in time. The second reason is an increase in local resistance in the water diversion units to the sprinklers. The solution to this problem is to develop special water diversion structures that would be characterized by minimal local resistance.

Effect of some irrigation systems on water stress levels of Washington navel orange trees

BackgroundThis experimental study was conducted during two successive seasons 2021–2022 on 10-year-old Washington navel orange trees (Citrus sinensis) budded on sour orange rootstock (Citrus aurantium) under sandy loamy soil conditions in Belbeis district, Sharkia Governorate, Egypt. This experimental study was conducted to compare some irrigation systems with different water stress levels on Washington navel trees and to determine the best system in terms of irrigation water use efficiency using different irrigation systems (drip and micro-sprinklers) under different levels of water supply (100, 80, and 60% of ETc, i.e., the estimated water requirements of crops).ResultsThe included data demonstrated that irrigation water amounts can be reduced by 20% for Washington navel trees, while maintaining production, with the possibility of increasing by using micro-sprinkler irrigation systems. In summary, water use efficiency increased with micro-sprinkler irrigation systems under ETc 80%, which resulted in 2.57 and 2.67 kg of fruit per cubic meter of irrigation water in the first and second seasons, respectively.ConclusionThe results of the present study showed that using ETc 80% combined with micro-sprinklers irrigation system had a high economic return through increasing total yield, water use efficiency, and water unit return (WUR) which reached to 10.26 EGP/one cubic meter of irrigation water and using less water irrigation amount by 20% at the same time. Thus, we recommend applying the treatment of ETc 80% combined with micro-sprinklers irrigation system to Washington navel orange trees budded on sour orange rootstock to gain a high economic return.

Alternate micro-sprinkler irrigation and organic fertilization decreases root rot and promotes root growth of Panax notoginseng by improving soil environment and microbial structure in rhizosphere soil

It is a challenge to improve Panax notoginseng production and soil environment in arid area of Southwest China. Therefore, the objective of this study was to propose a new and promising alternate micro-sprinkler irrigation (D2) to cope with the challenge based on moderate deficit micro-sprinkler irrigation (D1) and slight deficit micro-sprinkler irrigation (D3). A two-year greenhouse experiment was conducted to evaluate the root rot incidence of Panax notoginseng among of the D1, D2 and D3 treatments by analyzing the soil water content (SWC), soil microbial biomass carbon (SMBC), nitrogen (SMBN), total phosphorus (TP) and total potassium (TK), soil available nutrients(AN, AP and AK), soil enzyme activity, soil microbial structure, plant growth parameters, plant dry matter, nutrients uptake (N, P and K), and root rot incidence. Experiment treatments consisted of three irrigation amounts (D1, D2 and D3) and four organic fertilizer levels [500 (F1), 1000 (F2), 1500 (F3), and 2000 (F4) kg hm−2] in 2017 and 2018, respectively. All treatments were designed using a randomized complete block with three replications. The results indicated that no significant differences in growth parameters [PH (plant height), SD (stem diameter), and LAI (leaf area index)] of Panax notoginseng were found among of the D1, D2 and D3 treatments in 2017 and 2018. Compared with the D1 and D3, the D2 treatment significantly increased shoot dry weight (SDW), root dry weight (RDW), total N, P, K uptake and decreased SMBC, SMBN, TP, TK, AN, AP, AK and root rot incidence in 2017 and 2018. The result suggested the D2 treatment had greater production advantages than the D1 and D3 treatments. In addition, compared with the F3 treatment, other F treatments (F1, F2, and F4) in the D2 treatment significantly enhance total plant dry matter, total N, P and K uptake. However, root rot incidence significantly increased with the increase of application F levels, and D2F3 can significantly decrease fungi/bacteria and fungi/actinomycetes in rhizosphere soil of healthy Panax notoginseng in 2018. According to analyzing the root rot incidence of different application F treatments, we found that 1500 kg hm−2 in the alternate micro-sprinkler irrigation might be recommended as an appropriate application F level to decrease root rot incidence of Panax notoginseng in the semi-arid area of Southwest China.

Coupling Effect of Water and Soluble Organic Fertilizer on Yield and Quality of Panax notoginseng under Micro-Sprinkler Irrigation in Southwest China

The cultivation of Panax notoginseng has been plagued by a multitude of challenges, including recurrent diseases, suboptimal value, inadequate quality, and environmental degradation resulting from improper water and fertilizer management. To address these issues and improve the yield of P. notoginseng and its saponin content, this study endeavors to identify the optimal irrigation and fertilization levels in shaded environments in Yunnan Province in Southwest China. In this field experiment, three-year-old plants were tested to evaluate the effects of water, soluble organic fertilizers, and their combinations on plant growth, physiological parameters, yield, and saponin content. The experiment included 12 treatments with three types of irrigation (10 (W1), 15 (W2), and 20 (W3) mm), totaling 440, 660, and 880 mm, and four levels of the total amount of fertilization (F1 (60, total N 12.6, total P 5.5, and total K 10.5 kg ha−1), F2 (90, total N 18.9, total P 8.3, and total K 15.7 kg ha−1), F3 (120, total N 25.2, total P 11.0, and total K 20.9 kg ha−1), F4 (150, total N 31.5, total P 13.8, and total K 26.1 kg ha−1)). The randomized complete block design was used, with 36 plots in total and 3 replications. The study utilized the TOPSIS method to determine the most effective water and fertilizer management strategy for the growth and production of P. notoginseng. The assessment of yield, water and fertilizer productivity, and saponin content across all treatments revealed that the W3F3 treatment resulted in significant increases in the plant’s height, stem diameter, and net photosynthetic rate. Meanwhile, the W2F3 treatment exhibited the best root morphological traits. The W3F4 treatment effectively increased dry matter and transpiration. The combination of water and fertilization had a coupling effect that not only increased yield to 1400 kg ha−1 but also improved water–fertilizer productivity. The application of the W2F3 treatment resulted in a significant increase in the accumulation of active components, leading to a total P. notoginseng saponin (PNS) content of 24.94%. Moreover, the comprehensive index obtained through the TOPSIS model indicated that the W2F3 treatment outperformed other treatments. Therefore, this treatment can be considered a promising water and fertilizer model for P. notoginseng cultivation, which can enhance its yield, quality, and productivity while promoting sustainable green development.

Plant growth regulator on micro-sprinkler for mango `Palmer’ floral induction in Brazilian Semiarid

Application of the plant growth regulator paclobutrazol (PBZ) to aid mango floral induction has been widely performed by mango producers. However, its application has been done manually, resulting in low uniformity of application and losses with labor. The objective of this study was to adjust the PBZ dose to be applied via micro-sprinkler system for floral induction, indicating an efficient management of ‘Palmer’ mango in the Brazilian semiarid. The experiment was conducted at Saúde Farm, located in Petrolina-PE, Brazil. The experimental design used was randomized blocks, with five doses of PBZ, applied via irrigation system (T1 - 0.56; T2 - 1.12; T3 -1.68; T4 - 2.24; and T5 - 2.80 g a.i. linear m-1 canopy) and a conventionally applied dose (T0 - 2.80 g a.i. linear m-1 of canopy, manually applied broadcast), with four replicates. The variables analyzed were: photosynthesis rate, stomatal conductance, transpiration, leaf temperature, number and length of panicles, number of fruits per plant, average fruit weight, yield, pulp firmness, titratable acidity and total soluble solids in the fruits. At the conventionally applied dose (2.8 g a.i. linear m-1 of canopy), PBZ application via micro-sprinkler irrigation system proved to be the most efficient way to reduce photosynthesis rate, stomatal conductance and transpiration. PBZ applied via micro-sprinkler irrigation system at a dose of 0.56 g a.i. linear m-1 of canopy promotes greater number of panicles and yield in ‘Palmer’ mango.

Effect of Working Pressure on the Anticlogging Performance of Micro-Sprinkling Hose with Different Structures

A micro-sprinkling hose is a new type of water-saving irrigation equipment, which can become clogged when using sand-laden surface water sources for irrigation. To test the clogging process and mechanism of the micro-sprinkling hose, as well as the influence of working pressure and hose structure, an intermittent micro-sprinkling irrigation experiment was performed using four different micro-sprinkling hoses with different folded diameters (45, 45, 48, and 60 mm). The number of orifices in the single-cycle orifice cluster was three, five, five, and five. The results showed that, when the working pressures were 30 and 40 kPa, the micro-sprinkling hose was prone to complete blockage. When the working pressures were 50 and 60 kPa, the micro-sprinkling hose was partially clogged. The structure of the micro-sprinkling hose affected the mass and gradation of the deposited sediment by mediating the flow rate inside the hose. The particle size range and content of sediment under irrigation using the N48-5 (folded diameter = 48 mm, with five orifices) and N60-5 (folded diameter = 60 mm, with five orifices) hoses were much larger than those of the original soil samples. Micro-sprinkling hose N60-5 had the best anticlogging performance in this study. The results of this study can provide technical support for the application of micro-sprinkler irrigation systems with sand-laden water.

Water Use Efficiency in Young Citrus Trees on Metalized UV Reflective Mulch Compared to Bare Ground

A precise estimation of plant water use is crucial for efficient irrigation management and understanding of plant–water interactions. Metalized-polyethylene mulch as a ground cover, combined with irrigation management, can improve water and fertilizer use, efficiency growth, and yield of young citrus trees, compared to bare ground. Thus, a study was undertaken to (i) compare daily water use, using the stem heat balance (SHB) method on ≤4-year-old citrus trees using three irrigation methods, and (ii) to determine soil moisture content, as well as total available soil water (TASW) in the irrigated zone. Three irrigation methods, regulated deficit irrigation (RDI), conventional drip irrigation (CD), and microsprinkler irrigation (MS), were applied on two sandy soils in central and southwest Florida with treatments further split between trees grown on 2.4 m mulched beds (M) and bare ground (NM) to form a factorial design. Measurements included sap flow, canopy size, leaf area index (LAI) and soil moisture. The result of this study shows greater values for the trunk cross-sectional area, canopy volume and LAI for both mulch treatments, in comparison to bare ground treatments. The sap flow data suggest that RDI resulted in higher water use than both CD and MS. The hourly sap flow was 120, 99 and 163% greater in M-RDI than M-CD, NM-CD and NM-MS, respectively. Mulched ground cover showed a higher soil moisture average at all soil layers (8-, 15- and 45-cm depth). For instance, the mulched ground cover showed higher soil moisture (37%) at a 15 cm depth at the Entisol site, followed by 30% at a 45 cm depth and 25.3% at depth 45 cm for the Spodosol site. The TASW values varied between 100 to 136% for both mulch and bare ground treatments. The irrigation systems used showed water contents close to field capacity, indicating that water was not limiting despite the different irrigation schedules. The high-water uptake is ascribed to frequent irrigation applications and pulses, and improved water distribution in the irrigated zone as a result of the mulch. These findings demonstrate the potential of metalized-polyethylene mulch and regulated drip irrigation to enhance water use efficiency.

Improving wheat yield, quality and resource utilization efficiency through nitrogen management based on micro-sprinkler irrigation

Improving wheat yield, quality and resource utilization efficiency through nitrogen management based on micro-sprinkler irrigation