Microsprinkler Irrigation System Research Articles

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.

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.

Produção, trocas gasosas e bioquímicas em pereira cultivada no semiárido sobre diferentes manejos de irrigação

ABSTRACT The objective of this study was to evaluate the influence of irrigation systems and water depths on physiological, biochemical and production processes of pear trees grown in the Brazilian semi-arid region. The experimental design was randomized blocks, with 2 × 4 factorial scheme, corresponding to two irrigation systems (drip and microsprinkler) and four irrigation depths (60, 80, 100 and 120% of the crop evapotranspiration - ETc), with four replicates. Water deficit and excess applied to plants are harmful to gas exchange as well as to biosynthesis and accumulation of carbohydrates, amino acids and proteins in leaves, compromising the cultivation cycle of pear plants grown in the Sub-Middle São Francisco region. The irrigation depth of 91.8% ETc promotes the highest production of pear (18.49 kg plant-1) under drip and microsprinkler irrigation systems, under the edaphoclimatic conditions of the Sub-Middle São Francisco region.

Water Management of Organic-Based Pineapple in Upland Sloping Production Areas

Irrigation of crops in the upland is one major problem in crop production because of water availability during the dry season which includes the right irrigation water method, one of major factors in crop production. The main objectives of the study were to assess the growth and yield of organically grown pineapple at different water management; and to evaluate the cost and economic returns of organically grown pineapple at different water management. Study conducted at BPSU Bangkal, Abucay, Bataan (N 14°46’ East 120°30’). The total rainfall depth at BPSU-AWS Station for July 2020 to June 2022 was 5,002.4 mm during the study period. The micro-sprinkler irrigation system (90 lph, 5.5 m – 12.5 m WD) was used to supplement the irrigation water. Four treatments were subjected for verification (T1 – no supplemented water, T2 – Irrigate up to 30% soil MC, T3 - Irrigate up to 50% soil MC, and T4 – Irrigate up to 70% soil MC) with the aid of an Atmometer and Soil Moisture Meter. Pineapple (T4) has 72.7 cm high, 109.5 cm crown diameter with 25.7 leaves, and T4 has the most number of large size (126/179). Pineapple production has a good return in terms of income, and ROI, and has a short payback period compared with other commodities. With the application of supplemented irrigation water to upland and rolling production areas, the farmer’s income could increase with the right irrigation method for specific and selected crops to be raised.

Pipeline Optimization for an Economical Microsprinkler Irrigation System Based on a Hybrid Genetic Algorithm

The pipeline combination scheme is optimized to reduce the cost of irrigation units in an economical microsprinkler system. With the standard number of segments of branch and capillary pipes as the decision variables, the lowest pipe cost per unit irrigation area as the objective function, the maximum pressure difference allowed in the system, the minimum number of pipes in the network, and the shape of the irrigation area as constraints, a hybrid genetic algorithm is used to calculate the minimum cost per unit area of the pipe and the corresponding optimal combination of pipelines. The results show that when the irrigation area is a rectangular plot of 30 m × 22 m, the lowest cost of pipeline per unit area, 5192.7 RMB/hm2, is achieved when the capillary pipes are laid bidirectionally along the length of the plot. The cost of bidirectional laying of capillary pipes is less than that of unidirectional laying, and the cost of capillary pipe laid along the length direction of the plot saves 2.3% compared with that of capillary pipe laid along the width direction of the plot. The most extended length of capillary pipe on one side is 103.65 m. Compared with the cost obtained by farmers based on experience, the pipeline cost per hectare was 1.04%∼13.6% lower. It is recommended that farmers lay capillary pipes bidirectionally along the length of the plot and choose branch pipes with smaller diameters to help reduce the cost of the pipe unit area of the irrigation system.

Development of green energy based micro-sprinkler irrigation system for small holdings of SAT region

The Indian agriculture in the region of semi-arid tropics (SAT), characterized by small holders, small water harvesting and recycling system assumes a significant potential to sustain agricultural productivity by providing supplemental as well aslifesaving irrigation and mitigating mid-season drought. In Indian Agriculture, major energy consuming activities include on-farm water management. Efficient and cost-effective irrigation system matching the small-scale water harvesting and storage, are anot available in this region. In view of this, a carry-and-irrigate type micro-sprinkler irrigation system was designed and developedin order to achieve the holistic utilization of water resources and niche-potential of solar energy and gravity. The performance was measured on various parameters of application rate, Christiansen uniformity coefficient and pattern efficiency and were quantified as 14.2 mm/h, 91.3% and 89.01% respectively. The develop irrigation system qualified the performance criteria as standardized by ASAE, 1996. Given the characteristics of low cost and portability, it can considerably substantiate the vegetable production at household scale. Though, this system is developed exclusively for the location representing typical dryland agriculture of India, it can be easily and effectively replicated in other part of the world having similar agro-ecosystem. This simple water management technique utilizing the niche potential of gravity and solar energy can significantly contribute to the various objectives of sustainable development goal.

Root distribution and its relations with soil chemical attributes and yield of banana under fertigation with and without soil covering

This study evaluated the effects of fertigation, banana biomass as a soil covering under drip and micro-sprinkler irrigation system on the root growth and distribution and their relations with chemical soil attributes, soil water availability, and productivity. This work was conducted in a field with banana 2.5 × 2.0 m spacing and irrigated every two days using a drip and micro-sprinkler irrigation system during the first crop cycle. The experiment followed a random block design with six treatments, two irrigation systems, two fertilization methods of fertigation and side-dressing, as well as two cultivation types with and without soil covering. Roots were collected from each plot using soil monoliths and digitalization allowed the determination of root length density, and diameter at several distances from the plant and at different soil depths. Total root length, density, and distribution by diameter were evaluated based on the treatment interactions with respect to the distance from the plant and the soil depth. Our results showed that the combination of the irrigation system, fertilizer application and soil covering influenced root growth and distribution. In addition, we found that the better soil conditions for root growth were in drip or micro-sprinkler systems with fertigation and cultivated biomass covering.

Numerical simulation of the effects of sandy water on regulator labyrinth channel in micro-sprinkler systems

Abstract The effects of sandy water on the W-shaped labyrinth channel of micro-sprinkler irrigation systems with large flowrate were investigated using Computational Fluid Dynamics (CFD). Using ANSYS FLUENT software and different inflow conditions (e.g., pressure, velocity, sediment concentration, and sand particle diameter), internal turbulent multiphase flow and sand deposition were simulated by the Eulerian multiphase flow model. Particle erosion in the labyrinth channel was calculated by the Discrete Phase Model (DPM). The results show that vortex movements and shear actions at the boundary layer cause self-flushing in the channel. The location of sand particle deposits and the turbulent dissipation rate are related to the operating pressure, which is optimal at 300 kPa. The erosion rate of the channel wall is proportional to the inflow sediment concentration but has no obvious relationship with inflow velocity. Based on the movement regulation of sand particles in the labyrinth channel, recommendations on filtration requirements and operating pressure of irrigation systems are proposed.

Statistical quality control to emission uniformity in micro sprinkler with autonomous photovoltaic pumping

This work aimed to evaluate a microsprinkler irrigation system using photovoltaic energy without energy storage. The influence of photovoltaic pumping on irrigation was evaluated from the Emission Uniformity, Shewhart control charts and Process Capacity. The experiment consisted of two amorphous photovoltaic panels connected in parallel, directly connected to a water pump, where the flow of the pumping system was carried out through a ½” tube (main line), to the irrigation system composed of four microsprinklers. The voltage and current parameters were collected, and the power of the photovoltaic system was calculated, while for the irrigation system the pressures of the four microsprinklers were measured to later calculate the flow rate of the irrigation system. The experiment was conducted at the State University of Western Paraná, UNIOESTE, where 25 days of collection were carried out, in the open, at four different times, from 10:00 am to 11:00 am, from 11:05 am to 12:05 pm, from 2:00 pm to 3:00 pm and from 3:05 pm to 4:05 pm . Power generation presented a low coefficient of variation throughout the day, which resulted in flow and pressure stability, culminating in an Emission Uniformity (UE) value qualified as excellent (93.66%) according to the ASAE. The values of energy generation, flow, pressure, and emission uniformity presented a Process Capacity (CP) value above 1.33, defining the process as capable and adequate throughout the analyzed period.

EFFECT OF IRRIGATION SYSTEM AND PLANTS DISTRIBUTION ON GROWTH, YIELD AND WATER USE EFFICIENCY OF SOME SNAP BEAN CULTIVARS

An experimental field trial was conducted at on a farm in Al-Khatatba area, Menoufia Governorate, Egypt (latitude of 30o 52/ 66// and a Longitude of 30o 38/ 11//), during the growing season of 2019 and 2020. This study aimed to assess the optimum irrigation system and plants distribution on growth, yield and water use efficiency (WUE) of some snap bean cultivars under sandy soil condition. The field trial was arranged in a split- split -plot design with two irrigation systems (drip and microsprinkler), two plants distribution (regular and irregular distribution) and four snap bean cultivars (Alfa, Giza 6, Alkarnak, and Nebraska). The Results showed that drip irrigation system exhibited the highest values of vegetative growth ((number of plants ha-1), (number of branches/ plant), (number of leaves/plant), (number of pods/plant), (weight of the pods, Mg ha-1), (weight of dry seeds, Mg. ha-1) and (weight of 100 dry seeds (g)); and WUE while microsprinkler irrigation system produced the lowest values in the same concern during studied seasons. However, under the interaction (drip irrigation + regular distribution + Alfa cultivar) exhibited its superiority in growth parameters. While, under the interaction (microsprinkler irrigation + irregular distribution + Nebraska cultivar) recorded the lowest in growth parameters. In conclusion under the conditions of the experiment Alfa snap bean cultivar is recommended in cultivation (for export or local marketing) with drip irrigation at 5851 m3/ha/season and regular distribution, due to its superiority in yield/ha and (WUE).

Performance of cabbage at different irrigation levels under drip and microsprinkler irrigation systems*

AbstractField experiments were conducted for 3 years to investigate an appropriate irrigation management strategy that would lead to increased cabbage productivity along with saving in irrigation water. Cabbage was grown with microsprinkler and drip irrigation methods with four irrigation levels based on crop evapotranspiration (ETc) as 0.8 ETc, 0.9 ETc, 1 ETc, and 1.1 ETc. It was found that cabbage crop performed better with the microsprinkler system than the drip system. All the growth‐ and yield‐contributing characters in the microsprinkler irrigation method were significantly superior over drip irrigation. The maximum yield of cabbage was obtained by the microsprinkler method (37 t ha−1) with irrigation scheduling at 1 ETc followed by 0.9 ETc (35.5 t ha−1). However, highest water use efficiency (114 kg ha−1 mm−1) was obtained in drip irrigation with 0.9 ETc irrigation level, and the highest net income per mm of water (Rs 622) was obtained in drip irrigation with 1 ETc irrigation level. Microsprinkling gave 7.30% more yield of cabbage than the drip method, whereas the drip method saved 32% more water than the microsprinkler method. It is therefore recommended to adopt the microsprinkler irrigation method to obtain a potential yield of cabbage. However, when water is a limiting factor, it is recommended to grow cabbage with the drip irrigation method.

Studies on solar water pumping based micro-irrigation for sustainable vegetable cultivation

The growing demands of energy and water particularly in the present agricultural sector have necessitated the adoption of reliable, environment-friendly and water saving technologies so as to combat against the energy crisis and water stress in near future. It has been established that conventional sources of energy like oil, gas, coal etc. will not be able to provide the desired levels of energy security to mankind in foreseeable future. Hence, there is a global consensus for exploitation and utilization of different renewable energy resources. The search for new options should be eco-friendly as well as abundant in nature. Among the different available renewable energy resources, solar energy seems to be more promising and sustainable. Solar powered agricultural irrigation may be an attractive application for renewable energy in replacing fossil fuel powered irrigation devices to achieve energy security. The use of solar photovoltaic systems may provide good solution not only for all energy related problems of the present society but also perform excellently in terms of productivity, reliability, sustainability and environmental protection ability. Solar photovoltaic water pumping systems can provide water for irrigation without the need for any kind of fuel or the extensive maintenance as required by diesel and electric pump sets. Therefore, an attempt has been made to develop an affordable and portable solar PV water pumping system for irrigating vegetable crops in the state of Odisha. Micro-irrigation method through sprinkler system has been integrated with the solar PV device to achieve judicious utilization of water. Monthly income of Rs. 15,000/- throughout the year was possible by adopting remunerative tomato cultivation in 1 acre of land both during rabi and summer seasons in the year 2017 in coastal region of Odisha. Pay- back period of the developed set up was calculated to be only half year, due to which, it may be easily accepted by the small and marginal farmers of the state in spite of its high initial cost. The popularization of this technology would not only achieve assured water availability to the crops with improved water use efficiency measures by micro-sprinkler irrigation system compared to traditional flooded method of irrigation but also protect the environment against release of green house gases and noise pollution by the use of rising diesel and electric pump sets in the state.

Regulations and Guidelines for Chemigation

Chemigation is a process where an irrigation system is used for transport and delivery of agrochemicals, generally fertilizers and pesticides, to a crop (Haman and Zazueta, 2017). Drip or micro-sprinkler irrigation systems are often used in chemigation. If the irrigation is properly plumed and chemigation properly implemented, chemigation can help growers reduce chemical usage and costs as it is applied using existing irrigation distribution infrastructure. However, the irrigation system must first be outfitted with properly designed injection and safety equipment. In addition, it is important that the irrigation system is built to allow the injection of chemicals or fertilizers at a known rate and that ensures application uniformity. Knowing the correct concentration of chemicals during chemigation is critical as some chemicals could potentially damage plants. Chemigation of chemicals/fertilizers at higher concentrations could also lead to leaching and contamination of freshwater bodies. The purpose of this document is to provide a brief overview of the regulations and some helpful tips for growers interested in chemigation.

WATER AND ENERGY SAVINGS IN MICROIRRIGATION SYSTEMS DESIGN USING OPTIMIZATION MODELS

The main disadvantage of trickle irrigation systems is its comparatively high initial cost, which depends on the layout, design, and management of its hydraulic network. Designing the sub-main and lateral lines aiming the emitter uniformity maximization can reduce the microirrigation system costs. This research aimed to compare linear and nonlinear programming models and maximization versus minimization criteria to optimize the crop net benefit, considering the water and energy savings. Two versions of LP and NLP models were developed: the first minimized the equivalent annual cost of the irrigation system considering the pipeline cost and the energy cost; the second maximized the yearly increment in the net benefit (Bn) of the irrigated crop. In both cases, uncertainty about the crop price was considered. The models were applied in a 40 ha citrus orchard in São Paulo State, Brazil. The highest net benefit was found using the NLP model with the maximization criterion. The worst result was obtained with the LP model and the minimization of the total annual cost. The layout and management previously established by the designer are subjective and rarely results in the best solution, although the linear programming model always gets the global optimum. The NLP models get local optimal, but they defined the layout, design, and management of the systems, with more chance to obtain a higher net benefit. The NLP model for maximization showed to be an adequate option for designing microsprinkler irrigation systems, defining the hydraulic network and the operational conditions that maximize Bn and WUE, with the lowest water consumption and lowest energy cost.

Physiological and productive characteristics of the banana 'Prata-Anã' subjected to different irrigation intervals and emitter heights

This study aimed to evaluate the productive characteristics, gas exchange and water use efficiency of the banana 'Prata-Anã' clone Gorutuba under different irrigation intervals associated with different emitter heights. Therefore, a field experiment was conducted in a 2 x 4 factorial scheme: two irrigation intervals (daily and every two days) and four emitter heights (50, 70, 90, and 110 cm) in a completely randomized design with four replicates. The irrigation depths applied by the microsprinkler irrigation system were calculated as a function of crop evapotranspiration. The gas exchanges were evaluated during the period of greatest climatic stress, and the productive characteristics were evaluated at harvest. The economic water use efficiency was determined indirectly by considering the production divided by the applied irrigation depth, which was the same in all the treatments. The instantaneous water use efficiency was estimated with an infrared gas analyzer in the critical climatic period. There was no interaction between the irrigation intervals and emitter heights. The two-day irrigation interval resulted in lower values of leaf temperature and photosynthetically active radiation incident on the leaves, resulting in a higher fruit weight and, consequently, higher yields and a higher water use efficiency. The highest fruit weights were obtained at heights of 70 and 90 cm.

Deficit Irrigation Scheduling and Superabsorbent Polymer‐ Hydrogel Enhance Seed Yield, Water Productivity and Economics of Indian Mustard Under Semi‐Arid Ecologies

AbstractOilseed brassicas are extensively grown in the water‐stressed ecologies of India. Sufficient irrigation, deficit irrigation scheduling (DIS) with limited irrigation water and rainfed (no irrigation) conditions were assessed with and without the use of superabsorbent polymer‐hydrogel (SAP‐hydrogel) under a micro‐sprinkler irrigation system (MIS) for Indian mustard. Irrigation scheduling at an irrigation water/cumulative pan evaporation ratio (IW/CPE) of 0.8, 0.6 and 0.4, along with use of SAP‐hydrogel, produced almost equal dry matter per plant (113, 115 and 109 g plant−1), which was, however, significantly higher (P ≤ 0.05) over rainfed (86 g plant−1). The seed yield under DIS (0.6 IW/CPE) increased by 39.3% over rainfed + hydrogel (HG). Also, the seed yield obtained under irrigation scheduling at a ratio of 0.4 IW/CPE was found to be similar to that obtained in rainfed + HG treatment. A similar water productivity (WP) of 10 kg ha−1 mm−1 was obtained with DIS at 0.4 IW/CPE + HG and at 0.8 IW/CPE‐HG; however, a higher total water productivity (WPt) was recorded under DIS at 0.6 and 0.4 IW/CPE + HG (23 and 29 kg ha−1 mm−1, respectively) over the same irrigation schedules excluding HG. The economics of HG application under DIS was better due to higher net returns, although the highest B : C ratio (1.92) was recorded in DIS (0.4 IW/CPE), trailed by irrigation scheduling at IW/CPE 0.8 and 0.6. Overall, it could be concluded that DIS through micro‐sprinkler and use of HG enhanced seed, oil, water productivity and energy dynamics under water‐constrained conditions in semi‐arid ecologies. © 2019 John Wiley & Sons, Ltd.

Uncertainties in leaching assessment in micro-irrigated fields using water balance approach

Leaching is an important aspect of irrigation water management, as it must be minimal to save available irrigation water resources, prevent shallow groundwater tables, and reduce nutrient loadings to the groundwater. However, at the same time, leaching should be sufficient to maintain root zone salinity levels below the threshold to prevent yield reduction. Therefore, monitoring leaching is the key component in evaluation and optimization of irrigation water management practices. Water balance (WB) is a common approach used to estimate leaching in agricultural fields and was applied in this study to assess field-scale leaching and the associated uncertainties for an almond orchard under drip and micro-sprinkler irrigation systems. In this study, we showed that change is soil water storage (ΔS) is highly influenced by the extent of monitoring depth, the location and number of monitoring points. Local measurement of WB parameters showed that leaching is highly variable across the field, thereby introducing considerable uncertainty on estimated leaching using WB approach. It was also shown that unknown input of water through fog interception added to the complexity of closing water balance at field scale.

Upscaling point measurements of N2O emissions into the orchard scale under drip and microsprinkler irrigation

Agricultural activity is one of the major sources of nitrous oxide (N2O) emission into the natural environment. Yet, due to the soil’s spatial heterogeneities it is hard to accurately upscale point N2O emission measurements into the orchard scale. This study aims to introduce a simple, yet robust, way for upscaling point N2O emission measurements into the orchard scale, under drip and micro-sprinkler irrigation systems. Surface point measurements of N2O emissions were performed at five distances from drip and micro-sprinkler emitters in two almond orchards, following irrigation and fertigation events. Principal component analysis (PCA) and linear regression were used to study the correlations between the soil water filled pore-space (WFPS), and subsurface N2O, NO3− and NH4+ concentrations down to depth of 60 cm. The correlation tables indicated that most of the N2O emission resulted from microbial nitrification in the top soil (< 10 cm). However, in many cases the correlations did not provide meaningful explanations to the relations between the subsurface parameters and the surface N2O emission flux. It was suggested that the main limitation of the analysis results from the current soil sampling method, where soil samples are not taken from the profile inside the collar in-order to keep the soil profile undisturbed over long measuring periods. In the microsprinkler irrigation, relative water application depth of the emitter, showed strong positive linear correlation to the soil NH4+ concentration and surface N2O emission flux. These correlations could be used for upscaling the point measurements into the tree and orchard scale. In the drip irrigation, the N2O emission flux was found to follow the water and NH4+ distribution pattern, and could be upscaled to the tree and orchard level using a sinusoidal function using only measurement of the peak emission and the radius of the wetting pattern. These results improve current understanding on the dynamics of N2O production in orchards irrigated with micro-irrigation systems in arid and semi-arid ecosystems and might contribute to modeling of N2O emissions using less rigorous methods.

Low-volume irrigation systems influence Pratylenchus penetrans populations, root colonization by arbuscular mycorrhizal fungi, and replant establishment of sweet cherry

Abstract A four-year study was conducted to establish the effects of drip and microsprinkler irrigation systems on populations of Pratylenchus penetrans, early plant growth, and fruit yield of sweet cherry trees planted into soil previously used for apple production. The effects of irrigation type on root colonization by arbuscular mycorrhizal fungi, the abundance of soil microbial antagonists, soil biological suppressiveness, plant nutrition, and soil water content were also evaluated. Trees that received drip irrigation had larger trunk diameters than trees irrigated with microsprinklers throughout the first four years of orchard establishment, with greater total fruit yield also observed with drip irrigation in the fourth growing season. Populations of P. penetrans in soil and roots were smaller under drip irrigation than microsprinkler. Trees irrigated using drip emitters had higher per cent root colonization by arbuscular mycorrhizal fungi than those irrigated by microsprinklers, and had a greater density of fine roots in soil. Drip irrigation also increased soil volumetric water content in the root zone, with soil moisture content often approaching or exceeding field water-holding capacity relative to that of microsprinklers. Overall, drip irrigation shows potential as a component of an integrated pest management strategy for reducing the effect of P. penetrans on newly planted sweet cherry.