Irrigation Pipe Research Articles

Machine learning‐driven microwave imaging for soil moisture estimation near leaky pipe

AbstractCharacterizing soil moisture around drip irrigation pipes is crucial for precise and optimized farming. Machine learning (ML) approaches are particularly suitable for this task as they can reduce uncertainties caused by soil conditions and the drip pipe positions, using features extracted from relevant datasets. This letter addresses local moisture detection in the vicinity of dripping pipes using a portable microwave imaging system. The employed ML approach is fed with two dimensional images generated using back projection as a radar‐based algorithm and the Born approximation as an inverse scattering method, based on spatio‐temporal (collected data at various positions over the soil surface and at different time points.) measurements at various frequencies. The study investigates the performance of K‐nearest neighbour (KNN) and convolutional neural networks (CNN) algorithms for moisture classification based on these imaging techniques. We also explore the potential of KNN and CNN for moisture estimation around the plant roots and in the presence of pebbles. In general, CNN outperforms KNN in moisture content detection from microwave data, especially after applying imaging algorithms. A combination of CNN as the ML approach and the back projection algorithm to provide training data, yielded accuracy more than other models for moisture content estimation. Also, the practical results demonstrate that our method can detect soil moisture with an estimation error of less than 10%.

Modification of Risers in Buried Pipe Irrigation System to Improve their Performance

This study identified the problems associated with the design, construction, operation, and maintenance of risers in buried pipe irrigation systems and proposed a modified design. The problems of buried pipe irrigation systems were assessed by inspecting three deep tube wells (DTWs) supplying water through buried pipes with twenty-five outlets. One DTW of the Bangladesh Agricultural Development Corporation (BADC) with five outlets in Netrokona, and one with fifteen outlets in Bara Kailati village and one with five outlets in Bali Bazar, both in Netrokona Sadar, were selected. Data were collected from farmers, field staff, and management authorities by employing pretested questionnaires and field investigations. Site visits revealed that the primary problems were the water leakage through outlets and cracks in the riser structure around the outlet. These problems were due to unsuitable outlet design of the buried pipe system. To overcome these problems, the riser design has been modified structurally, that may lead the buried pipe to suitable and durable performance of buried pipe irrigation system and reduce water losses. J Bangladesh Agril Univ 22(2):225-230, 2024

Groundwater Quality Status of the Parambikulam Aliyar Palar Basin, Tamil Nadu, India Using RS and GIS Techniques

The dependency of ground water is rising day by day. The ground water gets recharged mainly through rainfall. Thirty five water samples were collected from Parambikulam Aliyar Palar basin from open wells, bore wells and dug cum bore wells and analysed for chemical properties such as pH, Electrical Conductivity, cations and anions for two years duration (2020 and 2021) at three months interval (summer, winter, southwest monsoon, northeast monsoon) and analysed for the quality parameters. T Electrical conductivity values were ranged from 0.3 to 5.19 dsm-1, 0.29 to 6.80 dsm-1 0.3 to 6.84 dsm-1 and 0.64 to 4.17 dsm-1 during south west, north east, winter and summer seasons of 2020, respectively. The salt content was slightly increased during winter and summers seasons as compared to south west and north east. he samples were classified under USSL classification. Most of the samples come under medium salinity class (C2) (48.57%) followed by low salinity class (C1), high salinity class (C4) and very high salinity class (C3) with 28.57, 14.29 and 8.57 per cent respectively in all the seasons. Majority of the samples exhibit there is no permeability hazard. Salinity persists in the basin and possibility of salt accumulation in irrigation pipes observed from LSI values. Using remote sensing and GIS technique, the mapping was done for the groundwater quality of PAP basin. The variations in the ground water quality of the basin are directly positively correlated with rainfall pattern and geology of the basin. For effective utilization of saline water in the basin, management strategies were formulated and field experiments were conducted in the farmer’s holdings in the sampling area of the basin.

Establishment of critical non-depositing velocity prediction model for sediment in drip irrigation laterals based on PSO-SVM

Accurately determining the critical non-depositing velocity for sediment (CNDVS) in drip irrigation laterals is essential to address issues of sediment deposition and clogging in drip irrigation pipes caused by the use of muddy water. This paper focuses on three main factors: the percentage of intermediate-sized sediment particles (P), pipe diameter (D), and sediment concentration (S), all of which significantly influence the CNDVS in drip irrigation laterals. To predict the CNDVS, a comprehensive gradient test was developed and the Particle Swarm Optimization-Support Vector Machine (PSO-SVM) algorithm was applied to establish a response surface for predicting the CNDVS. Additionally, the PSO algorithm optimized the penalty parameter (C), loss parameter (ε), and kernel parameter (δ) in the SVM, resulting in a prediction model for the CNDVS. The proposed model was trained and tested using experimental data, and its prediction performance and accuracy were compared with the regression fitting model. The results indicate that within a specific range, the CNDVS increases with higher values of the three factors. The PSO-SVM model, with optimal parameters combination values of C = 486.37, ε = 0.04, and δ = 68.49, provided the most prediction accurate. Compared with the regression fitting model, the PSO-SVM model has the smaller values of Mean Absolute Error (MAE) = 0.0049, Root Mean Square Error (RMSE) = 0.0057, and Percent Bias (PBIAS) = 0.0004, and the larger value of Nash–Sutcliffe Efficiency (NSE) = 0.9874, Willmott index (WI) = 0.9401, and Coefficient of Determination (R2) = 0.9875. These results demonstrate that the PSO-SVM model established in this study exhibits high prediction performance and accuracy. The findings of this research can serve as a foundation for developing optimal operating and flushing flow velocity within the laterals in muddy water drip irrigation systems.

Unintended consequences, conflict and resilience in a small-scale irrigation development, Marakwet, Kenya

AbstractThis article examines the development, early operation and subsequent failure of the Tot-Kolowa Red Cross irrigation scheme in Kenya’s Kerio Valley. Initially conceived as a technical solution to address regional food insecurity, the scheme aimed to scale up food production through the implementation of a fixed pipe irrigation system and the provision of agricultural inputs for cash cropping. A series of unfolding circumstances, however, necessitated numerous modifications to the original design as the project became increasingly entangled with deep and complex histories of land use patterns, resource allocation and conflict. Failure to understand the complexity of these dynamics ultimately led to the project’s collapse as the region spiralled into a period of significant unrest. In tracing these events, we aim to foreground the lived realities of imposed development, including both positive and negative responses to the scheme’s participatory obligations and its wider impact on community resilience.

Evaluation of UVLED disinfection for biofouling control during distribution of wastewater effluent

Abstract A commercially available UVLED flow-through device, operating at 40 mJ/cm2, was examined for biofilm control on irrigation pipe material fed by wastewater effluent. Biofouling was monitored through total coliform counts, crystal violet (CV) staining, and ATP analyses. A UV fluence of 40 mJ/cm2 at 280 nm retarded biofilm formation; however, complete biofilm prevention by UV treatment was not achieved despite a high inactivation of planktonic cells. After 5 days of the study, the total coliform and CV biofilm quantification assays between the UV-treated and control bioreactor coupons were not statistically different. The total coliform counts indicated a stable biofilm cell concentration was reached; the CV assay showed biofilm biomass accumulation with time. The ATP results revealed higher coupon ATP on the UV-treated coupons than the control coupons by day 5. The results provoke an interesting discussion surrounding the contribution of viable cells, represented by total coliforms, and extracellular polymeric substance (EPS) to total biofilm biomass. This study also highlighted a need for further investigation into the relationship between ATP responses and complex UV-stress responses of diverse microbial communities as opposed to pure bacteria cultures.

Effects of Burial Furrow Parameters on Soil Water Movement under Subsurface Stalk Composite Pipe Irrigation

Stalk composite pipe (SCP), a novel product used for subsurface irrigation, is primarily composed of crop stalks, soil, and water. In subsurface SCP irrigation (SSI), comprehending the effects of burial furrow parameters on soil water movement is critical. However, the precise effects are not known. Here, we aimed to assess the effects of varying burial furrow dimensions, including widths of 15, 20, and 25 cm, depths of 10, 15, and 20 cm, and backfilling-soil bulk densities of 1.1, 1.2, and 1.3 g cm−3, on wetted distance and soil water movement. We conducted an indoor soil bin experiment and numerical simulation using HYDRUS-2D in 2020–2021 in Zhengzhou City, Northern China. Wider burial furrows resulted in increased wetted distance and soil water content, ultimately leading to greater effect in a horizontal direction. In the horizontal profile, the average soil water content of the SSI treatments, which used burial furrow widths of 15, 20, and 25 cm, were 1.121, 1.230, and 1.280 times higher, respectively, than those of CK. The burial furrow depth had minimal effect on the wetted distance, whereas adjusting the burial furrow depth primarily affected the saturation depth. The speed of wetting-front migration was affected by the backfilling-soil bulk density. For a given soil and crop, it is advisable to determine first the burial furrow width and backfilling-soil bulk density. Subsequently, the burial furrow depth should be established based on the distribution of the crop’s roots. Our findings offer a scientific basis for using SSI.

Adapted Irrigation Pump Load in Solar PV and Wind Energy Systems through Stepped Variable Frequency Drives

Wind and solar photovoltaic (solar-PV) power are highly variable and intermittent as exhibited by corresponding generation profiles. When this power is utilized directly for water pumping, the availability and reliability of water automatically follow the Renewable Energy Sources (RES) characteristics. On the other hand, Deferrable Irrigation Load (DIL), follows a specific irrigation water need profile. The DIL profile is determined by crop cycles and corresponding water needs. It is also affected by aspects of weather mainly precipitation, temperature, and wind. In this research, discrete switches and Variable Frequency Drives (VFDs) are applied as a combined solution. Combined discrete and continuous switching through VFDs is applied to separately adapt pump load to DIL and RES profiles. Discrete switches are applied to engage the exact number of pumps required to match an expected irrigation load. A VFD is further used to ensure continuous matching of irrigation pump load to the anticipated DIL curve, through adjustment of pump speed points. Finally, the system is repeated to adapt the pump power to the RES curve. The adapting technique was implemented to improve elasticity, hence the efficiency of the system. The results showed that the adapted system to the DIL curve was 94.7% compared with a discrete-only system (91.4%). This represented a slight improvement of 3.3%. The results demonstrated the smoother operation of the pump system and increased energy utilization efficiency. A further improvement on the control strategy for VFD coupled with the re-design of irrigation pipe networks was required to improve efficiency beyond 94.7%.

Accumulation, sources, and health risks of phthalic acid esters (PAEs) in road dust from heavily industrialized, urban and rural areas in southern Iran

In this research, a total of 51 road dust samples were collected from three districts (Asaluyeh, Bushehr, and Goshoui) in the south of Iran from April to June 2022 and analyzed for the concentration of 7 phthalic acid esters (PAEs) compounds. Asaluyeh was considered as an industrial area (near gas and petrochemical industries), Bushehr as an urban area, and Goshoui as a rural area (far from pollution sources). The PAEs concentration of the street dust samples was determined using a mass detection gas chromatography (GC/MS). The mean ± SD levels of ƩPAEs in samples from industrial, urban, and rural sources were 56.9 ± 11.5, 18.3 ± 9.64, and 5.68 ± 1.85 μg/g, respectively. The mean concentration levels of ƩPAEs was significantly (P < 0.05) higher in samples from the industrial area than urban and rural areas. The mean levels of di(2-Ethylhexyl) phthalate (DEHP) in industrial, urban, and rural areas were 20.3 ± 8.76, 4.59 ± 1.71, and 2.35 ± 0.98 μg/g, respectively. The results of the PCA analysis indicate that the likely major sources of PAEs in the road dust in the studied areas are the application of various plasticizers in industry, solvents, chemical fertilizers, waste disposal, wastewater (e.g., agricultural, domestic, and industrial), and the use of plastic films and plastic-based irrigation pipes in greenhouses. As well as, it was found that the non-cancer risk of exposure to dust-bound PAEs was higher for children than for adults. These values were <1 for both age groups (children and adults) and the exposure of inhabitants to PAEs in road dust did not pose a notable non-cancer risk. The cancer risk from exposure to DEHP in road dust was below the standard range of 10−6 in all three areas. Further studies that consider different routes of exposure to these contaminants are needed for an accurate risk assessment. Moreover, since higher PAEs level was found in industrial area, decision-makers should adopt strict strategies to control the discharging of pollution from industries to the environment and human societies.

Effect of Humic acid, Cytokinin and Arginine on Growth and Yield Traits of Bean Plant Phaseolus vulgaris L. under salt stress

To achieve optimal plant growth and production under salt stress, some products were added in adequate quantities to give a good yield, especially bean plants which are sensitive to salinity. For this purpose, this experiment was carried out during the spring growing season in 2022 in Baghdad, to study the effects of humic acid, cytokinin, arginine and their interaction with 9 parameters that reflect the overall traits of vegetative growth and yield of common bean plants Phaseolus vulgaris L. var. Astraid (from MONARCH seeds, China). The factorial design with 3 replicates was used, each with 7 plants treated via foliar spraying or by addition to the soil. The first factor included three groups; H0, H1 and H2 (0, 6, 12 Kg.h-1 Humic acid). The second factor included two groups; C0, and C1 [0, 100 mg.l-1 Cytokinins], and the third factor included three groups; A0, A1 and A2 (0, 100, 200 mg.l-1 Arginine). During the period of plant growing, furrow irrigation with drip pipe irrigation was used regularly with non-saline water EC= 2.2, during the first growth stage until it reaches the stage of four true leaves then irrigated with well saline water EC=3.4 for the rest of the plant life cycle. As for the treatment with humic acid, the results revealed that H2 treatment caused significantly higher values in most the studied traits. For cytokinin treatment, the results showed that C1 treatment resulted in significantly higher values in most the studied traits. And, there was no significant difference between A0, A1, and A2 except for leaves area, shoot dry weight, and root dry weight which exerts a significant difference between (A1, A2) in comparison to control A0. Based on the results of the binary overlap among treatments, H2C1, H2A2, H2A1 and, triple overlap H2C1A2 and H2C1A1 treatments resulted in the highest values as compared to all other treatments for all the studied traits. In conclusion, the present study comes up with the following: humic acid, cytokinin, arginine, and their interactions enhance most of the plant growth parameters and the pods production of common bean plants under salt stress.

The Concept of Farming Schools and Branding Digital Agrotourism for Farmer Communities and Students English Department

The article gave an assistance to develop Farmer Schools Karangerjo and Students English Department of Universitas Ma’arif Lampung in order to improve skills and provide an understanding of agricultural management, namely the concept of agricultural mechanization. Hence, they can get access to learning about agricultural management for free and sustainably. Improving the skills and creativity of the farming community in building a roadmap for the digital marketing media movement. it would have an impact on the ability of farmer groups to recognize and utilize online digital media. The method used Asset Based Community Development (ABCD). This assistance has a significant impact on the solidarity of the farmer group community. From the various activities that have been carried out, some farmers have been creative in utilizing the vacant land yards around their yards for vegetable farming activities, in addition to the availability of a PVC pipe irrigation system, which was one of the outcomes of the agricultural mechanization concept. They also apply the concept of organic farming by preparing superior seeds that have been sown properly, from preparing the land to planting vegetable seeds. In addition, there was online digital media, namely Instagram, to improve the skills and creativity of the farming community in building a roadmap for the digital marketing media movement.&#x0D; Keywords: Farming School, Branding Digital, Digital Media Marketing

Application of Numerical Newton-Raphson Method in Calculation of Emitter Water Discharge of Drip Irrigation System in “Mutis Cemerlang” Coffee Plantation

Based on the slope class, the shape of the area and the elevation of dry land in Nusa Tenggara, agricultural land in Noepesu Village is suitable for planting coffee plants with an agroforestry scheme. To overcome the problem of limited water, drip irrigation system technology can be applied. The use of drip irrigation as an agricultural technology in Noepesu village has been carried out by many farmer groups. Still, the installation process does not consider the pipe specifications (pipe length and pipe diameter) and the condition of agricultural land. This causes the service life of drip irrigation to be not long. If this continues, of course, it will increase system installation costs. To optimize service life, a hydraulics analysis method is needed for drip irrigation pipe network systems that take into account pipe specifications and agricultural land conditions.The hydraulics analysis of the drip irrigation network system determines the emitter’s water flow rate. The emitter flow rate forms a nonlinear equation known as the closed pipe equation. In the process of solving these equations, numerical methods can be used, specifically the Newton-Raphson method. This study focuses on applying the Newton-Raphson method to calculate the amount of water discharge from each emitter of the drip irrigation network system on the farmland of the Mutis Cemerlang Farmer Group in Noepesu Village. The drip irrigation system is designed with 250 nodes, 275 pipes, 26 loops, and 86 outlets divided into two sides, with the left side containing 84 outlets with one emitter and the right side containing 102 outlets with two emitters. The amount of water discharge for each emitter is 0,0008 ml/second≤Q≤2,6 ml/second for the left side and 0,001 ml/second≤Q≤1,1 ml/second for the right side, as determined by simulation calculations utilizing the Newton-Raphson method and Matlab software. The simulation results show that the amount of water discharge at each emitter is ideal in the first iteration because it has a discharge correction value (∆Q)≈0.

The Effect of Depth of the Smart Artificial Subsurface Irrigation Pipes and the Distance on the Efficiency of the System Performance and Yield of Sunflower

A field experiment was conducted to study the effect of pipes depth and the distance between them in the smart artificial subsurface irrigation system on the efficiency of the system performance and the yield of sunflower (Helianths annuus L.), in one of the fields of Al-Raed Research Station/Ministry of Water Resources located 25 km west Baghdad for the growing season 2022. Two factors were used in the experiment, the first factor included the depths of the subsurface irrigation pipes at three levels 10, 15, and 20 cm. The second factor included the between subsurface irrigation pipes at three levels 50, 60, and 70 cm. The characters studied were soil moisture content %., irrigation water amount, cm3 h-1. depth of irrigation water added cm, plant height cm, and sunflower grain yield ton ha-1. Nested system was used according to the randomized complete block design (RCBD) with three replicates. The pipes depth was allocated to the main plot and the distance in the sub-plots. Least significant difference was used under the probability (LSD 0.05) to compare the averages of treatments. The results showed that the highest and lowest values of moisture content were 23.21 and 16.69 % for treatment depth 20 and distance 60 cm and treatment depth 10 and distance 70 cm, respectively. The highest and lowest values for irrigation water depth were 7.99 and 5.31 cm for the treatment depth 15 and distance 50 cm, and treatment depth 10 and distance 60 cm, respectively. The highest and lowest values for the amount of water consumed were 234.59 and 96.7 cm3 h-1 for treatments depth 10 and distance 50 cm, and treatment depth 20 and distance 60 cm, respectively. The highest and lowest values for plant height were 150.6 and 117.0 cm for the treatment depth 20 and distance 50 cm and treatment depth 10 and distance 70 cm, respectively. The highest and lowest values of grain yield were 4.97- and 2.62-ton ha-1 for treatments depth 20 and distance 50 cm and treatment depth 10 and distance 70 cm, respectively.

Investigating the Effect of Saturated Hydraulic Conductivity in Porous Pipe Irrigation System and Comparing to Other Parameters

A subsurface porous pipe irrigation system has been widely used, water seeps from the porous pipe into the soil. Such systems can carry out both conveyance and seepage in the same time. Hence by this research, it is investigated the effect of saturated hydraulic conductivity of the porous pipe on the movement of soil moisture contents by using five values of 0.05, 0.075, 0.1, 0.125, and 0.15 cm/hr for the pipe. The pipe is installed at a depth of 15 cm with 6 cm as the outer diameter. Then water heads of 25, 50, and 75 cm are applied for 2 hours as an operation time. Preparations in the HYDRUS/2D are done and all movements of soil moisture contents are recorded with time. Empirical functions are found with the collected data in both sides of horizontal and vertical directions with an average relative error value not exceeds 4 % and with coefficients of determination more than 0.97. Therefore, these empirical functions are well fitted and can be used as an indicator in designing system of subsurface porous pipe irrigation.

Leaching characteristics and potential risk of heavy metals from drip irrigation pipes and mulch substrate in agricultural ecosystems

Drip irrigation is a valuable method for optimising water and fertiliser usage, motivating its increasing use. However, the ecological effects of drip irrigation fertilisation have not been sufficiently evaluated, limiting its effective and widespread use. Within this context, we aimed to determine the effects and potential ecological risks of using polyethylene irrigation pipes and mulch substrate under various drip irrigation conditions as well as burning of waste pipes and mulch substrate. Laboratory simulations of field conditions were used to determine the distribution, leaching, and migration pattern of heavy metals (Cd, Cr, Cu, Pb, and Zn) from plastic drip irrigation pipes and agricultural mulch substrate into various solutions. Maize samples obtained from drip-irrigated fields were analysed to determine the presence of heavy metal residues and assess the risk of heavy metal contamination. Heavy metal leaching from pipes and mulch substrate was high under acidic conditions, while the migration of heavy metals from plastic products was low in alkaline water-soluble fertiliser solutions. After combustion, heavy metal leaching from pipes and mulch residues increased considerably, with the migration capacity of Cd, Cr, and Cu increasing by >10-fold. Heavy metals in plastic pipes migrated primarily to the residue (bottom ash), whereas those from mulch substrate migrated to the fly ash component. Under experimental conditions, the migration of heavy metals from plastic pipes and mulch substrate had a negligible effect on the heavy metal content in aqueous environments. Although heavy metal leaching increased, the effect on water quality under actual irrigation conditions was relatively minor (in the order of 10−9). Thus, the use of plastic irrigation pipes and mulch substrate did not result in significant heavy metal contamination and potential risk to the agriculture ecosystem. Our study findings provide evidence for the effective application and widespread promotion of drip irrigation and fertiliser technology.

Spatio-Temporal Study on Irrigation Guarantee Capacity in the Northwest Arid Region of China

Irrigation guarantee capacity is the critical factor in evaluating the development level of irrigated agriculture and is also a future development trend. It is necessary to carry out scientific planning and reasonable allocation of irrigation water resources to ensure the sustainable development of irrigated agriculture and improve the efficiency and effectiveness of water resource utilization. This study is based on remote sensing meteorological data and the principles of the Miami model and water balance. We calculated the annual irrigation water requirement and effective irrigation water, and used the ratio between the effective irrigation water and irrigation water requirement as the basis for evaluating an irrigation guarantee capability index. By using irrigation guarantee capability evaluation indicators from multiple years, we evaluated and assessed the irrigation guarantee capability in the arid region of northwest China. In addition, we analyzed three indicators (i.e., irrigation water requirement IWR, effective irrigation water EIW, and irrigation guarantee capacity index IGCI) to explore the rational allocation of water resources in the northwest arid area. IWR, EIW, and ICGI in northwest China from 2001 to 2020 were analyzed, and the average values were 379.32 mm, 171.29 mm, and 0.50, respectively. Simultaneously, an analysis was conducted on the temporal and spatial distribution of IWR, EIW, and IGCI in the northwest region of China from 2001 to 2020. The results indicated that the rainfall in the southwestern edge of the Yellow River Basin and the eastern part of the Qaidam Basin could meet the irrigation water demand. The northwest edge of the Yellow River Basin, the central Hexi Inland River Basin, most of Northeast Xinjiang, central and southeastern Xinjiang, and other regions mainly rely on irrigation to meet agricultural water requirements. The rest of the region needs to rely on irrigation for supplementary irrigation to increase crop yield. All districts in the ‘Three Water Lines’ area of northwest China should vigorously develop sprinkler irrigation, micro-irrigation, pipe irrigation, and other irrigation water-saving technologies and support engineering construction. Under the premise of ensuring national food security, they should reduce the planting area of rice, corn, and orchards, and increase the planting area of economic crops such as beans and tubers in the ’Three Water Lines’ area. That is conducive to further reducing the agricultural irrigation quota and improving the matching degree of irrigation water resources. It provides a scientific reference for optimizing water resource allocation and improving irrigation water-use efficiency in northwest arid areas.

Sustainable Farming Practices: A Comprehensive Study on Rain Pipe Irrigation System Performance

Sustainable Farming Practices: A Comprehensive Study on Rain Pipe Irrigation System Performance

Design and Analysis of Extruder Head Flow Channel of Cladding Infiltration Irrigation Pipe

To solve the problem of deformation and to drop off buried infiltration irrigation pipe, a kind of extruder co-extrusion die that can effectively produce clad infiltration irrigation pipe is proposed from the structure and production infiltration irrigation pipe. Through the innovative design method, the flow passage and some parts of the extruder head were designed. The model of the extruder head runner was established, and the structure of the extruder head runner was optimized by finite element analysis. Compared with the original coextrusion die, this design reduces the size of the extruder die, and can effectively enhance the plasticizing effect and uniformity, and the material flow is more stable. This method is conducive to strengthening the strength and quality of the subsurface irrigation pipe, prolonging its service life, and reducing the difficulty of maintenance and replacement of the buried subsurface irrigation pipe.

Life cycle assessment of eight urban farms and community gardens in France and California

Urban agriculture (UA) is often positioned as an environmentally sustainable food supply for cities. However, life cycle assessments (LCA) measuring environmental impacts of UA show mixed results, because of inconsistent application of LCA and reliance on hypothetical case studies. To address these shortcomings, we performed an LCA of eight urban farms and community gardens in Paris, France and San Francisco, California, USA. We collected primary data from sites representing diverse growing systems (low-intensity open-field to open-air hydroponics) and motivations (education, civic engagement, and commercial production). We found that medium-tech farms, with minimum social engagement had the lowest impacts using a kilogram-based functional unit, but socially-oriented farms had the lowest impacts with an area-based functional unit. Most impacts came from infrastructure (irrigation pipes, hydroponics structures), irrigation, compost, and peat for seedlings. Our findings can help LCA practitioners perform UA LCAs more completely/consistently, and help urban farmers/gardeners target high-environmental-impact practices to optimize.

Design of Venturi-Type Fertilizer Injectors to Low-Pressure Irrigation Systems

Twenty prototypes of Venturi-type fertilizer injectors for low-pressure agricultural irrigation systems were designed based on functional hydraulic pressure head and variation of their structural designs. These prototypes were modelled in three dimensions (3D) and evaluated using simulation through Computational Fluid Dynamics software (CFD). The main structural design characteristics come from a real necessity to complement an low pressure multigate irrigation system project named in Spanish &amp;ldquo;El Manzano&amp;rdquo; (The Apple tree) and bring it the fertigation possibility. The aim of this research was to select the best prototype, in order to identify the convergent and divergent angles, throat diameter and hydraulic pressure head to efficiently produce a Venturi-type injector for use in gated-irrigation pipe irrigation systems for use in a future in &amp;ldquo;El Manzano&amp;rdquo; project. As a result of the simulations, the physical characteristics of the injector were defined. The inlet and outlet diameters should be 152.4 mm, the throat diameter 76.2 mm and the suction diameter of 50.8 mm. The convergent and divergent angles showing most improved performances were 7.5 and 10&amp;deg;, respectively. This methodology can be used to construct Venturi-type fertilizer injectors for low-pressure gated-pipe agricultural irrigation systems, which, on one side, can reduce significantly the fertilizer application costs and, on the other side, the fertilizer management efficiency can be also improve considerably to save water resources. There is relatively very little experience in using this type of fertilizer injectors in low-pressure irrigation systems.