Cost-effective Irrigation Research Articles

Assessment of dry season garden egg production among small-scale farmers in Edu Local Government Area of Kwara State, Nigeria

The study was carried out for the purpose of assessing dry season garden egg production among small-scale farmers in Edu Local Government Area of Kwara State. The study adopted a snowballing sampling technique to sample 120 small-scale garden egg farmers. Five research questions were formulated to achieve the objectives of this research work. Descriptive statistics, cost and return analysis and OLS regression were used to analyze data collected. Cost and return analysis shows that the total revenue generated from the sales of irrigated garden egg produce for a typical farmer was N 36,596.5k while the total fixed cost (depreciated) and variable input cost amounted to 1,279.22K to give a net farm income (NFI) of N 24,582.68k. The OLS regression results revealed that the coefficients of farm size and household size were positive and significant at the 1% and 10% levels of probability respectively. This implies that an increase in farm size by 1 ha will increase the production of dry season garden egg by 1 percent. While the results of stochastic production frontier estimate show that the parameters of labour, fertilizer and farm size were highly significant, chemical use was significant at 10% level. This result implies that the farmers were technically efficient in the use of labour, fertilizer, chemical and farm size. Therefore, it is recommended that farmers should be encouraged to form cooperative societies, whereby they can join their resources together to provide a cost-effective irrigation system. Also, government authorities and other non-governmental organizations are encouraged to give farmers fertilizers and other chemicals at subsidized rates. There is a need for revitalization of the marketing board in Nigeria to further strengthen the marketing of agricultural produce and reduce marketing, storage and transportation problems.

Wastewater Reuse for Agriculture: Development of a Regional Water Reuse Decision-Support Model (RWRM) for Cost-Effective Irrigation Sources.

Water scarcity has become a critical problem in many semiarid and arid regions. The single largest water use in such regions is for crop irrigation, which typically relies on groundwater and surface water sources. With increasing stress on these traditional water sources, it is important to consider alternative irrigation sources for areas with limited freshwater resources. One potential irrigation water resource is treated wastewater for agricultural fields located near urban centers. In addition, treated wastewater can contribute an appreciable amount of necessary nutrients for plants. The suitability of reclaimed water for specific applications depends on water quality and usage requirements. The main factors that determine the suitability of recycled water for agricultural irrigation are salinity, heavy metals, and pathogens, which cause adverse effects on human, plants, and soils. In this paper, we develop a regional water reuse decision-support model (RWRM) using the general algebraic modeling system to analyze the cost-effectiveness of alternative treatment trains to generate irrigation water from reclaimed wastewater, with the irrigation water designed to meet crop requirements as well as California's wastewater reuse regulations (Title 22). Using a cost-minimization framework, least-cost solutions consisting of treatment processes and their intensities (blending ratios) are identified to produce alternative irrigation sources for citrus and turfgrass. Our analysis illustrates the benefits of employing an optimization framework and flexible treatment design to identify cost-effective blending opportunities that may produce high-quality irrigation water for a wide range of end uses.

A modeling approach for agricultural water management in citrus orchards: cost-effective irrigation scheduling and agrochemical transport simulation.

The water flow and the mass transport of agrochemicals in the unsaturated and saturated zone were simulated in the extended alluvial basin of Keritis river in Crete, Greece (a predominantly flat and most productive citrus growing area) using the hydrological model MIKE SHE. This model was set up based on information on land use, geology, soil structure, meteorological data, as well as groundwater level data from pumping wells. Additionally, field measurements of the soil moisture at six different locations from three soil depths (0.1, 0.2, and 0.3 m) were used as targets to calibrate and validate the unsaturated flow model while for saturated condition, groundwater level data from three well locations were used. Following the modeling approach, the agrochemical mass transport simulation was performed as well, based on different application doses. After the successful calibration processes, the obtained 1D modeling results of soil moisture-pressure related to soil depth at different locations were used to design a proper and cost-effective irrigation programme (irrigation timing, frequency, application rates, etc.) for citrus orchards. The results of the present simulation showed a very good correlation with the field measurements. Based on these results, a proper irrigation plan can be designed at every site of the model domain reducing the water consumption up to 38% with respect to the common irrigation practices and ensuring the citrus water productivity. In addition, the effect of the proposed irrigation scheduling on citrus yield was investigated. Regarding the agrochemical concentration in the groundwater for all dose cases was below the maximum permissible limit. The only exception was for the highest dose in areas where the water table is high. Thus, this modeling approach could be used as a tool for appropriate water management in an agricultural area estimating at each time and location the availability of soil water, contributing to a cost-effective irrigation plan.

Effects of fixed partial root-zone drying irrigation and soil texture on water and solute dynamics in calcareous soils and corn yield

► In field evaluation FPRD proved that it is a cost effective irrigation method for row crops. ► Deep percolation under FPRD drip irrigation is limited. ► Salt built up in high levels in the soil surface of the non irrigated interrow positions and decreased with depth. ► Transport and distribution of soluble salts are affected by the soil textural class, the CaCO 3 content and possibly the dissolution and precipitation of salts. ► Corn yield reached the usual standards despite the fact that the salinity levels encountered during the sensitive growth stages exceeded the salt tolerance threshold of corn. Water dynamics and salt distribution in the soil were studied under Fixed Partial Root zone Drying irrigation (FPRD) conditions in corn fields in Northern Greece. FPRD irrigation technique was applied without deficit treatment in two calcareous soils, a sandy clay loam and a sandy loam. Soil water content was recorded in the vertical profile of 0.6 m with the use of capacitance sensors in the row and interrow positions of plants. Salt built-up was monitored to the depth of the root zone, bi-weekly, by measuring electrical conductivity (EC e ) and the concentrations of soluble cations Ca 2+ , Mg 2+ , Na + and K + of the saturation extract on irrigated and non irrigated interrow positions. Soil moisture distribution and salt built-up in soil were used to evaluate the potentials and constraints of FPRD efficiency to sustain plant growth and crop production as a low cost drip irrigation technique. The results indicated that FPRD application on both soils was capable of supplying sufficient amounts of water on plant row. Soil analyses showed that salts accumulated to high levels in the soil surface and decreased in depth at the non irrigated interrow positions. Spatial and temporal variability of salt movement and distribution in the soil profile of 0.6 m were ascribed to soil textural differences. The development and yield of corn plants for both soils reached the usual standards for the area with a minor decrease in the sandy loam soil.

English

The purpose of Phase II of this study was to determine if a single application of a time-released water gel (TRWG) with the added nutrients zinc and acetic acid could provide enough moisture to successfully establish the root system of a native plant during the warmest time of the year. Phase II follows the plants from Phase I throughout a complete growing season. A TRWG was applied to one group of plants providing 90-days of continuous moisture during late summer/fall plantings. Plants that were hand watered (controls) were given 2.5 gallons of potable water, without nutrients, each week for 12 weeks. The study takes place in Santa Rosa, CA and presents initial results from June 2010 of dry root mass weights from plantings in August, September and October of 2009. Final results for Phase II were gathered in November 2010 showing first season root mass growth and upper plant height measurements. Planting trees in August appears to provide a sufficient timeline allowing roots to push growth for a few months prior to plants becoming dormant. The challenge is providing cost effective irrigation from August until the dormant season around November. Results for Phase II of this study show root mass had the greatest overall increase when plants went into the ground during August with a TRWG. Phase II data indicates a 139% average increase in root mass growth and a 68% increase in upper plant growth for plants established in August with a TRWG over controls which were given water on a weekly basis.

Performance of Low Energy Water Application Device

Considering the overall farming situation in developing countries particularly India it has been observed that the available options of efficient irrigation technologies are unable to cover up small and marginal farm holders due to lack of the applicability and acceptability in terms of their needs, priorities and financial capabilities. This makes imperative to develop a substitute of existing technologies that could be cheap simple and less capital intensive as well as applicable for small farms. This paper discusses the performances of a low cost water and energy efficient device called LEWA which can be used in place of overhead impact sprinklers to irrigate field and row crops efficiently at small farms. LEWA can be operated at an operating pressure range 39 to 98 kPa at its nozzle head, with discharge rate 0.87–1.10 m3/h, and throw diameter 6–8 m. Since operating pressure at the nozzle head governs overall system pressure and reflects the total cost of the system, size of prime mover pump required and its operational cost; therefore the developed device holds greater promise in development of a cost effective water and energy efficient pressurized irrigation system for small and marginal farmers possessing small and fragmented land.

Trade-off analysis for restoring environmental flows through irrigation demand management

The aim of this paper is to evaluate economic trade-offs of introducing irrigation demand management measures to modify river flows in order to mimic natural flow variations in the rivers. A number of irrigation demand management options were identified through rigorous discussions with the key stakeholder groups in the Murrumbidgee Catchment. The impacts of alternative demand management options are presented in terms of a matrix of economic costs and associated water savings. The modelling results revealed that 10–15% of peak water use during summer can be reduced from the average total annual water use of 1400 GL. This may result in reduced economic return or require private and public investments in the form of on-farm water saving technologies, canal lining or construction of en-route storage. However, if we value the saved water at current market prices, then benefits are expected to be higher than the costs involved. Among all other options, spreading water use over summer and winter season through new crop mixes promises to be the most cost-effective irrigation demand management option for improving seasonality of flow in the rivers. The study also found that increasing on-farm water use efficiency to reduce peak water use is in the farmer’s economic self-interest through reduced water inputs per unit of production; it will also help increase streamflows if suitable mechanisms for securing environmental flows can be implemented.

Optimizing the layout and design of branched pipeline water distribution systems

Branched distribution systems are found in a large number of situations, including rural irrigation, reclaimed water distribution, and effluent disposal. Much research has been developed around optimizing pipeline design assuming a predetermined geographical layout of the distribution system. There has been less work done, however, on the problem of optimizing the configuration of the network itself, which is a particularly crucial issue in lower-income areas where the need for cost-effective irrigation systems is greatest. Generally, engineers develop the basic layout through experience and sheer intuition. In this paper, a method is developed for determining an optimal layout for a branched distribution system given only the spatial distribution of potential customers and their respective demands. The technique utilizes a mixed integer linear programming (MILP) algorithm to optimize an empirically derived objective function. The method is tailored for practical application and allows the decision maker to simultaneously solve for the optimal customer/user base and pipeline layout. The method is illustrated with a simple example.

Cost-Effective Temporary Microirrigation System for Grass Establishment on Environmentally Sensitive Steep Slopes

An advanced technology cost-effective drip irrigation system design and setup on environmentally sensitive elevated steep slopes (batters) of a coal train derailment site in Central Queensland, Australia, are presented. The final profile of the coal burial site consists of six batters and associated berms with a drop in elevation of about 35 m. A small dam constructed downstream of the confluence of the two main drainage channels at the site supplied water for irrigation of the batters to aid the establishment of grass to control erosion. Water was periodically pumped from the small dam to three storage tanks using a petrol (gas) pump. Three solar pumps drew water from the storage tanks and dam to irrigate the top four batters. Contactors, pressure switches and irrigation control valves in turn shared a single solar power source between the solar pumps. Level balls (floating switches) placed in the storage tanks cut the solar power supply to the pumps when the storage tanks were nearly empty. On the whole, the irrigation system worked very well and excellent grass cover was established within 12 weeks. Given the environmental risks associated with the on-site burying of coal, and the estimated cost of about AU$$11.73/m{sup 2} (every 10 years) in maintenance if the railway batters are not treated, the estimated total cost of AU$$4.61/m{sup 2} of batter area treated with irrigation, including AU$3.08/m{sup 2} in irrigation cost, is justified.

Pond Water Source for Irrigation on Steep Slopes

Existing technologies have been tailored to deliver cost-effective irrigation on a railway embankment and excavated steep slopes (referred to as batters) within a semiarid environment. Irrigation is to aid the establishment of 100% grass cover within a few weeks to mitigate soil erosion problems. It is based on water sourced from a temporary excavated pond plus the use of a solar powered pump and a drip irrigation system. Railway batter erosion remediation is timed for the wet summer season when irrigation can be used to supplement natural rainfall. For a given irrigation demand and catchment area, critical (minimum) pond volume is estimated from regional charts developed for ungauged catchments. About 20% of the critical volume is added to account for evaporation losses and dead storage. Also, seepage losses need to be considered if the soil is medium to coarse textured and if the pond is not lined with an impermeable material. Initial results are very encouraging with a cost estimate of AU$2.74/m² of batter area treated (irrigated). Irrigation unit cost is expected to decrease with a larger scale irrigated batter area and the refinement of technologies and installation procedures. Although irrigation methodologies were developed for railway embankments and excavated slopes, they can also be used for erosion control on steep slopes such as road embankments or excavated slopes and earth dam side slopes.