Cyclic Irrigation Research Articles

Effect of salinity and drip fertigation on maize (<i>Zea mays</i>) and water use efficiency

Climatic variability is immensely pressurised on freshwater availability in arid and semi-arid ecosystems, leading to poor quality water for crop production not becoming uncommon, especially in coastal ecosystems. A field experiment was conducted during winter (rabi) season of 2022–23 at the Saline Water Scheme at Agricultural College Farm, Acharya N. G. Ranga Agricultural University, Bapatla, Andhra Pradesh to assess the impact of saline water on maize growth, yield and water use efficiency under drip fertigation. The experiment consisted 8 treatments laid in randomized block design (RBD) with 4 replications. The utilization of the BAW irrigation method, together with the application of a prescribed quantity of fertilizer, resulted in the highest plant height and dry matter accumulation during all phases of crop growth. These outcomes were comparable to those achieved by using a combination of fresh water and saline water with an electrical conductivity of 2 dS/m. The maximum values for the number of kernels per cob (451), cob length (17.2 cm), cob weight (164.4 g), kernel yield (7.38 t/ha), stover yield (9.61 t/ha) and water use efficiency (18.5 kg/ha mm) of maize were observed under the irrigation treatment T4. The parameters exhibited their minimum values when irrigation was conducted using water with a salt level of 4 dS/m and no fertilizers were used. However, there was no statistically significant difference observed in the number of cobs per plant and harvest index of maize when saline water was used in conjunction with drip fertigation. In the context of maize cultivation, employing a cyclic irrigation technique that alternates between salty (EC 2–4 dS/m) and freshwater sources, in conjunction with recommended dose of fertiliser (RDF) has the potential to deliver comparable crop development, productivity, and economic benefits when compared to the use of freshwater sources alone.

Response of Soil Microenvironment and Crop Growth to Cyclic Irrigation Using Reclaimed Water and Brackish Water.

The scarcity of freshwater resources has increased the use of nonconventional water resources such as brackish water, reclaimed water, etc., especially in water-scarce areas. Whether an irrigation cycle using reclaimed water and brackish water (RBCI) poses a risk of secondary soil salinization to crop yields needs to be studied. Aiming to find an appropriate use for different nonconventional water resources, pot experiments were conducted to study the effects of RBCI on soil microenvironments, growth, physiological characteristics and antioxidation properties of crops. The results showed the following: (1) compared to FBCI, the soil moisture content was slightly higher, without a significant difference, while the soil EC, sodium and chloride ions contents increased significantly under the RBCI treatment. With an increase in the reclaimed water irrigation frequency (Tri), the contents of EC, Na+ and Cl- in the soil decreased gradually, and the difference was significant; the soil moisture content also decreased gradually. (2) There were different effects of the RBCI regime on the soil's enzyme activities. With an increase in the Tri, the soil urease activity indicated a significant upward trend as a whole. (3) RBCI can alleviate the risk of soil salinization to some extent. The soil pH values were all below 8.5, and were without a risk of secondary soil alkalization. The ESP did not exceed 15 percent, and there was no possible risk of soil alkalization except that the ESP in soil irrigated by brackish water irrigation went beyond the limit of 15 percent. (4) Compared with FBCI, no obvious changes appeared to the aboveground and underground biomasses under the RBCI treatment. The RBCI treatment was conducive to increasing the aboveground biomass compared with pure brackish water irrigation. Therefore, short-term RBCI helps to reduce the risk of soil salinization without significantly affecting crop yield, and the irrigation cycle using reclaimed-reclaimed-brackish water at 3 g·L-1 was recommended, according to the experimental results.

Root Exploration, Initial Moisture Conditions, and Irrigation Scheduling Influence Hydration of Stratified and Non-Stratified Substrates

Soilless substrate stratification (i.e., layering unique substrates within a single container) is an emerging substrate management strategy that may provide opportunities to augment nursery resource use. As such, this research aimed to analyze water movement through containers during hydration events under different initial moisture conditions. The results indicated substrate stratification had minimal influence on water movement compared to non-stratified systems (uniformly filled nursery containers). Cyclic irrigation significantly increased the stratified substrates’ ability to retain water when irrigated at 20% volumetric water content (p < 0.0001) and significantly decreased the total volume leached (p < 0.0001). Moreover, irrigating the substrate profile with shallow and more frequent irrigations facilitated stratified substrates ty reach effective container capacity conditions (p < 0.0001n compared to non-stratified systems. The stratified systems took longer to leach all gravitational pores (p = 0.0266). In dry moisture conditions, non-stratified substrates were more hydrated when cyclic irrigation applications were applied compared to single applications (p = 0.0492). This study demonstrated that cyclic irrigation scheduling enhanced water retention in both non-stratified and stratified profiles under different initial moisture conditions and can be used as an irrigation strategy when dry substrate conditions prevail.

Significance to the Horticulture Industry

Significance to the Horticulture Industry

Changes in Physicochemical Properties of Typical Subtropical Soils under Different Treated Domestic Wastewater Irrigation Modes

Irrigation with treated domestic wastewater (TWW) affects the physicochemical properties of soils, but little research has been conducted for different soils in subtropical regions. Consequently, in order to evaluate the effects of domestic wastewater (treated by A2/O process) irrigation on the hydraulic properties, soil salinity and sodicity of four typical subtropical agricultural soils, a soil-column experiment was conducted for one year with eight cycles of wetting and drying. A clay soil (red soil), a silty clay soil (aquic soil), a loamy clay soil (purple soil), and a silty clay loam soil (paddy soil) were subjected to three irrigation modes: (a) cyclic irrigation with TWW (W1), (b) alternating irrigations with TWW and distilled water (W2), and (c) irrigation with distilled water as a control (CK). Our results indicated that EC values increased significantly (p < 0.05) with TWW irrigation for all the soils. TWW irrigation increased the concentrations of Na+, K+, Ca2+, Mg2+, and SAR, ESP values in the red soil, for the W2 treatment especially. In contrast, it decreased Na+, K+, Ca2+, Mg2+ accumulation and ESP values in the aquic soil. Moreover, the soil physical properties exhibited correlations with soil salinity. The saturated hydraulic conductivity (Ks) of the red soil, purple soil, and paddy soil were lower under the W1 and W2 treatments than CK, but the Ks of the aquic soil for W1 were 183.7% higher than that under CK. The unsaturated hydraulic conductivity (Kψ) of the purple soil and paddy soil decreased after TWW irrigation, but those of the aquic soil increased. The water-retention capacities (WRCs) of the TWW-irrigated red soil and aquic soil decreased as a consequence of a shift in the pore-size distribution toward wider pores, but the those of the purple soil and paddy soil improved, associated with narrower pores. The W2 treatment alleviated the impact of TWW on the aquic soil, purple soil, and paddy soil but negatively affected the physical properties, salinity, and sodicity of the red soil. Our results will provide useful information for managing soil and water under TWW irrigation in subtropical regions.

Effectiveness of cyclic irrigation on yield, yield components and water productivity

The efficiency of cyclic irrigation (CI) (using river water (RW) and drainage water (DW)) was investigated and compared with normal irrigation (NI) (using only RW). A 24 × 30 m research area was selected and divided into three plots – A (maize), B (soybean) and C (sunflower). Plot A was designed to produce DW for the irrigation of plots B and C. In plot B, a split-plot design was applied with randomised complete blocks with two treatments: irrigation type and rate of urea fertiliser application. The experimental design of plot C was similar to that of plot B except for the rate of fertiliser application. Analysis of variance (Anova) results for soybean revealed that the interaction between irrigation type and urea level had significant effects on growth yield and biological water productivity (WP) (P < 0.01) and fresh leaf weight (P < 0.05). The Anova results for sunflower showed that the interaction between irrigation type and urea level had significant effects on 100-seed weight, seed yield and seed WP (P < 0.05). The highest increase in WP for sunflower was for forage WP (0.768 kg/m3 for NI and 2.603 kg/m3 for CI). The WP of RW for total forage, total seed and total biological yields for CI compared with NI increased by 76.67%, 72.95% and 75.45%, respectively. The lowest increase in WP was for sunflower seed yield (0.276 kg/m3 for NI and 0.821 kg/m3 for CI). Overall, the data showed that, compared with NI, CI led to water savings of 45.59% and increased WP.

Environment Conservation and Water Use Efficiency Improvement by Cyclic Irrigation for the New Long-term Plan of Land Improvement

Environment Conservation and Water Use Efficiency Improvement by Cyclic Irrigation for the New Long-term Plan of Land Improvement

Effect of cyclic irrigation using moderately saline and non‐saline water on onion (Allium cepa L.) yield and soil salinization in semi‐arid areas of Northern Ethiopia*

AbstractDue to the scarcity and/or unreliability of canal water supply, seepage water is haphazardly used for sole irrigation or in conjunction with canal water in most small‐scale irrigation schemes in northern Ethiopia. This has been a major cause of low crop yield and has aggravated soil salinization. The problem is more exacerbated for onion, which is the major irrigated vegetable crop and is sensitive to salinity. Thus, it is essential to assess a sustainable way to use both water resources conjunctively for the production of onion. A new study in the Ethiopian context was conducted to evaluate the effect of cyclic irrigation using non‐saline canal water (EC, 0.41–0.78 dS m−1) and moderately saline seepage water (EC, 0.82–2.19 dS m−1) on onion yield and soil salinization for two seasons (2014/2015 and 2015/2016) in the Gumselassa irrigation scheme, Ethiopia. Four irrigation water treatments were applied with three replications consisting of: C (canal), S (seepage), 2CS (two canal and seepage) and CS (canal and seepage). In both seasons, the onion bulb yield variations between the C, 2CS and CS treatments were not significant; however, the S treatment reduced the onion yield significantly compared to all but CS in 2015/2016. The S treatment resulted in significant salt accumulation in the upper soil profile (0–20 cm). The alternate (C : S) cyclic option is thus recommended for alleviation of the problem of freshwater scarcity, without undue onion yield reduction and soil salinization in Gumselassa and similar irrigation schemes.

Characteristics of Drainage Water Quality and Loading from Paddy Field under Cyclic Irrigation and Its Management Options

The cyclic irrigation system has been practiced in Japan for reducing pollutant outflow loadings from paddy fields. The cyclic irrigation is an irrigation method to reuse water by pumping drainage water and re-distributing it to the farmland. Quantification and assessment of the effects of the cyclic irrigation are needed to identify management options for maximizing the benefits of cyclic irrigation. The study was aimed at assessing loading characteristics from paddy field area under the cyclic irrigation and developing a model for simulating water and material flow in paddy field area that can be used as a management tool. The study was carried out in a paddy field in the Asagoi District, Oumihatiman city in Shiga Prefecture, Japan. Using the results of water quality analysis, the average net loadings of T-N and T-P were estimated for both cyclic and non-cyclic irrigation sites. The result indicates a higher nutrient absorption rate in the cyclic irrigation site than that in the non-cyclic irrigation site. The developed cyclic irrigation model showed good agreements between observed and simulated drainage volumes and nitrogen loadings. The scenario analysis by application of the model showed a potential of reducing the loading amount by increasing the cyclic irrigation ratio and reducing the amount of fertilizer application without affecting the rice yield.

Long-Term Impact of Cyclic Use of Sodic and Canal Waters for Irrigation on Soil Properties and Crop Yields in Cotton–Wheat Rotation in a Semiarid Climate

A 12-year field experiment (1996–2008) was conducted on a sandy loam soil under semiarid climate to study the impact of use of sodic water (SW) and canal water (CW) in various cyclic modes in a cotton–wheat rotation. Treatments included irrigation with CW and SW (residual sodium carbonate 10 meq L−1) and different variants of cyclic modes of CW and SW irrigation. Irrigation with SW caused increase in pH, electrical conductivity (EC), exchangeable sodium percentage (ESP) that resulted in reduced cotton and wheat yields. The mean yield reduction after 6 years was more for seed-cotton (28%) than for wheat (15%); yield reduction in cotton and wheat after 12 years was 35 and 22%, respectively. Cyclic irrigation of CW and SW resulted in lower pH, EC and ESP than under SW irrigation and increased mean yields of both crops. Cyclic treatments starting with CW involving one SW (2CW:SW, CW:SW) or starting with one SW followed by 2CW irrigations (SW:2CW) produced optimum (>90% yields relative to CW) wheat and seed-cotton yields after 6 years. These cyclic modes could sustain optimum crop yields even after 12 years. Reduction in cotton yield after 6 years was more (18%) than in wheat (10%) in cyclic modes starting with SW involving one CW (SW:CW, 2SW:CW). However, extent of reduction in seed-cotton (25%) and wheat yields (17%) after 12 years made these treatments unsustainable on long-term basis. Based on sustainable yield index and buildup of sodicity, 2CW:SW treatment was found to be the most sustainable among various cyclic modes for the cotton–wheat rotation.

Farmersʼ Perceptions of Cyclic Irrigation under Consideration of Water Usage and Water Quality

Farmersʼ Perceptions of Cyclic Irrigation under Consideration of Water Usage and Water Quality

Temporal and Spatial Distribution of Phosphorus in Paddy Fields Under Cyclic Irrigation of Drainage Water

Considering the potential of cyclic irrigation to increase rainfall use efficiency and reduce agricultural non-point pollution, the experiment of phosphorus transport in paddy fields under cyclic irrigation of drainage water was conducted to address the problem of phosphorus loss pollution and the mismatch between rainfall temporal distribution and crop requirement in the south of China. Lotus pond water and fishpond water were used to irrigate paddy fields for monitoring concentrations of total phosphorus (TP), dissolved phosphorus (DP), and dissolved reactive phosphorus (DRP) in surface water and leachate, and soil profile total phosphorus and Olsen-P concentrations. The results showed that the concentrations of TP, DP and DRP in surface water and leachate decreased along the field under cyclic irrigation of drainage water, especially the phosphorus concentrations of leachate dropped more obviously. As the phosphorus content of cyclic irrigation water sources varied within a certain range, phosphorus concentrations of surface water and leachate did not increased. The concentrations of TP, DP and DRP in surface water and leachate varied with cyclic irrigation time, and the least phosphorus concentrations were observed in August. Top soil Olsen-P concentration decreased along the field and increased with phosphorus content of cyclic irrigation water sources, and soil profile TP concentration was not influenced by cyclic irrigation. Phosphorus removal ratio of paddy field could be increased by extending field length or cyclic irrigation in August.

Endoscopic ultrasonography-guided drainage combined with trans-duodenoscope cyclic irrigation technique for walled-off pancreatic necrosis

BackgroundEndoscopic ultrasonography-guided drainage has been established as a good treatment modality in the management of walled-off pancreatic necrosis, but the unmanageable infection of postoperation is still a thorny problem due to the poor drainage ability for solid necrotic debris only through transmural stent and nasocystic catheter. AimsIntroduce a novel therapeutic method, namely endoscopic ultrasonography-guided drainage combined with cyclic irrigation technique in managing patients with walled-off pancreatic necrosis. Methods18 patients with severe acute pancreatitis complicated with walled-off pancreatic necrosis received treatment with endoscopic ultrasonography-guided drainage combined with cyclic irrigation were involved in this retrospective study. Results17 of 18 patients with walled-off pancreatic necrosis were treated by this new therapeutic method. Subsequent surgery was performed in 1 case due to uncontrolled infection, complications such as perforation, bleeding or multiple organ failure were not observed. Treatment success rate was high (16 in 17, 94.12%). ConclusionEndoscopic ultrasonography-guided drainage combined with cyclic irrigation is an effective treatment option for symptomatic walled-off pancreatic necrosis to facilitate drainage and obviate the need for subsequent surgery or endoscopic necrosectomy.

Технология циклического орошения в Центральном Черноземье

Технология циклического орошения в Центральном Черноземье

Water Movement through a Pine-bark Substrate during Irrigation

Regulatory and economic incentives to improve water and fertilizer use efficiency have prompted the nursery industry to seek new and advanced techniques for managing the production of ornamental crops. The development of best management practices, especially with regard to fertilizer and irrigation management, is largely based on research that looks at season-long trends in water and nutrient use. Understanding how water moves through a substrate during a single irrigation event may allow for the refinement of recommended best management practices that improve water and fertilizer use efficiency in container-grown plant production systems. Therefore, a study was conducted to characterize the movement of irrigation water at three growth stages [4, 9, and 17 weeks after transplanting (WAT)] throughout the production cycle of Ilex crenata Thunb. ‘Bennett’s Compactum’ that were container-grown in a bark-based substrate alongside fallow (i.e., without a plant) containers. Tensiometers were placed at three horizontal insertion depths and three vertical heights throughout the substrate profile to detect changes in matric potential (ψ; kPa), during individual irrigations. At 4 WAT, the pre-irrigation ψ in the upper substrate profile was 12.3 times more negative (i.e., drier) than the substrate near the container’s base and 6.0 times more negative than the middle of the container. This gradient was decreased at 9 and 17 WAT as roots grew into the lower portion of the substrate profile. On average, water began to drain from the base of containers 59.9 s ± 1.0 se and 35.7 s ± 1.3 se after irrigation commencement for fallow containers and plant-containing treatments, respectively, indicating channeling through the substrate of plant-containing treatments. A pattern of plant water uptake by roots induced a gradient in the substrate’s pre-irrigation moisture distribution, where portions of the substrate profile were relatively dry where plant roots had taken up water. Consequently, the application of water or fertilizer (i.e., fertigation) through irrigation has the potential to be highly inefficient if applied under dry substrate conditions where channeling may occur. Therefore, water application using cyclic irrigation or substrate moisture content (MC) thresholds (not letting MC fall below an undetermined threshold where channeling may occur) may improve water application efficiency. Furthermore, fertigation should occur when the substrate MC in the upper portion of the container is higher than the pre-irrigation MCs observed in this study to minimize the occurrence of channeling. The effect of root growth should also be taken into account when seeking the proper balance between pre-irrigation substrate MC and irrigation application rate to reduce the risk of unwanted channeling.

Remote sensing used to detect moisture status of pecan orchards grown in a desert environment

Remote-sensing techniques can detect and up-scale leaf-level physiological responses to large areas, and provide significant and reliable information on water use and irrigation management. The objectives of this study were to screen leaf-level physiological changes that occur during the cyclic irrigation of pecan orchards to determine which responses best represent changes in moisture status of plants and link plant physiological changes to remotely sensed surface reflectance data derived from the Landsat Thematic Mapper and Enhanced Thematic Mapper Plus (ETM+). The study was conducted simultaneously on two southern New Mexico mature pecan orchards. For both orchards, plant physiological responses and remotely sensed surface reflectance data were collected from trees that were either well watered or in water deficit. Remotely sensed variables included reflectance in band 1, the ratio between shortwave infrared (SWIR) bands (B5:B7), the normalized difference vegetation index, and SWIR moisture indices. Midday stem water potential (Ψsmd) was the best performing leaf-level physiological response variable for detecting moisture status in pecans. The B5:B7 ratio positively and significantly correlated with Ψsmd in five of six irrigation cycles while multiple linear regression weighted with six remotely sensed surface reflectance variables revealed a significant relationship with moisture status in all cycles in both orchards (R2 > 0.73). Because changes in the B5:B7 band ratio and multiple regression of spectral variables correlate with the moisture status of pecan orchards, we conclude that remotely sensed data hold promise for detecting the moisture status of pecans.

A Study on Effect of Water Quality Conservation by Cyclic Irrigation in Paddy Field Area

A Study on Effect of Water Quality Conservation by Cyclic Irrigation in Paddy Field Area

Carbon Isotope Discrimination, Gas Exchange, and Growth of Container-grown Conifers Under Cyclic Irrigation

The objective of this study was to quantify the effects of cyclic irrigation on growth and physiology of container-grown conifer species in pot-in-pot (PIP) production in the upper Midwest. Trees of four conifer species (Picea glauca var. densata, Picea pungens, Abies fraseri, and Pinus strobus) were grown in 25-L containers and assigned to one of four combinations of irrigation rate (low or high) and daily irrigation cycle frequency (one or four). Irrigation rates were based on common nursery practice in the region (2 cm rainfall equivalent/day) and one-half the standard rate (1 cm rainfall equivalent/day). Cyclic irrigation increased relative height growth and relative caliper growth of Pinus strobus by over 80% and 35%, respectively, compared with once-daily irrigation. The high-rate irrigation increased relative caliper growth of Picea pungens by 40% compared with the low rate. The effects of irrigation regime on needle- or shoot-level gas exchange varied by species and date of measurement. Carbon isotope discrimination (Δ13C) of needle and wood tissue was positively correlated (r ≥ 0.64, P < 0.001) with needle conductance to water vapor (gwv) and negatively correlated (r ≤ −0.60, P< 0.001) with intrinsic water use efficiency (WUEi). Carbon isotope discrimination of wood and needle tissue decreased with the low irrigation rate, indicating increased WUEi associated with reduced gwv. Cyclic irrigation had relatively little effect on Δ13C except for Pinus strobus. Our findings suggest that carbon isotope composition of wood and needle tissue provides a sensitive and accurate representation of plant response to varying moisture availability. From a water management perspective, identifying optimal irrigation rates appears to be more important than number of daily cycles for these crops grown in the midwestern United States.

Performance analysis of on-farm irrigation tanks on agricultural drainage water reuse and treatment

Water reuse and pollutant removal efficiency analysis of the on-farm irrigation tanks (OFTs) was carried out in rice paddy field region of Zhanghe Irrigation District, Southern China through field experiments during the rice growing season of 2009–2011. Water flow measurements indicate that 20.6–68.9% of drainage water captured by OFTs was reused for supplemental irrigation. Rainfall was the most important factor that determines the water reuse efficiency (WRR) of OFTs, since higher rainfall resulted in higher surplus irrigation water draining out of OFTs without reuse, and thus decreased WRR. Fully using the storage capacity for storing return flow, and releasing totally for supplemental irrigation also enhanced WRR of OFTs. Water quality analysis shows that OFTs removed 47.2% of total phosphorous (TP) and 60.8% of total nitrogen (TN) of inflow and have a great effect on increasing sedimentation for return flow as the mean of removal efficiency of pollutant load (REL) for suspended solids (SS) amounted to 68.4%. For water treatment effectiveness of OFTs, high hydraulic retention time (HRT) is most beneficial to increase REL of TN whereas REL of TP is not sensitive to HRT. These results confirm that OFTs can effectively increase agricultural return flow reuse and remove pollutants. As the cascade OFTs irrigation system recycle return flow for several times, the irrigation water demand from outside of region was reduced significantly for rice production. Coupling with the effect of cyclic irrigation on the nutrients recycling by paddy fields, OFTs irrigation system also considerably mitigate the N and P off-site emission. Therefore, it is advisable to integrate the role of OFTs on water reuse and treatment for water saving irrigation and ecological management of paddy fields landscape.

Reducing the phosphorus effluent load from a paddy-field district through cyclic irrigation

Phosphorus (P) effluent load discharged from paddy fields has a substantial impact on water quality in downstream areas. We evaluated the effectiveness of cyclic irrigation, in which drainage water is reused for irrigation purposes, in reducing the P load from a paddy-field district neighboring Lake Biwa, Japan. We measured temporal variations in the P concentration in drainage water and estimated the P mass balance for the study district for three consecutive years (2007–2009). A simple model was developed to characterize the hydrological structure and effects of cyclic irrigation using three parameters: the ratio of the P concentration in drainage water to that in irrigation water, the degree to which drainage water is reused, and the ratio of surplus irrigation water to the total amount of irrigation water. The total annual exports of P were 2.62–3.13kgha–1. Phosphorus exports during the cyclic irrigation periods (April–June) were 0.27–0.63kgha–1 (period average rate=3.7–8.8gha–1d–1), lower than those during the lake water irrigation periods (July–August) of 0.82–1.66kgha–1 (8.9–18.0gha–1d–1). Phosphorus export was lowest during the cyclic irrigation period, consistent with the small amounts of discharged drainage water. Our results suggest that cyclic irrigation is an effective district-scale method for reducing effluent P loads. Reuse of drainage water and efficient use of irrigation water are important in reducing the P load from the district.