Measurement Of Losses From On-Farm Channels And Drains

Water use and groundwater rises are two important problems facing irrigators in the southern irrigated region of NSW. Water loss through percolation has been extensively studied for irrigated farms and major supply channels but there have been no studies of loss through on-farm channels and drains. This study aimed to determine the magnitude of percolation losses attributable to on-farm channels and drains. It also aimed to consider approaches and for need to identify problem were and to consider likely remediation techniques. Investigations were carried out within selected farms in Coleambally and Murrumbidgee Irrigation Areas in southern NSW during the irrigation seasons of 1997/98, 1998/99 and 1999/00. The Idaho Seepage Meter was used to make point infiltration measurements. Seepage losses were not estimated for all channels on every farm but for only those channels being used by the landholder in the periods seepage measurements were taken. Only 3 of the 9 farms investigated were using all of the channels and drains on the farm during monitoring activities. Only permanent channel and drain structures on the farm were measured. This potentially causes the annual seepage losses calculated per farm to be underestimated. The Idaho Seepage Meter was used for this investigation. Measuring seepage using the Idaho Seepage Meter is rapid, direct, and cheap. The success of this method depends upon the high degree of homogeneity in natural soils. Tests using seepage meters can be conducted in channels without interfering with their normal water delivery operation. Three or four measurements were taken across channels and drains at intervals of 50 - 100 metres. Due to the age and lack of maintenance of these channels their cross-sections had deteriorated. In these situations it was difficult to place the Idaho Seepage Meter on the sides of the channels. Extreme care was taken to cause minimal disturbance to the local soil so that the seepage pattern would not be appreciably affected. A series of test wells was drilled adjacent to the irrigation channels and drains using information obtained from EM 31 electromagnetic surveys. The Idaho Seepage Meter can be used to rapidly locate channel sections with high seepage losses. This enables total seepage losses from a section of channel to be estimated economically. The seepage results from 15-30 year old channels indicate that a combination of weeds and sediment deposition may be the major factor for reduction of seepage. Silt sediments were deposited on the channel bed, or on only part of the bed where the channel was curved, not the entire wetted perimeter of the channel. However, some old channels, which were cleaned prior to the irrigation season, had significant seepage volumes. In new channels and drains low seepage rates were also found at many sites. These sites could have been influenced by factors such as compaction beneath the bed of channel, soil sodicity, biological activity, and slope/bend of channel, and silt deposition in the channel bed. EM-31 surveys were used to characterize soil differences along channel and drainage lines and the apparent electrical conductivity (ECa) values were compared with direct seepage measurements using an Idaho Seepage Meter. This method proved successful in identifying actual seepage sites. ECa values obtained from the EM-31 surveys provided an insight into the most likely locations to have high seepage rates. The EM-31 method was shown to be an important initial predictive tool. Highest seepage rates were found where ECa values were low. In some areas seepage rates were found to be low despite low ECa values at these locations. These anomalies were attributed to various factors which included compaction of substrate, clay layers below channel bed, sodicity, biological activity and sediment deposition. Combining the seepage-monitoring program with the EM31 electromagnetic survey method proved to be highly effective in detailing the nature and extent of the problem. Despite its limitations, the EM31 method is considered to be an important predictive tool in the first stage of loss assessment. Investigation was carried out with in selected farms to quantifying seepage losses from sections of channels and drains in the Murrumbidgee Irrigation Area and Coleambally Irrigation Area. This study enabled those sections with high seepage rates to be identified. As the price of water becoming a realistic figure in terms of meeting actual cost, water distribution efficiencies are being very closely examined. Water loss through seepage in on-farm channels and drains is one of the many elements of the system under investigation. Detection and accurate measurement of seepage is important for the efficient and effective management of on-farm water. However, it is necessary to firstly determine whether a problem exists, and secondly to quantify the extent and seriousness of that problem, before putting resources into seepage control. At high seepage rates it is uneconomical to apply the various treatments available. It is suggested that only methods compatible with and complementary to the natural sealing process will be successful. Lining a leaky channel site will not always completely eliminate seepage losses. In fact, all that can be reasonably expected is a reduction in the seepage rate. The amount of reduction will depend upon the lining used and the magnitude of the loss prior to lining. Investigation sites were established within irrigation channels and drains on each of nine farms, each with an average of approximately 3-4km of unlined on-farm channels carrying water within the farm boundaries and about 1-3km of drains that are used for recycling runoff water

Measurement Of Losses From On-Farm Channels And Drains

Water use and groundwater rises are two important problems facing irrigators in the southern irrigated region of NSW. Water loss through percolation has been extensively studied for irrigated farms and major supply channels but there have been no studies of loss through on-farm channels and drains. This study aimed to determine the magnitude of percolation losses attributable to on-farm channels and drains. It also aimed to consider approaches and for need to identify problem were and to consider likely remediation techniques. Investigations were carried out within selected farms in Coleambally and Murrumbidgee Irrigation Areas in southern NSW during the irrigation seasons of 1997/98, 1998/99 and 1999/00. The Idaho Seepage Meter was used to make point infiltration measurements. Seepage losses were not estimated for all channels on every farm but for only those channels being used by the landholder in the periods seepage measurements were taken. Only 3 of the 9 farms investigated were using all of the channels and drains on the farm during monitoring activities. Only permanent channel and drain structures on the farm were measured. This potentially causes the annual seepage losses calculated per farm to be underestimated. The Idaho Seepage Meter was used for this investigation. Measuring seepage using the Idaho Seepage Meter is rapid, direct, and cheap. The success of this method depends upon the high degree of homogeneity in natural soils. Tests using seepage meters can be conducted in channels without interfering with their normal water delivery operation. Three or four measurements were taken across channels and drains at intervals of 50 - 100 metres. Due to the age and lack of maintenance of these channels their cross-sections had deteriorated. In these situations it was difficult to place the Idaho Seepage Meter on the sides of the channels. Extreme care was taken to cause minimal disturbance to the local soil so that the seepage pattern would not be appreciably affected. A series of test wells was drilled adjacent to the irrigation channels and drains using information obtained from EM 31 electromagnetic surveys. The Idaho Seepage Meter can be used to rapidly locate channel sections with high seepage losses. This enables total seepage losses from a section of channel to be estimated economically. The seepage results from 15-30 year old channels indicate that a combination of weeds and sediment deposition may be the major factor for reduction of seepage. Silt sediments were deposited on the channel bed, or on only part of the bed where the channel was curved, not the entire wetted perimeter of the channel. However, some old channels, which were cleaned prior to the irrigation season, had significant seepage volumes. In new channels and drains low seepage rates were also found at many sites. These sites could have been influenced by factors such as compaction beneath the bed of channel, soil sodicity, biological activity, and slope/bend of channel, and silt deposition in the channel bed. EM-31 surveys were used to characterize soil differences along channel and drainage lines and the apparent electrical conductivity (ECa) values were compared with direct seepage measurements using an Idaho Seepage Meter. This method proved successful in identifying actual seepage sites. ECa values obtained from the EM-31 surveys provided an insight into the most likely locations to have high seepage rates. The EM-31 method was shown to be an important initial predictive tool. Highest seepage rates were found where ECa values were low. In some areas seepage rates were found to be low despite low ECa values at these locations. These anomalies were attributed to various factors which included compaction of substrate, clay layers below channel bed, sodicity, biological activity and sediment deposition. Combining the seepage-monitoring program with the EM31 electromagnetic survey method proved to be highly effective in detailing the nature and extent of the problem. Despite its limitations, the EM31 method is considered to be an important predictive tool in the first stage of loss assessment. Investigation was carried out with in selected farms to quantifying seepage losses from sections of channels and drains in the Murrumbidgee Irrigation Area and Coleambally Irrigation Area. This study enabled those sections with high seepage rates to be identified. As the price of water becoming a realistic figure in terms of meeting actual cost, water distribution efficiencies are being very closely examined. Water loss through seepage in on-farm channels and drains is one of the many elements of the system under investigation. Detection and accurate measurement of seepage is important for the efficient and effective management of on-farm water. However, it is necessary to firstly determine whether a problem exists, and secondly to quantify the extent and seriousness of that problem, before putting resources into seepage control. At high seepage rates it is uneconomical to apply the various treatments available. It is suggested that only methods compatible with and complementary to the natural sealing process will be successful. Lining a leaky channel site will not always completely eliminate seepage losses. In fact, all that can be reasonably expected is a reduction in the seepage rate. The amount of reduction will depend upon the lining used and the magnitude of the loss prior to lining. Investigation sites were established within irrigation channels and drains on each of nine farms, each with an average of approximately 3-4km of unlined on-farm channels carrying water within the farm boundaries and about 1-3km of drains that are used for recycling runoff water

Integration of 1401 Graduate Studies (Groundwater Management for Sustainable Farming Systems)

This report presents the integration of research studies carried out by the graduate students at UTS and UNSW as part of the CRC for Sustainable Rice Production Graduate Studies Program. It evaluates the methodologies and modelling scenarios in rice-based irrigation areas. Moreover, the report collates the research findings and conclusions to establish the benefits to rice industry. The main objective of the graduate studies was to develop strategies for managing groundwater for salinity mitigation at farm and regional scale. Through field experimentation and modelling approaches, the studies examined the impacts of land use on the environment and the effect of irrigation water with different quality levels on the rising watertable and the subsequent salinisation. These studies developed hydrogeological information base for rice growing areas mainly MIA (Murrumbidgee Irrigation Area) and WID (Wakool Irrigation District) has been developed that includes monitoring groundwater levels, groundwater quality, soil analysis and geophysical surveys. The modelling exercises show strong interaction between shallow and deep aquifer. The simulations show significant rise in groundwater levels during the rice crop season and fall during the fallow season. Subsurface lateral groundwater flows are dominant from east to west; from Narrandera to Hay. Groundwater monitoring indicated a rapid response to rainfall as well as irrigation events with a recharge estimation of about 80% for the shallow aquifer and 50% for the deep aquifer. The shallow aquifer (2 m) responds slightly faster than the deep aquifer (7 m) to irrigation events. Groundwater quality at Whitton (M.I.A) is classified as brine and therefore not suitable for irrigation. However, the irrigation water was classified as fresh. Sodium, Sulfate and Chloride were the most abundant elements found in the four water samples. The piezometers in irrigated paddocks showed substantially lower salinity indicating that irrigation water was recharging the aquifer. The deep aquifer piezometers monitoring displayed conductivity values of about 5 to 6 ms/cm. The geophysical resistivity imaging has shown a great promise for developing understanding about surface-ground water interactions and salinization. Large spatial variations in apparent resistivity were observed in irrigated and non-irrigated areas. Resistivity decreases with depth in a linear fashion. Variations in resistivity have been noticed in the upper 10 metre layer of soil indicating recharge zone. Increase of resistivity closer to rice paddocks during irrigation is due to the fresh water infiltrating to the aquifer. Irrigation events resulted in decreased resistivity at most depths, particularly at 15 m that reflecting rising water table or input of fresh water from the irrigated paddocks. These studies have shown a strong correlation between resistivity and electromagnetic responses from EM31 and EM34. The MODFLOW model developed by the UTS graduates with a 10 m minimum discretisation and a refined time scale (2 days stress period) simulated the groundwater dynamics with 80% accuracy. Six key parameters are identified influencing the system. They include rice ponding, precipitation, drainage, evapotranspiration deep leakage and lateral groundwater flow. The solute transport model revealed that the groundwater salinity is controlled by rising groundwater levels due to rice ponding. Salinity concentration is higher in top 2 metres below -2- ground surface. The solute transport model has successfully simulated salinity trends. The irrigated areas are affected by irrigation water salinity. The salinity of top 3 m profile is higher and decreases with depth. Groundwater salinity ranges from 1500 mg/l directly below and is approximately 2500 – 3000 mg/l in the fallow paddocks adjacent to the rice pond. According to the optimization results, an extensive bore network of several hundred pumping bores at shallow depths would be necessary to lower water levels around the irrigated area. However, it impossible to pump out the necessary groundwater volumes in order to lower water table to the targeted levels in low permeability areas as vertical hydraulic conductivity is one order of magnitude lower than horizontal hydraulic conductivity. The UNSW PhD (Xu, 2003) study in Wakool region predicted that about 2 kg/m2 salt will be added to root zone per one rice crop per season. This prediction quantifies to 20 t/ha per crop season each year. Moreover, if repeated irrigation with saline water is practiced, the salt concentration in root zone will continue to increase with time, which is alarming for future of rice industry. Therefore, careful decisions need to be done while working out the soil suitability for rice growers regarding existing soil salinity and the EC levels in irrigation water. The ponded rice irrigation is a major contributing factor to groundwater accessions resulting in rising watertables and subsequent salinity problem. The alternative use of fresh and low salinity water could be practiced on short-term basis for ponded irrigation as long as it does not affect rice growth or rice yield. This will help remove accumulated salts in the root zone by fresh water irrigation after the irrigation with water containing salts. The six graduate modelling studies described in this report are site specific. Efforts to apply these methods to other farms or regions will need to incorporate site specific information on cropping, topography and groundwater systems to describe and calibrate the salinisation processes

Normalized difference vegetation index sensor-based nitrogen management in bread wheat (Triticum aestivum L.): Nutrient uptake, use efficiency, and partial nutrient balance

The present experiment was conducted to assess the impact of fixed and variable doses (using a normalized difference vegetation index-sensor) of nitrogen (N) on wheat yields, nutrient uptake, nitrogen use efficiency, and soil nitrogen balance through the optimization of nitrogen dose. There were 10 treatments based on fixed and variable doses with different splits, and each treatment was replicated three times under a randomized complete block design. The treatments comprised fixed doses of 120 and 150 kg N ha–1 with different splits; variable doses based on sensor readings after application of 60, 90, and 120 kg N ha–1; 225 kg N ha–1 as a nitrogen-rich control; and no application of nitrogen as the absolute control. It was revealed that the application of a basal dose of 60 kg N ha–1 and another 60 kg N ha–1 at the crown root initiation stage followed by a sensor-guided N application significantly improved wheat grain yields and grain nitrogen uptake. However, straw nitrogen uptake was highest in N-rich plots where 225 kg N ha–1was applied. It was found that any curtailment in these doses at basal and crown root initiation stages followed by nitrogen application using a normalized difference vegetation index sensor later could not bring about higher crop yields. On average, wheat crops responded to 152–155 kg N ha–1 in both years of the study. Partial factor productivity along with agronomic and economic nitrogen use efficiency showed a declining trend with an increased rate of N application. Apparent N recovery values were comparable between normalized difference vegetation index sensor-based N application treatments and treatments receiving lesser N doses. Soil N status decreased in all the treatments except the nitrogen-rich strip, where there was a marginal increase in soil N status after the wheat crop harvest in the rotation. Partial nitrogen balance was negative for all the treatments except the control. From these 2-year field trials, it can be concluded that applying a normalized difference vegetation index sensor could be an essential tool for the rational management of fertilizer nitrogen in wheat grown in eastern sub-Himalayan plains

Growth, nodulation, yield, nitrogen uptake, and economics of lentil as influenced by sowing time, tillage, and management practices

Crop management practices and variety are two very important parameters that decides the crop performance. A field experiment was carried out during the two consecutive rabi seasons of 2018–19 and 2019–20 to determine the impact of sowing timing, tillage operation, and variety on the growth, development, yield characteristics, and nitrogen uptake in lentil crops. The experiment was conducted in a split-split plot design with 3 replications comprising two different sowing conditions (S1: early sowing after harvesting of short duration kharif rice, S2: delayed sowing after harvesting of long duration kharif rice) in main plots, three different tillage operations (T1: Relay cropping, T2: Zero tillage, T3: Conventional tillage) in subplots and two different varieties (V1: short duration: L4717, V2: long period: Moitri) in subplots. The findings demonstrated a substantial interaction between sowing time, tillage, and variety on various growth and yield parameters of lentil crops. The early sowing of lentil crops (early November) yielded 4.8% more (1,105 kg ha−1) than late November sowing and adapting to the short-duration variety L4717 over the long-duration cultivar Moitri resulted in a yield increase of 5.9% (1,086 kg ha−1). Apart from providing a higher yield, it also provided an opportunity to take another crop like leafy vegetables. Among the three tillage practices adopted, conventional tillage produced the lowest yield (1,017 kg ha−1) in both experimental years. In contrast, a yield increase of 6.9% and 26.9% in relay cropping and zero tillage systems was observed, respectively. Early-sown lentils with no-tillage and a short-duration variety reached a certain phenophase faster than other combinations (life cycle: 96.2 and 98.7 days for lentils in both years). For both the sowing times, the growth parameters and the number of nodules plant−1 were highly correlated with nitrogen uptake at different stages of the life cycle. High net returns (Rs. 51,220 and 59,257) leading to higher benefit-cost ratios were observed under the treatment combination of early sowing + zero tillage + short duration variety. Therefore, the study found that short-duration lentil cultivars in combination with early sowing in the zero-tillage system are the best agronomic approach for the sustainability of lentil production after the monsoon rice harvest

Combining imaging techniques with nonparametric modelling to predict seepage hotspots in irrigation channels

Using the Murrumbidgee Irrigation Area, Australia as a case study, we present an integrated approach for identifying seepage hotspots and predicting seepage losses from open channel. The approach is particularly important to facilitate investments for improving irrigation conveyance efficiencies, thus enabling sustainable agricultural water use. A qualitative assessment is used for capturing seepage hotspots with electromagnetic inductance (EM31) imaging techniques, followed by actual seepage measurements. Based on data from major irrigation systems in the southern Murrumbidgee Irrigation Area, a case is made for cost-effective methodology to locate seepage hotspots and quantify seepage losses in channels. In particular, a predictive model was developed based on EM31 survey and direct measured channel seepage data. The main input data for the model were EM values, soil types, water depth in channels, wetted perimeter of channels and whether water is flowing in channels. The output from the model was a seepage loss value in channels. The three different modelling techniques considered were the Generalised Linear Mixed (GLM) model, Random Forest (RF) model and Generalized Boosted Regression Model (GBM), and a best performing model for seepage prediction was identified. The RF model was found to the most reliable, explaining 60% of the variability in the data and with the least mean absolute error. The study indicated that the RF model can be used to locate seepage hotspots in channels and determine the magnitude of seepage losses

Antioxidant, antibacterial, and cytotoxic activities of cimemoxin derivatives and their molecular docking studies

Purpose: The cimemoxin derivatives and their biological importance in antioxidant, antibacterial, and cytotoxic activities were the main focus of this study. By using a one-step reaction and green chemistry method, this study was able to synthesise derivatives of cimemoxin-related Mannich base compounds. Methods: Green chemistry can be used to prepare new, one-pot syntheses of cimemoxin derivatives (1a-i) Mannich base derivatives. FTIR, mass spectrometry, elemental analysis, and 1H and 13C NMR were used to analyse the newly synthesised compounds. The cytotoxic, antibacterial, and antioxidant activities of synthesized compounds (1a-i) were investigated. To test all synthesised compounds (1a–i) for cytotoxicity against normal Vero cell lines and MCF-7, the antioxidant activities were studied using DPPH, NO, H2O2, and ABTS•+ assays. The synthesised compounds were screened for anti-tyrosinase and antibacterial activities. Highly active compounds were investigated using molecular docking studies. Results: The compound 1h showed considerable activity in H2O2 (IC50: 13.79 µg/mL) and DPPH-scavenging was significantly active (IC50: 19.62 µg/mL) compared to the standard BHT (IC50: 27.16 and 33.88 µg/mL). Compound 1f was more effective than trolox (85.28 %) against ABTS and AAPH antioxidants. The most potent inhibitory activity was observed for compound 1h (IC50 = 15.16 µg/mL) which was more potent than kojic acid (IC50 = 17.79 ± 0.95 µg/mL). All synthetic substances were tested for their cytotoxic potential. Compound 1f (IC50 = 0.12 µg/mL) was extremely active compared to doxorubicin (IC50 = 0.74 µg/ml) and other compounds were lowly active compared to the MCF-7 cell line. In terms of anti-tyrosinase activity, compound 1h was highly active compared with the standard, and compound 1d was highly active against K. pneumonia. Conclusion: In this study, strong antioxidant, antibacterial, and cytotoxic activities were reported for all the compounds. In molecular docking studies, compounds 1d and 1h had higher binding affinities than the other compounds. Compounds 1d and 1h performed well in all tests. Additionally, this investigation successfully identified a number of intriguing compounds with cytotoxic and antioxidant properties

Correction: Gobinath, P., et al. Grindstone Chemistry: Design, One-Pot Synthesis, and Promising Anticancer Activity of Spiro[acridine-9,2′-indoline]-1,3,8-trione Derivatives against the MCF-7 Cancer Cell Line. Molecules 2020, 25, 5862

In the original article [...

Grindstone Chemistry: Design, One-Pot Synthesis, and Promising Anticancer Activity of Spiro[acridine-9,2′-indoline]-1,3,8-trione Derivatives against the MCF-7 Cancer Cell Line

In this study, the synthesis of one-pot 10-phenyl-3,4,6,7-tetrahydro-1H-spiro [acridine-9,2′-indoline]-1,3,8-trione derivatives was achieved via a four-component cyclocondensation reaction, which was carried out in solvent-free conditions, and using p-toluenesulfonic acid (p-TSA) as a catalyst. The product was confirmed by FT-IR, 1H-NMR, 13C-NMR, mass spectra, and elemental analysis. Furthermore, the anticancer activity was screened for all compounds. Among these compounds, compound 1c was more effective (GI50 0.01 µm) against MCF-7 cancer cell lines than standard and other compounds. Therefore, the objective of this study was achieved with a few promising molecules having been demonstrated to be potential anticancer agents