Automation and control in surface irrigation systems: current status and expected future trends

Surface irrigation systems are the most popular methods for irrigating crops and pastures not only in Australia but the world over. However, these systems are often labour intensive and exhibit low water use efficiency. Rising labour costs especially in the developed world and competition for scarce water resources have generated renewed interest in the automation of surface irrigation systems. This paper provides a comprehensive review of the current level of automation and control of surface irrigation systems. The automation techniques discussed utilise various devices including mechanical, electronic, pneumatic and hydraulic means. The use of telemetry is also discussed. With the almost universal access to high performance computers and fast internet, the concept of real-time control in surface irrigation is not far-fetched. Towards this end, an on-going research project at USQ aimed at modernising furrow irrigation by use of automatic control systems in real time is discusse

Irrigated agriculture responds to water use challenges

Presented at Irrigated agriculture responds to water use challenges - strategies for success: USCID water management conference held on April 3-6, 2012 in Austin, Texas.Includes bibliographical references.A system for the real-time optimization of furrow irrigation is described. The system estimates the soil infiltration characteristics in real-time and utilizes the data to control the same irrigation event to give optimum performance for the current soil conditions. The main features of the system are: the use of a model infiltration curve and a scaling process to describe the current soil infiltration characteristic; measurement of the inflow rate to the furrows; measurement of the water advance at a point approximately midway down the furrow; and a microcomputer running a hydraulic simulation program based on the full hydrodynamic model to predict the optimum time to cut-off. The system was trialed on a furrow-irrigated commercial cotton property utilizing pipes through the bank (PTBs) to supply groups of furrows. The initial observations from these trials are presented in this paper and demonstrate that improvements in water use efficiency are potentially achievable through the use of the system. Extensions to the system to improve its performance and to make it applicable to bay irrigation are described

Maternal and perinatal outcomes in women with eclampsia by mode of delivery at Riley Mother Baby Hospital: A longitudinal case-series study

Background: Eclampsia, considered a serious complication of preeclampsia, remains a life-threatening condition among pregnant women. It accounts for 12% of maternal deaths and 16–31% of perinatal deaths worldwide. Most deaths from eclampsia occurred in resource-limited settings of sub-Saharan Africa. This study was performed to determine the optimum mode of delivery, as well as factors associated with the mode of delivery, in women admitted with eclampsia at Riley Mother and Baby Hospital. Methods: This was a hospital-based longitudinal case-series study conducted at the largest and busiest obstetric unit of the tertiary hospital of western Kenya. Maternal and perinatal variables, such as age, parity, medications, initiation of labour, mode of delivery, admission to the intensive care unit, admission to the newborn care unit, organ injuries, and mortality, were analysed using the Statistical Package for the Social Sciences software version 20.0. Quantitative data were described using frequencies and percentages. The significance of the obtained results was judged at the 5% level. The chi-square test was used for categorical variables, and Fisher’s exact test or the Monte Carlo correction was used for correction of the chi-square test when more than 20% of the cells had an expected count of less than 5. Results: During the study period, 53 patients diagnosed with eclampsia were treated and followed up to 6 weeks postpartum. There was zero maternal mortality; however, perinatal mortality was reported in 9.4%. Parity was statistically associated with an increased odds of adverse perinatal outcomes (p = 0.004, OR = 9.1, 95% CI = 2.0-40.8) and caesarean delivery (p = 0.020, OR = 4.7, 95% CI = 1.3–17.1). In addition, the induction of labour decreased the risk of adverse outcomes (p = 0.232, OR = 0.3, 95% CI = 0.1-2.0). Conclusion: There is no benefit of emergency caesarean section for women with eclampsia. Instead, it increases the risk of perinatal adverse outcomes, including the risk of admission to the newborn unit and perinatal death

Modelling Impacts of Climate Change on Maize (Zea mays L.) Growth and Productivity: A Review of Models, Outputs and Limitations

The use of crop modelling in various cropping systems and environments to project and upscale agronomic decision-making under the facets of climate change has gained currency in recent years. This paper provides an evaluation of crop models that have been used by researchers to simulate maize growth and productivity. Through a systematic review approach, a comprehensive assessment of 186 published articles was carried out to establish the models and parameterization features, simulated impacts on maize yields and adaptation strategies in the last three decades. Of the 23 models identified, CERES-maize and APSIM models were the most dominant, representing 49.7% of the studies undertaken between 1990 and 2018. Current research shows projected decline in maize yields of between 8% - 38% under RCP4.5 and RCP8.5 scenarios by the end of the 21st century, and that adaptation is essential in alleviating the impacts of climate change. Major agro-adaptation options considered in most papers are changes in planting dates, cultivars and crop water management practices. The use of multiple crop models and multi-model ensembles from general circulation models (GCMs) is recommended. As interest in crop modelling grows, future work should focus more on suitability of agricultural lands for maize production under climate scenarios

Combined linkage and association mapping of putative QTLs controlling black tea quality and drought tolerance traits

The advancements in genotyping have opened new approaches for identification and precise mapping of quantitative trait loci (QTLs) in plants, particularly by combining linkage and association mapping (AM) analysis. In this study, a combination of linkage and the AM approach was used to identify and authenticate putative QTLs associated with black tea quality traits and percent relative water content (%RWC). The population structure analysis clustered two parents and their respective 261 F1 progenies from the two reciprocal crosses into two clusters with 141 tea accessions in cluster one and 122 tea accessions in cluster two. The two clusters were of mixed origin with tea accessions in population TRFK St. 504 clustering together with tea accessions in population TRFK St. 524. A total of 71 putative QTLs linked to black tea quality traits and %RWC were detected in interval mapping (IM) method and were used as cofactors in multiple QTL model (MQM) mapping where 46 putative QTLs were detected. The phenotypic variance for each QTL ranged from 2.8 to 23.3% in IM and 4.1 to 23% in MQM mapping. Using Q-model and Q + K-model in AM, a total of 49 DArTseq markers were associated with 16 phenotypic traits. Significant marker-trait association in AM were similar to those obtained in IM, and MQM mapping except for six more putative QTLs detected in AM which are involved in biosynthesis of secondary metabolites, carbon fixation and abiotic stress. The combined linkage and AM approach appears to have great potential to improve the selection of desirable traits in tea breeding.James Finlay (Kenya) Ltd., George Williamson (Kenya) Ltd., Sotik Tea Company (Kenya) Ltd., Mcleod Russell (Uganda) Ltd., the TRI of Kenya and Southern African Biochemistry and Informatics for Natural Products (SABINA) as well as the Technology and Human Resources for Industry Programme (THRIP), an initiative of the Department of Trade and Industries of South Africa (dti), the National Research Foundation (NRF) of South Africa, and the University of Pretoria (South Africa).https://www.springer.com/journal/106812020-09-11hj2020BiochemistryGeneticsMicrobiology and Plant Patholog

Functional annotation of putative QTL associated with black tea quality and drought tolerance traits

The understanding of black tea quality and percent relative water content (%RWC) traits in tea (Camellia sinensis) by a quantitative trait loci (QTL) approach can be useful in elucidation and identification of candidate genes underlying the QTL which has remained to be difficult. The objective of the study was to identify putative QTL controlling black tea quality and percent relative water traits in two tea populations and their F1 progeny. A total of 1,421 DArTseq markers derived from the linkage map identified 53 DArTseq markers to be linked to black tea quality and %RWC. All 53 DArTseq markers with unique best hits were identified in the tea genome. A total of 5,592 unigenes were assigned gene ontology (GO) terms, 56% comprised biological processes, cellular component (29%) and molecular functions (15%), respectively. A total of 84 unigenes in 15 LGs were assigned to 25 different Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathways based on categories of secondary metabolite biosynthesis. The three major enzymes identified were transferases (38.9%), hydrolases (29%) and oxidoreductases (18.3%). The putative candidate proteins identified were involved in flavonoid biosynthesis, alkaloid biosynthesis, ATPase family proteins related to abiotic/biotic stress response. The functional annotation of putative QTL identified in this current study will shed more light on the proteins associated with caffeine and catechins biosynthesis and % RWC. This study may help breeders in selection of parents with desirable DArTseq markers for development of new tea cultivars with desirable traits.http://www.nature.com/sreppm2020BiochemistryGeneticsMicrobiology and Plant Patholog

Results and Impacts of the Integrated Land and Water Management for Adaptation to Climate Variability and Change (ILWAC) Project: Evaluation Report

The objective of the evaluation was to assess the results and impacts of the activities of all ILWAC Trust Fundfinanced projects in West Africa using a selected subset, to identify key lessons learned, and to document best climatesmart practices for scaling up. The study entailed participatory evaluation of the results and impacts of various interventions geared towards integrated water resources management for climate change and variability preparedness in West Africa. In this respect, the study identified key lessons learned and documented best climate-resilient practices for scaling up and dissemination to multiple stakeholders in the West African region. 1. Agriculture remains the backbone for sustaining livelihoods in West Africa but faces numerous challenges. Agriculture is an important source of income, food and raw materials in West Africa, employing more than half of the region’s population, which culminated in the adoption of the Comprehensive Africa Agriculture Development Programme (CAADP) in 2003. Few countries, however, have managed to mobilize their agriculture sector to deliver on development outcomes such as food and nutrition security, poverty reduction, economic growth, job creation, youth employment and industrialization. Agriculture is vulnerable to climate change, resulting from sensitivity and exposure to climate shocks and lack of capacity to cope with and adapt to such changes. ILWAC evaluation study results from household surveys, focus group discussions and key informant interviews indicate that agricultural productivity in the region remains low, lagging far behind other regions of the world. Contributors to such low productivity include incidence of climate risks (drought, floods and high temperatures), pests and diseases, low technology adoption, limited access to financial services, limited access to markets and market information and limited access to good road networks (Plate 1). All the aforementioned contributors are valid denominators for all the seven ILWAC project areas that were evaluated. 2. Farmers in West Africa are particularly vulnerable to climatic shocks because of their high dependence on rainfed agriculture for their livelihoods. There is an evident lack of access to formal safety nets as indicated by farmers in Senegal (ENRACCA-WA) and Burkina Faso (AmREACCAF and APESS) projects. Climate change has already exerted significant impacts in the region. Since the 1970s, the region has experienced the occurrence of many droughts. Temperatures have increased in the second half of the 20th Century, especially in the latter 20 years of the same period. Farmers reported drought (about 40% of treatment and control groups), as the most prevalent climatic shock experienced over the last five years, followed by erratic rainfall, floods and invasion of crop pests and locusts. We identified eleven coping strategies, out of which three strategies were categorized based on a gradient of severity of food insecurity into low, moderate, and high food insecurity. During low food insecurity, households employ food-maximizing strategies such as purchasing food and eating less food and involving a low commitment of domestic resources that all enable quick recovery of households once the crisis eases. In times of moderate food insecurity, a greater commitment of household resources is increasingly required to meet subsistence needs. Coping strategies developed by households include sale of food reserves, use of savings, sale of livestock, borrowing food, and borrowing money (from friends, relatives, private lenders and banks). During high food insecurity, strategies are a sign of failure to cope with the food crisis and may involve drastic options that may undermine their future ability to prevent, mitigate, cope, and recover from shocks. Households adopt sale of assets such as land and homes, keeping children home from school, food aid and migration. The use of irrigation and rainfall water harvesting for agriculture remain low, despite prevalent droughts and widespread rainfed agricultural practices. One of the reasons is that most farming communities are far from rivers: hence considerable investment is required to develop irrigation in many project areas. 3. Although farmers use various strategies highlighted above, they will need support to double their efforts with innovative climate- smart agricultural practices and technologies to remain food secure. Areas where ILWAC interventions were targeted showed positive results, but broader efforts to scale out the successes are needed to achieve a greater impact. Overall, the ILWAC project beneficiaries reported higher adoption rates of climate-smart practices, demonstrating a favourable impact of the project. However, low awareness of the most appropriate technologies to cope with climate shocks was reported across all study areas yet, the region is expected to experience increasing climatic shocks with total precipitation predicted to increase for the most part more notably between July and October by 2050. Increases in precipitation are predicted to cause crop damages and floods. Overall, temperatures will rise by about 2°C to 3°C over the same time period. Higher temperatures of 3°C to 6°C are projected for the end of the 21st century (Niang et al., 2014). Despite these impending changes, few farmers have adjusted their farming strategies in response to climate risks, owing to limited knowledge on appropriate adaptation options and low endowment with production resources. As a result, ILWAC interventions were targeted to reverse these challenges. Their successful implementation showed positive results, which are largely limited to specific areas of implementation. Therefore, broader scaling out ILWAC interventions provided success stories tailored to specific contexts (biophysical and socio- economic); hence offered lessons and opportunities for replicating the bright spots with a regional approach. Across the seven projects, evaluation results indicated a couple of selected successes in the region (Plate 1). Selected successes make up potential candidates for scaling up climate-smart agricultural technologies and practices, and innovative approaches notably, including: i. Innovation platforms as a pillar for change: The successful establishment of innovation platforms across all project countries was evident but have remained largely underdeveloped and not utilized to their full potential. Platforms provided a framework for sharing knowledge on adaptation innovations to climate change, providing a good entry point for technology dissemination in target areas across all project countries. The study showed that the innovation platform model can offer the potential to organize stakeholders to address the objective of improving the livelihood of their members. IPs, however, need a strong voice to demand the needed services from service providers, negotiate and advocate for collective interests with the private sector and government. The use of a participatory development communication (PDC) within IPs would greatly increase their sustainability; ii. Increased human and institutional capacity for stakeholders: The enhancement of capacity for diverse stakeholder groups, including farmers, players in all segments of priority value chains, extension agents, policymakers and researchers (All project countries) resulted in significant positive results such as increased capacity towards awareness of CSA technologies and application of appropriate adaptation measures in their communities. This highlights the need to prioritize linkages amongst farmer organizations, extension and agricultural research; iii. Integrated landscape approaches for natural resources management provided exponential benefits: The pioneering of integrated land and water management for adaptation to climate variability and change improved management of natural resources in specific target countries, for example, in Burkina Faso, the relative reduction in sedimentation by up to 70%; and that in reduced runoff by up to 30% which helped improve the farmers’ agricultural practices and livelihoods (AmREACCAF-Burkina Faso). This also increased storage of water in the Boura reservoir through avoided sedimentation. Beyond water provision for household use, these reservoirs serve as key food baskets for fisheries and irrigation for households; iv. Integrated and diversified options offered opportunities to increase resilience and unlock the potential for rural smallholder livelihoods: The ILWAC project improved implementation of innovative agronomic interventions that substantially reduced the yield gap for millet for example the use of improved crop varieties (drought tolerant and early maturing) resulted in a 10 fold yield increase in grain biomass (ENRACCASenegal). Additional strategies include soil amendments in the form of organic and inorganic fertilizer sources, weed control practices as well as improved storage techniques (ISFM-Benin); Household enterprise diversification with agroforestry tree species enhanced the resilience of smallholder communities with climatesmart benefits such as windbreaks, these modified the micro-climate of the area that enhanced food security and revenue generation within target communities, increased farmer adaptive capacity and overall soil health attributes (ENRACCA- Senegal). 5. Women empowerment resulted in improved rural livelihoods: Improved gender dynamics regarding the roles, activities and representativeness within the selected projects had a positive impact on women empowerment for all project countries. There are numerous ways by which women were empowered e.g. conducting off-season vegetable cultivation allowed women to fetch increased returns (3 times than the normal price) in the off-season months. There were efforts to promote increased participation of women in the projects, offering opportunities to freely express themselves, highlight their needs and specific experiences. However, participation of women in leadership positions was generally low (less than 10%). In addition, women were able to benefit from the capacity building provided by the project, and access technologies and inputs resulting in higher production and subsequent incomes than before. Male-headed households were more likely to practice more CSA technologies by a factor of about 1 compared to female headed households. There was evidence of better access to financial services and training through village savings and loan associations, and gender empowerment. A key attribute of the assessed projects was that for the most part, women farmers were not well organized into interest groups with the capacity to promote their interests and engage in advocacy activities geared at influencing policy for their ultimate benefit. This was a missed opportunity especially in the context of existing innovation platforms that needs concerted efforts and strengthening. 6. More economic and social safety nets for smallholder livelihoods beyond ILWAC beneficiaries are needed: ILWAC enhanced farmers’ access to climate-resilient and low-emission practices and technologies, including crop, livestock, soil and water management options and energy saving technologies. ILWAC increased the number of CSA practices implemented by three practices more compared to non-participation. Results further showed that education level is associated with higher income. Higher value assets such as livestock did also significantly influenced income. ILWAC increased significantly the value of assets to almost 90%; a factor attributable to additional assets that were distributed to farmer groups such as the case of Gambia, Senegal and Sierra Leone. This study therefore confirms that more assets in ILWAC supported households offered better livelihood options than those in the control group. Results further show that male-headed households have a higher value of assets than female-headed households. On the overall, although participation in ILWAC increased income by 19%, there remains room for further improvement amongst the ILWAC beneficiaries given the lower differences in the economic domain for sustainable intensification exemplified before and after the ILWAC project on Plate 2. Likewise, Plate 2 highlights that better options are needed in the social domain to ensure that ILWAC beneficiaries can significantly gain from social dividends (e.g. strengthened farmer groups, collective action, and shared labor). Given the highlighted successes among the ILWAC beneficiaries, efforts will be needed to scale these bright spots beyond the ILWAC beneficiaries to wider geographical coverages. 7. There is need for concerted efforts towards supporting technical, financial, institutional and governance needs within the target countries in order to make community livelihoods more resilient to climate change. Despite the recorded successes there remains room for improvement in several institutional and governance realms. Farmers in the project sites are faced by poor extension, with the ratio of government paid extension officers to that of farmers being low, only 33% of the households have access to extension service. This has a negative impact on the quality of extension services being offered and building adaptive capacity to deal with climate change. A significant challenge remains in all project countries to get the technologies widely used due to the lack of a suitable enabling environment among others — extension services, financial resources, infrastructure, risk management and cross-sectoral linkages. Farmers are further constrained by having limited access to climatic information. Effective research and innovation are also needed to continuously improve practices and technologies. This calls for a policy recommendation where concerted efforts are needed to mobilize financial resources and build the capacity of West African researchers, policy-makers and institutions to understand, carry out and use good quality data towards informed decision making and scenario analyses (Also see evidence revealed by Plate 2).Enabling policy and institutional environment can provide the conditions and incentives for scaling out

Automated real time optimisation for control of furrow irrigation

Furrow irrigation is one of the oldest techniques of surface irrigation and is the most popular method for the irrigation of row crops. In Australia the method is widely used for the irrigation of cotton and in some years it has accounted for about 95% of the total production. The furrow system is however often associated with high labour requirement and low water used e�ciency. In furrow irrigation the soil is used both as a medium for infiltration and also for conveyance of water from one end of field to the other. However, the spatial and temporal soil infiltration variability causes non-uniformity in water absorption rates and furrow stream advance rates. This significantly reduces water use e�ciency because current design and management practices do not take this variability into account. Most operations in the furrow system are undertaken manually, and are hence labour-intensive. Real time optimisation and control of furrow irrigation has been proposed for the management of infiltration variability. The system estimates the soil infiltration characteristics in real time and uses the data to control the same irrigation, potentially leading to improvement of water use e�ciency. The major goal of this research was therefore to develop, prove and demonstrate an automated system for real time optimisation of furrow irrigation. The hypotheses of the research were that: (i) use of real time optimisation and control in furrow irrigation can lead to signi�cant improvement in irrigation performance, and (ii) automation of furrow irrigation is feasible. The system developed in this research is an integration of a simulation model and associated automation hardware and consists of �five main components: (i) a water delivery system, (ii) an inflow measurement system, (ii) a water sensor to monitor advance of water along the furrow, (iv) computer running the simulation model (AutoFurrow), and (v) a radio telemetry system to facilitate communication among the system components. AutoFurrow uses a scaling technique to adjust the soil infiltration characteristic and determine the soil conditions prevailing for the particular irrigation. Hence it optimises the current irrigation to satisfy the soil moisture deficit and other user-defined objectives (for example target effi�ciency, uniformity and run-o�) and determines the time to end the irrigation in suffi�cient time for effective control of the irrigation. Trials to test and prove the new system were undertaken on two separate commercial cotton properties over two consecutive irrigation seasons. The system implemented for the field trials was not fully automated, and operations such as starting and cutting of flow was achieved manually. Apart from evaluations of the optimisation system, full advance data and other measurements were taken for all trials to enable a post-irrigation complete (actual) irrigation evaluation to be undertaken. Performances expected as per the grower's irrigation management practices were also evaluated. The SISCO simulation model was used for analysis of data. The results suggested that the optimisation system was successful in delivering irrigation performance significantly better than achieved by the grower. However, in the 2010/11 irrigation season this performance (predicted by the optimisation system) was found to be slightly higher than the actual performance and much less than that suggested by a post irrigation optimisation undertaken using the full measured data for each irrigation. This suggested that the system had not reached its full potential and further improvements were necessary. Factors investigated for their possible contribution to performance of the real time optimisation system were: flow rate, objective function, selection of the model curve, and the infiltration scaling process. The investigations involved an exhaustive series of simulations using the SISCO model, varying each of these factors in turn. The key changes in the evaluation methodology effected as a result of these investigations and used for the 2011/12 irrigation season trials were: the adoption of a simpler objective function consisting only of RE, and (ii) taking the average shape of the previous in�filtrations curves and using it as the model curve. The benefit of these changes was clearly evident in the results obtained from the 2011/12 trials - the performance of the optimisation system improved and the difference between the actual performance predicted by the optimisation system was reduced to � 4%. This research has therefore achieved its overall goal of designing and testing a real time optimisation system for furrow irrigation. It has also successfully demonstrated the potential benefits of real time optimisation and shown that the automation of the furrow system is feasible. Further research has been recommended including a comprehensive economic analysis and the trialling of the system in bay irrigation

The effect of irrigation non-uniformity on carrot production

Field trials were conducted at three field sites in the Fassifern Valley to determine the effect of irrigation non-uniformity on carrot production. Catch cans were used to measure the distribution uniformity. The total seasonal water at each catch can position over the entire growing period was calculated by summing the depths for each irrigation and rainfall. Yield samples were then taken at each catch can position prior to harvest and compared with the total seasonal water. Options to improve irrigation performance using simulation modelling were identified. The distribution uniformities of the solid-set and travelling gun systems evaluated were found to be lower than the suggested industry standard of 85%. The sampled yield across the three trial sites did not show any correlation with the total seasonal water, implying that carrot yield did not vary significantly with varying irrigation uniformity. This may have been caused by the unusually high rainfall during the season. The SPACE program was used to in identify the optimal configuration of the solid-set system, while the TRAVGUN program was used to identify the optimal lane spacing and sector angles for the travelling guns

Simulation modelling in surface irrigation systems

Australia is one of the driest countries in the world and hence irrigation, and particularly surface irrigation, is a significant agricultural activity. In the recent past, efforts have been made towards devising strategies necessary for efficient use of water. The desire to optimise the dollar output of this scarce resource while at the same time conserving the environment is the main motivation for these efforts. Computer simulation models have the potential to improve the efficiency of irrigation systems and thus deliver significant water savings. This can be achieved by optimising the design and management decisions at the field level. The purpose of this paper is to review the simulation models that have been developed for surface irrigation. The impacts of these models in the irrigation industry in Australia as well as their limitations are also discussed. In the majority of the surface irrigation simulation models currently in use, previous field characteristics are used to optimise future irrigations. However, numerous researchers have established that these characteristics change both with time and space, and hence the accuracy of such models may be affected. A conceptual design of a computer simulation model suitable for use in automated furrow systems utilising adaptive real time control is presented. This is part of an on-going research project at USQ aimed at modernising the furrow syste