CERES :: Browsing by Author "Knox, Jerry W."

Browsing by Author "Knox, Jerry W."

Now showing 1 - 20 of 83

Open Access
Assessing evidence on the agronomic and environmental impacts of turfgrass irrigation management
(Wiley, 2018-01-15) Gómez‐Armayones, Carlos; Kvalbein, Agnar; Aamlid, Trygve S.; Knox, Jerry W.
In recent years, rising competition for water coupled with new environmental regulations has exerted pressure on water allocations for turfgrass irrigation. In this article, we reviewed published scientific and industry evidence on the agronomic and environmental impacts of turfgrass irrigation using a robust systematic review methodology. Our focus was on the links between (i) irrigation management (amount and frequency), (ii) agronomic responses to irrigation (turf quality, growth rates and rooting) and (iii) environmental impacts (nitrogen leaching). Based on an initial screening of 653 studies and data extracted from 83 papers, our results show that in most cases, under moderate levels of deficit irrigation (50%–60% of actual evapotranspiration), turf quality can be maintained at an acceptable level but with lower water consumption compared to irrigating back to field capacity. Irrigation beyond field capacity was found to increase the risk of nutrient leaching. However, evidence also showed that the concentration and total loss of math formula in leachate were influenced more by nitrogen (N) rates, soil characteristics, turfgrass species and turfgrass growth rates than by irrigation practices. Our analyses suggest that turfgrass irrigation should be scheduled to apply water at moderate levels of deficit irrigation, sufficient to maintain turfgrass quality but limited to promote a deep and extensive rooting system. The findings provide new insights and valuable evidence for both scientists and practitioners involved in turfgrass research and management.
Open Access
Assessing future drought risks and wheat yield losses in England
(Elsevier, 2020-11-24) Clarke, D.; Hess, Tim M.; Haro Monteagudo, David; Semenov, Mikhail M.; Knox, Jerry W.
Droughts pose a major risk to agricultural production. By comparing the outputs from an ecophysiological crop model (Sirius) with four drought severity indicators (DSI), a comparative assessment of the impacts of drought risk on wheat yield losses has been evaluated under current (baseline) and two future climate scenarios. The rationale was to better understand the relative merits and limitations of each approach from the perspective of quantifying agricultural drought impacts on crop productivity. Modelled yield losses were regressed against the highest correlated variant for each DSI. A cumulative distribution function of yield loss for each scenario (baseline, near and far future) was calculated as a function of the best fitting DSI (SPEI-5July) and with the equivalent outputs from the Sirius model. Comparative analysis between the two approaches highlighted large differences in estimated yield loss attributed to drought, both in terms of magnitude and direction of change, for both the baseline and future scenario. For the baseline, the average year differences were large (0.25 t ha−1 and 1.4 t ha−1 for the DSI and Sirius approaches, respectively). However, for the dry year, baseline differences were substantial (0.7 t ha−1 and 2.7 t ha−1). For the DSI approach, future yield losses increased up to 1.25 t ha−1 and 2.8 t ha−1 (for average and dry years, respectively). In contrast, the Sirius modelling showed a reduction in future average yield loss, down from a baseline 1.4 t ha−1 to 1.0 t ha−1, and a marginal reduction for a future dry year from a baseline of 2.7 t ha−1 down to 2.6 t ha−1. The comparison highlighted the risks in adopting a DSI response function approach, particularly for estimating future drought related yield losses, where changing crop calendars and the impacts of CO2 fertilisation on yield are not incorporated. The challenge lies in integrating knowledge from DSIs to understand the onset, extent and severity of an agricultural drought with ecophysiological crop modelling to understand the yield responses and water use relations with respect to changing soil moisture conditions.
Open Access
Assessing optimum irrigation water use: additional agricultural and non- agricultural sectors. Environment Agency Science Report - SC040008/SR1
(2008-04-01T00:00:00Z) Knox, Jerry W.; Weatherhead, E. K.; Rodriguez Diaz, J. A.
The Water Act (2003) and its preceding legislation requires the Environment Agency to assess and justify authorisations for irrigation abstraction, whether for agricultural, horticultural, amenity, sports turf or other use. A previous study, Optimum use of water for industry and agriculture (W6-056), has provided a framework for assessing the ‘optimum’ or ‘reasonable’ needs of a wide range of crops. In this study, water use was analysed for a range of other agricultural and non-agricultural sectors dependent on irrigation, but not included in the W6-056 study. These include some sectors where new authorisations for trickle will be required, as well as for existing and new spray irrigation abstractions. The sectors considered include golf courses, racecourses, turf production, frost protection, horticultural nursery stock, pot plant and bedding plant production and glasshouse pro
Open Access
Assessing performance of small-scale pumped irrigation systems in Sub-Saharan Africa: evidence from a systematic review
(Wiley, 2016-03-16) Kamwamba-Mtethiwa, Jean; Weatherhead, E. K.; Knox, Jerry W.
Small-scale irrigation (SSI) has significant potential to increase crop productivity in Sub Saharan Africa (SSA). Pumped irrigation systems are one of the technologies increasingly being used by smallholder farmers. The aim of this study was to systematically review evidence on the performance of SSI pumped systems, including motorized, treadle, rope and washer, solar and wind pumps. The study revealed a lack of standardization and use of a wide range of indicators to assess performance. Most evidence related to motorized pumps, these studies confirmed mixed levels of performance; studies relating to other types of pumped system mostly reported a positive impact, although the method of assessment used was critical. Studies reporting positive impacts tended to be those that used socio-economic based factors such as yield and profitability, whereas studies reporting mixed performance tended to be those that relied more on technically based indicators such as pumping and irrigation system efficiency. The analysis highlights the sensitivity of interpreting findings from different studies, and how caution should be exercised when comparing performance within and between different types of irrigation system. The implications for supporting policy development and identifying future research gaps are discussed.
Open Access
Assessing the financial and environmental impacts of precision irrigation in a humid climate
(Czech Academy of Agricultural Sciences, 2019-03-29) El Chami, D.; Knox, Jerry W.; Daccache, Andre; Weatherhead, E. K.
Precision agriculture is increasingly used where in-field spatial variability exists; however, the benefits of its use in humid climates are less apparent. This paper reports on a cost-benefit assessment of precision irrigation with variable rate technique (VRI) versus conventional irrigation, both compared to rainfed production, using a travelling hose-reel irrigator fitted with a boom on onions in eastern England. Selected environmental outcomes including water savings and CO2e emissions are evaluated. The modelled precision irrigation system, which responds to soil variability, generates better environmental outcomes than the conventional system in terms of water savings and reduced CO2e emissions (22.6% and 23.0% lower, respectively). There is also an increase in the ‘added value’ of the irrigation water used (£3.02/m3 versus £2.36/m3). Although precision irrigation leads to significant financial benefits from water and energy savings, these alone do not justify the additional equipment investment costs. However, any changes in yield or quality benefits, equipment costs or greater soil variability than on this site would make investment in precision irrigation more viable.
Open Access
Assessing the impacts of drought on UK wheat production
(Cranfield University, 2017-01) Clarke, David; Knox, Jerry W.; Hess, Tim M.
Water limitations typically reduce UK wheat yields on average by 1-2 t ha- 1 , although this can be considerably more in extreme drought years. With the frequency and intensity of droughts expected to increase under a changing climate, an improved understanding of the impacts of drought and better systems for agricultural drought monitoring are required. Previous studies, however, have found no significant relationship between UK wheat yields and commonly employed drought severity indices (DSI). Using historical (1911-2015) daily weather data for Cambridge the Standardized Precipitation Index (SPI), the Standardized Precipitation and Evapotranspiration Index (SPEI), the Palmer Drought Severity Index (PDSI) and the Potential Soil Moisture Deficit (PSMD) were calculated on various time steps (e.g. 1-12 months for SPI and SPEI) to provide a drought record for the site. A wheat crop growth simulation model (Sirius) was then used to simulate the effects of the identified historic droughts on wheat yields. The use of the Sirius crop model removed the non-drought related yield losses (e.g. disease, pests, and lodging) present in national yield records. Using the Spearman’s Rho correlation coefficient (r) the simulated yield record was then correlated against the different DSIs. The droughts of 1921, 1976 and 2010 were found to be the most extreme in term of yield reduction. In addition, there were also two noticeable periods of successive yield loss in the early 1940s and between 2009 and 2013. All DSIs showed significant (p = 0.05) correlations on monthly time steps between April and August. The SPI, SPEI and PSMD showed a strong correlation to wheat yields (r = 0.64 to 0.66) on time steps incorporating the end of the ‘construction’ and the entirety of the ‘production’ phases for wheat growth. The PDSI showed the weakest correlation (r = 0.55), although it may be helpful in identifying yield-limiting droughts earlier in the year. The research has contributed new scientific insights and understanding of the impacts of historic droughts on wheat productivity, and demonstrated the application of DSIs in monitoring potentially yield-limiting droughts. The research also provides new evidence to support developments in UK food security and drought management for agriculture.
Open Access
Assuring the microbiological quality of water used to irrigate salad crops: an assessment of the options available
(2004-03-02T00:00:00Z) Tyrrel, Sean F.; Knox, Jerry W.; Burton, C. H.; Weatherhead, E. K.
- Headline. Although no evidence to link the irrigation of salads to disease outbreaks in the UK has been found, the industry should be seen to be taking the issue of irrigation water quality seriously. The strategy should be to take proactive measures to pre-empt the adoption of unnecessarily cautious standards within grower protocols. - Background and expected deliverables. Concerns have been expressed by some of the major supermarkets that salad vegetables may become contaminated with pathogens as a result of crop irrigation using poor quality water sources. As salads are likely to be eaten raw and will have received a minimal level of processing there are fears that consumers may be put at risk if irrigation water quality is not controlled. To assure product quality and to protect consumer confidence, some supermarkets may set stringent irrigation water quality standards in future grower protocols. Product quality is of paramount importance to growers, processors, retailers and consumers alike. However, the salad growing industry advocates a proportionate, science-based approach to the development of grower protocols rather than the adoption of an excessively precautionary principle. The aim of this project was to generate the baseline information needed by the industry to respond in a positive way to the concerns of retailers. The findings should help to inform the decisions and actions necessary to demonstrate and assure the quality of these products. The work should also support and contribute to the broader commercial objectives of the HDC regarding the efficient use of water. - Summary of the project and main conclusions. The following research tasks were undertaken in pursuit of the project’s aim. 1 A review of literature relating to the microbiological quality of irrigation water and of salad crops. 2 A survey of current UK irrigated salad production to assess current usage and underlying trends. 3 An evaluation of the technological and economic feasibility of on-farm water treatment options. 4 An analysis and discussion of the data collected and development of recommendations for the industry. The main conclusions of this work are: Irrigation water is one of many potential sources of contamination of salads. No published direct evidence has been found to link the irrigation of salads to disease outbreaks in the UK. However, there is a clear potential for this to occur. Published laboratory trials have shown that pathogens associated with poor quality irrigation water may survive on lettuce until harvest. Epidemiological investigations (not from UK) have indicated a link between disease and poor quality irrigation water. On occasions, some UK salad crops are probably irrigated with water of a lower microbiological standard than that recommended for comparable uses (e.g. reuse of wastewater for irrigation and bathing). The actual extent to which this occurs should be quantified and reviewed. The lack of guidance on irrigation water quality is a deterrent to proper water quality monitoring as most growers are unsure how they should respond to the data that is generated. This situation should be corrected as a matter of priority. It is reported that some of the multiple retailers in the UK favour a standard for irrigation water close to that which would meet the requirements for drinking water (i.e. absence or infrequent presence of E. coli in 100 ml water). Our review of standards suggests that this may be an unnecessarily cautious and expensive option. A grower faced with doubts about water quality appears to have four options: Demonstrate existing water is of adequate quality; Treat existing water; Change water source; Relocate crop. A site specific water resources study should be undertaken before assuming that treatment is necessary. Where water quality cannot be assured by management or sourcing strategies, treatment technologies may be considered. Of the many options, three technologies are likely to be suitable: ultra-violet (U/V) treatment, thermal treatment, and sand filters. U/V is considered to be attractive when taking all of the factors into account. Thermal treatment is the most rigorous and reliable. With heat recovery, such treatment could be viable in some cases. Sand filters offer the most farmer-friendly solution but these systems offer less assurance of water quality. - Financial benefits. There are no direct financial benefits to be gained by growers from this work. It may be prudent for growers to take proactive measures to improve monitoring procedures to pre-empt the adoption of unnecessarily cautious (and costly) standards in future grower protocols. - Action points for growers. There is likely to be increasing scrutiny of the microbiological quality of irrigation water. It is advised that growers review their monitoring strategy as a matter of priority. Regular sampling of water sources, at least monthly during the irrigation season, for faecal indicator bacteria would be a good start. The development of such a dataset would aid future decisions regarding the acceptability of particular sources.
Open Access
Building adaptive capacity of smallholder agriculture to climate change: evidence synthesis on learning outcomes
(IOP, 2021-12-31) Silici, Laura; Rowe, Andy; Suppiramaniam, Nanthikesan; Knox, Jerry W.
Increasing climate uncertainty coupled with more frequent extreme events poses a serious threat to the sustainability of smallholder communities dependent on agriculture for their livelihoods. Whilst there is extensive literature on adaptation options, there is a pressing need to understand what interventions have been successful in building smallholder’s adaptive capacity, and how these have been transferred (nationally and internationally)through learning outcomes. The aim of this rapid evidence assessment was to assess the extent to which learning outcomes have supported initiatives to mainstream adaptation, focussing on three key areas, (i)scaling up climate sensitive adaptive interventions, (ii)the role of knowledge management to promote effective adaptive solutions, and (iii) human-ecosystem interactions in climate change adaptation. A protocol for the review was defined, from which 806 sources of evidence were retrieved. After screening for relevance using inclusion criteria, 91 were selected and the salient evidence extracted and synthesised. Access to knowledge remains one of the most important determinants of smallholders’ decisions to respond to climate risk and a critical element in building adaptive capacity. The way knowledge is generated and exchanged is also directly relevant to securing effective scaling-up pathways. Learning platforms through participatory action research, farmer field schools and community-based initiatives were found to be particularly effective. However, knowledge based on local practices alone may be insufficient to prompt transformative action. Bridging local and external knowledge is critical because it widens the smallholders’ knowledge base and encourages ‘proactive’ adaptation alongside more typical ‘reactive’ strategies. The contribution of evidence reviews to provide new insights to inform decision-making and investment in international development and the implications for advocating climate-sensitive policies at national and global levels are discussed.
Open Access
Catchment-scale challenges for water resources management: assessing ‘reasonable’ peak needs for irrigated agriculture in a humid climate
(MDPI, 2024-02-27) Knox, Jerry W.; Weatherhead, E. Keith
Rising demands and competition for water resources within all sectors are placing increasing pressure on the environment. Almost all direct abstractions in England require a licence (permit) from the regulatory authority, the Environment Agency. Assessing and setting ‘reasonable’ peak quantities of water that can be legally abstracted in an environmentally sustainable manner is central to the whole licence determination process. To protect environmental flows and other abstractors within each catchment, the regulatory authority needs to be able to set sensible limits in the licence conditions, including total seasonal volumes and peak rates of water use, particularly for abstractions from hydrologically sensitive surface water sources. This paper describes the development of a methodology to assess the ‘reasonable’ peak rates of water use for agricultural irrigation in support of catchment water resources management and planning. A daily time step water balance model was used to simulate peak monthly and daily water requirements for irrigation using long-term historical weather records for agroclimatically contrasting sites. The model-simulated outputs were then compared against observed data from selected case study farms, and against data reported in a national water abstraction database. Guidelines were then developed for setting peak monthly, daily, hourly, and absolute abstraction rates for irrigation, taking into account the environmental sensitivity of different types of water source. The application of the procedure and its relevance in other countries where catchment water resources are under intense pressure from agriculture are described.
Open Access
CCDeW: Climate Change and Demand for Water.
(2003-02-01T00:00:00Z) Downing, T. E.; Butterfield, R. E.; Edmonds, B.; Knox, Jerry W.; Moss, S.; Piper, B. S.; Weatherhead, E. K.
The Climate Change and Demand for Water Revisited project (CCDeW) revisits and updates the benchmark study by Herrington (1996) and takes advantage of new data sets, regional coverage of demand projections and new methodologies for climate impact assessment. Domestic demand, industrial and commercial water use and irrigated agriculture and horticulture are included in the CCDeW study. Leakage was excluded from the CCDeW study. This report presents the outcome of an extensive UK research programme concerning: demand forecasting; demand management; sensitivity of demand to climatic variations; and sources of risk and uncertainty. While the CCDeW study focuses on demand, climate change uncertainties feed into supply side and demand estimates of water requirements. Therefore, the report’s conclusions should be seen as one element in the dynamic management of the supply/demand balance over the course of the next twenty years and beyond (see Section 9). Clearly, the extent to which water consumption will be influenced by climate change depends upon the sensitivity of different sectors to specific aspects of climate change as well as potential behavioural and regulatory changes, in part related to different socio-economic and climatic future
Open Access
The challenges of developing an irrigation strategy for UK agriculture and horticulture in 2020: industry and research priorities
(CABI, 2020-10-14) Knox, Jerry W.; Kay, M. G.; Hess, Tim; Holman, Ian P.
In many countries, including the UK, water resources are under intense stress with recent droughts highlighting the risks to the security of supplies for different sectors including domestic water supply, industry, agriculture (including horticulture), power generation and the environment. A changing climate with greater rainfall uncertainty, coupled with new regulations, increasing competition for water and demands for sustainable development will only exacerbate the current situation, with major supply-demand imbalances expected over the next few decades. In the UK, irrigated agriculture constitutes a volumetrically small but economically high value use of water, to maximise crop yields and quality. However, the importance of irrigation is also changing; driven by the intensification and transformation of the agricultural sector, the need to recognise water as an 'essential' use, policy incentives to increase domestic food production and an industry imperative to increase water use efficiency and ensure agricultural expansion can continue to underpin the rural economy. This review considers the key climate and water-related risks facing the agricultural and horticultural crop sectors, the various environmental, regulatory and business externalities or 'drivers for change', and the strategic priorities for action, both from industry and research perspectives.
Open Access
Climate change and land suitability for potato production in England and Wales: impacts and adaptation
(Cambridge University Press, 2012-04-01T00:00:00Z) Daccache, Andre; Keay, Caroline A.; Jones, Robert J. A.; Weatherhead, E. K.; Stalham, M. A.; Knox, Jerry W.
The viability of commercial potato production is influenced by spatial and temporal variability in soils and agroclimate, and the availability of water resources where supplemental irrigation is required. Soil characteristics and agroclimatic conditions greatly influence the cultivar choice, agronomic husbandry practices and the economics of production. Using the latest (UKCP09) scenarios of climate change for the UK, this paper describes a methodology using pedo-climatic functions and a GIS to model and map current and future land suitability for potato production in England and Wales. The outputs identify regions where rainfed production is likely to become limiting and where future irrigated production would be constrained due to shortages in water availability. The results suggest that by the 2050s, the area of land that is currently well or moderately suited for rainfed production would decline by 74 and 95% under the "most likely" climate projections for the low and high emissions scenario respectively, owing to increased droughtiness. In many areas, rainfed production would become increasingly risky. However, with supplemental irrigation, around 85% of the total arable land in central and eastern England would remain suitable for production, although most of this is in catchments where water resources are already over-licensed and/or over-abstracted; the expansion of irrigated cropping is thus likely to be constrained by water availability. The increase in volumetric water demand due to the switch from rainfed to irrigated potato cropping is likely to be much greater than the incremental increase in water demand solely on irrigated potatoes. The implications of climate change on the potato industry, the adaptation options and responses available, and the uncertainty associated with the land suitability projections, are discussed.
Open Access
Climate change impacts on rain-fed and irrigated rice yield in Malawi
(Taylor & Francis, 2014-08-05) Daccache, Andre; Sataya, W.; Knox, Jerry W.
There is extensive scientific evidence on climate impacts and adaptation in rice (Oryza sativa L.) but the majority relates to production in south Asia and China. Only a handful of studies have been conducted in Sub-Saharan Africa and none in Malawi. In this paper, the climate impacts on rain-fed and irrigated rice yield have been assessed by combining the downscaled outputs from an ensemble of general circulation models (GCM) (HADCM3, INCM3 and IPCM4) with data from the LARS-WG weather generator to drive the CERES-Rice crop model. This was calibrated and validated using 10 years (2001-2010) field data from three rice schemes to simulate the baseline (1961-90) yield (t ha-1) and then model future yield changes for selected (B1 and A2) emissions scenarios for the 2050s. Although relatively small increases in average yield were projected (+8% and +5% for rainfed and irrigated rice, respectively) there was large uncertainty (-10% to +20% yield change) when considering different GCMs and emission scenario. Farmer responses to cope with the projected impacts include both autonomous and planned adaptation strategies, such as modifying planting dates to maximise crop growth calendars and available soil moisture, increased use of on-farm water conservation measures and land levelling to improve water efficiency in rice schemes dependent on surface irrigation.
Open Access
Climate change impacts on water for irrigated horticulture in the Vale of Evesham. Final Report
(Cranfield University/Environment Agency, 2007-02-19) Knox, Jerry W.; Rodriguez Diaz, J. A.; Weatherhead, E. K.; Khan, K.
This project has undertaken a scoping review and assessment of the impacts of climate change on irrigated horticulture in the Vale of Evesham, an area of intense irrigated production located within the Environment Agency’s Warwickshire Avon CAMS Catchment. The research was based on a combination of methodologies including desk-based review of published and grey literature, computer agroclimatic and water balance modelling, GIS mapping, meetings with key informants and a stakeholder workshop. Future climate datasets were derived from the latest UK Climate Impacts Programme (UKICIP02) climatology, using selected emission scenarios for the 2020s, 2050s and 2080s. These scenarios were then used to model and map the future agroclimatic conditions under which agriculture might operate and the consequent impacts on irrigation need (depths of water applied) and volumetric demand. This was complimented by a postal survey to abstractors and a stakeholder workshop, to identify, review and assess farmer adaptation options and responses. The key findings arising from the research, implications for water resource management and recommendations for further work are summarised below. Using a geographical information system (GIS), a series of agroclimate maps have been produced, for the baseline and selected UKCIP02 scenario. The maps show major changes in agroclimate within the catchment over the next 50 years. The driest agroclimate zones are currently located around Worcester, Evesham, Tewkesbury and Gloucester, corresponding to areas where horticultural production and irrigation demand are most concentrated. By the 2020s, all agroclimate zones are predicted to increase in aridity. By the 2050s the entire catchment is predicted to have a drier agroclimate than is currently experienced anywhere in the driest parts of the catchment. This will have major impacts on the pattern of land use and irrigation water demand. Cont/d.
Open Access
A comparative assessment of trickle and spray irrigation: Science Report - SC040008/SR3, Environment Agency
(2007-06-01T00:00:00Z) Knox, Jerry W.; Weatherhead, E. K.; Rodriguez Diaz, J. A.
Recent research (Assessing optimum irrigation water use: additional agricultural and nonagricultural sectors SC040008/SR1) complements existing guidelines (W6- 056) for the Environment Agency to assess and set the ‘optimum’ or ‘reasonable’ irrigation needs for an abstraction licence, across a wide range of agricultural, horticultural, amenity and sports turf sectors. For those abstractors with time-limited licences, demonstrating efficient use of water is one of three tests required by the Environment Agency for successful licence renewal. However, the definition of efficiency under UK conditions of supplemental irrigation has been the subject of widespread debate between academics, the regulator, industry and individual abstractors. To improve our understanding of efficiency, and particularly the differences between overhead (spray) and micro (trickle) irrigation, this report offers a comparative study of the efficiency of water use with these contrasting irrigation
Open Access
Crop coefficients, growth rates and quality of cool-season turfgrasses
(Wiley, 2016-01-01) Aamlid, Trygve S.; Knox, Jerry W.; Riley, H.; Kvalbvein, A.; Pettersen, T.
Determination of crop coefficients (Kc), the ratio between actual (ETa) and reference evapotranspiration (ET0), is necessary to schedule irrigation. Our objective was to determine Kc, turf quality and growth rate under daily irrigation to field capacity (FC = −3 kPa tension) and drying. Minilysimeters installed in a green (mowing height 3–5 mm) and fairway (15 mm) were weighed during four periods of 4–10 days duration in 2009 and 2010. Crop coefficients on the second and subsequent days after irrigation were not significantly different among species and averaged 0.81 and 0.91 on green and fairway, respectively. On the first day after irrigation, the Kc varied from 1.67 to 2.85 and decreased in the order Agrostis capillaris > Festuca rubra ssp. litoralis > F. rubra ssp. commutata > A. stolonifera > A. canina on the green, and F. rubra ssp. litoralis > Lolium perenne > F.rubra ssp. rubra > Poa pratensis > F. rubra ssp. commutata on the fairway. Drying reduced the average daily height growth from 0.98 to 0.74 mm on the green and 1.97–1.72 mm on the fairway. Scores for turf quality were reduced but remained acceptable. Although the Kc during the first day after irrigation to FC may be overestimated due to latent soil heat and a possible oasis effect, we conclude that irrigation to FC should be avoided as it causes excessive water use.
Open Access
D-Risk: a decision-support webtool for improving drought risk management in irrigated agriculture
(Elsevier, 2019-05-22) Haro Monteagudo, David; Knox, Jerry W.; Holman, Ian P.
Drought constitutes a significant production and business risk in agriculture, particularly for those enterprises dependent on irrigation to deliver high quality continuous supplies of fresh produce to the retail sector. Whilst most farmers are well attuned to managing short term weather-related crop risks, they lack access to tools that can support medium-term decision-making and risk management strategies under conditions of increasing water scarcity and climate uncertainty. This paper describes D-Risk, an intuitive online webtool designed to help farming enterprises easily understand their existing and emergent drought and irrigation abstraction risks and thereby support more robust decision-making regarding future changes in crop planning and water resources infrastructure investment.
Open Access
Developing a strategy to improve irrigation efficiency in a temperate climate A case study in England
(Ip Publishing, 2009-12-31T00:00:00Z) Knox, Jerry W.; Weatherhead, E. K.; Diaz, J. R.; Kay, Melvyn G.
Irrigation is an essential component of agricultural production in England, but the water resources required are under intense pressure due to rising competition, demands for greater environmental protection and the longer-term threats from climate change. This paper describes the development of a water strategy for agriculture to assure its future sustainability by reducing water wastage and maximizing the benefit from the water used. Three themes have been defined - working together, making best use of available water and developing a knowledge base. The approaches described have international relevance to countries where agricultural irrigation is an important component of water abstraction.
Open Access
Developing a water strategy for sustainable irrigated agriculture in Mediterranean island communities – Insights from Malta
(Sage, 2019-04-07) Papadimitriou, Lamprini; Hallett, Stephen; Sakrabani, Ruben; Borg, Malcolm; Thompson, Andrew; Knox, Jerry W.
The future sustainability of irrigated agriculture in Mediterranean island communities faces a raft of economic, environmental and socio-economic challenges. Many of these are inextricably linked to the extreme levels of water scarcity that exist in the region. With a focus on Malta, we developed a water strategy to identify the priorities for action to support decision makers, practitioners and the agrifood industry in achieving agricultural and water resources sustainability. The methodology involved a combination of evidence synthesis, to inform the development of a Drivers-Pressures-State-Impact-Response framework. These priorities were then used to define a set of key actions under three thematic pillars of sustainability (environment, economy and society). Our analysis confirmed that irrigated agriculture in Malta is not only impacted by environmental factors such as the challenging climate and geography of the region but also strongly influenced by a range of economic (tourism development, European Union accession) and societal (population growth, environmental regulation) drivers of change. The developed strategy is underpinned by priority actions relating to improved water and soil management. The reduction of water and energy footprints in crop production, the establishment of demonstration farms and the support of policies that promote ‘value adding’ activities are examples of key priority actions for the environmental, economic and societal pillar, respectively. Regarding the scale of intervention, the analysis distinguishes research as being important for supporting many of the economy-focused actions.
Open Access
Developing drought resilience in irrigated agriculture in the face of increasing water scarcity
(Springer , 2017-02-08) Rey, Dolores; Holman, Ian P.; Knox, Jerry W.
In many countries, drought is the natural hazard that causes the greatest agronomic impacts. After recurrent droughts, farmers typically learn from experience and implement changes in management to reduce their future drought risks and impacts. This paper aims to understand how irrigated agriculture in a humid climate has been affected by past droughts and how different actors have adapted their activities and strategies over time to increase their resilience. After examining recent drought episodes from an agroclimatic perspective, information from an online survey was combined with evidence from semi-structured interviews with farmers to assess: drought risk perceptions, impacts of past drought events, management strategies at different scales (regional to farm level) and responses to future risks. Interviews with the water regulatory agency were also conducted to explore their attitudes and decision-making processes during drought events. The results highlight how agricultural drought management strategies evolve over time, including how specific aspects have helped to reduce future drought risks. The importance of adopting a vertically integrated drought management approach in the farming sector coupled with a better understanding of past drought impacts and management options is shown to be crucial for improving decision-making during future drought events.