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Increased water demands and drought have resulted in the need to provide data to guide deficit water management decisions in irrigated sugarbeet ( Beta vulgaris L.) production. The objective of this study was to quantify the yield response of sugarbeet to water input and actual crop evapotranspiration (ETa) on a soil type (silt loam) common to sugarbeet production in the Northwest U.S. These relationships are valuable to understanding sugarbeet response over a range of water availability and in developing tools to assess future production under water shortages. This paper consolidates data from three studies consisting of ten site-years from 2009 to 2016. The studies were at the USDA-Agricultural Research Service facility in Kimberly, ID on a Portneuf silt loam soil. Treatments consisted of varying levels of cumulative seasonal Kimberly-Penman ET model estimated crop evapotranspiration (ETc) rates ranging from rain-fed to 125% of ETc. Irrigation methods consisted of surface drip irrigation (3 site-years), linear/pivot overhead sprinkler (6 site-years), and solid-set sprinkler (1 site-year). Irrigation frequency was consistent for all studies with applications occurring 2–3 times per week depending on ETc demand. Estimated recoverable sucrose (ERS) yield and root yield were measured, and soil water contents were measured. Across all site-years, quantitative relationships between both actual crop ET (ETa) and water input, and sugarbeet yield and quality variables were developed. Significant (0.05 probability level) positive linear relationships were found between ETa and sugarbeet ERS and root yields (r 2  = 0.78). Estimated recoverable sucrose and root yields increased at rates of 19.4 kg ha −1  mm −1 ETa and 0.13 Mg ha −1  mm −1 ETa, respectively. When ETa depths of 719 and 729 mm were reached by the crop, root and ERS yields were maximized, respectively. When water input (irrigation + precipitation) depths of 598 and 605 mm were applied root and ERS yields were maximized, respectively. The quantitative relationships between both ETa and water input, and sugarbeet yields can be used to quantify sugarbeet production under deficit irrigation conditions (data derived from pivot/linear, drip, and solid set irrigation types), which may arise due to water shortage scenarios, or when drought occurs in non-irrigated areas. [ABSTRACT FROM AUTHOR]

Drip irrigation emitter clogging is one of the key barriers to the development and application of reclaimed water drip irrigation technology. Reclaimed water typically contains large amounts of bacteria, and their excretions, the sticky extracellular polymeric substances (EPS). Indeed, different amounts and types of microorganisms affect drip irrigation emitter clogging, especially bio-clogging process, via excretive EPS. Therefore, it is important to study the dynamic microbial community structure and its effect on the emitter bio-clogging process. In this paper, a drip irrigation experiment using reclaimed water was carried out. Phospholipid fatty acids (PLFAs) in biofilm (bio-clogging substance) were taken as the biomarker of microbial community inside emitters, and the dynamic variation of microbial community in drip irrigation emitter and its effect on the clogging process were studied. The results showed that the microbial growth of biofilms inside 9 types of drip irrigation emitters could enhance emitter clogging, and the PLFAs showed S-shaped pattern with emitter clogging degrees (R 2 > 0.95, p < 0.01), which was closely associated with the variation of microbial community. There were 3–7 types of PLFAs commonly in biofilms within drip irrigation emitters, among which gram positive bacteria (i15:0, 16:0 and 18:0) were dominant in amounts, with the close contents of 24.4%–34.2%, 24.8%–37.2% and 24.2%–39.0%, respectively, and their total proportion exceeding 76.3%. The Pseudomonas (16:0) was found to be the most critical bacteria to affect emitter clogging as it performed better to decompose and utilize organic matters, and showed the best relation with clogging degrees, along with significant relations with other types of bacteria. Therefore, controlling gram positive bacteria, especially Pseudomonas was the most effective way to relieve emitter clogging. Their variation also changed the microbial community structure, and the diversity index ( H ), evenness index ( J ) and dominance index ( D ) of microbial community in biofilms varied within 1.08–1.53, 0.75–1.11 and 0.65–0.75. The diversity index and dominance index both decreased as the amounts and types of microorganisms increased. The total amount of the gram positive bacteria increased after their decrement, and resulted in the similar variation of the microbial community evenness index. The results of this study will establish a theoretical basis for exploring the effects of microbial community variation on emitter bio-clogging, and provide insight into the emitter clogging mechanisms and possible mitigation strategies. [ABSTRACT FROM AUTHOR]

• We examine whether water rights trading can encourage agricultural water conservation. • Water rights trading has a moderation effect on agricultural water conservation via technology improvement. • The moderation effect is driven by two forces: the "revenue-driven" effect and the "industrial water pressure-driven" effect. • There exists bottleneck on the moderated technology improvement due to the reduced water rights supply capacity. Although agricultural irrigation technology in China has been steadily improved for decades, the realized water conservation in the agricultural sector is not as good as expected. This paper examines whether water rights trading can encourage agricultural water conservation through technology improvement. Our fixed effects model specification confirms that water rights trading has a moderation effect on agricultural water conservation via technology improvement. We further identify that the moderation effect is driven by two forces which we label as the "revenue-driven" effect and "industrial water pressure-driven" effect. In general, the revenue effect drives farmers to improve the technology. However, the pressure from industrial water demand has more pronounced effects than the revenue-driven channel. Under the dual pressure of high industrial water consumption and low water endowment, farmers tend actively promote irrigation technology and reduce agricultural water use even if there is no revenue-driven effects. In addition, this paper reveals the existence of bottleneck on the moderated technology improvement, due to the reduced capacity on water rights supply in the agricultural sector. [ABSTRACT FROM AUTHOR]

Irrigated agriculture is the primary sector demanding water resources in the world. Given that, improved irrigation technologies could play a crucial role in enhancing water use efficiency. This paper uses causal inference estimators to evaluate the effect of these technologies on irrigators at the farm level in two irrigated valleys in Central Chile. Doubly robust estimators were employed to address the selection bias of the adoption of improved irrigation technologies. The results show first a low level of technology adoption, with only 18% of irrigators adopting irrigation, where access to credits and education plays a crucial role in their adoption. Despite this low rate, the estimates show consistently positive and significant impacts on adopters in terms of annual margins and land use. As a result, our research calls for attention towards focusing programs and policy targeting on reducing entry barriers and broadening the adoption of irrigation technologies, allowing to reduce the gap in terms of economic wellbeing and the long-term sustainability and adaptation to climate change of irrigated areas. • Assessment of impacts of efficient irrigation technologies (drip, sprinklers). • Most of the farmers (83%) still irrigate with traditional methods. • Significant impacts on economics and land-use outcomes for technology adopters. • Broadening adoption is needed aiming for economic wellbeing and long-term. sustainability [ABSTRACT FROM AUTHOR]

Increasing agricultural productivity through irrigation technologies is recognized as an effective way to improve smallholders' livelihoods and food security in developing countries. However, most smallholder farmers do not have access to irrigation technologies. Using a double-bounded contingent valuation survey data from smallholders in Ethiopia and probit and bivariate probit models, this paper analyzes smallholder farmers' demand for agricultural water lifting technologies (WLTs) and the factors affecting the demand for these technologies. Assessment of farmers' preferences among three water lifting technologies available in local markets (motorized pump, rope and washer and pulley) show that farmers prefer motorized pumps to pulley or rope and washer technologies. Use of motorized pumps is more efficient and save labour than pulley or rope and washer technologies. However, results show that smallholders are constrained by inadequate access to financing options to adopt more efficient and labour-saving water lifting technology and hence operate below the production possibility frontier. Enhanced access to finance could help ease this constraint and allow smallholders to acquire more efficient irrigation technologies, enhance adoption and improve productivity. With a growing population pressure and land fragmentation in rural Ethiopia, the livelihoods of smallholders depend mainly on the meagre land endowment they possess. Increasing the productivity of land using yield enhancing technologies, particularly multiple cropping per year via small-scale irrigation is key to improve their livelihoods. Targeted interventions are thus warranted to mitigate the key adoption constraints such as improving access to credit and technical know-how of smallholders. • We analyze smallholder farmers demand for irrigation water lifting technologies. • Supply and demand side credit-constraints are key determinants of adoption and demand for irrigation technologies. • Farmers prefer motorized water pumps to pulley and rope and wash technologies. • Farmers with smaller landholdings require targeted interventions for improving their access to irrigation technologies and land productivity. [ABSTRACT FROM AUTHOR]

Sloping farmland (SpF) is an important component of cultivated land resources. In the context of food security and sustainable agricultural development, comprehensive SpF utilization has drawn wide and increasing attentions. A systematic analysis on the research progress of comprehensive SpF utilization is critical for a better understanding of the sustainable agricultural cultivation, facilitating the macroeconomic decision-making. This paper conducted a quantitative analysis of literature related to comprehensive SpF utilization over the past few decades (1946–2019) by using scientometrics methods, with the objectives to: (1) identify the research hotspots and summarize the relevant research processes in different time periods; (2) reveal the temporal evolution of those hotspots. Our results showed: 1) research on SpF dramatically increased over the past few decades (1946–2019), which can be classified into four chronological periods (I, II, III, and IV); (2) research regarding land productivity improvement and hydrological and erosion processes on SpF were dominant in the period I; (3) the research hotspots were switched to land use changes and associated soil erosion response, ecological disturbance and restoration as the social demand was intensifying in the period II; (4) the research focus of period III was aiming at the governance and rational utilization of SpF and gradually transforming to a large regional scale; (5) the intercross and penetration between disciplines had been continuously enhanced in the period IV, and the application of high and new technologies had also promoted the diversification of research methods, with aims to achieve sustainable agricultural development. Although considerable progress had been achieved around the world, more theoretical and empirical studies are required to understand the comprehensive SpF utilization and their implications to better support sustainable agricultural development. • Comprehensive sloping farmland utilization was systematically reviewed. • Research focus has changed from land productivity to multi-disciplinary fields. • Methodology is developing to be on multiple scales involved in information technology. [ABSTRACT FROM AUTHOR]

• Adoption of irrigation technologies is affected directly by intention to do so. • Subjective norms, perceived control and attitudes are mediators explaining adoption. • Social pressure exerts a strong influence on farmers behavior. • Social capital triggers adoption by increasing social pressure and self-confidence. Water scarcity is becoming a major challenge worldwide. The agricultural sector, as a main user of freshwater, may significantly increase its water use efficiency by promoting water saving strategies. This paper proposes a socio-psychological model that builds upon the Theory of Planned Behavior and social capital variables to examine how psychological constructs and their interaction with the environment and farmers' backgrounds influence the switch from traditional to pressurized irrigation. Considering temporal precedence, we measured farmers' intention to adopt irrigation technologies, and one year later their actual behavior. We used a structural equation model and estimated marginal effects for direct and indirect relations. The results show that actual adoption is affected directly by intention, and the effect of subjective norms, perceived control, and attitudes on adoption are mediated through intention. Social pressure exerts a strong influence on farmers, particularly in comparison to their own attitudes. Social capital triggers the adoption of pressurized irrigation by increasing social pressure and strengthening farmers' perceived self-confidence. [ABSTRACT FROM AUTHOR]