Irrigation

https://srbpodcast.org/2021/02/05/watering-the-soviet-lands/

The desiccation of the Aral Sea is one of the greatest environmental catastrophes of the late twentieth century. But efforts to harness and divert the Aral’s freshwater are rooted in efforts to use technology to terraform the landscape in the modern era. Using water to irrigate a wasteland was a hallmark of modernity, progress, productivity, and prosperity. Water was also emblematic of the colonial infrastructure of Russia and the Soviet Union. Here’s Maya Peterson and Christopher Ward to discuss the role of water in the wider environmental history of the Soviet project.

https://www.byuradio.org/7f0f20e4-00c0-42ec-b4d9-f6ce1b96f7a4

Guest: Maya Peterson, Associate Professor of History at the University of California, Santa Cruz, and author of "Pipe Dreams: Water and Empire in Central Asia’s Aral Sea Basin"

The Aral Sea was once the fourth-largest lake in the world. Now, most of it has receded into desert. In the Soviet Era, its tributaries were diverted for irrigation to produce more cotton, but the Sea was threatened at least a century before that. Here are lessons for arid lands around the world, including the American West.

ABSTRACT The coastal plain bordering the southern Venice Lagoon is a reclaimed lowland characterized by high subsidence rate, and ground level and water-table depth below sea level. In this agricultural region, where the surface hydrologic network is entirely artificially controlled by irrigation/drainage canals, salinization problems have long been encountered in soils and groundwaters. Here we use isotopic and geochemical tracers to improve our understanding of the origin of salinization and mineralization of the semi-confined aquifer (0–40 m), and the freshwater inputs to this hydrological system. Water samples have been collected at different seasons in the coastal Adriatic Sea, lagoon, rivers and irrigation canals, as well as in the semi-confined aquifer at depths between 12 and 35 m (14 boreholes), and in the first confined aquifer (three boreholes drilled between 40 and 80 m depth). Stable isotopes (δ18O and δD) and conductivity profiles show that direct saline intrusion from the sea or the lagoon is observed only in a restricted coastal strip, while brackish groundwaters are found over the entire topographic and piezometric depression in the centre of the study area. Fresh groundwaters are found only in the most western zone. The sharp isotopic contrast between the western and central regions suggests disconnected hydrological circulations between these two parts of the shallow aquifer. The border between these two regions also corresponds to the limits of the most strongly subsiding zone.Our results can be interpreted in terms of a four end-member mixing scheme, involving (1) marine water from the lagoon or the open sea, (2) alpine and pre-alpine regional recharge waters carried either by the main rivers Adige, Bacchiglione and Brenta (irrigation waters) or by the regional groundwater circulation, (3) local precipitation, and (4) evaporated waters infiltrated from the surface. Infiltration from the surface is also revealed by the stratification of the electrical conductivity profiles, showing that the brackish groundwaters are overlain by a shallow layer of less saline water all over the central depression. In the first confined aquifer, the groundwaters have isotopic compositions similar to the deep groundwaters of the Venetian confined aquifers (40–400 m depth). The isotopic data and the Br/Cl ratio show that the origin of the salinization of the phreatic aquifer can be ascribed to seawater intrusion alone, with no indication of the involvement of deep brines (identified at 450 m depth) in the process.The chemical composition of the saline and brackish groundwaters is characterized by an excess of sodium and a deficit of calcium compared to conservative mixing between fresh groundwaters and seawater. This suggests that the phreatic aquifer is progressively freshening, as a consequence of the beneficial influence of the extensive irrigation/drainage network, including raised canals acting as a hydraulic barrier along the coast. This freshening tendency may have been lasting since the reclamation in the mid-twentieth century, and has probably been accelerated by the ban on groundwater abstraction since the 1970s.

The development of smallholder irrigation is a policy priority in Ethiopia, yet little consideration has been given to the role state interventions play in enabling or constraining effective self-governance in farmer-managed schemes. To address this gap in evidence, research was conducted in Tigray, northern Ethiopia, in two irrigation sites. Focus group discussions and semi-structured interviews with key informants were the primary means of collecting data on local institutional arrangements, government interventions and management challenges. An opinion poll provided additional insights. Our case studies indicate that effective self-governance cannot easily be crafted by external actors. The introduction of modern irrigation technologies and formalized management arrangements has fostered dependency on external support and increased state influence in key decision-making processes, whilst traditional water user associations remain largely autonomous but have little access to financial resources. State interventions have also been poorly tailored to local context with negative consequences for performance, although there have been some successes where traditional arrangements for water management have been integrated into new institutions. The incorporation of farmer perspectives into performance assessments could facilitate more responsive interventions, and remains an important area of irrigation research and practice. Copyright © 2017 John Wiley \& Sons, Ltd.

Good health is essential for good performance and the welfare of dairy cows, and nutrition is an important component of good health. Health is influenced by the interaction between the innate adaptive components of the immune system and other factors, such as the local and systemic inflammatory response, which can sometimes be more harmful than useful. Therefore, for dairy cows, particularly those in the periparturient period, it is important to avoid, or reduce as much as possible, any kind of infectious, parasitic or metabolic disease and the associated inflammation. Such inflammation can impair cow performance by lowering milk yield, dry matter intake, fertility and energy efficiency, and can reduce liver function. Good nutrition is essential in maintaining a functional immune system, while also avoiding other causes of inflammation, such as tissue damage, and digestive and metabolic syndrome-related disorders. Provision of appropriate nutrients, such as antioxidants, omega-3 pol...

The accuracy of diagnosis of subacute rumen acidosis (SARA) with a single measurement of the ruminal pH remains contradictory. To clarify this aspect, a large assessment of rumen, faecal and blood parameters was performed in several herds characterised by diets rich in non-structural carbohydrates. Rumen fluid was collected by rumenocentesis 6 h after feeding from 114 dairy cows (half 30–90 and half 150–250 days in milk) from 10 herds. In the same day, blood and faecal samples were collected and milk yield was recorded. The herds were ex-post classified as healthy (CTR n = 6) or as at risk for SARA (n = 4), based on ruminal pH. SARA versus CTR herds had lower rumen pH (5.67 vs 5.97 P < 0.01) and higher concentration of VFA, with lower acetate (P < 0.01) and higher propionate and valerate (P < 0.05) proportions. Moreover, the faecal DM was lower (P < 0.05), whereas the milk yield was higher with a lower concentration of fat (P < 0.05). At blood level, no significant di...

ABSTRACT Exploitation of energy crops irrigated with non-conventional water resources on a large scale could decrease negative impacts from fossil fuel use, at the same time saving potable supplies and reducing disposal of polluting effluents in surface water, particularly in environments with water scarcity as Mediterranean basin.To this end, three energy crops (Typha latifolia, Arundo donax and Phragmites australis) were planted in experimental plots and irrigated over a 2-year period with the effluents of an urban wastewater depuration plant. Biomass and energy yields of the crops were evaluated; the effects on the main physical and chemical properties of soils (e.g. pH, EC, SOC, N, P) and leachate (pH, EC, COD) resulting from irrigation with wastewater were compared to those of irrigation with conventional water.In general, treatment with wastewater increased the biomass yield: this may be ascribed to the fertilising value of the wastewater. Irrigation with wastewater did not result in either notable changes of the soil's physical and chemical properties, or risks of soil structure decay, when compared to irrigation with conventional water. Only a slight and insignificant reduction of the soil's hydraulic saturated conductivity was measured.Percolation of contaminants (such as organic compounds and salts) into groundwater reserves was limited, as shown by the analysis of the leachate accumulated in lysimeters after irrigation with wastewater.Heating values measured by calorimetric tests were higher for T. latifolia in comparison to the other experimental species; nevertheless, the higher biomass productivity of A. donax makes the energy yield per unit of cultivated surface much higher than those of T. latifolia and P. australis.Even though the results achieved require further verification by mid- or long-term research, the present investigation shows that herbaceous crops irrigated with wastewater can produce appreciable biomass and energy yields. This is also an environmentally and economically sound way of wastewater disposal.