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An assessment is given of the hydrogeological potential of the Terek-Kuma sands of the Western Caspian region, the strata of which contain significant reserves of underground water (artesian, ground water) of the Caspian lowland, which are located near the feeding glaciers of the Greater Caucasus. In terms of their chemical composition, they are suitable for irrigating woody and herbaceous ameliorant crops, as evidenced by the long-term scientific and experimental experience of the Achikulak Research Forestry Experimental Station of the All-Union Scientific Research Institute of Agroforestry Reclamation (now the North Caucasus Branch of the Federal Scientific Center for Agroecology, Integrated Land Reclamation, and Protective Afforestation, Russian Academy of Sciences) on the sands of the Bazhigan massif, which provides a wide potential for the use of self-pressure (artesian) and free-flow (ground) underground water in oasis irrigation of sandy lands. Compared to the capital-intensive model of preliminary reservoir accumulation of self-flowing artesian waters for irrigating pastures, the project of using ground water for irrigating fodder phytocenoses directly from wells, by pulsed sprinkling using renewable energy sources (sun, wind energy), appears to be more profitable and faster to pay for itself. According to forecast estimates, the potential of the region's underground water is sufficient for hydromelioration of more than 100 000 ha of sandy lands in an arid territory. [ABSTRACT FROM AUTHOR]

Alfalfa is a forage species widely used in Uruguay in intensive livestock and dairy farming. Supplementary irrigation makes it possible to mitigate the negative effects of climate change, increasing and stabilizing the productivity of pastures. It is necessary to evaluate its joint effect with grazing. Two irrigation thresholds were evaluated, with entry of animals. The treatments were: frequent irrigation (30% depleted), spaced irrigation (65% depleted) and rainfed. The experimental design was complete randomized blocks, and 30 months of evaluation. The average annual yield of irrigated alfalfa was 25,333 and 23,177 kg DM ha-1, first and second year of evaluation, respectively. The accumulated production (30 months) did not show a significant difference between the irrigated treatments, but it did between irrigated and rainfed. In the last summer-autumn, the yield of all treatments fell to 8660 kg DM ha-1 (irrigated) and 1756 kg DM ha-1 (rainfed). Seasonal productivity indicates the convenience of irrigating alfalfa in summer since the yield increased 43% in the second year and 4.3 times more in the last year. Furthermore, after the extreme summer drought, in the following autumn, the irrigated treatments yielded 7 times more than the rainfed. Management with spaced irrigation and irrigation depth that do not return the soil to its field capacity increases the effectiveness of precipitation, saving water and energy allocated to irrigation. The apparent density increased towards the end of the experiment as a result of grazing, however, there was no difference between the evaluated irrigation managements.

ABSTRACT Iron mining tailings have limitations for plant growth and development due to low fertility, coupled with great restriction of physical characteristics such as low water retention, high density, and lack of structure. This study aimed to evaluate whether different irrigation depths applied to Xaraés grass grown in mining tailings influence its yield and bromatological aspects. The experiment was carried out in a completely randomized design with five irrigation depths (40, 60, 80, 100, and 120% of the crop evapotranspiration), two additional treatments consisting of grass grown in tailings with soil conditioner and in natural soil, and three repetitions. Forage dry mass, plant height, leaf: stem ratio, as well as neutral detergent fibre, acid detergent fibre, crude protein, and mineral matter content, were evaluated during four cutting cycles. Xaraés grass could establish and produce forage despite cultivation limitations in iron mining tailings, which are due to their properties. Irrigation depths showed positive and linear effects on Xaraés grass dry matter yield and heights of plants grown in iron mining tailings. The soil conditioner has potential for use in pasture cultivation in iron mining tailing.