Due to unavoidable, prolonged irrigation with marginal quality water, secondary salinization of irrigated soils in Pakistan has necessitated to a need for better understanding of the water management alternatives

Ensuring food security is accompanied by risks which can significantly weaken it. Water resources are distributed on the land area extremely unevenly; differ in the wide range of variability on security per capita, high temporary variability. It was revealed that in 2014 more than 2.5 billion people in 46 countries lived in conditions of a water stress and deficiency. Russia is one of the few countries with rather high level of specific water security, but has extremely uneven distribution of water resources to districts which don't correspond to population distribution. Low water availability in the Crimean federal district, Moscow and the Moscow region, the Belgorod and Kursk regions, Stavropol region is noted. In shallow years in these regions there can be very serious problems with water supply. The international experience convincingly proves that melioration promotes stabilization of agricultural production. In Russia the reclaimed lands occupy less than 5% of grounds and 8% of an arable land, but even they are used not always effectively. Water resources in the majority of regions of Russia don't limit development of agriculture. The approaching global water crisis creates very favourable conditions for the countries with water security as the increase in demand and prices of water capacious production is inevitable. Russia has competitive advantages in production of water capacious agricultural production and can become one of the leaders in the corresponding world markets. The most perspective export goods are grain and meat. The increase in the export potential of grain up to 150 mln t, the increase in production of the cattle and poultry (in live weight) – up to 15 mln t, are possible by 2020. | Обеспечение продовольственной безопасности сопряжено с рисками, которые могут существенно ее ослабить. Водные ресурсы распределены по территории суши крайне неравномерно, отличаются широким диапазоном изменчивости по обеспеченности в расчете на душу населения, высокой временной изменчивостью. Выявлено, что в 2014г. более 2,5 млрд. человек в 46 странах жили в условиях водного стресса и дефицита. Россия – одна из немногих стран с достаточно высоким уровнем удельной водообеспеченности, но имеет крайне неравномерное распределение водных ресурсов по округам, которое не соответствует распределению населения по численности. Отмечена низкая водообеспеченность в Крымском федеральном округе, г. Москва и Московской области, Белгородской и Курской областях, Ставропольском крае. В маловодные годы в данных регионах могут возникать весьма серьезные проблемы с водообеспечением. Мировой опыт убедительно доказывает, что мелиорация способствует стабилизации с.-х. производства. В России мелиорируемые земли занимают менее 5% угодий и 8% пашни, но даже они используются не всегда эффективно. Водные ресурсы в большинстве регионов России не ограничивают развитие сельского хозяйства. Надвигающийся глобальный водный кризис формирует исключительно благоприятные условия для водообеспеченных стран, поскольку неизбежен рост спроса и цен на водоемкую продукцию. Россия обладает конкурентными преимуществами в производстве водоемкой с.-х. продукции и может стать одним из лидеров соответствующих мировых рынков. Наиболее перспективные экспортные товары – зерно и мясо. К 2020 г. возможно увеличение экспортного потенциала зерна до 150 млн т, увеличение производства скота и птицы (в живом весе) – до 15 млн т.

Due to unavoidable, prolonged irrigation with marginal quality water, secondary salinization of irrigated soils in Pakistan has necessitated to a need for better understanding of the water management alternatives. Although H2SO4 and gypsum have far been recognized for their benefits in treating brackish water but during field trials, their relative performance still remains controversial for counteracting the Na-hazards in soil/water system. As alternative sulfur burners are also being marketed but up till now there is not even a single field study published in some journal about their efficiency and economical viability for the treatment of brackish water. Therefore a field study was carried out to compare the effectiveness of sulfurous acid generator (SAG) and other water/soil applied amendments on a normal, calcareous, well drained, sandy loam soil. Rice 2001, wheat 2001-02, and rice 2002 were planted in rotation during the experimentation period with a total of 54 treated and 8 untreated irrigations (each of 7.5 cm). Tube well water used had EC = 3.24 dS m-1, SAR=17.23 and RSC = 5.44 mmolc L-1. The treatments were: T0) Brackish tube well water without any amendment; T1) All irrigation with water passed through SAG; T2) Alternate irrigation-one of SAG treated and one of tube well water, T3) One irrigation with SAG treated water and two with untreated tube well water; T4) FYM @ 15 t ha-1yr-1; T5) Soil applied gypsum to each crop equivalent to affect a decrease in WRSC of tube well water treated with SAG, and T6) H2SO4- fertigation at each irrigation equivalent to affect a decrease in RSC of tube well water with SAG. Water analysis after treatment with SAG (an average of 20 irrigations) revealed that SAG treatment affected only one parameter i.e. water RSC from 5.44 to 3.55, and had no beneficial effect on SARiw and ECiw. After three crops, a minor decrease (up to 2.5%) and increase (up to 5.3%) in soil pHs over initial values was noted at 0-15 & 15-30 cm depth. After three crops the soil ECe and SAR were maintained below the threshold levels and the treatments had non-significant differences. On the basis of three crops, net benefit was maximum, from T4 followed by T5, T3, T0, T2, T6 and T1. The use of sulfur burner/ sulfuric acid was found to be 5 times costlier than gypsum in our study. It is concluded that soil application of gypsum and/or farmyard manure to counter the sodic hazards of irrigation water will be useful as well as economical for rice-wheat rotation on a normal, calcareous well drained soil. However, for fine textured soils with low infiltration rates, to expect similar situation might not be correct for which additional studies are imperative.