Non-irrigated Land Research Articles

Assessing the Convective Environment over Irrigated and Nonirrigated Land Use with Land–Atmosphere Coupling Metrics: Results from GRAINEX

Abstract Land-use land-cover change affects weather and climate. This paper quantifies land–atmosphere interactions over irrigated and nonirrigated land uses during the Great Plains Irrigation Experiment (GRAINEX). Three coupling metrics were used to quantify land–atmosphere interactions as they relate to convection. They include the convective triggering potential (CTP), the low-level humidity index (HIlow), and the lifting condensation level (LCL) deficit. These metrics were calculated from the rawinsonde data obtained from the Integrated Sounding Systems (ISSs) for Rogers Farm and York Airport along with soundings launched from the three Doppler on Wheels (DOW) sites. Each metric was categorized by intensive observation period (IOP), cloud cover, and time of day. Results show that with higher CTP, lower HIlow, and lower LCL deficit, conditions were more favorable for convective development over irrigated land use. When metrics were grouped and analyzed by IOP, compared to nonirrigated land use, HIlow was found to be lower for irrigated land use, suggesting favorable conditions for convective development. Furthermore, when metrics were grouped and analyzed by clear and nonclear days, CTP values were higher over irrigated cropland than nonirrigated land use. In addition, compared to nonirrigated land use, the LCL deficit during the peak growing season was lower over irrigated land use, suggesting a favorable condition for convection. It is found that with the transition from the early summer to the mid/peak summer and increased irrigation, the environment became more favorable for convective development over irrigated land use. Finally, it was found that regardless of background atmospheric conditions, irrigated land use provided a favorable environment for convective development.

A Multicriteria Decision Analysis Model for Optimal Land Uses: Guiding Farmers under the New European Union’s Common Agricultural Policy (2023–2027)

Focusing on sustainability, the new Common Agricultural Policy (2023–2027) sets ambitious goals for water management, as reducing irrigation water use is a vital issue. Cooperation among farmers, relevant authorities, and researchers plays a significant role in achieving these objectives. Therefore, this study applies a multicriteria mathematical programming model to optimize land use, considering water use, profit, labor, and cost. The model was applied to three farmer groups located in Greece and proved to be valuable in the implementation of irrigation water use. Using the same methodology, two additional cases of farmer groups that utilize drylands are presented in complementary ways to investigate how the new CAP affects non-irrigated land uses. Regarding the irrigated case, reducing water usage involves decreasing the land dedicated to crops characterized by high water demand, such as rice, corn, vetch, and clover. This adjustment stems from the necessity to replace irrigated land with non-irrigated land because climate change demands low water consumption for crops and underscores the importance of the new policy framework to promote sustainable agriculture. As for the non-irrigated case, achieving optimal farm planning entails reducing the cultivated areas of vetch, grassland, and sunflower. This result is driven by the need to increase crops receiving primary subsidies, highlighting the necessity for non-irrigated farms to enhance their profitability through the benefits provided by the Common Agricultural Policy. Lastly, it is important to note that this study significantly contributes to guiding decision-makers in achieving alternative agricultural land uses and farm plans while also aiding in the comprehension of the new cross-compliance rules.

Irrigated Agriculture Significantly Modifies Seasonal Boundary Layer Atmosphere and Lower-Tropospheric Convective Environment

Abstract Modification of grasslands into irrigated and nonirrigated agriculture in the Great Plains resulted in significant impacts on weather and climate. However, there has been lack of observational data–based studies solely focused on impacts of irrigation on the PBL and convective conditions. The Great Plains Irrigation Experiment (GRAINEX), conducted during the 2018 growing season, collected data over irrigated and nonirrigated land uses over Nebraska to understand these impacts. Specifically, the objective was to determine whether the impacts of irrigation are sustained throughout the growing season. The data analyzed include latent and sensible heat flux, air temperature, dewpoint temperature, equivalent temperature (moist enthalpy), PBL height, lifting condensation level (LCL), level of free convection (LFC), and PBL mixing ratio. Results show increased partitioning of energy into latent heat relative to sensible heat over irrigated areas while average maximum air temperature was decreased and dewpoint temperature was increased from the early to peak growing season. Radiosonde data suggest reduced planetary boundary layer (PBL) heights at all launch sites from the early to peak growing season. However, reduction of PBL height was much greater over irrigated areas than over nonirrigated croplands. Relative to the early growing period, LCL and LFC heights were also lower during the peak growing period over irrigated areas. Results note, for the first time, that the impacts of irrigation on PBL evolution and convective environment can be sustained throughout the growing season and regardless of background atmospheric conditions. These are important findings and applicable to other irrigated areas in the world. Significance Statement To meet the ever-increasing demand for food, many regions of the world have adopted widespread irrigation. The High Plains Aquifer (HPA) region, located within the Great Plains of the United States, is one of the most extensively irrigated regions. In this study, for the first time, we have conducted a detailed irrigation-focused land surface and atmospheric data collection campaign to determine irrigation impacts on the atmosphere. This research demonstrates that irrigation significantly alters lower atmospheric characteristics and creates favorable cloud and convection development conditions during the growing season. The results clearly show first-order impacts of irrigation on regional weather and climate and hence warrant further attention so that we can minimize negative impacts and achieve sustainable irrigation.

Impacts of irrigation on a precipitation event during GRAINEX in the High Plains Aquifer Region

Land use land cover change, including irrigation, impacts weather and climate. In this paper a precipitation event that occurred on the morning of 23 July 2018 during the Great Plains Irrigation Experiment (GRAINEX) is investigated. Six Weather and Research Forecasting (WRF) model-based experiments were conducted, which involved the increase or decrease of soil moisture by 5 % and up to 15 % over the irrigated croplands. These changes approximated soil moisture content in response to different levels of irrigation applications. An additional experiment, where irrigated land use was changed to grassland, was conducted to capture pre-irrigation land use and its impacts. It was found that regardless of strength of irrigation, precipitation decreased. In addition, the model did not produce precipitation over non-irrigated land use. When grassland replaced irrigated agriculture, increases in precipitation were estimated. With increased irrigation, latent heat flux increased compared to the control simulation and decreased when irrigation decreased. On the other hand, sensible heat flux was decreased compared to control when irrigation increased. The planetary boundary layer over irrigated land use was shallower than over non-irrigated land use while over grassland it was higher than irrigated but lower than non-irrigated land use. The changes in precipitation, the surface energy balance, and the planetary boundary layer served as a reminder of irrigation's complex effects on the atmosphere. Additional analysis of other precipitation events during GRAINEX would be helpful to better understand the effects of irrigation.

Shrew Communities in Mediterranean Agro-Ecosystems of Central Greece: Associations with Crop Types, Land Uses, and Soil Parameters.

Shrew communities play a crucial role in a diverse range of natural, urban, and agricultural ecosystems. We used Barn owl diet analysis as the ideal proxy to assess small-mammal distribution patterns on large spatial scales. More than 10,000 pellets were analyzed from Thessaly, the largest agricultural prefecture located in central Greece. A total of more than 29,000 prey items were identified, one of the largest datasets used in similar analyses in Europe. Three discrete shrew species were present in Thessaly agricultural plains, central Greece (Güldenstädt's shrew Crocidura gueldenstaedtii, Bi-coloured shrew Crocidura leucodon, and Pygmy white-toothed shrew Suncus etruscus), which comprised a total of 7452 shrews, representing 25.64% of the total small-mammals' dataset. C. gueldenstaedtii and S. etruscus demonstrated strong associations with heavy argillaceous-clay soils and Vertisol soil types, whereas S. etruscus was also associated with non-irrigated land and non-intensive cultivated plots. C. leucodon demonstrated no significant associations to any environmental gradient and demonstrated habitat plasticity, most possibly shaped by existing resources and competition. Our study highlights the important insights gained from Barn owl diet analysis in respect of small-mammal assemblages on broad geographical scales, and the inclusion of soil parameters as drivers of habitat suitability and distribution patterns for small-mammal responses.

The management of microbiological regime of the irrigated light chestnut soils in the Nizhnee Povolzhye under drip irrigation

There is a certain relation between soil fertility and its microorganism content. The article considers the microbiological characteristics of irrigated light chestnut soils in the Nizhnee Povolzhye on various media. The soil samples were taken in the plow horizon (0-20 cm) in five replications for each experimental variant. To determine and account for the microorganism groups in the studied soil, the following nutrient media were used: MPA (meat-and-peptone agar), Wort – Agar and Czapek’s, Waksman’s. The studies also included the determination of the nutrient content in the soil in order to adjust the fertilizer application system for drip irrigation, since the soil arable layer on the experimental plot was poorly provided with easily hydrolyzed nitrogen and exchangeable potassium, and in medium way with mobile phosphorus. On the irrigated area one selected the plots with onion and cucumber crops with different mineral nutrition and the levels of maintaining pre-irrigation soil moisture, as well as a variant with a virgin (nonirrigated) plot. The development features of microbial communities on irrigated and non-irrigated lands were revealed. In the arable layer of the irrigated light chestnut soil of the Volgograd region, a fungus of the genus Fusarium, bacteria Bacillus subtilis, bacteria of the genus Erwinia were found, which can make it difficult to grow and store agricultural products. The options for maintaining pre-irrigation soil moisture during drip irrigation of vegetable crops did not have any significant effect on the quantitative and qualitative composition of microorganisms. The studied soil, according to agro-chemical analysis, is fertile and can be used for crop growing. Crop cultivation on non-irrigated areas should be carried out with the application of appropriate fertilizers.

A monthly distributed water and salt balance model in irrigated and non-irrigated lands of arid irrigation district with shallow groundwater table

Water scarcity and soil salinization are two major problems threatening the sustainability of irrigation districts in arid regions with shallow groundwater table. To study water and salt balances in arid irrigation districts, we developed a monthly distributed water and salt balance model for arid irrigation district (DAHMID-S) with shallow groundwater table by integrating models of major hydrological processes and the associated salt transport processes, including irrigation, evapotranspiration, soil water and groundwater and salt balances, drainage of water and salt through ditches, and interior drainage of water and associated dry drainage of salt between irrigated and non-irrigated lands. The model was successfully applied to the Hetao Irrigation District (HID), the largest irrigation district in the arid region of China. Results indicate that evapotranspiration is the dominant water consumption component in the HID and accounts for about 95% of the total irrigation and precipitation, while drainage through ditches accounts for 10.5% of the total irrigation. Only 49.4% of the introduced salt is discharged from the HID through drainage ditches. Consequently, most parts of the HID are in the state of salt accumulation except the northern Wulate sub-irrigation district, and the problem of salt accumulation is more serious in the western and southern HID under more favorable conditions of water use. Dry drainage plays a crucial role in salt balance of both irrigated and non-irrigated lands, which results in desalinization in most irrigated lands while salt accumulation in non-irrigated lands. Appropriate measures should be taken to solve water and salt-related problems to improve the sustainability of the HID. In the western HID, irrigation water diversion should be decreased, and the drainage system should be further improved to decrease the salt accumulation to a lower level. Meanwhile, the irrigation water diversion can be increased in the southeastern HID by planting more corn and wheat. Besides, irrigation management should be improved to reduce the surface water return flow to increase the groundwater drainage capacity, especially in the southwestern HID.

Rising temperature threatens China’s cropland

The rising demand for calories and protein together with urbanization, pose significant challenges to China’s food security. The determination of policy actions requires accurate estimates of climatic impacts on both crop yields (intensive margin) and cropland area (extensive margin). However, the analysis of the latter has been limited, especially in developing countries. Here, we assess the impact of temperature on land use in China by matching high-resolution satellite data on land use with daily weather data from 1980 to 2010. We find that extremely hot weather (daily average temperature above 30 °C) has a long-lasting effect on reducing cropland in China. Combining climate projections from 39 downscaled climate models, we predict that climate change is likely to reduce China’s cropland area by 2.09%–25.51% under IPCC’s slowest and fastest-warming scenarios by the end of this century. In addition, we find that non-irrigated land is more susceptible to rising temperatures in the short term; however, irrigated land is subject to a similar impact in the long term. This result suggests that the adaptive effect of irrigation could be limited under persistent rising in temperature.

The main occupations of new farms in the Pishpek district of the Semirechensk region at the beginning of the 20th century

The relevance of the study is due to the fact that this problem remains insufficiently studied in historiography.The purpose of the article is to reveal the economic development of the new villages of the Pishpek district of the Semirechensk region in the n. XX century based on the analysis of statistical and archival materials.The methodological basis for writing the article was the principles of historicism and objectivity using specific historical methods, including statistical analysis. The materials of resettlement statistics collected in the Pishpek district by a commission led by P.P. Rumyantsev, as well as the works of pre-revolutionary authors, were analyzed. The socio-economic structure of new farms in the Pishpek district is considered in detail, it is concluded that the farms that the Russian settlers were engaged in grain farming. The composition of crops on irrigated and non-irrigated lands was almost the same, the areas of crops sown on them were not the same. Cultivated crops were varied: rye, wheat, barley, millet, oats, sunflower, flax, hemp, potatoes, melons, alfalfa were sown. There was no proper crop rotation (winter – spring – fallow). Settlers were engaged in meat and dairy cattle breeding, horticulture, gardening. The economy was natural. The peasants were also engaged in crafts, they were handicraftsmen and small retailers, agricultural workers and farm laborers. Social stratification in new villages was just beginning. Key words: Semirechensk region, migrant peasants, new village farms, agriculture, cattle breeding, horticulture, beekeeping, crafts.

A monthly distributed agro-hydrological model for irrigation district in arid region with shallow groundwater table

Agro-hydrological processes in arid irrigation districts mainly include precipitation, water diversion, irrigation, drainage, evapotranspiration (ET), and soil water and groundwater flow, which interact with each other and are controlled by complex natural and anthropogenic drivers. To better understand the agro-hydrological processes in arid irrigation districts with shallow groundwater table, we developed a novel monthly distributed agro-hydrological model for irrigation districts (DAHMID) based on the concepts of canal command area (CCA) and sub-drainage command area (SDCA). The DAHMID model is driven by meteorology, irrigation, and evapotranspiration (ET) estimated by remote sensing-based ET model, and considers soil water and groundwater balances in both irrigated and non-irrigated lands and interior drainage between them. The model was applied to Hetao Irrigation District (HID), the largest irrigation district in arid region of China with a total irrigated area of 0.68 million ha. The DAHMID model was calibrated with groundwater table depth measurements in 13 CCAs of HID from 2008 to 2010, and validated from 2012 to 2013. Results depicted that the root mean square errors (RMSEs), normalized RMSEs (NRMSEs), Nash-Sutcliffe efficiency coefficients (NSEs), and coefficients of determination (r2) of groundwater table depth in both irrigated and non-irrigated lands for all CCAs were in the ranges of 0.19–0.34 m, 0.10–0.25, 0.30–0.82, and 0.68–0.91, respectively. The simulation results from 2008 to 2014 indicated that interior drainage from irrigated land to non-irrigated land is an important approach of drainage in HID, which is about 14.3% of total irrigation water diversion and 34.9% more than the drainage through ditches. The interior drainage process is basically similar to irrigation and ditch drainage processes, all reaching their peaks in May and October. ET is the major water consumption in HID, which is about 95% of total irrigation water diversion and precipitation in average. The net capillary rise of irrigated land is significantly less than that of non-irrigated land due to the impact of irrigation infiltration. The DAHMID model has less parameters and requires less inputs, and can be better applied to continuous simulation of agro-hydrological processes in irrigation districts in medium and long periods with satisfactory simulation accuracy.

Ecological-Mathematical Modeling in Planning Production of Agricultural Products in Conditions of Risks

The article proposes an ecological-mathematical model to optimize the production of agricultural products, taking into account the risks associated with climatic events. The model describes a combination of crop and livestock production on irrigated and non-irrigated agricultural land. In this model, the target function characterizes the maximum income and damage to the environment as a result of farming in conditions of natural risks. Restrictions describe the availability of land and labor resources, production volumes, soil and water pollution, erosion of agricultural land, the combination of crop and livestock products in conditions of severe droughts or heavy rainfall. When implementing the model, a special case was considered: an ecological-mathematical model for non-irrigated lands, taking into account severe drought. The proposed model is implemented on the example of an agricultural enterprise in the Irkutsk region, which is subject to significant risks caused by extreme climatic events, primarily drought.

A Quantitative Review of Irrigation Development in the Yazoo–Mississippi Delta from 1991 to 2020

The Yazoo–Mississippi Delta is one of the regions within the Lower Mississippi River Basin where substantial irrigation development and consequent groundwater depletion have occurred over the past three decades. To describe this irrigation development, a study was conducted to analyze existing geospatial datasets and to synthesize the results with those of past government surveys. The effort produced a quantitative review characterizing three aspects of irrigation development from 1991 to 2020. First, the expansion of irrigated area was tracked in terms of absolute area and in terms of fraction relative to total land or cropland area. Second, trends in irrigated land cover were traced in terms of irrigated crop mix, irrigated fractions of main crops, and comparisons with non-irrigated land. Third, changes in irrigation systems were examined in terms of water sources, energy sources, and application methods. Original findings of this study for the end of 2020 included moderate positive spatial autocorrelation in the density of irrigated areas; a higher irrigated crop preference for soybean and rice over cotton and corn in highly hydric soils; and 91% and 3% of permitted areas studied being respectively under groundwater withdrawal permits exclusively and under surface water diversion permits exclusively. By compiling such information, this paper can serve as a convenient reference on the recent history and status of irrigation development in the Yazoo–Mississippi Delta.

Обробіток ґрунту та густота стояння рослин як заходи адаптування до змін клімату

Abstract. The article presents the results of research of the South-Ukrainian branch of UkrNDIPVT L. Pogoriloho on the adaptation of winter wheat cultivation technologies in grain and steam crop rotations to increase the aridity of the climate by optimizing the density of standing plants, methods and depth of basic tillage. The purpose of research is to adjust the seeding rate by changing the width of the rows when growing winter wheat, as an agro-technological measure of accumulation and rational use of soil moisture (agro-technological direction of adaptation to climate change). Determining the influence of sowing rate, with different methods of tillage, on the productivity and economic efficiency of growing winter wheat in crop rotations on non-irrigated lands of southern Ukraine. Methods and Materials: field, quantitative-weight, visual and laboratory methods. Mathematical and statistical methods were used to systematize and generalize the obtained results. Research results. It has been experimentally established that the replacement of plowing to a depth of 28-30 cm for winter wheat crops with shallow (10-12 cm) disc tillage and reduction of the sowing rate of winter wheat variety «Kherson-99» to 2.25 million pieces similar seeds per hectare, by increasing the width between rows, provided an increase in grain yield by 16.7 % in 2020 and 7.7% in 2021. The profit per 1 hectare with this technology amounted to UAH 13280,5 in 2020 and UAH 28484,9 in 2021, which is 18.4 % and 9.3 % more than similar indicators in deep plowing and 31.3 % and 8.9 % more than the classic sowing rate (4.5 million units/ha). Conclusions. The efficiency of replacing deep plowing with shallow disc loosening and reducing the sowing rate to 2.25 million units/ha in the cultivation of winter wheat Kherson-99 in grain and steam crop rotation of the South of Ukraine was confirmed. A regularity in the size of the effect of reducing the seeding rate under drier conditions of the growing season was revealed.

Ефективність використання органічних добрив як засобу адаптації до змін клімату

Abstract. The article presents the results of research on the use of liquid organic fertilizer in the cultivation of winter wheat in compliance with the requirements of organic farming in the grain-steam crop rotation of the experimental field of the South-Ukrainian branch of L. Pogorilyy UkrNDIPVT in 2020-2021. The purpose of research is to analyze the effectiveness of organic fertilizers as a strategic priority for the development of low-carbon agricultural land use (agrochemical direction of adaptation to climate change). Determining the impact of liquid organic fertilizer "Riverm" on the quality of the soil and its ability to retain moisture, as well as to increase the productivity of winter wheat in crop rotations on non-irrigated lands of southern Ukraine. Research methods: field quantitative-weight, visual and laboratory methods. Mathematical and statistical methods used to systematize and generalize the obtained results. Research results. It has been experimentally established that the use of new generation organic fertilizers suspends the reduction of humus content and contributes to the achievement of its deficit-free balance. In particular, during the study period there was a significant increase in the content of organic matter (labile humus) in the soil by 6.01 %, which in two years rose to the level of average values (2.10 %), against a low level of security (1.98 %) to use of “Riverm” fertilizer. Conclusions. The effectiveness of liquid organic fertilizer "Riverm" in the cultivation of winter wheat Khersonskaya-99 in the southern steppe of Ukraine, which improves nutrition and significantly increases the content of mineral nutrients (NPK), and as a result helps to increase the yield of winter wheat on average at 14 %.

ОЦЕНКА ДИНАМИКИ ОСНОВНЫХ АГРОХИМИЧЕСКИХ ПОКАЗАТЕЛЕЙ КАШТАНОВЫХ ПОЧВ НА ОРОШЕНИИ В УСЛОВИЯХ РИСКОВАННОГО ЗЕМЛЕДЕЛИЯ СТАВРОПОЛЬЯ

Irrigation is an important element of agricultural production in the arid conditions of the Stavropol Territory. The combination of irrigation, chemicalization and complex mechanization provides highly productive use of land that requires specific scientific support. The purpose of the research is to identify differences in the dynamics of the main agrochemical indicators (organic matter, pH, mobile phosphorus, mobile potassium) on irrigated and non-irrigated chestnut soils. The object of research is chestnut soils located in an extremely arid climatic zone of the Stavropol Territory. The data of complex monitoring of soil fertility in the Apanasenkovsky district were used as the source material. The data for the period from 1991 to 2020 were prepared by the staff of the State Center for Agrochemical Service “Stavropolsky”. The content of soil organic matter was determined by the Tyurin method in the modification of CINAO. Mobile compounds of phosphorus and potassium were determined by the Machigin method in the modification of CINAO. The value of the hydrogen pH index of the aqueous suspension was determined by the potentiometric method. The content of organic matter in chestnut soils increased from 1.8 to 2.0–2.1% both on irrigated and non-irrigated lands. A tendency to leaching of irrigated lands by 0.2 units has been revealed; therefore, in this case, it is recommended to use chemical ameliorants. Moreover, on irrigation, an increase in the content of mobile phosphorus (from 0.8 to 4.0 mg/kg) compared to non-irrigated areas was revealed. The reason for this is the increased doses of phosphorus-containing fertilizers applied during irrigation. During the study period, the content of mobile potassium increased from 77 to 93 mg/kg irrigated chestnut soils compared to non-irrigated ones. The negative dynamics in the content of mobile potassium on irrigation was revealed. It amounted to 364 mg/kg (as of 2020), which is lower than the data of the previous survey period by 81 mk/kg. Particular attention should be paid to the use of potash fertilizers since there is increased removal of this element, despite the high potash potential of chestnut soils in the arid zone of the Stavropol Territory.

Smart Farming using AI and IoT

To survive in this world the occupation of farming plays an important role as it provides maximum needs for human beings to live in this world. But in the advancement of the technologies with the invention of the Internet of Things, Automation (Smarter technologies) is replacing the traditional methodologies which in cause resulting in wide range improvement of the Fields. Now we are in the state of automation where the upgradation of smarter technologies is improving day by day in maximum sectors starting from smart homes, waste management, vehicles, industries, Farming, health, grids, and so on. In the field of Farming, the improvement with the implementation of Automation is also taking place with the invention of the Internet of Things, Artificial Intelligence, Machine Learning, etc. Applications related to precision agriculture and technologies related to farm management and robotic automation etc. will benefit the environment a lot and will increase the overall efficiency. This system measures a number of different physical parameters to help in decision making like type of soil, irrigated, or non-irrigated land using IoT with the help of sensors. The data collected from the sensors will be monitored and further, the farmers will be able to know which crop is in demand, the availability of fertilizers and insecticides for that crop, climatic conditions using AI. Further, using IoT our system will provide automated maintenance of humidity/water level and automated maintenance of the fertility of the soil.

The conservation activities and land use changes in the upstream Bedadung watershed

Bedadung watershed is one of the largest watersheds in Jember Regency. The Bedadung watershed in upstream area is generally hilly with steep slopes, so it is prone to landslides and potential to erosion. The upstream area is a protected forest that functions as a water catchment area, turning into plantation and production forest to become the target of logging and deforestation. Conservation activities in the upstream watershed area is essential in the management of water resources. Natural resource management activities in the upstream area significantly affect the success of efforts to provide water and control water resources downstream damage. This study aimed to identify conservation activities in the upstream Bedadung watershed and the impact of changes in upstream land use on environmental damage. The conservation activities in the Jompo, Antrokan, Rempangan, and Rembangan Sub-watersheds is coffe plantation, cover crop, forestry, terrace, restoration, bush, grassland. The highest increase in land change in the four sub-watersged was irrigated land / field, while the decrease was non-irrigated land. The results of comparisons between the 2001 RBI map with the 2015 Landsat Image show an 8% forest loss and 7% increase in irrigated fields.

ОЦЕНКА АГРОКЛИМАТИЧЕСКИХ РЕСУРСОВ И ЕСТЕСТВЕННОЙ ВЛАГООБЕСПЕЧЕННОСТИ ТЕРРИТОРИИ БАССЕЙНА САНЫ

The aim of the study is to study the possibility of obtaining agricultural products from non-irrigated lands in arid climatic conditions of mountain areas, depending on the natural moisture supply. The possibility of assessing the natural moisture supply on the basis of average long-term precipitation, conditional indicators of annual natural atmospheric moisture and the water balance equation is considered. However, with current hydrological knowledge of the Sanaa basin area in the absence of the necessary data for calculating the water balance of the productive soils, there is proposed the a methodology for assessment of components of water balance and calculation of natural moisture provision of arable landson the level of «black box» with an accuracy sufficient for assessment of land productivity under natural moistening and a possibility of intensification of dry farming.

Impact of meteorological drought on vegetation in non-irrigated lands

Drought is a natural phenomenon that causes a lot of damages annually in various sectors, including agriculture and natural resources. The aim of this study is to evaluate the influence of meteorological drought index on vegetation index. For this purpose, the standard precipitation index (SPI) as a meteorological drought index is calculated using the precipitation data of 28 meteorological stations located on the area of Lorestane province, Iran, during the years 1987–2017. Then, the vegetation condition index (VCI) is computed using normalized difference vegetation index (NDVI) images that obtained from MODIS images of Terra satellite during 2000–2017. Dry, normal, and wet years were obtained based on the SPI results for 2008, 2013, and 2016, respectively. SPI and VCI were correlated using Pearson's correlation method. The results of the relationship between VCI and SPI showed that the highest Pearson correlation coefficient related to 9-month SPI in November was equal to 0.64. Multivariate linear regression was also performed between SPI and VCI, and the results showed that SPI was significantly correlated with VCI at 5% level over a period of 9 and 12 months. Finally, a confusion matrix was used to evaluate the compliance of the SPI and VCI drought classes. Results showed that the VCI had the highest compliance in the moderate drought class with SPI.

Hemijska svojstva dugotrajno zalivanih livadskih zemljišta doline Belog Drima u području Kline

The impact of long-term (> 100 yr) irrigation on soil chemical properties was studied on eight plots in the Beli Drim river valley in Kosovo and Metohija near Klina, Serbia. For these studies, soil samples from shallow profiles were collected from only one or two depth zones of the Ah horizon; and from moderately deep and deep profiles, from two to three depth zones for the purpose of comparing irrigated field and non-irrigated meadow lands. Water from the Beli Drim River and surface gravity systems (irrigation furrows or border strip irrigation) were used for irrigation. Chemical variables included determination of pH-H2O, content of CaCO3, content of humus, hydrolytic acidity, sum of basic cations, cation exchange capacity, and base saturation. On irrigated soils, the results of chemical analysis showed on average a small increase in pH-H2O (0.07 pH units), as well as a significant decrease in humus content (2.00-4.75%), sum of basic cations (4.98-12.98%) and cation exchange capacity (12.8%) compared to the non-irrigated land of the study area. Long-term irrigation had no effect on hydrolytic acidity and base saturation in the Ah horizon of the investigated lands. Namely, the mentioned variations in the chemical properties of the investigated soils show that slight processes of reduction in the humus content and reduction of the content of base cations occured. Data on the chemical properties of the investigated soils indicate that the destructive processes of reduction in the humus content and leaching of base cations must be controlled in order to achieve a stable sustainable system of high productivity and prevent their further deterioration.