Modeling wind drift and evaporation losses during sprinkler irrigation in arid areas (case of Touggourt - Algeria)

In recent years, agriculture development in South-eastern Algeria progressed rapidly which increased the demand for agricultural products. Given that this region is characterized by hard agro-climatic conditions, irrigation seems to be a necessary factor for ensuring optimal development and high agricultural production. Like many irrigation technics widely used, sprinkler irrigation performance was considerably affected by these conditions, mainly evaporation, which causes water losses. This study aims to propose an adequate mathematical model predicting wind drift and evaporation losses under different weather conditions resume by the complex indicator of climatic intensity (ɸ). Results showed that complex indicators of climatic intensity, were significant factors affecting the wind drift and evaporation losses, puissance relationship between wind drift and evaporation losses, and complex indicators of climatic intensity, obtained model are adopted can be useful tools in the determination of the overall losses in terms of environmental conditions (air temperature, relative humidity, and wind speed). Totally 25 measure samples were used for training the model, and 15 measure samples for testing and validation of the model. The developed model for the WDEL modeling shows high good performance with a coefficient of determination (R2) = 0.808, mean squared error (RMSE) = 3.39%, and Mean Absolute Error MAE = 8.41%.

STRUCTURE OF CEREAL-LEGUME HERBALS WITH DIFFERENT METHODS OF SOWING AND IRRIGATION IN ARID CONDITIONS OF THE LOWER VOLGA

In recent years, livestock farms in the Astrakhan region have mainly used grasses from natural hayfields and pastures for fodder. But, due to the sharp aridization of the climate, and, as a consequence, the more frequent droughts, as well as the unregulated growth of the number of animals on farms, the reserves of natural herbage are often insufficient. Therefore, the region began to increase the area of sown hayfields for irrigation. The aim of the work is to study the effect of various irrigation methods on the productivity of cereal-leguminous mixtures with multi-cut use in the conditions of light chestnut soils of the Northern Caspian region. The studies were carried out in 2017-2020 in the Astrakhan region. All studied irrigation methods (sprinkler irrigation, drip irrigation with a belt laying depth of 0.0, 0.15, 0.25, 0.35 and 0.45 m, periodic flooding), with the exception of subsoil irrigation, with an ordinary method of sowing contributed to the development of both cereals and legumes. In these variants of the experiment, cereals occupied a significant part in the total herbage - from 40.0 to 61.0%. When using the spread sowing method, only in one variant, the share of cereal grasses was 54.0% (periodic flooding). In all others with this method of sowing, the amount of cereals in the total mass was insignificant, or they were completely absent. The widespread method of sowing was also the most productive in all the years of research. The maximum yield in the experiment was noted in all variants of the experiment in the third year of the life of grasses in 2019.The highest productivity with the spread method of sowing was noted in 2019 in the variants of the experiment with a belt laying depth of 0.25, 0.35 and 0.45 m and amounted to 98.1, 104.4 and 111.0 t/ha, respectively. In the variants with the row-sowing method, the yield was lower than with the wide-spread one. The highest yield with this method of sowing was also noted in 2019 in variants with subsurface drip irrigation with a belt laying depth of 0.35 and 0.45 m and amounted to 105.5 and 104.8 t/ha, respectively

Typical engineering design of potato micro-sprinkler irrigation in Northern Shanxi

The Loess Plateau in the northern part of Shanxi Province has uneven rainfall and large evaporation, so droughts often occur. The drought has restricted the development of the local planting industry and the economy. Micro sprinkler irrigation has the advantages of strong adaptability, saving water, saving labor and land, increasing production, and preventing salinization, which is very suitable for this area. This micro-sprinkler irrigation design is carried out in typical plots, based on potato plant characteristics, rainfall data over the years, combined with corresponding specifications and actual conditions. This article uses a refraction micro-sprinkler with a spray diameter of 2.4 m. In the water transmission and distribution network, underground pipelines share 1,860 m of main pipes and sub-main pipes; surface pipelines share 1,200 m of branch pipes and 90,000 m of capillary pipes. The design meets the verification indicators of all irrigation groups, conforms to local actual conditions.

Wind Drift Evaporation Loss and Soil Moisture Distribution under Sprinkler Irrigated Blackgram (Vigna mungo L.)

An experiment was conducted during March–June 2018 with the sprinkler irrigation system covered in an area of 39×42 m2. Proper design and management of sprinkler irrigation systems improves the uniformity of moisture distribution and reduces wind drift and evaporation losses (WDEL) for effective crop growth. Uniformity coefficient, wind drift and evaporation loss of the sprinkler system at a different pressure head of 2 kg cm-2, 2.5 kg cm-2 and 3 kg cm-2 were studied. Wind speed was observed by using handheld anemometer. The wind speed ranged between 0.9 to 4.5 m s-1. The highest uniformity coefficient of 88.19% and wind drift and evaporation loss of 3.5% were obtained at the pressure head of 3 kg cm-2 and the wind speed of 0.9 m s-1. Soil samples were collected at different depths of 0–10 cm, 10–20 cm, 20–30 cm and at a radial distance from 0 m, 3 m, 6 m, 9 m, 12 m respectively to determine the soil moisture distribution pattern. The soil moisture content values were plotted by using the computer software, surfer 10 of the windows version and contour maps were drawn. The moisture content was found to be more at 0–10 cm depth, as compared to 10–20 cm and 20–30 cm depth. The percentage of moisture was found to be highest at a 6 m distance, which was due to overlapping of the sprinkler system.

Beneficial Effect of Biochar on Irrigated Dwarf-Green Coconut Tree

The coconut tree is considered one of the greatest consumers of irrigation water, ranging from 100 to 240 L day−1. The objective of the present study was to evaluate the effect of biochar application on decreased irrigation water needs in a 2-year irrigated dwarf coconut palm orchard field experiment. Biochar was characterized chemically and by electron microscope images. Biochar morphology presented several micropores indicating water retention potential. Amounts of biochar were tested (0, 5, 10, 20, 40 g of biochar per kg of soil), representing 0.0; 0.5; 1.0; 2.0; and 4.0 kg per plant. Micro sprinkler irrigation started following the planting of the 90-day old hybrid dwarf coconut seedlings. The impacts of the application of the biochar on the chemical attributes of the soil, biometry of the coconut plants, water storage in the 0–0.3 m soil layer, and the volume of irrigation water required by treatment were evaluated. After two years (2017 and 2018), the application of the biochar resulted in no statistically significant differences in the chemical attributes of the soil and biometric variables of plants between different treatments. The volume of annual irrigation water per plant versus biochar quantity demonstrated a decreasing effect, due to the increase of soil water storage. The dose of 40 g of biochar per kg of soil presented the highest two-year average soil water retention (0–0.3 m layer) among treatments (34, 36, 34, 38, and 45 mm, respectively), resulting in lower 2-year irrigation water demand (28, 36, 29, 28 and 20 L plant−1 day−1, respectively).

Socioeconomic and Climatic Impacts of Photovoltaic Systems Operating High-Efficiency Irrigation Systems: A Case Study of the Government Subsidy Scheme for Climate-Smart Agriculture in Punjab, Pakistan

This paper presents the results of a field study conducted in the Punjab, Pakistan, to evaluate the socio-economic and climatic impact of Photovoltaic (PV) systems installed under government subsidy scheme for operating high efficiency irrigation systems (HEIS) i.e., drip and sprinkler irrigation systems. Agriculture provides livelihood to almost half of the rural population and recent energy crisis in the country has adversely affected the rural communities. Farmer’s dependence on fossil fuels has significantly increased for operating irrigation systems which has resulted in high costs of agriculture production. Government of Punjab has launched a subsidy scheme to install PV systems for operating efficient drip and sprinkler irrigation systems on cost sharing basis. Photovoltaic systems having a capacity of 17.30 megawatt, were installed to operate high efficiency irrigation systems at around twenty thousand acres under this subsidy project, that has resulted in an annual saving of 0.0066 billion liters of diesel. The average capacity of installed PV systems was 9.0 kilowatt, which matched the 7.50 horse power of installed water pumps. On average, the cost of a PV system per acre was calculated to be 0.000142 billion PKR, while the cost per kWp was calculated to be 0.000149 billion PKR. The research results show that the installation of photovoltaic systems has increased the adoption rate of high-efficiency irrigation systems, reduced carbon dioxide emissions, and reduced the high operating costs associated with diesel powered pump systems. The primary data about on-farm agriculture and irrigation practices used in this study were collected through in-depth farmer surveys, while the secondary data information came from reports, official documents and statistics issued by the government.

Sultansuyu Tarım İşletme Müdürlüğüne Ait Silajlık Mısır Üretim Alanlarındaki Vejetasyon Değişiminin Landsat-8 Uydu Görüntüleri ile Değerlendirilmesi

Remote sensing (RS) is used effectively in agriculture as well as in many different fields. There are many mathematical models developed to predict characteristics such as yield, plant water consumption, plant growth and development in agricultural areas using RS techniques. In this study, the Normalized Vegetation Change Index (NDVI) and Vegetation Index Considering Soil Reflections (SAVI) were used. NDVI and SAVI satellite images are calculated using bands of near infrared (NIR) and red (RED) light wavelengths. Within the scope of the study, by using LANDSAT 8 satellite images of 2018 and 2019, the change in the silage corn production areas irrigated by the circular moving sprinkler irrigation (Center Pivot) systems in Yeniköy belonging to the General Directorate of Agriculture, Sultansuyu Agriculture Operation Directorate was analyzed during the plant development period. In this context, NDVI and SAVI maps obtained from satellite images were determined. Plant growth changes were evaluated for the period from sowing to harvest from the maps obtained. According to the results obtained from the study, it was determined that the plant growth and development satellite images of maize silage can be followed by NDVI and SAVI plant parameters obtained by using NIR and RED bands.

Spatiotemporal responses in crop water footprint and benchmark under different irrigation techniques to climate change scenarios in China

Adaptation to future climate change with limited water resources is a major global challenge to sustainable and sufficient crop production. However, the large-scale responses of crop water footprint and its associated benchmarks under various irrigation techniques to future climate change scenarios remain unclear. The present study quantified the responses of maize and wheat water footprint per unit yield (WFP, m3 t−1) and corresponding WFP benchmarks under two representative concentration pathways (RCPs) in the 2030s, 2050s, and 2080s at a 5-arc minute grid level in the case for China. The differences among rain-fed and furrow-, micro-, and sprinkler-irrigated wheat and maize were identified. Compared with the baseline year (2013), maize WFP will increase under both RCP2.6 and RCP8.5, by 17 % and 13 %, respectively, until the 2080s. Wheat WFP will increase under RCP2.6 (by 12 % until the 2080s), while decrease by 12 % under RCP8.5 until the 2080s. WFP will increase the most for rain-fed crops. Relative to rain-fed crops, micro irrigation and sprinkler irrigation result in the smallest increases in WFP for maize and wheat, respectively. These water-saving managements will more effectively mitigate the negative impact of climate change. Furthermore, the spatial distributions of WFP benchmarks will not change as dramatically as those of WFP. The present study demonstrated that the visible different responses to climate change in terms of crop water consumption, water use efficiency, and WFP benchmarks under different irrigation techniques must be addressed and monitored. It also lays the foundation for future investigations into the influences of irrigation methods, RCPs, and crop types on WFP and its benchmarks in response to climate change in all agricultural regions worldwide.

Numerical simulation of the effects of sandy water on regulator labyrinth channel in micro-sprinkler systems

The effects of sandy water on the W-shaped labyrinth channel of micro-sprinkler irrigation systems with large flowrate were investigated using Computational Fluid Dynamics (CFD). Using ANSYS FLUENT software and different inflow conditions (e.g., pressure, velocity, sediment concentration, and sand particle diameter), internal turbulent multiphase flow and sand deposition were simulated by the Eulerian multiphase flow model. Particle erosion in the labyrinth channel was calculated by the Discrete Phase Model (DPM). The results show that vortex movements and shear actions at the boundary layer cause self-flushing in the channel. The location of sand particle deposits and the turbulent dissipation rate are related to the operating pressure, which is optimal at 300 kPa. The erosion rate of the channel wall is proportional to the inflow sediment concentration but has no obvious relationship with inflow velocity. Based on the movement regulation of sand particles in the labyrinth channel, recommendations on filtration requirements and operating pressure of irrigation systems are proposed.