This study combined continuous monitoring in the field using computer modeling to understand soil water movement and salt transport so as to design a suitable irrigation system for cotton using ...mulched drip irrigation with brackish water. A reasonable irrigation regime was determined and verified using thresholds of water and salinity stress in the various stages of cotton growth. In addition, some key factors, such as emitter discharge rate, emitter spacing, and initial water content, were screened for simulation, and irrigation uniformity and desalination rate were selected as the indicators for evaluation. The results showed that: (i) The HYDRUS-3D model was a useful tool for designing suitable irrigation regimes, and the determined suitable irrigation quota was 5160 m3 hm−2 under mulched drip irrigation with brackish water during the growth period of cotton in 2019. (ii) The irrigation uniformity and leaching rate decreased with an increase in the emitter discharge, and the linear relationship between uniformity, leaching rate, and emitter discharge could be identified. (iii) The irrigation uniformity and leaching rate decreased with an increase in emitter spacing, and power functions might be used to calculate uniformity, leaching rate, and emitter spacing. (iv) The irrigation uniformity and leaching rate increased with an increase in initial water content, and the relationship between the two indexes and initial water content was defined by a linear function and a power function, respectively. These results provided a valuable reference for the rational use of drip irrigation with brackish water. La présente étude combinait la surveillance continue sur le terrain et la modélisation sur ordinateur en vue de mieux comprendre les déplacements de l’eau et le transport du sel dans le sol, et ainsi concevoir un système d’irrigation au goutte-à-goutte utilisant de l’eau saumâtre qui conviendrait à la culture du coton sur paillis. Les auteurs ont établi un régime d’irrigation raisonnable puis l’ont vérifié avec le seuil de tolérance au stress hydrique et le stress causé par la salinité à divers stades de croissance de la plante. Parallèlement, ils ont contrôlé quelques paramètres importants comme le débit de sortie du goutteur, l’espacement des goutteurs ainsi que la teneur en eau initiale du sol. L’uniformité de l’irrigation et le taux de dessalement ont été retenus comme indicateurs pour l’évaluation. Les résultats de l’étude sont les suivants. (i) Le modèle 3D HYDRUS s’avère un outil utile pour créer un programme d’irrigation adéquat et, en 2019, le taux d’irrigation avec de l’eau saumâtre qui convenait à la croissance du coton sur paillis se situait à 5 160 m3 par cent mètres carrés. (ii) L’uniformité de l’irrigation et le taux de lixiviation diminuent quand le débit du goutteur augmente et les auteurs ont établi un lien linaire entre ces trois paramètres. (iii) L’uniformité de l’irrigation et le taux de lixiviation diminuent avec un plus grand écartement des goutteurs et on peut se servir des fonctions de puissance pour calculer l’uniformité de l’irrigation, le taux de lixiviation ainsi que l’écartement des goutteurs. (iv) L’uniformité de l’irrigation et le taux de lixiviation augmentent avec la teneur en eau initiale du sol et une fonction linéaire ou de puissance définit respectivement les liens entre chaque indicateur et la concentration d’eau au départ. Ces résultats s’avéreront de précieuses références en vue d’un usage rationnel de l’irrigation au goutte-à-goutte avec de l’eau saumâtre. Traduit par la Rédaction
The article outlines how computer control technology is used in agriculture to monitor and manage environmental conditions for optimal production. It discusses the complexity of agricultural systems, ...the hardware and software components involved in control systems, and various control strategies. It also mentions commercially available systems, do-it-yourself options, and emerging technologies like real-time expert systems, computer modeling, and robotics. Overall, it suggests that computer-controlled systems are becoming increasingly important in agriculture, offering improved efficiency and resource management.
In Florida, the major portion of rainfall occurs from June through September. However, rainfall is scarce during the dry period from February through May, which coincides with the critical stages of ...bloom, leaf expansion, fruit set and fruit enlargement. Irrigation provides water when rainfall is not sufficient or timely to meet crop needs. Adequate irrigation management is key to optimize water use, increase crop yield and improve fruit quality. Several weather-, soil- and plant-based methods are available for irrigation management. The most used methods rely on weather stations to calculate evapotranspiration (ET), the combination of water lost by plant transpiration and soil evaporation.
The estimation of land-surface evapotranspiration (ET) at high spatial and temporal resolutions is important for management and planning of agricultural water resources, but available remote sensing ...data generally have either high spatial resolution or high temporal resolution. To overcome this limitation, we evaluated the use of a data fusion scheme, Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM), to determine the surface parameters needed to estimate daily ET at a Landsat-like scale (100 m). In particular, we fused Moderate Resolution Imaging Spectroradiometer (MODIS) data with Landsat Enhanced Thematic Mapper Plus (ETM+) data in analysis of the Heihe River Basin (HRB), an arid region of Northwest China. The surface parameters were then used to drive the revised Surface Energy Balance System (SEBS) model to estimate daily ET at a spatial resolution of 100 m for this an arid irrigation area during the crop growth period (April to October) in 2012. The results showed that the daily ET estimates had a mean absolute percent error (MAPE) of 12% and a root mean square error (RMSE) of 0.81 mm/day relative to ground measurements from 18 eddy covariance (EC) sites in the study area. The validation results indicated good accuracy for land cover types of maize and vegetables, a slight overestimation for residential and wetland sites, and a slight underestimation for orchard site. Our comparison of the input parameter fusion approach (IPFA) and the ET fusion approach (ETFA) with field measurements indicated the IPFA was superior than the ETFA for land surfaces with high spatial heterogeneity. Furthermore, our high spatiotemporal ET estimates indicated that irrigation water efficiencies of the irrigation districts (mean: 70%) and villages (mean: 62%) had large spatial heterogeneity. These results point to the need for calculating ET at a high spatiotemporal resolution for monitoring and improving irrigation water efficiency at local scales. Our findings suggest that the proposed framework of estimating daily ET at a Landsat-like scale using multi-source data may also be applicable to other heterogeneous landscapes by providing a foundation for management of water resources at the basin or finer scales.
•An estimation scheme for daily High-Temporal Landsat-Like (HiTLL) ET was proposed.•The input parameter fusion approach (IPFA) performs well for heterogeneous surface.•The HiTLL ET facilitate assessment of irrigation water efficiency at a finer scale.
Water scarcity is a major constraint in arid and semi-arid regions. Crops that require less irrigation water and those, which are considered drought-tolerant such as date palm (Phoenix dactylifera ...L.), are dominant in these regions. Despite the tolerance of these crops, the development of technologies that ensure efficient use of irrigation water is imperative. Taking these issues into consideration, the study was conducted to investigate the impact of limited irrigation water using a new subsurface irrigation system (SSI) on gas exchange, chlorophyll content, water use efficiency, water productivity, fruit physicochemical characteristics, and yield of date palm (cv. Sheshi). The impact of the SSI system was compared with two surface irrigation systems, namely, surface drip irrigation (SDI) and surface bubbler irrigation (SBI). The field experiment was carried out during 2018 and 2019 at the Date Palm Research Center of Excellence, King Faisal University, Kingdom of Saudi Arabia. The annual crop evapotranspiration (ETc) was 2544 mm. The applied irrigation water was set at 50%, 75%, and 125% of ETc for SSI, SDI, and SBI, respectively, which were based on the higher crop water productivity recorded in an initial field study. The total annual volume of water applied for SSI, SDI, and SBI was 22.89, 34.34, and 57.24 m3 palm−1, respectively. The crop water productivity (CWP) at the SSI system was significantly higher, with a value of 1.15 kg m−3, compared to the SDI (0.51 kg m−3) and SBI systems (0.37 kg m−3). The photosynthetic water use efficiency (WUE) was 10.09, 9.96, and 9.56 μmol CO2 mmol−1 H2O for SSI, SBI, and SDI, respectively. The maximum chlorophyll content (62.4 SPAD) was observed in SBI, followed by SSI (58.9 SPAD) and SDI (56.9 SPAD). Similarly, net photosynthesis and the transpiration rate were significantly higher in SBI and lowest in SSI. However, the SSI system substantially increased palm yield and enhanced fruit quality. The new SSI system, through its positive impact on the efficiency of irrigation water use and enhancement on fruit yield and fruit quality of date palm, seems quite suitable for the irrigation of palm trees in arid and semi-arid regions.
In order to investigate the effect of wastewater on the soil minerals movement, irrigation water use efficiency (IWUE) and leaf nutrients uptake of medicinal-industrial-landscape
Lavandula
(
...Lavandula angustifolia
L.) by two types of irrigation systems, the experiment was performed as a factorial experiment in a randomized complete block design with three replications. Experimental treatments were included quality of irrigation water (fresh water and treated wastewater) and irrigation method surface irrigation (SI) and subsurface irrigation with permeable tubes (SSI). Soil samples were collected at the end of the experiment for each treatment at depths of 0–15, 15–30 and 30–60 cm to analyze Electrical Conductivity (EC), phosphorus (P), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) and total nitrogen (N). Plots were irrigated with treated wastewater by SSI method showed fresh and dry weights of canopy higher than irrigation with fresh water by SI method. The results suggested that contrary to IWUE, water quality was more effective than irrigation system on the wet and dry weights of the canopy and leaf nutrients uptake. Based on the results, SSI method with treated wastewater increased the IWUE by 64% compared to SI method with fresh water. The highest and lowest IWUE were obtained by application of the treated wastewater (0.44 kg m
−3
) and the fresh water (0.25 kg m
−3
), respectively. The higher levels of most minerals, including N, Ca, Mg, Na, K and P, were recorded when plots were irrigated by SSI system and received treated wastewater. The subsurface irrigation created significantly higher EC, Na, Mg and Ca compared to the surface irrigation in the topsoil. The EC, K, Mg and Na of second and third soil layers that received the wastewater were less compared to the fresh water. No significant effect on soil N, P and Na was observed in all three depths of soil due to application of the wastewater for irrigation.
Agriculture consumes more than two thirds of the total freshwater of the planet. This issue causes substantial conflict in freshwater allocation between agriculture and other economic sectors. ...Regulated deficit irrigation (RDI) is key technology because it helps to improve water use efficiency. Nonetheless, there is a lack of understanding of the mechanisms with which plants respond to RDI. In particular, little is known about how RDI might increase crop production while reducing the amount of irrigation water in real-world agriculture. In this review, we found that RDI is largely implemented through three approaches: (1) growth stage-based deficit irrigation, (2) partial root-zone irrigation, and (3) subsurface dripper irrigation. Among these, partial root-zone irrigation is the most popular and effective because many field crops and some woody crops can save irrigation water up to 20 to 30 % without or with a minimal impact on crop yield. Improved water use efficiency with RDI is mainly due to the following: (1) enhanced guard cell signal transduction network that decreases transpiration water loss, (2) optimized stomatal control that improves the photosynthesis to transpiration ratio, and (3) decreased evaporative surface areas with partial root-zone irrigation that reduces soil evaporation. The mechanisms involved in the plant response to RDI-induced water stress include the morphological traits, e.g., increased root to shoot ratio and improved nutrient uptake and recovery; physiological traits, e.g., stomatal closure, decreased leaf respiration, and maintained photosynthesis; and biochemical traits, e.g., increased signaling molecules and enhanced antioxidation enzymatic activity.
The aim of this study is to explore suitable drip irrigation system on the water saving and high yield of pear-jujube from 2009 to 2012 years in the mountain of northern Shaanxi. The treatments ...consisted of combinations of 5 drip irrigation systems (DP). The irrigation quota of DP-1, DP-2 and DP-3 treatment was 100 m3 hm-2, 135 m3 hm-2 and 180 m3 hm-2, respectively, irrigated 4 times. The irrigation quota of DP-4 and DP-5 treatment was 135 m3 hm-2 and irrigated 3 and 2times, respectively; and with no irrigation as the control (C). Results indicated that bearing branch length of jujube, fruit set and yield of different drip irrigation system are significantly better than C (P<0.05). Bearing branch length and yield of DP-3 treatment are reached maximum in 2012, which are 22.0 cm and 16772.8 m3 hm-2. And they are increased by 47.7% and 13.2% compared with C, respectively. In addition, the water consumption of different irrigation treatment increases along with the increasing of irrigation amount. And the DP-3 treatment is the highest in different years. The water use efficiency of pear-jujube of low irrigation quota is better than the high irrigation quota. Water use efficiency of 135 m3 hm-2 and irrigated 2 times treatment is the best, which is 1.92 m3 hm-2. Considering the lack of high annual precipitation, we conclude that DP-5 treatment was the best drip irrigation system in the mountain of northern Shaanxi.
Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 ...concentrations may affect irrigation requirements in the Mediterranean region by 2080–2090. Future demographic change and technological improvements in irrigation systems are taken into account, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL (Lund–Potsdam–Jena managed Land) after an extensive development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries such as Syria, Egypt and Turkey have a higher savings potential than others. Currently some crops, especially sugar cane and agricultural trees, consume on average more irrigation water per hectare than annual crops. Different crops show different magnitudes of changes in net irrigation requirements due to climate change, the increases being most pronounced in agricultural trees. The Mediterranean area as a whole may face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (4 and 18 % with 2 °C global warming combined with the full CO2-fertilization effect and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the southern and eastern Mediterranean. However, improved irrigation technologies and conveyance systems have a large water saving potential, especially in the eastern Mediterranean, and may be able to compensate to some degree for the increases due to climate change and population growth. Both subregions would need around 35 % more water than today if they implement some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect. Nevertheless, water scarcity may pose further challenges to the agricultural sector: Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain have a high risk of not being able to sustainably meet future irrigation water requirements in some scenarios. The results presented in this study point to the necessity of performing further research on climate-friendly agro-ecosystems in order to assess, on the one hand, their degree of resilience to climate shocks and, on the other hand, their adaptation potential when confronted with higher temperatures and changes in water availability.
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