Water use efficiency (WUE) is a critical aspect of modern agriculture, especially in the context of water scarcity and environmental sustainability. Water is crucial for food production, and with a growing population of 10 billion by 2050, it is essential to ensure safe and secure water use. Improper irrigation practices, such as flood irrigation, lead to water alarming situations. Modern tools and sustainable irrigation methods can help reduce water waste and improve crop productivity.
Precision agriculture plays a vital role in water security, and efficient irrigation scheduling, practices like deficit irrigation and conservation tillage can improve efficiency. Avoiding over-irrigation can also help prevent soil erosion, soil structure disturbance, and nutrient runoff, ultimately increasing agriculture productivity.
What is Water Use Efficiency?
Water Use Efficiency (WUE) is a measure of how efficiently plants utilize water to produce biomass or yield. It quantifies the relationship between the amount of water used by plants and the amount of biomass or yield produced. In other words, WUE reflects the ability of plants to convert water into usable products.
WUE is typically expressed as the ratio of the amount of biomass or yield produced to the amount of water transpired or consumed by the plant. It can be calculated at different scales, such as the leaf level, plant level, or crop level. The units of measurement vary depending on the context, but common units include grams per litre (g/L), kilograms per cubic meter (kg/m³), or kilograms per hectare per millimetre (kg/ha/mm).
Introduction:
Water is used for producing food in 2050 population of about 10 billion means food demand will increase so in the future food production become a serious challenge faced globally level water is the backbone for producing food. If we do not use safe water and do not secure water in the future prospective way then it leads water alarming situation.
We lose most of the water by improper irrigation practices such as flood irrigation. if we use modern tools for irrigation purposes then a lot of water is safely used so we should use such modern tools and adopt modern irrigation methods that are useful for water security.
Current water status
The earth holds near about 326 million trillion gallons and if we look at water distribution on earth then the estimated value is that mostly ocean holds 97.2% total volume of water, 2.1% earth is covered by glaciers, 0.65% of groundwater, 0.005 % is covered by soil moisture,0.009% water stored in lakes,0.001% water stored in streams,97.2% not suitable for drinking purpose only 2.8% water is freshwater. The threatening point is that 50% of water is wasted in the agriculture sector.
The global sector shows that 70% of annual water is used by farming practices and 30 % of water is wasted by evaporation and different climatic variations. All these facts show the importance of modern tools used for irrigation.
Water plays an important role in agriculture as blood in humans. water plays a significant role in crop production. water plays an active role in plant metabolism as well as plant growth processes such as photosynthesis and absorption of nutrients which lead to increased agriculture productivity and food security. water is wasted in the agriculture sector in many ways as improper lining of canals, poor water management, percolation, runoff and so many ways.
If we use proper water management device and adopt modern and sustainable methods then it has many advantages as the amount of water is less wasted, proper water is used in the field, by use of these devices we can determine which crop need how much water and when we apply irrigation to the crop. sometimes we irrigate the field even when the crop needs no more water in this case two possibilities chances of damage to yield as water is wasted by evaporation and gravitational water and becomes unavailable to plants and plant roots are damaged by the production of Reactive Oxygen Species.
Precision Agriculture plays a vital role in water safety as global position systems use irrigation methods for water security. Irrigation efficiency can be improved by irrigation scheduling, adopting practices such as deficit irrigation and conservation tillage, and installing more efficient irrigation systems.
Approaches for Efficient Water Use
1. Avoid over-irrigation:
Over-irrigation in the field creates many problems one of them is soil erosion because when water is absorbed by the upper layer of soil it is prone to erosion as removed from fertile soil, when soil is saturated with water then no entry of gaseous exchange because over-irrigation create a layer of water additionally so it leads to damage plant survival.
Irrigation disturb soil structure because when additional water is absorbed by soil particles the soil’s capacity to provide nutrients low and crop yield decline by creating waterlogged condition and anaerobic condition. Nutrient runoff by use of irrigation that’s is a big problem because if nutrients are not present in the soil, then how can crops grow?
Over-irrigation is multifaceted as leaching losses, runoff losses, soil health and water depletion. If we overcome these losses then agriculture productivity must increase so we avoid over-irrigation. Frequent, light irrigations help keep water and mobile nutrients in the root zone where plants can use them.
2. Schedule Irrigations based on Evapotranspiration:
Consumption of water has a seasonal time that varies by crop. The most appropriate moment to irrigate a certain field is also determined by when the agricultural product last got water and the soil’s water retention capacity. Understand your soil’s water-holding capability. Because sandy loam soil does not retain the same water as silt loam soil, it must be watered more frequently and with less water each cultivation. Water is lost by outflow and deep diffusion.
3. Use deficit Irrigation:
Deficiency drainage refers to applying a lesser quantity of water than the crop requires for complete growth. Analyze the tolerance of each crop to drought stress and water accordingly. Some plants are far more resistant to drought stress than others. Sugar beets and lucerne can extract moisture from deeper in the soil profile than most crops, allowing them to grow without irrigation as long as water reserves are available deeper in the soil profile.
Potato plants may be mildly stressed very early on, but not after tuber formation. Water stress has an impact on onion output and quality, as well as on the proportion of bulbs with solitary centres. Water stress during the blossoming stage is the most unfavourable to many seeds and grain varieties.
4. Practice Conservation Tillage:
Conservation agricultural strategies like limited tillage, no-till, and strip-till aid in the conservation of soil water. Tillage is decreased, and agricultural residue from the preceding crop is kept on the soil surface to some extent. Crop storage of residue minimizes water loss from the soil to the atmosphere and cools the soil. When the soil is tilled, it is subject to drying; on the other conjunction, reducing tillage conserves soil water.
When using strip tillage, cultivate exclusively inside the row zone and leave the inter-row zone undisturbed. After planting, at least 30% of the previous crop residue should remain on the surface. The inter-row zone’s soil infiltration capacity is improved, permitting water to go where it is necessary. By taking ploughing maintains water while additionally preventing sugar from the root vegetable seedlings from being blown out of the soil’s texture by the winds.
5. Carefully Manage Surface Irrigation:
Water irrigation procedures are inherently unsustainable. They provide a large flow of water directly onto the substrate, eliminating soil particles. Change irrigation settings shortly after the water reaches the end of the furrow rather than at a predetermined time of day to conserve water using furrow irrigation. Watering the top of the field too much strains the plants and produces a nitrogen deficit because nitrogen leaches below the root zone.
Drought straining the bottom of the field typically results in output losses equivalent to over-watering the top of the field. Mulch the bottom of the field with straw to allow the water to soak in. To promote water penetration in tight soils (those with low water infiltration), use PAM (polyacrylamide) or straw mulching.
6. Site-Specific Irrigation:
Water infiltration rates are well-established and known to differ between irrigation episodes, but they also differ within the field. Soil types, chemical properties, subsurface conditions, topography, drainage, insect/weed/disease problems, soil compaction, weather patterns, and wind deformation of irrigation structures, as well as external factors such as herbicide drift, can all cause yields and crop water use to vary across a field and among fields.
As a result, it may be more profitable to vary applications for water across a field to account for possible productivity disparities and environmental repercussions caused by the unpredictability of these various elements than to manage the complete field as one cohesive entity.
Modern Tools for Efficient Water Use in Field Crops:
- Drip irrigation systems
- Sprinkler irrigation systems
- Soil sensors
- Irrigation management mobile apps
- Drones
1. Drip Irrigation System:
In the modern era of science drip irrigation system is a good method for irrigating field as drip irrigation use less water compared to other irrigation method. The drip irrigation system is not used in cereals crops somehow case and the drip irrigation system has 90% irrigation efficiency. drip irrigation has low water wastage as seepage loss, evaporation loss and others because it provides drop-by-drop water that is efficiently used by plants.
No doubt drip irrigation system is high cost but in the future point of view it move toward water sustainability and we irrigate large area with a small amount of water and use low water quantity. Drip irrigation systems save water, labour expenditure, save crop yield. Soil ties, climate factors and water quality factors are considered during the installation phase Orchid and greenhouse plants have good efficiency in drip irrigation.
Drip irrigation system have components Drip Tube, Emitters, Filters, Pressure Regulators, Backflow Preventers, Distribution Manifolds, Plugs Fitting, Pressure Guage, Flush Valves, Control Valves and Main water supply. The use of drip irrigation is one of the more profitable methods of supplying water to agriculture while wasting as little as possible.
It is currently employed on fewer than 2% of the world’s irrigated land, although it has the potential to cut water usage by 30 to 70%. Though it has an expensive initial investment, it has several advantages such as reduced evaporation, reduced water wasted by weeds, and irrigation to an accurate root depth for plants.
2. Sprinkler Irrigation:
This is one of the advanced methods of irrigation in which the field is irrigated through sprinklers which have the same effect as rainfall. This method is used to save waste water and is mostly used in water shortage areas. The method is less adopted in Pakistan, on the other hand in developed countries like USA, Russia and China this method is widely used by large land-holding farmers.
In Pakistan, farmers mostly use traditional methods of irrigation like flood, furrow and basin irrigation which are less effective than sprinklers. There is a need to spread awareness to farmers about the use of this method especially in arid areas. It reduces the loss of water by minimizing evaporation and runoff.
Types of Sprinkler Irrigation:
Sprinkler irrigation has different types mostly based on area and soil condition. Adopt that method which is efficient for irrigating the crops.
- Stationary Sprinkler: The sprinkler is fixed in one position and throws water towards the field in a circular and semicircular way. This method is mostly used for small areas.
- Oscillating Sprinkler: Sprinklers moved forward and backward to irrigate special shape type fields like square or rectangular. The method is used for large fields.
- Rotary Sprinkler: Sprinklers move in circular ways to give water to fields. This method is efficient for large open area fields.
- Micro Sprinkler: Precisely distribute water to small gardens and plants in pots.
Advantages of Sprinkler Irrigation:
- Distribute water efficiently.
- Less water wastage.
- Irrigate fields in a short period.
- Effective for arid areas farming.
- Easy to operate.
Disadvantage of Sprinkler Irrigation:
- High-cost system.
- Difficult to operate intercultural practices.
- Not effective for small farmers.
- Skilled labour is required for installation.
3. Soil Sensors:
Analyzing soil parameters like wetness can assist farmers in determining exactly how much water is required to keep crops suitably irrigated. The ideal precision agricultural system, developed by the University of Nebraska, contains a sensor in the soil that is linked to a device that analyses the data.
Soil sensors can assist farmers in recognizing the status of roots, indicating when it is recommended to hydrate or when the plant’s thirst has been satisfied, preventing water waste, nutrient loss, and the development of a shallow bottom arrangement.
Irrigation Management Mobile Apps:
Smartphone applications that help farmers maintain drainage are constantly evolving. Field NET Mobile, for example, enables users to manage and monitor irrigation equipment from their iPhone or Android mobile, allowing farmers to instantly alter irrigation based on changing conditions.
A University of Georgia agricultural scientist created Smart Irrigation Apps to assist southeast farmers in planning irrigation depending on what quantity of rainfall their crops demand and data from local weather stations.
Drones:
According to the Association for Unmanned Vehicle Systems International, farms will ultimately account for 80% of the commercial drone industry. Drone thermal cameras may be used to identify leaks and evaluate whether crops are receiving either insufficient or excess water.
While the FAA does not officially permit commercial use of drones, there is an amendment under consideration to amend the legislation, and producers can currently seek permissions.
Ali Haider, Noor Fatima, Muhammad Usama, Abdul Rehman Javed, Muhammad Abdullah Khalid, Tasadaq Hussain Ali, Muhammad Nouman, Muhammad Usman, Muhammad Talha
University of Agriculture Faisalabad Pakistan
