The technical basis for improving agricultural water use efficiency is illustrated. This may be achieved by increasing the total amount of the water resource that is made available to plants for transpiration and/or by increasing the efficiency with which transpired water produces biomass.
How can agricultural water use efficiency be improved?
The technical basis for improving agricultural water use efficiency is illustrated. This may be achieved by increasing the total amount of the water resource that is made available to plants for transpiration and/or by increasing the efficiency with which transpired water produces biomass.
Can better crop management improve agronomic water use efficiency?
Appropriate crop management practices contribute to improve several components of agronomic water use efficiency. Substantial increase of water use efficiency by better crop management is documented by Xu and Zhao ( 2001) in north China where water use efficiency improved threefold between 1949 and 1996.
Do fertilizers affect water use efficiency of crop plants?
Fertilizer effects on water use efficiency are related to physiological leaf processes, root system dynamics as well as radiation use within a field crop stand. Nutrient supply and crop water status interact in determining the balance of dry matter accumulation to transpiration losses. Most studies were made on nitrogen fertilization.
What is the implication for agricultural water management?
The implication for agricultural water management is that the irrigation agricultural scale has to be controlled under the condition of available water resource, while improving agricultural water use efficiency. 1. Introduction
How can we increase crop water efficiency?
Enhancing WUE at the canopy level can be achieved by adopting practices that reduce the soil water evaporation component and divert more water into transpiration which can be through crop residue management, mulching, row spacing, and irrigation.
How efficiency of irrigation can be increased?
The efficiency of irrigation can be increased by: (i) Drip and sprinkler system – It increases the efficiency of irrigation as it sprays water through pipes and a sprinkler. (ii) River lift system – It is useful in those areas where canal flow is insufficient or irregular due to inadequate water release.
What is water use efficiency in agriculture?
Water use efficiency (WUE) is usually calculated based on the grain yield or total biomass produced per unit of water consumed by crops. The quantity of water consumed by crops is estimated according to the total amount of water used from the plant and soil surfaces in addition to that retained within plant structures.
What is water application efficiency?
Water application efficiency can be defined as the ratio between the amount of water retained in the root zone of the plant and the amount of applied irrigation water (Hsiao et al., 2007).
How can we increase the water-efficient irrigation system Mcq?
How can we increase the water efficient irrigation system? Explanation: Drip irrigation is a method of controlled irrigation in which water is slowly delivered to the root system of multiple plants. Drip irrigation increases the water efficient irrigation system and hence it is very helpful in water conservation.
What are the factors affecting the efficiency of water delivery to the farm?
Many factors affect WUE in the irrigation sector. They include seepage, percolation, soil depth and texture, evaporation and evapo-transpiration, design of irrigation structures and their operation and maintenance, and management skills.
How can we improve agricultural productivity?
How to Improve Farming ProductivityImplementation of land reforms. For improving the production, land reforms are the first and predominant point. … Interplant. … Plant more densely. … Plant many crops. … Raised beds. … Smart water management. … Heat Tolerant Varieties. … Use nitrogen.More items…•
Which method has maximum water application efficiency?
Drip irrigation has the highest irrigation efficiency. Drip irrigation is a type of micro-irrigation system that has the potential to save water and nutrients by allowing water to drip slowly to the roots of plants. Either from above the soil surface or buried below the surface.
What is application efficiency?
Application Efficiency (AE) is a performance criterion that expresses how well an irrigation system performs when is operated to deliver a specific amount of water. AE is defined as the ratio of the average water depth applied and the target water depth during an irrigation event.
Which efficiency is also called on farm efficiency?
1. Which efficiency is also called on-farm efficiency? Explanation: The water application efficiency is the ratio of water stored in the root zone to the water actually delivered to the field. It takes into consideration the water lost in the farm hence, it is also known as on-farm efficiency.
What is the most efficient form of irrigation?
Drip irrigation is the most water-efficient way to irrigate many different plantings. It is an ideal way to water in clay soils because the water is applied slowly, allowing the soil to absorb the water and avoid runoff.
What factors affect irrigation efficiency?
Physical factors that affect the choice of irrigation technologies are the terrain (slope), soil type, and the type of crops planted. Farmers adopt an irrigation technology if a given irrigation technology needs little maintenance and provides the necessary water for crop growth and maximum yield efficiency.
Which are very effective and efficient technique of irrigation?
Drip irrigation is the most water-efficient irrigation system, with up to 90% water use efficiency especially compared to sprinkler systems, flood irrigation or center pivot irrigation. Because drip irrigation is a low-pressure method for delivering crop watering needs, it can also have low energy requirements.
How do you increase your irrigation pressure?
Adjust Your Pressure Loss Data:Increase the mainline size. … Lower the sprinkler head operating pressure. … Reduce the pressure loss in the laterals. … Increase the size of the backflow preventer or valves. … Lower the Initial Design Flow. … Add a booster pump to increase the water pressure.
Abstract
With the world’s population set to increase by 65% (3.7 billion) by ∼2050, the additional food required to feed future generations will put further enormous pressure on freshwater resources. This is because agriculture is the largest single user of fresh water, accounting for ∼75% of current human water use.
1. Introduction
To date the global change community has had a strong focus on the causes and impacts of increased atmospheric CO 2 level, i.e. global warming and climate change.
2. The most important global change
Fig. 1 is based on United Nations Population Division data and shows that the total population of the world has increased by 125% since 1950 ( Fischer and Heilig, 1997 ). This figure also shows the best available estimates of how the world population will increase in the next 50 years.
3. Water resource implications
Assuming the median population projection ( Fig. 1 ), what are the water resource implications of having 3.7 billion more people in the world? These are largely associated with the water needed to grow their food, since large amounts of water are associated with food production.
4. Agricultural water use efficiency
A summary of the current efficiency with which water is used in both rain fed and irrigated agriculture is given in Table 2. In irrigated agriculture, a considerable amount of water is lost as evaporation and/or leakage during storage and transport of the water to the fields where the crops are grown.
5. The technical basis for improvement
In principle, there are only two ways of increasing water use efficiency in agriculture. First, it may be possible to use more of the water resource as transpiration. Second, it may be possible to fix more carbon per unit of water transpired. For clarity, it is worth considering these two possibilities separately.
6. Water use efficiency and scale
The above techniques for improving water use efficiency can be considered in terms of different spatial scales. At the smallest scale of an individual plant the transpirational water use efficiency is most applicable. Here breeding and genetic manipulation may be used to improve growth per unit of water transpired.
How can improved water use efficiency be achieved?
Improved water use efficiency by better agronomy is achieved most effectively by an integral set of measures that are evaluated over the whole crop rotation. Processes underlying most improvements of water use efficiency in agronomy suggest that research should target plant water uptake capacity.
How to increase yield of fresh water?
Traditional ways to increase yield by extending the area under cultivation, using high intensity of external inputs and breeding for yield potential in high …
Associated Data
Data are available on request due to restrictions, e.g., privacy or ethical. The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the strict management of various data and technical resources within the research teams.
Abstract
Agricultural water use accounts for the largest proportion of water withdrawal, so improving agricultural water use efficiency is an important way to alleviate water shortage.
1. Introduction
In the context of finite supply and climate change, the growing demand for freshwater is one of the most significant challenges facing humanity [ 1 ]. Agriculture is the largest user of water globally.
2. Theoretical Analysis of Agricultural Water Rebound Effect
Since the theory of the energy rebound effect was first proposed, two different methods of estimating the rebound effect have been developed. One method is to directly compare the demand before and after the improvement of efficiency, and the other method focuses on elasticity as a proxy variable [ 32, 33, 34, 35, 36, 37, 38 ].
3. Materials and Methods
The meta-frontier data envelopment analysis (DEA) method, based on technical heterogeneity, was used to estimate the agricultural water use efficiency, which is consistent with the actual situation of China’s economy [ 4 ].
4. Results
Equation ( 8) is estimated to get the efficiency elasticity of agricultural water use in order to calculate the average rebound effect of agricultural water in China.
5. Discussion
Most of the existing studies have focused on estimation of the agricultural rebound effect. The measures of the rebound effect are based on an assumption which is that a 1% increase in agricultural water efficiency requires a 1% reduction in agricultural water use.