**6.5 Laser land leveling**

Traditional land leveling techniques, including utilizing an engineer's level and staff rod, are time-consuming, exhausting, ineffective, and costly. For farmers to accurately level their fields, the Department of Agriculture, Government of Punjab, adopted Laser Land Leveling technology. The technique of laser land leveling involves employing drag buckets that are equipped with lasers to smooth the ground surface with a maximum allowable variation from its average height of no more than 2 cm. With the help of laser land leveling, it is possible to level the fields at a slope of zero, distributing irrigation water evenly across the head, middle, and tail of the fields. The GPS and laser-guided equipment used for laser land leveling are installed on high-horsepower tractors and soil movers. Therefore, laser land leveling of irrigated areas can also result in the following advantages, either directly or indirectly. The land receives an even distribution of water, which increases irrigation effectiveness. In laser-leveled fields, about 30% of the water is conserved; as a result, more land can be watered. The leveled field will yield 20 percent more because of more consistent germination. Due to the equal distribution of fertilizer, its effectiveness and efficiency will both increase. Erosion risks would be reduced. It increases the effectiveness of machine usage (**Figure 2**).

#### **Figure 2.**

*Laser land leveling at WMRC, UAF, experimental area. Source: Water Management Research Center, University of Agriculture, Faisalabad Pakistan.*

#### **6.6 Zero tillage**

No-tillage, also known as zero tillage, is a farming technique in which crop leftovers are left on the field after harvesting but the ground is not plowed. The following crop is directly sown using no-till planters (Zero Tillage Machines). For instance, in a rice-wheat rotation, wheat is planted using a Zero Tillage Drill right into a field that has previously produced rice without the use of any tillage equipment. Such methods, especially on sloppy terrains, are very effective in reducing soil erosion caused by wind or water. Due to the roots of the previous crop remaining in the soil and crop residue covering the ground surface to lessen the effects of heavy rainfall, zero-tillage reduces soil erosion.

## **7. Problems of irrigation system**

The irrigation and drainage infrastructure of Pakistan, which is now experiencing serious issues, will determine the country's agricultural destiny. Some of these issues include rising salinity and water logging, overuse of fresh GW, low water use efficiency, and unequal and erratic supply. Rigid system design and inadequate drainage, low delivery efficiency and inequitable distribution of water, waterlogging and salinity, and over-exploitation of groundwater in fresh areas represent major problems in Pakistan's irrigation system.

#### **7.1 Rigid system design**

Despite the greater distribution control provided by the development of barrages, reservoirs, and link canals, the irrigation system is nevertheless managed following outdated canal diverting patterns that frequently do not match water demands. Due to inadequate reservoir capacity as well as the seasonal pattern in river flows, which can provide about 85% of the water throughout the summer, limited water supply occurs at the beginning and end of the summer and throughout the winter. The inconsistency between water supply and demand reduces agricultural productivity.

#### **7.2 Inadequate drainage**

Because of its flat terrain and lacking well-defined drainage channels, the Indus Plain has an urban drainage problem, which is being made worse by the construction of roads, railroads, flood bunds, and water systems that obstruct natural drainage flows. In irrigated areas, drainage has been a priority since the 1960s, and numerous sizable drainage programs are still in operation today. About 6.5-million-hectare acres of the 16.7-million-hectare acres of gross canal-controlled land need to be drained, of which 1.86 million-hectare acres are being worked on right now. It is a significant task to provide drainage to such a huge area. The predicted water table depth for a region of 2.38 million hectares is less than five feet.

#### **7.3 Low delivery efficiency and inequitable distribution**

Canal delivery is incredibly inefficient as a result of aging, excessive use, and poor maintenance. From the canal head to the root zone, delivery efficiency is between 35 and 40 percent on average, with the majority of losses happening in watercourses. There is less water available for agriculture because of the significant surface water loss, which enhances water logging and salinity. Excess water and water losses during irrigation are frequently returned to rivers and utilized once more downstream in irrigation systems with drainage. As a result, there is less efficiency damage to the river basin as compared to efficiency loss to individual systems. Unfair distribution is a key concern as well.

#### **7.4 Waterlogging and salinity**

According to the World Bank (1992), Pakistan may be unable to produce about 25% of the important crops that may be produced there because of soil salinity. In an area such as the Indus Basin, which has a flat topography, insufficient natural drainage, permeable soils, and just a semi-arid climate with significant evaporation, it is unavoidable that water tables will rise and salinity will grow. As a consequence of the greater diversion of stream flow for irrigated and seepage through canals, and watercourses, especially irrigated regions, the groundwater level has gradually risen. By the 1960s, many SCARPs had already been established. Nevertheless, despite these precautions, the gross protected area is wet in around 30% of instances, with about 13% of those instances being classified as extremely waterlogged.

#### **7.5 Inadequate operation and maintenance (O&M)**

Because of neglected maintenance and overuse, Pakistan's irrigation and drainage system has been deteriorating. Provinces agreed to keep spending on surface irrigation and subsurface saline drainage facilities at 1988 levels as part of Bank Projects.

#### **7.6 Poor investment planning**

In Pakistan, there are three stages to the investment planning process for drainage and irrigation. A sectorial plan provides a framework for intermediate- to long-term Sectorial development, five-year plans are used for short-term planning, and the Annual Development Programme allows monies annually (ADP). Sectorial planning has previously attracted a lot of attention. Plans like the Revised Action Programme (RAP) and the Water Sector Investment Planning Study (WSIPS), which were developed with assistance from abroad, thoroughly evaluate the needs and objectives of each sector.

#### **8. Sustainable irrigation for best crop yields**

Sustainable irrigation is the sensible use of all activities associated with the watering of plants, whether in agriculture, landscape, or ornaments, in such a way that it aids in meeting current survival and welfare needs without jeopardizing future generations. The term "sustainability" is frequently used to refer to the management, use, and protection of natural resources in such a way that future generations will have access to them [17–19]. In anthropocentric words, "sustainability" refers to a state in which current generation demands are met "without jeopardizing future generations' ability to fulfill their wants." [20]. As a result, sustainable irrigation encompasses the need to examine a variety of factors, particularly those relating to the deterioration, loss, or depletion of resources such as soil, water, and energy, as well as biodiversity and environmental preservation. Because water is a renewable resource, it is possible to aspire for great sustainability when it comes to irrigation. Of course, water resources may be non-renewable on a local level, like in arid regions with low

rainfall inputs and large non-renewable groundwater reserves. The exploitation of groundwater (commonly referred to as "groundwater mining") is a classic example of unsustainable water usage in such areas [21]. The aspect of sustainable irrigation encompasses not only the geographical location where irrigation is used but also the production and transportation of necessary equipment and supplies, as well as discharges and waste consequences. The consequences of the construction, operation, and maintenance of the works, which are either directly or indirectly required for irrigation and are frequently located over great distances, should not be overlooked.

Irrigation must be able to adapt to changing climates to remain sustainable. As a result, it must combat droughts as well as the impacts of global climate change on a broader scale. As a response, relying on other disciplines like crop selection and development, automation and telecommunications, institutional governance, and others might be critical.

Irrigation can help with climate change adaptation, labor and energy savings, and the production of higher-value crops. On the other hand, irrigation agriculture must be made more egalitarian, efficient, and sustainable to achieve zero hunger in an increasingly waterscarce world. Irrigated agriculture is contributing to, and being affected by, increased strains on freshwater resources, with more than 60% of global irrigated cropland under significant water stress. To ensure equal access to water and environmental sustainability, investments in expanded and enhanced irrigation must be matched by improvements in water governance. Improved data and knowledge on water resources and their use and well-defined water rights are cornerstones of better water governance [4].

Finally, just as sustainable irrigation must be able to cope with water scarcity, it must also be resilient to other resource scarcities throughout time, such as energy and finance. The themes of "water resources sustainability, "sustainable water usage," and "agricultural and rural development" are all intertwined in the concept of "sustainable irrigation."

Water resource sustainability refers to the ability to use water in sufficient quantities and quality on a local, regional, national, and global scale to meet the needs of humans and ecosystems now and in the future to sustain life and protect humans from natural and human-caused disasters that threaten life.

"Water usage that supports human society's potential to persist and thrive indefinitely without jeopardizing the integrity of the hydrological cycle or the biological systems that rely on it" is what sustainable water use means.

#### **9. Sustainability concerns in irrigated agriculture**

Irrigation is a considerable change in the physical, environmental, and social aspects of the area. Existing equilibriums are disrupted in the process, and new ones emerge over time. Fact, the essential principle of irrigation development is that new conditions meet mankind's goals better than old ones. This premise has proven to be correct in many ways. Irrigation was a major driving force in the growth of many ancient civilizations, and it continues to be so today. While just approximately a 6th of the world's agricultural land is irrigated, this part produces about a third of the world's food. The irrigated area of the world is not uniform. Different locations are afflicted by various sustainability issues. Many of the sustainability challenges raised by irrigated agriculture in affluent countries are like those raised by modern high-input agriculture, which places a heavy demand on natural resources and often exceeds the capacity for environmental assimilation. Many of the concerns about irrigated agriculture's sustainability in emerging countries, on the other hand, stem from the general development problems that these countries face, such as a lack of public capital, macroeconomic reliance on agricultural commodity exports, widespread poverty,

population pressure, insufficient management, and human resource development, institutional and regulatory shortcomings, and so on [22].

#### **9.1 Water resources**

Many countries, particularly those in the dry climatic zone with high rates of population growth, urbanization, and industry, are finding water to be a precious resource. Increased water competition in these nations will have a considerable influence on irrigated agricultural water supply [23]. The competing industries' water demand will always be a modest proportion of the naturally accessible supply in most countries. In most nations, the need to use water more efficiently will steadily rise. Most occurrences of groundwater mining are caused by a lack of sufficient legislation and enforcement, as well as a lack of awareness of the environmental implications.

#### **9.2 Land resources**

The deterioration of land resources because of agricultural usage is a major cause of worry across the world. Irrigation development has worsened this problem by generating conditions that have led to deforestation and soil erosion accidentally. This is especially true of land degradation in river diversion schemes upstream catchment regions [24].

#### **9.3 Waterlogging and salinity**

Irrigation has resulted in waterlogging and salinization of irrigated land on a huge scale. The incidence of this dual issue is usually limited to dry regions. About half of the world's already irrigated territory, or 270 million hectares, is thought to be desert.
