Since the immemorial times, agriculture is adopted by man as a profession that provides him food, clothes and shelter. Agriculture not only provides raw material for primitive industry but also plays a role in the uplift of social status of human in the society.
The history of world shows that the nations achieved their rise when they become self sufficient in food but faced fall when their agriculture destroyed. Like other Asian countries, Pakistan also has an agro-based economy. It accounts for 20.9 percent of GDP and employs 43.4 percent of the total work force.
Agriculture contributes to growth as supplier of raw materials to industry as well as market for industrial products and also contributes substantially to Pakistan‘s exports earnings. Almost 66.7 percent of country‘s population lives in rural areas and is directly or indirectly linked with agriculture for its livelihood.
The crop production in Pakistan is lowest as compared to the world‘s averages. The main reason behind this is the water logging and salinity which directly effects the crops production and indirectly affects the livelihood of the depended people.
Water logging is the saturation of the soil by groundwater sufficient to prevent or hinder agriculture. Water logging in its purest sense is the soil condition with little or no oxygen in it so the plants root function is impaired, restricting its ability to take up nutrients and photosynthesis properly.
It is mainly caused due to the inadequate provision of surface and sub surface drainage and poor water management. Poor agricultural and drainage system and also occur due to the seepage from the rivers, canals and other irrigation channels into the nearby lands.
When water collects in the soil for prolonged time without infiltrating, it causes to increase the water table of the soil which leads to the water logging. When water accumulates in a specific area the amount of salts and minerals also becomes dissolved and moves to the upper horizon which forms white salty layer and leads to salinity.
The adverse effects of water logging on plants are the decreased availability of Oxygen and accumulation of phytotoxins .Oxygen deficiency inhibits aerobic respiration, resulting in severe energy deficiency and eventually death). Water logging can also reduce the availability of some essential nutrients, e.g. nitrogen, and increase the availability of nutrients, e.g. Fe and Mn .Such increases in micronutrients in soil and subsequently in shoots may affect plants both during water logging and also after water logging .Water logging during sowing or germination generally kills the seed or seedling. The seedling’s radical and roots do not adapt readily to water logging or are more susceptible to seedling diseases which cause long-lasting adverse consequences leading to poor growth and reduced grain yields.
Water logging and salinity is one of the most severe restrictions in Pakistan’s agricultural productivity of Irrigated lands. Water logging and salinity has been eroding the potential agricultural productivity. Water logging is the major problem which causes the lower production of agricultural crops in Pakistan. Water logging and salinity affects 25% of irrigated land in Pakistan, reducing crop yields. It has been reported that 48% of the soils in Sindh and Punjab are saline while 18% of the soils are strongly saline.
Pakistan has almost 6 Mha of salt affected lands, of which about half is found in the canal irrigated areas. While an area of 2 Mha has been reportedly abandoned due to severe salinity. Similarly in Khyber Pukhtoonkhwa 63500 acres are affected due to water logging and salinity. Extent of water logging and salinity reported by different agencies gave quite different figures. WAPDA (1979) reported 0.023 ha surface soil salinity based on the survey of 8.50 Mha of Indus Basin in Khyber Pukhtoonkhwa. It had also been reported that the total salt affected soil of Khyber Pukhtoonkhwa is 0.472 Mha. Similarly water logging in irrigated areas of Khyber Pukhtoonkhwa estimated by WAPDA (1980-81) is 0.176 Mha out of which 0.113 Mha has water table depth above 5 feet.
Thus knowing the severity of the problem proper mitigation measures like growing of Eucalyptus in water logged areas, using of Gypsum, modification and up gradation of existing SCARP project and renovating and implementation of modern and scientific agricultural and irrigation practices should be addressed for the minimizing and reducing the impacts on crops production which will not only helps in the increase agricultural yield but will also boost the agricultural economy and would lead to the sustainable development.
This Article is Written By “Muhammad Ziad” Guest Author At Envirocivil.com