Zikrullah Safia, Ghulam Mohammad Bahramc, Mohammad Alem Alem
Kabul, bowl like capital city of Afghanistan is located at elevation of 18, 00 m a s l. with the current population of 4.2 million. The constructed areas have been encircled by urban fields. Climate is highly continental; rainfall always contributes water as a supplemental irrigation to agricultural crops. Sedimentations in streams, water courses, and in Kabul River are often observed. Urban fields have been regularly used for fresh vegetables and cereals in the rotation for food and feed production. Agriculture productions rely on fertilizers, but use of night soil and city bio-wastes are in abundance. Torrential rainfall is often observed as a main source of soil erosion. The run-off degrades environment by contamination of surface water, underground water, Kabul River and other low laying water bodies. A study on “Organic matter and nutrient (NPKC) losses via run-off in the Urban Agriculture (UA) of Kabul”, was conducted (March-December, 2016) to quantify soil and nutrient losses via run-off in urban areas of Kabul. Four endemic crops of Kabul Province were planted in the rotation. The results showed neglect erosion according to the universal soil loss
equation. The total Monthly average soil losses in two farms (n= 30) were 2.52 kg ha-1. Maize and wheat plots had higher soil losses (19.30 and 18.52%), respectively. Barley and millet had lesser
soil losses (15.37, and 12. 49%), respectively. Control plots of both farms showed 17.65% soil
losses. The average total N, P, K losses were neglected due to low rainfall and short period of study, statistically the variation of soil losses under different cropping system was not significant (p >0.05).
Lastly, based on our findings, few recommendations have been suggested to scientists, farmers and policy makers.
Keywords: Run-off, Soil erosion, Kabul urban area, Afghanistan.
Kabul is one of the largest city and the national capital of Afghanistan, located in a narrow valley along the Kabul River, overlooked by the Asmai and Sherdawaza mountain ranges, in the east-central part of the country. Kabul is an old city with a history of more than 3000 years. The city was for centuries a way-station and a major trading center at the trade routes between South and Central Asia (see figure 1). Kabul, one of the highest capitals in Asia, with its current population of 4.2 million (CSO. 2014/2015) is located at 18.00 m a s l. Kabul’s soil has developed under arid and semiarid climatic condition. Unplanned use of city bio-wastes and sewage water for irrigation remained always main sources of
nutrients imbalance in the urban soil (Safi et al., 2010). The elemental overloaded sewage waters increases the materials toxicities in the soil during irrigation which degrades the environment. Despite of economic losses, leaching of nitrite, nitrate, phosphate, and ammonium contaminate surface and underground water. It is reported that Kabul basin is indicating deposits including sand, silt and clay which have been imported from the surrounded mountains originated by carbonates, marls, sand stones and from melted magma karsts. Ground water in some places of Kabul city is affected by sedimentation which contained toxic materials such as NO2, NO3, Bo2 and other soluble contaminants (Initial Environmental Examination., 2011; Mohummad et al., 2014). The 10.8% contaminated wells of Kabul with nitrate can be good example (Houben. 2005). Leaching of nitrate, phosphate and ammonium in the vegetable production areas were reported high too (Safi et al., 2011). Contamination of Kabul River in the low laying area of Peshawar with some toxic elements was also reported. (IUCN, Pollution and the Kabul River, 1994). This can be solved by study of the current ongoing farming system and applying different practices such as soil and crop management, soil erosion control will increases soil productivity. Chaudary and Shafiq reported that crop management is one of the best ways of soil erosion control (Chaudhry and Shafiq, 1986). The practice of good cultivation combination, optimum sowing method, use of mulching; disclose crop cultivation and precise use of chemical and organic fertilizers may enhance soil protection.(Safi, et. al. 2016; Khan, et. al. 2007).