Short communication: Soil characteristics in Attock district

Soil testing for physical and chemical characteristics of a soil is key in assessment of a soil fertility that leads to productivity of a soil. A total of 11231 soil samples from six tehsils of Attock district were collected during five years (2012-17). Samples were analyzed for different parameters like pH, EC (1:10), texture, organic matter, Olsen Phosphorus and NH4-acetate extractable Potassium. As regards pH, 98% samples ranged between 7.5-8.5 while 97% samples were normal with respect to salinity/sodicity (ECe<4 dSm and SAR<15). Similarly 22% samples were light and 78% were medium in texture. Soils (96% ) were poor in organic matter (<0.86%) while 99% had available phosphorus <7 mg kg. 1362 soil samples were also analyzed for potassium showing poor in 31% samples (<80 mg kg ) while 69% samples lie in satisfactory to adequate range (81-180 mg kg). Depending upon the soil analysis, farmers were guided for fertilizer recommendations according to climate suitability, crop/orchard/vegetable and water/rainfall conditions as being implemented throughout the rain fed conditions of the Punjab by the Directorate of Soil Fertility, Thokar Niaz Beg, Lahore.

The Attock district came into existence in 1908 with global positioning of 33.4620 o N latitude and 72.2260 o E longitude. District covers an area of 693 thousand hectares with total area sown of 242 thousand hectares in which 211 thousand hectares is un irrigated and 31 thousand hectares is irrigated through different sources like canals, wells, tube wells etc. (Punjab Dev. Statistics, 2016) and divided into six tehsils with 72 union councils consisting of 435 villages. According to 2017 census, total population of the district is about 1.88 million. Whole district is a combination of plains and sub mountain which is interspersed by an irregular hilly system. The most important is of Kala Chitta Hills spreading over a length of 72 km with 19 km in width. Due to low fertility of land and small holdings, the socioeconomic condition of people is poor. District Attock has a changeable climate with warm wet summers and cold winter. Maximum temperature in summer reaches up to 50 o C and winter minimum temperature touches -2 o C. The average rainfall in district Attock is 783 mm (Anonymous, 2018).
Soil analysis has been used as an aid to assess soil fertility and plant nutrient management or "Soil Health" and to maximize yield based on the recommendation of fertilizer (Kausar et al., 2016). Soil testing is a better way than deficiency symptoms and plant tissue analysis because it helps in calculating the nutrient need of the plant before crop is planted. It is simpler and less time consuming than other methods (Aamer et al., 2015). In order to maximize agricultural production and conserve land resources, the knowledge about fertility status of the site is very important (Farmanullah et al., 2011). Soil texture as physical property while EC, pH, organic matter and nutrient contents as chemical properties usually indicate fertility and productivity status of a soil (Khattak and Hussain, 2007).
Soil sampling, analysis and the interpretation of the analytical data are the major steps leading to fertilizer recommendations of a soil among the first of three equally important steps in managing the nutrients required by plants. The second is the interpretation of the analytical data leading to the third step, recommendations for nutrient additions, as fertilizers or manures, to optimize crop yields while minimizing any adverse environmental impact from their application. The nutrient additions recommendations to soil is currently based on well-established methods of soil analysis. This will pave the way to upscale the activities concerning Right fertilizer/nutrient at the Right rate at the Right time in the Right place i.e. 4R nutrient stewardship (FAO, 2017). Soil test calibration across disparate locations, however, remains necessary for establishing firm relationship between the level of soil nutrient and crop response to fertilizer in the real-life field situations (Dey, 2016). Soil fertility status of Attock, Rawalpindi and Gujrat have shown that soils are deficient in organic matter and available phosphorus and fertilizer recommendations/application based on soil tests are pre requisite for higher crop yields (Obaid et al., 2010). Soil testing provides very useful information about the changing productivity and fertility level of the soils from time to time (Amrit, 2016). Nutrient wise fertilizer offtake and use in 2016-17 of District Attock was NPK @ 5856: 1013: 0 Tons ha -1 which was very low as compared to other districts (NFDC, 2017).   For this purpose, an attempt has been made to characterize the soil fertility and salinity status of district Attock and hence a step forward for judicious use of fertilizer by following recommendations based on soil analysis.
Composite soil samples under advisory service from the whole district were collected during previous five years (2012-13 to 2016-17) from 0-15 cm and 15-30 cm depth for crops and vegetables while, 0-15 cm, 15-30 cm, 30-60 cm, 60-90 cm, 90-120 cm and 120-150 cm depths from fruit orchards. Samples were air dried, crushed and passed through 2 mm sieve before storing into plastic bottles. A total number of 11231 prepared soil samples were analyzed for physical and chemical properties from six tehsils of Attock district. Electrical conductivity (EC) was measured through 1:10 soil and water suspension while pH and texture were recorded by making soil saturated paste. Organic matter content and available phosphorus were determined by using methods as mentioned by Malik et al., 1984. The criteria used for classification of different characteristics is presented in table 1 soil salinity/sodicity, table 2 soil texture and table 3 soil fertility.
The number of soil samples analysed during the year 2012-17 are presented in table 4.
As higher number of soil samples were collected from tehsil Jand, Hazro and Fateh Jang, respectively, which shows a general progress of the farmers from these tehsils and a higher scope for the progress of crop productivity in tehsil Pindi Gheb, Hassan Abdal and Attock as to boost up agricultural activities.
As for as soil salinity is concerned, the data in table 5 showed that almost 97 percent soils of the district Attock are normal and each tehsil has more than 90 percent normal soil so can be used for agricultural purposes hence depicting a huge scope of commercial farming in the district.
The results are same as presented by Obaid et al., (2010) and data showed 99.60% of the soil samples analysed in district attock were free from salinity/sodicity. Out of total, all soil samples were normal (97.6%) with no hazard of salinity (Sohail et al., 2001). The electrical conductivity of more than 99 percent soil samples from Rawalpindi district were normal (Mahmood et al., 1998). The data of soil in vegetable growing areas of Peshawar are none saline (Sajida et al., 2010). On the basis of EC, maximum area had normal soil (86.76 percent) in Sargodha district however there were some patches of salinity in all tehsils which was 13.28 percent of total samples analysed  (Kausar et al.., 2016).
The pH of soil samples analysed is presented in table 6, which depicts that more than 97 percent soil samples of the district and more than 90 percent soil in all tehsils have pH within rage of 7.5-8.5, indicating that soil is normal and can support optimum nutrient uptake if nutrient availability is made possible by soil fertility management practices.     (Kausar et al., 2016).
The analysis data of soil texture is shown in table 7. Data revealed that 78 percent soils of the district are medium in texture i.e. sandy loam, loam and clay loam while 22 percent soils fall in category of light texture i.e. sandy soil. Data also shows that 05 tehsils are dominant with medium textured soil while tehsil Jand bears light textured soil in most of the areas. This variability of texture in the district compute that almost all types of crops, vegetables and fruits, which need good aeration and perforation of soil may be grown commercially.
Data regarding soil organic matter is presented in table 8. Almost 96 percent of the soils in the district were poor in organic matter while 3 percent soils have satisfactory and only 1 percent soils bear up to adequate level (>1.25%). Overall, all tehsils have soil more than 90 percent with deficient organic matter. Organic matter is considered as lifeblood of the soil so low content of organic matter justify the need for recovery of this source through some sustainable and productive management. The low nutrient concentration might be due to losses through leaching as these soils were found sandy in nature or due to rapid decomposition at some locations (Ashraf et al., 2015). The results are in line with other scientists as data revealed that 93 percent soil samples were deficient in organic matter and 7 percent were satisfactory (Sohail et al., 2001). Similarly, the data showed that 91 percent soils in Attock district were poor and only 7.82 percent were satisfactory with respect to organic matter (Rehman et al., 2010).
Available phosphorus (P) status in soils of the district Attock is described in table 9. Data regarding soil available phosphorus clearly explains that 99 percent soil of the district are deficient in available P, hence addition of P nutrient into soil for each crop is mandatory. Secondly, the P deficiency prevails at almost more than 98 percent soils of all tehsils. So maximum benefit from phosphatic fertilizers can be achieved if used at the time of sowing. These fertilizers have residual effect and subsequent crops are benefitted if full dose of phosphatic fertilizer is applied to the previous crop which utilizes only 18-20 percent of P. A large quantity of well rotten farm yard manure may be applied or green manuring should be done to increase the efficiency of phosphate fertilizers (Rehman et al., 2000).
1362 soil samples were also analyzed for available potassium presented in table 10 showing 31 percent poor while 69 percent samples lie in satisfactory to adequate  range. Tehsil wise comparison of K status shows that tehsil Hasan Abdal, Hazro and Fateh Jang have soils more than 75 percent with sufficient K while tehsil Attock, Jand and Pindi Gheb have more than 40 percent soils with deficient K which indicates the natural K status in soil however continuous cropping may ask to maintain the K adequate status by adding through sources. The nutrient index value of Chakwal soil in respect of soil organic matter and phosphorus were poor whereas satisfactory for potassium (Khalid et al., 2012).
By focusing on the characteristics of soil analysis, data shows that over all district has normal soil in view point of salinity and pH however soil fertility status is low due to low OM contents and available P which can be built up by different sources like farmyard manure, green manure (Guara, Dhancha, Sesbania etc.) and poultry manure which can also improve soil structure and water holding capacity. The fertility status can be boosted by adopting practices e.g., site specific fertilizer recommendations, regular additions of organic manures and appropriate agronomic practices (Denis et al., 2017). The 4R concept i.e. Right fertilizer at Right rate at Right time in Right place may also be helpful in low fertility soil for optimum crop growth.