Soil survey

Soil survey basically aims at taxonomical classification of soils .The properties studied in the survey are ultimately used to plot the extent of boundaries on a map. The maps are referred for various purposes particularly for predicting yields based on soil fertility.

Fertility surveys are carried out in profile studies. Profiles in representative locations in each soil series are opened and thoroughly examined. From samples collected at different depth wise layer, soil physical, chemical, and biological properties are thoroughly studied. The factors limiting crop growth are identified in field and laboratory estimations.

Aims and Objectives

•         To assess the fertility status of soils in the tract with the help of suitable laboratory techniques.

•         To suggest measure for the economic crop production through soil testing advisory service.

•         To control the salinity and alkalinity menace where ever it threatens good crop production by the use of amendments in quantities needed for reclamation.

•         To survey the status of micro elements and explore measures to cope with their deficiency or toxicity.

•         To analyses water for its suitability for irrigation purpose,

•         To analyze fertilizer and gypsum samples for their purity.

Soil Fertility Status of Gujar Khan (Rawalpindi

•         Humid to sub-humid in north and sub-humid in low land of Rawalpindi.

•         Sub humid high land is characterized by rainfall from both monsoon, giving a twin peak type distribution with maximum precipitation occurring in July to September.

•         Summer are pleasantly cool (90-100 F) while winter are severe with considerable frost and small quantity of snow in month of January.

•         The rainfall in this area varies from 500-1000 mm per annum.

•         70 % of annual precipitation is received in summer months of July and august (monsoon season) and 30 % in winters.

•         Winters are distinctly cold. The temperature ranges  0-45 ◦C through out the year at rawalpinpi.

•         High intensity rainfall and undulating topography are main causes of water erosion in this area.

•         Tree Species:

•                     In the gullied and rock land area the most common tree species is Phulai (Acacia modesta) In the higher elevation of kahuta and Murree Mulbery (Morus Alba), Chil (Pinus Longifolia), wild olive (Olea suspidate) are common.

•         Crops:

•         Wheat is dominant rabi crop while other crops sown in summer are gram, barley, lentils and oil seed but all are of minor importance due to usually sown mixed with main wheat crop. Most of sarson (mustard) crop is pulled out green for use as fodder. Additionally some farmers are sowing seed along the outer edges of fields millets(Bajra) are most common kharif crop. They are drought resistant and are widely grown the dried areas. Bajra is grown for  grain and sorghum is usually grown for fodder purpose. Maize, being less drought resistant is grown only in areas where rainfall more reliable. Ground nut have been grown in pothwar area where rainfall is too low for assured production of other valuable summer crops

PROCEDURE

•         pH:

Recorded the pH of the soil samples by dipping the electrode of pH meter in soil paste, after calibration of pH meter with standards 7 and 9 buffer solutions.

•         EC:

            For EC determination, soil and water were taken in 1:10 ratio. The instrument was standardizes with 0.01N KCl solution. The EC of this standard solution is 1.413dsm-1 at 25Co.

•         Organic Matter:

            1 g of soil weighed on electrical balance, put in a 250 ml conical flask. Then added 10 ml of K2Cr2O7 and 15 ml of H2SO4. 200 ml of D. water added in this solution and left for half an hour. Added 2-3 drops of diphenylamine and titrated with Fe2SO4 till green color.

•         Phosphorus:

            2.5 g of soil weighed and taken in a shaking bottle, 50 ml of NaHCO3 added and putt on shaker for half an hour. After shaking filter the content in bottles with the help of filter paper (Wattman-42). 5 ml of filtrate taken in 25 ml volumetric flask in which 5 ml of color developing reagent(mixed reagent + ascorbic acid)added and made volume. Take reading on spectrophotometer at 882 nm wavelength.

•         Potassium:

            2.5 g of soil weighed and taken in a shaking bottle, 50 ml of ammonium acetate added and putt on shaker for half an hour. After shaking filter the content in bottles with the help of filter paper (Wattman-42). Take reading on flame photometer.

Results

ECe, pH, Organic Matter and Texture:

ECe: ECe ranged from 0.64 to 1.5 soil with a mean value of 1.09±0.23

pH: pH ranged from 7.4 to 8.6 soil with a mean value of 7.68±0.16

Texture: Loam

OM:

            OM in the soil ranged from 0.2 to 0.99 % soil with a mean value of 0.67±0.20

Phosphorous:

            P in the soil of Gujar Khan ranged from 4.62 to 9.98 ppm soil with a mean value of 6.75±0.64

Potassium:

            K ranged from 96 to 200 ppm soil with a mean value of 129.1±25.19.7

Organic Matter:

            The 75 % soils of these union councils were deficient in organic and 25 % were in medium range.

Phosphorus:

            The 75 % soils were deficient in ‘P’ having varying levels and 25 % have medium amount of P.

Potassium:

            All the surveyed soils of Gujar khan had medium concentration of K (>80 mg/kg).

Organic Matter & Nutrient contents in soil on percent basis

Macronutrients	Deficient (%)	Medium (%)	Adequate (%)
P	75	25	-
K	-	100	-
OM	75	25	-