The study aimed at assessing the nutrient status of rangeland in upper Mustang. The assessment is necessary to know about the soil quality or productivity of soil of rangeland. Livestock rearing is one of the main occupations in upper Mustang but nowadays due to lack of palatable species for livestock, people are leaving the occupation which is directly affecting their livelihood status. Therefore this research was carried out to find out if the soil nutrient is the reason behind the lack of availability of palatable species in the rangeland. For soil sampling, north and south aspects were taken. In case of altitude, 3850 m, 3650 m and 3450 m were taken. Soil samples were taken from soil profile up to 60cm depth at interval of 20 cm. Available phosphorus and available potassium were found to be high at north aspect but total nitrogen was found to be high at south aspect. Both total nitrogen and available phosphorus were found to be high at 3650 m. Available potassium was gradually decreased with increasing altitude. Total nitrogen, available potassium and available phosphorus were gradually decreased with increasing soil depth. Nutrient status was high at top soil (0-20 cm).The soil nutrient (Nitrogen, Phosphorus, Potassium) status was found to be good in the study area. Further research on biophysical and ecological aspect of Rangeland in Upper Mustang is necessary to manage it properly. Key words: Nutrient, Nitrogen, Phosphorus, Potassium, rangeland, upper Mustang Nutrient status of rangeland in upper Mustang M. Maharjan1, K. D Awasthi2, K. R Pande3 and N. Thapa4 Rangelands of upper Mustang are major source to sustain livestock as well as people’s livelihood as they are rich in medicinal and aromatic plants and Trans- Himalayan biodiversity. They are also sources of other natural resources, tourism, carbon sink, valuable cultural landscape, place for recreation and aesthetic value, and beautiful scenery. Much of the Mustang landscape is dominated by pastures but the prevailing harsh climatic condition does not permit to grow sufficient grasses in these lands (Kunwar, 2003). Agricultural production in these areas is very limited due to scarcity of water, lack of proper irrigation, low temperature for longer periods and low rainfall (Thakali, 1994). Very limited research work carried out in the field of soil properties/quality/ nutrient in rangeland especially in upper Mustang. The study will be beneficial to find out the status of soil nutrient which is beneficial for improving livelihood of local people through proper management of rangeland. The objective of the study was to find out the status of nutrient of rangeland in upper Mustang. Materials and methods Study Area Upper Mustang, particularly Lo-manthang lies in the northern part of Mustang District approximately at 83o 45’ to 84o 15’ E and 29o 04’ to 29o 18’ N (Fig. 1). The climate of the area can be characterized as cold desert, desiccated by strong winds and high solar radiation. The total area of Lo-mangthang VDC is 282.25 sq. km. with total population of 800 (MOP, 2009). The altitude range of Lo-manthang VDC ranges from 3200 m to 6500 m. Sampling method The stratified sampling method was adopted for the study. The starting point was selected randomly and considered as centre point. After selecting the center point, two plots each having 50 m perpendicular distance from center line were 1 Tribhuwan University, Institute of Forestry, Hetauda, Nepal, Email: menuka48maharjan@gmail.com 2 Tribhuwan University, Institute of Forestry, Pokhara, Nepal 3 Tribhuwan University, Institute of Agriculture and Animal Science, Rampur, Nepal 4 Annapurna Conservation Area Project, Pokhara, Nepal 41 Banko Janakari, Vol. 24, No. 1 42 fixed. For soil sampling, north and south aspects were taken. Soil samples were collected from three different altitudes (3850 m, 3650 m and 3450 m). Three replication of soil samples were taken from each strata for computing nutrient as well as carbon stock measurement. For nutrient profile, soil was dug at the centre part of the plot up to 60 cm depth. Soil samples at different depths (0–20 cm, 20–40 cm, 40–60 cm) were collected. A core ring sampler (4.8 cm diameter and 10 cm long) was used for estimation of bulk density. Soil properties under study with methods of measurement Soils are generally categorized into three categories. They are i) acidic soils (with pH values less than 6.5), ii) nearly neutral soils (with pH value 6.5–7.5), and alkaline soils (with pH values more than 7.5) (NARC, 1993). Different methods are used to determine the soil properties (Table 1). The soil texture was measured using Hydrometer Method whereas the soil chemical properties: the pH, the total nitrogen (TN), the available phosphorus (AP) and the available potassium (AK) were measured using the Glass Calomel pH Meter, Kjeldahl Method and Olsen’s and Somers Method (1982) and the Frame Photometer Method respectively. The soil samples were analyzed at the Regional Soil Laboratory, situated at Lumle, Kaski District, to assess the status of the major physico-chemical properties.The textures of the soil were determined on the basis of the relative distribution of sand, silt and clay in the sample. Table 1: Soil properties under study with their methods of measurement Soil properties Methods Physical Texture Hydrometer method Chemical pH Glass calomel pH meter Total Nitrogen(TN) Kjeldahl method (Bremner and Mulvaney, 1986) Available Phosphorus (AP) Olsen’s and Somers method (1982) Available Potassium (AK) Flame Photometer method Interpretation of different soil properties Table 2 shows that pH range in soil according to pH value. If pH value is less than 4.5 then soil is strongly acidic. It’s value is between 4.5 to 5.5, soil considers as moderately acidic. If pH value is between 5.5 and 6.5 then soil is weakly acidic in nature. If the value is between 6.5 and 7.5 then soil is nearly neutral. If the value is greater than 7.5, soil is alkaline in nature. Table 2: Interpretation for soil pH pH Range <4.5 Strongly acidic 4.5–5.5 Moderately acidic 5.5–6.5 Weakly Acidic 6.5–7.5 Nearly Neutral >7.5 Alkaline Table 3 shows that level of different nutrients (TN, AP and AK) in soil. If TN (%) is less than 0.1, soil has low level of TN whereas if it is higher than 0.2 then soil has high level of TN. If AP (kg/ ha) is less than 31, soil has low level of AP and if it is more than 55 then soil has high amount of AP. Regarding AK (kg/ha), if the range is less than 110 then soil has low level of AK and if it is more than 280 then soil has high amount of AK. Maharjan et al. Fig. 1: Study area (Source: MOP, 2009) Banko Janakari, Vol. 24, No. 1 43 Table 4: Physico-chemical properties of soil at different aspect and altitudes Aspect/ Altitude pH Particle size distribution (%) TC* Sand Silt Clay Mean ± SE Mean ± SE Mean ± SE Mean ± SE N**/3850 m 8.4± 0.1 77.53± 2.5 20.99± 2.61 1.47± 0.95 LS S***/3850 m 8.6± 0.06 71.32± 0.29 27.22± 0.29 1.46± 0.0 SL N**/3650 m 8.7± 0.05 71.65± 0.48 27.05± 0.53 1.3± 0.98 SL S***/3650 m 8.6± 0.05 73.76± 0.48 24.39± 1.13 1.85± 0.72 LS N**/3450 m 8.5± 0.88 70.65± 0.86 27.78± 0.77 1.57± 0.11 SL S***/3450 m 8.7± 0.88 74.43± 1.63 4.33± 1.57 1.24± 0.72 LS * TC=Textural class; LS= Loamy sand; SL= Sandy loam, **N=North, ***S=South Table 3: Interpretation table for soil fertility TN (%) AP (kg/ha) AK (kg/ha) Range Level Range Level Range Level <0.1 Low <31 Low 110 Low 0.1–0.2 Medium 31–55 Medium 110–280 Medium >0.2 High >55 High >280 High Source: NARC, 1993 The texture of the soil was determined from the relative distribution of sand, silt and clay in the sample. Statistical analysis Data analysis was carried out using SPSS and Microsoft Excel. Descriptive statistics used to produce tables while inferential statistics also used to test the relationships between different variables under study. One-way ANOVA was carried out to test the variation of different properties of soils with respect to different factors under study. Multiple comparisons of means were carried out using LSD0.05. Results and discussion Physico-chemical properties of soil pH (8.7) was high at North(N)/3650 m and South (S)/3450 m followed by S/3850 m and S/3650 m (8.6) and N/3450 m (8.5), N/3850 m (8.4) as shown in table 4. The soil of the study area was basic in nature. Due to low rainfall the soil of the arid region is basic in nature. The dominant texture classes were sandy loam and loamy sand. Loamy sand texture class was found at N/3850 m followed by sandy loam text class at S/3850 m. Similarly, sandy loam texture class was found at N/3650 m, N/3450 m and loamy sand texture class at S/3650 m, S/3450 m. Status of nutrients at different aspects, altitudes and soil depths Total Nitrogen Total nitrogen was higher at south aspect (0.20%) than north aspect (0.19%) as shown in table 5. Due to high clay content and biomass, high nitrogen stock was found in the southern aspect. Table 5: Total nitrogen (%) at different aspects Aspect Mean Max. Min. Range Standard error North 0.19 0.23 0.16 0.07 0.008 South 0.20 0.34 0.14 0.20 0.021 Mean 0.19 TN was high at 3650m (0.22%) followed by 0.19% at 3450 m and 0.17% at 3850 m as shown in table 6. There was fluctuation in TN at different altitude. Due to presence of deep rooted vegetation, TN was high at 3650 m altitude. Table 6: Total nitrogen (%) at different altitudes Altitude (m) Mean Max. Min. Range Standard error 3450 0.19 0.23 0.16 0.07 0.01 3650 0.22 0.34 0.16 0.18 0.02 3850 0.17 0.23 0.14 0.09 0.01 Mean 0.19 Maharjan et al. Banko Janakari, Vol. 24, No. 1 44 Total nitrogen was high at 0–20 cm (0.23%) followed by 0.20% at 20–40 cm and 0.16% at 40–60 cm soil depth as shown in table 7. TN was gradually decreased with increasing soil depth. Vegetations present in the top soil were the main cause of this result. Table 7: Total nitrogen (%) at different soil depths Soil Depth Mean Max. Min. Range Standard error 0–20 cm 0.23 0.34 0.19 0.15 0.02 20–40 cm 0.20 0.28 0.16 0.12 0.02 40–60 cm 0.16 0.19 0.14 0.05 0.01 Mean 0.20 One way ANOVA test revealed that TN was significantly different at different soil depth (p value =0.04). LSD0.05 test showed that TN was significantly different between 0–20 and 40–60 cm soil depth but no significant different was found with other soil depth as shown in table 8. Total nitrogen in the soil is solicited because the nitrogen in the soils occurs in several forms band it takes into account all the nitrogen in organic and inorganic forms. Some scientists argue that TN does not give good indication of soil fertility because only a small portion of TN is available to plants. About 2 to 3% of TN is in the inorganic form, mostly ammonium (NH4+) and Nitrate (NO3-) which are only available to the plants (Bandel et al., 2000). Others present different views that organic and inorganic forms of nitrogen are always interchangeable and it would be better to consider the total nitrogen to investigate soil quality. Determination of Nitrate (NO3-) and Ammonium (NH4+) would not give an overall picture of the fertility, but give a snapshot of the N availability not only for plants but also, for micro-organisms in the soil (Truelsen and Lundsby, 2001). Available Phosphorus Available phosphorus was high at north aspect (71.86 kg/ha) followed by south aspect (60.01 kg/ha) as shown in table 9. This table showed that AP was found higher at north aspect than south aspect. Table 9: Available phosphorus (kg/ha) at different aspects Aspect Mean Max. Min. Range Standard error North 71.86 93.30 46.70 46.60 5.72 South 60.01 86.70 23.30 63.40 7.18 Mean 65.93 AP was varied at different altitude found high at 3650 m (77.78 kg/ha) followed by 69.46 kg/ha at 3850 m and 50.55 kg/ha at 3450 m. Both TN and AP were found high at 3650 m as shown in table 10. High clay content at this altitude caused to show high TN and AP. Table 10: Available phosphorus (kg/ha) at different altitudes Altitude (m) Mean Min. Max. Range Standard error 3450 50.55 23.30 93.30 70.00 9.86 3650 77.78 66.70 90.00 23.30 3.82 3850 69.47 50.00 86.70 36.70 5.80 Mean 65.93 One way ANOVA test revealed that AP was significantly different at different altitude (p value = 0.04). LSD0.05 test showed that AP was significantly different between 3450 m and 3650 m altitude where no significance difference found with other altitude (p≤0.05) as shown in table 11. Maharjan et al. Table 8: LSD0.05 for Total nitrogen (%) at different soil depths Factors Paris compared (cm) Mean difference Standard error Significance TN 0–20 and 20–40 0.33 0.24 1.85 0–20 and 40–60 0.68* 0.24 0.01 20–40 and 40–60 0.35 0.24 0.17 * denotes the mean difference at p≤0.05 Banko Janakari, Vol. 24, No. 1 45 Table 11: LSD0.05 for Available phosphorus (kg/ha) at different altitudes Factors Paris compared Mean difference Standard error Significance AP 3450 and 3650 m -27.23* 9.85 0.01 3450 and 3850 m -18.92 9.85 0.07 3650 and 3850 m 8.32 9.85 0.42 *denotes the mean difference at p≤0.05 AP was gradually decreased with increasing soil depth. AP was found 75 kg/ha at 0–20 cm followed by 65.01 kg/ha at 20–40 cm and 57.78 kg/ha at 40–60 cm soil depth as shown in table 12. Awasthi (2004) reported that nutrient stock was found high at top soil which was found true in this study also where AP was high at 0–20 cm soil depth similarly AK and TN was also found high at the same soil depth. Table 12: Available phosphorus (kg/ha) at different soil depths Soil Depth Mean Max. Min. Range Standard error 0–20 cm 75.00 43.30 93.30 50.00 7.44 20–40 cm 65.01 36.70 86.70 50.00 8.20 40–60 cm 57.78 23.30 80.00 56.70 8.42 Mean 65.93 Available Potassium Available Potassium was high at north aspect (742.90 kg/ha) followed by south aspect (531.37 kg/ha) as shown in table 13. This result showed that AK status was quite good in the study according to table 13. Table 13: Available Potassium (kg/ha) at different aspects Aspect Mean Max. Min. Range Standard error North 742.90 266.70 1643.00 1376.30 147.93 South 531.37 283.30 1083.00 799.70 102.91 Mean 637.13 AK was gradually decreased with increasing altitude. AK was high at 3450 m (753.22 kg/ha) altitude followed by 666.62 kg/ha at 3650 m and 491.57 kg/ha at 3450 m as shown in table 14. From table 14 it was concluded that AK status was good at all altitudes. Table 14: Available potassium (kg/ha) at different altitudes Altitude (m) Mean Min. Max. Range Standard error 3450 753.22 283.30 1643.00 1359.70 218.95 3650 666.62 283.30 1083.00 799.70 134.15 3850 491.57 266.70 1003.00 736.30 107.71 Mean 637.13 AK was gradually decreased with increasing soil depth. AK was high at 0–20 cm (1052.50 kg/ ha) followed by 20–40 cm (528.90 kg/ha) and 40–60 cm (330 kg/ha) soil depth as shown in table 15. The decreasing trend of AK was quite high according to depth of the soil but AK status was good at different soil according to table 15. Table 15: Available potassium (kg/ha) at different soil depths Soil Depth Mean Max. Min. Range Standard error 0–20 cm 1052.50 503.00 1643.00 1140.00 147.69 20–40 cm 528.90 360.00 870.00 510.00 77.58 40–60 cm 330.00 266.70 486.70 220.00 33.13 Mean 637.13 One way ANOVA revealed that AK was significantly different at different soil depth (p value=0.00). LSD0.05 test showed that AK was significantly different between 0–20 and 20–40 cm, 0–20 and 40–60 cm soil depth but no significant difference was found with other soil depth as shown in table 16. Table 16: LSD0.05 for Available phosphorus (kg/ha) at different altitudes Factors Paris compared Mean difference Standard error Significance AK 3450 and 3650 m 523.60* 138.87 0.00 3450 and 3850 m 722.50 138.87 0.00 3650 and 3850 m 198.90 138.87 0.17 *denotes the mean difference at p≤0.05 Maharjan et al. Banko Janakari, Vol. 24, No. 1 46 Conclusion Sandy loam and loamy sand are dominant soil texture found in the study area. Basic nature of soil was found in the study area. Soil properties like TN, AK and AP were found significant different. Nutrient status was high at top soil (0–20 cm). The soil nutrient (N, P, K) status was good in the study area. Further research on biophysical and ecological aspect of rangeland in upper Mustang is necessary to manage it properly. References Awasthi, K. D. 2004. Land Use Change Effect on Soil Degradation, Carbon and Nutrient Stocks and Greenhouse Gas Emission in Mountain Watersheds. Ph.D. Thesis, Agricultural University of Norway, Norway. Bandel, A. B. R. and Meisinger, J. J. 2000. Basic Principles of Soil Fertility I: plant nutrients. Maryland cooperative extension. University of Maryland, Maryland, USA. Bremner. J. M. and Mulvaney, C. S. 1986. Nitrogen total. Methods of soil analysis, Chemical and microbiological properties. ASA, SSSA, Madison, Wisconsin, 595–624. Kunwar, P. B. 2003. People-wildlife Conflict in the Upper Mustang of Annapurna Conservation Area. M.Sc. Thesis, Tribhuvan University, Institute of Forestry, Pokhara, Nepal. Management Operational Plan (MOP) 2009. Conservation Area Management Committee, Lomangthang. National Trust for Nature Conservation-Annapurna Conservation Area Project, Nepal. National Research Council. 1993. Soil and Water Quality: An Agenda for Agriculture. National Academy Press, Washington DC, USA. Olsen, S. R. and Somers, L. E. 1982. Phosphorus. P. Methods of soil analysis. Chemical and microbiological properties. ASA, SSSA, Madison, Wisconsin, 403–430. Truelsen, O. M. and Landsby, P. 2001. Application of the Nutrient Balance Concept to the Traditional Subsistence Farming System in the Middle hills of Nepal. M.Sc. Thesis, University of Royal Veterinary and Agriculture, Denmark. Thakali, S. 1994. Regenerating Tradition: Tourism and Cultural Invention in Nepal. M.A. Thesis, Roehampton Institute, University Survey, U.K. Maharjan et al.