PRELIMINARY STUDIES ON THE FERTILITY STATUS OF THE SOILS OF SRIGANGANAGAR DISTRICT, RAJASTHAN

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1 ANNALS 01' ARID zone VoL 12, No.1 & 2, March & Jane, 1973 PRELIMINARY STUDIES ON THE FERTILITY STATUS OF THE SOILS OF SRIGANGANAGAR DISTRICT, RAJASTHAN VINOD KUMAR, G.S. MATHUR AND S.P. SBTH AGRICULTURE CHEMISTRY SECTION, GOVT. AGRIC. RESBARCH FARM, DURGAPURA ( JAIPUR ) Received on ABSTRACT Preliminary studies on the soil fertility status of Sri Ganganagar soils were made. For tbis purpose in all 447S surface soil samples have been analysed. The soils can be grouped into three soil groups i. e. Desert, Sierozems and Reverine. The nutrient index values for these soil groups show that Desert and Sierozems soils are poor in organic matter status. while Reverine soils are medium in this respect. Desert soils are also poor in available P and K and normal. in reaction, while Sierozems are medium in available P and K. Reverine soils are tending to become alkaline with low available P and medium available K content. *Present address Assitant Chemist Cotton, HAU, Hissar.

2 60 VINOD KUMAR, G. S. MATHUR AND S. P. SETH INTRODUCTION Sri Ganganagar with an area of twenty one thousand square kilometers constitutes the borthern portion of semi-arid tract of Rajasthan. It comparises of three main soil types viz., Desert, SierozenlS & Reverine. In order to frame efficient fertilizers recommendation schedule, it is necessary to have a knowledge of soil fertility status of various regions in the area. Since no information is available en the subject, studies in this respect were under taken at soil testing laboratory. Sri Ganganagar (Rajasthan). MATERIAL AND METHOD For the purpose of preseht study in all 4475 surface soil samples were obtained from a\l soil types i.e samples from Desert soil, 1875 from Sierozems and 1400 from Reverine soil. These soil samples were analysed for different soil test values, viz., pif, soluble salts {Electrical Conductivity h organic carbon, available P & it by rapid soil test methods. The ph in the suspension of 1 : 2 soil 'Water ratio was measured electrometrically and conductivity by solubridge. The samples obtained from various soil types were I:ategoris~das suggested by Tamhane et al (1959) into low, medium and high. With a view to compare the fertility levels of different soil types, a single fertility index for each soil type has been calculated. RESULT AND DISCUSSION The percentage of soil samples falling in each category for three soil groups is given in table 1, the nutrient index and fertilizers recommendation for ea'ch roil group for important 'Crops is given in table 2 and 3 respectively. Desert Soils = Soils falling in this group are poor in structure with low organi'c carbon content, which ranges from 0.05 to 0.50 per cent. These 'soils are normal in reaction, and hence there is no problem of salinity and alkalinity. Soils are low in available P & K. Total per cent samples were low ill,avahable P and '6'6.0 per cent samples were low in available K. Only 5.5 per 'cent samples of this group had high available K conteut. Available P ranges frold tra<:e$to 76.0 lbsfacre. while available K was 25.0 to Ibsfacce.

3 THE SOIL or SRIGANGANAGER DISTRlQT I 61 Table 1. Table showing the percentage of the samples in different nutrients range Component Range Soil Types analysed Desert Sierozems Reverine ph Acidic ( <6.5) Normal ( ) Tending to become ( ) alkaline Alkaline (> 8.5) E.C. Normal ( <1.0) Mmimhosf Tending to become an. at 25 c critical (1-3) Critical (> 3.0) Organic Low ( %) carbon Medium ( %) High <>0.75%) AV3ilaNe P Low ( Ibi/acce) Medium ( do High (> do Available K Low.( Ibs{acre) Medium { do <' Higll {> do- 5.SO

4 62 I VINOD KUMAR, G. S. MATHUR AND S. P. SETH Table 2 Table showing nutrient index values for different soil types Soil type No. of Nutrient index samples Organic Available P. AvaIlable K. carbon Desert Soil Sierozems Soil Reverine Soil Average The nutrient index values show that soils are low in organic carbon and available P & K with poor structure and thus it is suggested that the heavy application of organic manures and green manuring practices should be adopted to improve the fertility status of these soils. Since leaching is the main problem where irrigation facilities exist, application of nitrogenous fertilizers should be done in split doses so as to check leaching losses and get maximum response of applied fertilizers. Sierozems I These cover a major portion of the district and most of area is canal irrigated. The ph of only 24.0 per cent soil samples is normal, while 72.3 per cent samples are under ph range 8.0 to 8.5. This shows that soils are tending to become alkaline and samail portion (4.0 per cent). has already become alkaline. About 76.0 per cent of the samples were low in organic carbon and the rest were medium to high in this respect. Most of the samples (70.0 per cent) are medium in available P and medium to high in available K. The availab]e P content ranges from 3.8 to 87.0 IbsJacre, while available K ranges from 95.0 to bs/acre. Since most of the soils are low in organic carbon and medium in available P, judicious application of fertilizers with organic manures would be advisable. As available K status is medium to high in these soils its application should only be done when recommended on the basis of soil test. Response of P in these soils is also expected to be poor as it is mt:dium in soil and moreover because of its possibility of fixhion due to the presence of Calcium Carbonate (2.7 per cent). On account of high ph value of most of the samples, use of soil amendments and acidic fertilizers be prefered.

5 THE SOIL OF SRIGANGANAGAR DISTRICT I 63 Reverine : The soil are located in Ghagger belt of the district. Only 40.0 per cent samples are normal while per cent are tending to become alkaline. Alkalinity and salinity problem in these soils is comparatively greater in comparasion to other soil groups. Organic carbon status of these soils is slightly higher. About 57.0 per cent area is medium to high in organic carbon and rest is low. These soils are low in available P and medium in available K, which ranges from 7.6 to and 66.0 to Ibsfacre respectively. As available P is low and salinity and alkalinity is the problem of these soils, hence the use of soil amendments, green manures and organic manures should be don~ along with the application of phosphatic fertilizers in order to get the response. The average of nutrient index values (Table 2) of all the three soil groups show that soils of Sri Ganganagar as a whole are low in organic Carbon medium in available P and K. The above results are in accordance with the findings of Pareek and Seth (1970). Table 3 Soil test recommendations kg/acre for seme important crops of the region. Crop Desert Soils Sierozems Reverine AS SP MP AS SP MP AS SP MP Hy. Jowar ] Hy. Bajra ] Groundnut ~ Barley Gram ]3 Mustard ll Maxican wheat Cotton Sugarcane Pc.tato Note: AS.,. Ammonium Sulphate SP Super phosphate MP = Muriate of Potash

6 VINOD KUMAR, G. S. MATHUR AND S. P. SETH With a vie.w to advise district extension staff and cultivators, soil test recommendations against various fertility groups of each soil has been given for some important crops (Table 3). The recommendations are based en the results of various agronomical experiments conduated in the district. These recommendations are definitely better than general state agronomical reccmmendations and would help in the areas where soil testing facilities to the farmers are not available. ACKNOWLEDGEMENT The Authors are thankful to Shri K. M. Mehta, Director of Agriculture Rajasthan, for providing the facilities for the present work a~d to Shri K. L. Sharda, Dim. Agriculture Officer, Sri Ganganagar for helping in collection of soil samples. REFERENCES Pareek, B. L. and Seth, S. P.; Soils of Rajasthan. pp Ferti. News. 15 : 3. Tamhane, R. V.; Subbiah, B. S. and Seth, S. P soil test summaries of some community project Soc. Soil. Sci. 7 : Soil fertility survey and area in India. J. Ind.