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Professor Jayashankar Telangana State Agricultural University, Hyderabad (Telangana State)

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2003 - 200964
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Subject: Soil Science and Agricultural Chemistry × Start date: 2000 × End date: 2009 ×
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    ThesisItemOpen Access
    CHARACTERISATION AND CLASSIFICATION OF SOME RED AND BLACK SOILS IN PODILI MANDAL OF PRAKASAM DISTRICT, ANDHRA PRADESH
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD, 2005) VIJAY BHASKAR, K; SESHAGIRI RAO, M
    The soils of the study area in Podili mandal of Prakasam district of Andhra Pradesh are of two types viz., red soils and black soils. Profiles selected at Katurivaripalem, Nandipalem, Akkacheruvu, Mallavaram and Amudalapalli are red soil profiles, whereas Talamalla and Eegalapadu are black soil profiles. All the profiles were described for their morphological features and horizon-wise soil samples were collected from each profile for laboratory analysis to study the physical, physico-chemical and chemical properties. The clay samples from the control section of all the profiles were analysed for X-ray diffraction. Based on the morphology and laboratory data, these soils were classified up to family level. The study area was influenced by semi-arid monsoonic climate with distinct wet and dry seasons. Both red and black soils were formed from calcic-gneiss parent material. Topography of the study area varied from very gently sloping (red soils) to plain lands (black soils). The red soils were light brown to brown in colour, sandy clay loam to clay loam in texture and granular to subangular blocky in structure. Black soils were greyish brown to dark greyish brown in colour, clay loam to clay in texture and granular, sub-angular blocky to angular blocky in structure. Black soils had relatively low bulk density and higher values of water holding capacity, porespace, volume expansion and sticky point than red soils. Red soils had low pH, CaCO3, CEC and base saturation than black soils. Calcium was found to be dominant cation on exchange complex followed by magnesium, sodium and potassium in all the profiles. Elemental composition data revealed that red soils had higher silica content than black soils. The nutrient index values of available N, P, K and S of surface soil samples were low, medium, high and medium, respectiv ely. The available P was low in black soils and medium in red soils. Among micronutrients copper and manganese were sufficient and zinc was deficient in all the surface soil samples. Regarding the available iron few samples among red soils and all samples of black soils were deficient. X-RDA data revealed that the clay fraction of all these soil profiles had dominance of smectite, followed by illite, kaolinite with small quantity of quartz. Based on morphological, physical, physico-chemical, chemical, mineralogical and meteorological data, these soils were classified as Profile 1 Loamy, smectitic, isohyperthermic, Typic Haplustept Profile 2 Loamy skeletal, smectitic, isohyperthermic Typic Ustorthent Profile 3 Loamy, smectitic, isohyperthermic, Typic Haplustept Profile 4 Loamy, smectitic, isohyperthermic, Typic Haplustept Profile 5 Clayey, smectitic, isohyperthermic, Typic Calciustept Profile 6 Loamy, smectitic, isohyperthermic, Typic Haplustept Profile 7 Clayey, smectitic, isohyperthermic, Vertic Calciustept The study area is exhibiting spatial variability in soil properties due to relief of the site and hence comes under low scale soil variability.
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    ThesisItemOpen Access
    SURVEY OF SALT-AFFECTED SOILS OF ONGOLE DIVISION, PRAKASAM DISTRICT, ANDHRA PRADESH
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD, 2009) Vijaya Kumar, M; LAKSHMI, G. V
    An investigation was carried out during months of March, April and June, 2009 to study the “Survey of salt-affected soils of Ongole division, Prakasam district, Andhra Pradesh”. Two hundred representative soil samples (100 surface and 100 sub-surface) were collected from twenty three mandals of Ongole division of Prakasam district by following the random sampling technique. The soil samples were analysed for various physical, chemical and physico-chemical properties. The soils were found to be neutral to strongly alkaline (pH 6.51 to 9.12) in reaction. The lowest and highest values were observed in Kandukuru and Ballikurava mandals, respectively. Sub-surface soils had high pH mean values (8.16) as compared to surface (7.88) soil sample. The ECe of surface and subsurface soil samples varied from 0.03 to 37.00 and 0.04 to 21.3 dS m-1 with a mean value of 4.05 (moderately saline) and 2.15 dS m-1 (slightly saline), respectively. The soils of the division are low in organic carbon and available nitrogen, medium to high in available phosphorus and high in available potassium. The soils were calcareous nature, which were having high calcium carbonate content, and the sub-surface soils had higher calcium carbonate content than surface soils with high cation exchange capacity (9.50 to 79.70 c mol (p+) kg-1). Texturally they are loamy sand, clay loam, and clay. Exchangeable calcium and magnesium and available sulphur were found to be above critical limit. Among the DTPA extractable micronutrient cations, manganese and copper were found in amounts well above critical limit, whereas the soils were deficient in iron (38%) and zinc (75%) supply. The most dominant exchangeable cation was calcium followed by magnesium, sodium and potassium with mean values of 28.37, 6.71, 5.22 and 0.82 c mol (p+) kg-1 soil, respectively. Exchangeable sodium percentage ranged from 1.69 to 48.99 with a mean value of 11.57. The lowest value was found in Kothapatnam mandal and the highest value was observed in S. N. Padu mandal of Ongole division. Soil pH had a significant and positive correlation with CaCO3, exchangeable sodium, ESP and had significant but negative correlation with available iron, manganese and copper. Soil ECe had a significant and positive correlation with CEC, exchangeable Mg, available S, Cu and Zn. Twenty seven per cent of surface soils were mildly alkaline and about 34 per cent of soils comes under moderately alkaline, whereas 11 per cent of surface samples had strongly alkaline in reaction. Out of 100 surface soil samples 16, 22, 7 and 5 per cent of soils were slightly saline, moderately saline, strongly saline, and very strongly saline, respectively. Among, the 100 surface soil samples estimated 26 per cent of samples were found to have more than 15 ESP, and 19 per cent of samples were observed in between 10 to 15, whereas remaining 55 per cent of soil recorded less than 10 ESP. The management practices required for their reclamation were leaching of soluble salts under saline conditions and gypsum for the reclamation of sodic soils. The highest (14.00 t ha-1) and lowest (3.00 t ha-1) values of gypsum requirements were observed in S. N. Padu and Mundlamuru mandals, respectively.
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    ThesisItemOpen Access
    Characterisation and Classification of Cotton growing soils in Amaravathi area of Guntur District, Andhra Pradesh
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD, 2009) JEJE NAIK, P; PRASUNA RANI, P
    Eight representative soil profiles of black and associated soils from Amaravathi area of Guntur district, Andhra Pradesh were selected and described for their site and morphological features. Horizon wise soil samples were collected from each profile and subjected to laboratory analysis to study the physical, physico-chemical and chemical properties. The clay samples from the control section of six profiles were analysed for clay minerals. The soils were classified up to family level as per USDA Soil Taxonomy (Soil Survey Staff, 1998). The soil survey data were interpreted for Land Capability Classification as per the guidelines given by Sehgal (1996). Suitability of the soils for growing cotton crop was evaluated using FAO criteria (FAO, 1976). The study area falls in semi-arid climate with distinct wet and dry seasons. All the profiles were derived from granitic-gneiss parent material. Topography of the study area varied from plain lands to gently sloping lands. The colour of the soils varied from very dark grayish brown to dark gray (1, 2, 3 and 6), brown to dark yellowish brown (4, 5 and 7) and brown to dark brown (8). The texture of the study area varied from sandy loam to clay and structure from granular to sub-angular blocky at surface and sub-angular blocky to angular blocky in sub surface layers among different profiles. The bulk density values of the soils were low at surface compared to subsurface layers. Pore space, water holding capacity, volume expansion and sticky point values varied according to clay content. The soils were slightly alkaline to moderately alkaline in reaction. EC values of the soils were low except in profile 6. Relatively high CEC values were observed in profiles 1, 2, 3, 5 and 6 compared to profiles 4, 7 and 8, where the CEC was less than 30 cmol (p+) kg-1 soil. Calcium was the dominant cation on the exchange complex, followed by magnesium, sodium and potassium in all the profiles. Elemental composition data revealed that silica and sesquioxides were the dominant fractions followed by calcium and magnesium oxides. The soils were low in N, medium to high in P and K. Among micronutrients copper and manganese were sufficient, while zinc and iron were deficient in these soils. X-RD data revealed that the clay fraction of all these soil profiles had dominance of smectite, with small quantities of illite and kaolinite. The soils were classified based on morphological, physical, physicochemical, mineralogical and meteorological data as Profile 1 & 2 : Very fine, smectitic, isohyperthermic, Udic Haplustert Profile 3 : Fine, smectitic, isohyperthermic, Udic Haplustert Profile 4 : Loamy, smectitic, isohyperthermic,Vertic Haplustept Profile 5 : Fine, smectitic, isohyperthermic, Typic Haplustert Profile 6 : Very fine, smectitic, isohyperthermic, Typic Haplustert Profile 7 and 8 : Fine loamy, smectitic, isohyperthermic, Typic Haplustept Land evaluation for land capability revealed that, the profiles 1, 2 and 3 were classed under sub class IIIwf. Profiles 4 and 5 were grouped under IIIsf, while profiles 6, 7 and 8 were classified under IIsw, IIIs and IVsf, respectively. The soils represented by profiles 1, 2, 3, 4 and 5 are marginally suitable (S3) due to severe limitations of fertility and moderate limitation of drainage and depth of the profiles, while profiles 7 and 8 are marginally suitable for cotton due to severe limitations of coarse fragments , depth and organic carbon content. Profile 6 is moderately suitable (S2) due to moderate limitation of organic carbon content of the soils.
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    ThesisItemOpen Access
    MANAGEMENT OF CHARCOAL ROT OF SESAME (Sesamum indicum L.); INCITED BY Macrophomina phaseolina (Tassi.) Goid
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD, 2004) DURAI, M; CHALAM, T.V
    Charcoal rot of sesamum caused by Macrophomina phaseolina (Tassi.) Goid is an important seed (externally as well as internally) and soil borne disease. A detailed study on isolation of native mycoflora and bacteria from the rhizosphere of sesamum, in vitro antagonism of native mycoflora and bacterial isolates against M. phaseolina, in vitro efficacy of systemic and nonsystemic fungicides against the pathogen and in vitro compatibility of fungicides with bioagents and integrated management of the disease with biological and chemical methods under glass house condition was carried out during the present investigation. The pathogen was isolated from infected root and stem bits of sesamum, purified and identified as M. phaseolina (Tassi.) Goid, and the pathogenicity was confirmed by soil infestation method under glass house conditions. The characteristic disease symptoms like poor germination, stunted growth of plants, followed by wilting and drying of leaves were observed. Roots of the infected plants exhibited blackening of tap root and formation of numerous sclerotia on roots. Among eleven antagonistic rhizosphere mycoflora of seamum, Trichoderma viride (T6) inhibited mycelial growth of M. phaseolina to maximum 74.70 per cent in dual culture technique. Among the three bacterial isolates isolated from the rhizosphere of sesamum, Pseudomonas fluorescens (B1) was found to be effective which inhibited 71.76 per cent of mycelial growth of the pathogen under in vitro conditions. Efficacy of five fungicides were tested in vitro against M. phaseolina of which, hexaconazole (50 ppm) and thiophanate methyl (50 ppm) were found highly effective in inhibiting the mycelial growth of the pathogen, followed by mancozeb (100 ppm), captan (500 ppm) and thiram (500 ppm). Out of two systemic and three non-systemic fungicides tested in vitro for compatibility with bioagents, mancozeb at 100 ppm was found compatible with native bioagents T. viride and P. fluorescens. An integrated disease management strategy was developed for charcoal rot of sesamum under green house conditions. Out of 15 treatment combinations, maximum disease reduction was achieved by integrated use of seed treatment with mancozeb (100 ppm) + soil application of native T. viride (10 g/kg of soil) and P. fluorescens (20 ml / kg of soil) as this treatment recorded PDI of only 10.67. This treatment not only reduced the disease incidence to a maximum extent, but also recorded maximum plant height (22.29 cm), shoot length (5.41 cm) and root length (4.27 cm), maximum dry weight of shoot (76.28 mg) and root (52.31 mg) of sesamum when compared to all other treatments.
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    ThesisItemOpen Access
    STUDIES ON NUTRIENT STATUS OF PAPAYA GROWN SOILS IN RELATION TO NUTRIENT CONCENTRATION AND YIELD UNDER VARIOUS LEVELS OF MANAGEMENT IN CUDDAPAH DISTRICT OF ANDHRA PRADESH
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD, 2004) SURESH BABU, B; MASTAN REDDY, C
    An investigation was carried out on nutrient status of papaya grown soils in relation to nutrient concentration and yield under various levels of management in Cuddapah district of Andhra Pradesh. For this purpose three mandals viz., Railway Kodur (21 villages), Chetivel (14 villages) and Obulavaripalli (6 villages) were selected for investigation. The soil samples were analysed for physical properties like texture, physico-chemical characteristics viz., pH, EC, OC, CEC and free CaCO3, chemical characteristics viz., available N, P, K, Ca, Mg, S, Fe, Mn , Zn, Cu and B. Similarly, leaf samples were analysed for N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu and B and fruit samples were analysed for total soluble solids and titrable acidity, and yield of papaya were also recorded. At the above respective mandals irrigation water was collected and analysed for pH, EC, SAR and RSC. The texture of the soils varied from loamy to clay loam and sandy loam to sandy clay loam. Majority of the soils were sandy clay loams. The soils were neutral to slightly alkaline in soil reaction, non-saline, low in organic carbon content and soils were non-calcareous in nature. Regarding the nutrients status, the papaya grown soils were low to medium in available nitrogen, medium to high in available phosphorus and medium to high in available potassium except a few. All the soils were sufficient in available Ca, Mg and S. Among the available micronutrients, Fe, Mn and Cu were present above their respective critical limits in the soils where as Zn and B were found to be deficient in 67.70 and 18.00 per cent of the sample respectively. The index leaf nitrogen and phosphorus contents were deficient to sufficient, range whereas leaf potassium was sufficient in all the leaf samples. Regarding secondary nutrients, the leaf calcium was found to be sufficient to high whereas leaf magnesium was found to be deficient in 2.20% of the leaf samples studied during the investigation. The leaf iron was found to be sufficient except one sample, leaf manganese was found to be sufficient except two samples leaf zinc was found to be deficient in all samples, leaf copper was found to be sufficient except two samples and leaf boron was found to be low to sufficient of the leaf samples studied during the investigation. The leaf N, P, K, Ca, Mg, S, Fe, Zn, Cu and B were positively and significantly correlated with their respective soil nutrients. With regard to fruit quality, there was a significant positive correlation between TSS and leaf N, K, Ca, Mg, S, Fe, Mn, Zn, Cu and B. The titrable acidity was significantly and positively correlated with leaf N, Ca and B. With regard to yield of papaya there was a significant positive correlation between yield and leaf N, K, Zn and B. The irrigation waters being used for papaya cultivation was neutral to slightly alkaline, total soluble salt content is less. The SAR and RSC values were less and they can be safely used for irrigation.
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    ThesisItemOpen Access
    PRODUCTIVITY OF COCONUT BASED MULTI-TIER CROPPING SYSTEMS IN RELATION TO FERTILITY STATUS OF THE SOIL
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD, 2004) SMITHA THOMAS; RAMAVATHARAM, N
    A survey was carried out in Trivandrum district of Kerala to study the yield and productivity of coconut based multi-tier cropping systems in relation to the fertility status of the soil and correlation coefficients worked out to find the relationship between soil and leaf nutrients and between leaf nutrients and yield. The study was carried out in the year 2003. The different cropping systems selected were coconut monocropping system, coconut-pepper-nutmeg-banana (C-P-N-B), coconut-pepper-nutmegcassava (C-P-N-C), coconut-pepper-cocoa-vegetable cowpea (C-P-C-V) and coconut-pepper-cocoa-ginger (C-P-C-G). Soils of the area selected for the study are red sandy clay loams, acidic and non-saline in nature with low to medium in organic carbon. The available nitrogen content was low, available phosphorous was medium, available potassium was low and Fe, Mn, Zu and Cu were above the critical limits. The study showed that as a result of multi-tier cropping systems, the available N, P, K and Ca content of soils increased, whereas Mg, S, Fe, Mn, Zn and Cu content decreased. The leaf nutrient concentration of all the nutrients studied in index leaf of coconut was more in multi-tier cropping systems, compared to coconut monocrop. Simple correlations worked out between soil and leaf nutrients showed significant positive relationship with respect to N, P, K and Ca. Consistent positive but not significant correlations were observed for P, K and Ca in pepper, for P, Ca, Mg, Fe and Mn in nutmeg and for N, K and Zn in cocoa. Significant positive correlations were observed for N, K, Ca in coconut leaf and yield, whereas a consistent positive correlation was observed for leaf P and yield. The average nut yield of coconut recorded in mono-cropped system was 69.5 nuts/palm/year, while it was 92.3 in C-P-N-B, 80.8 in C-P-N-C, 87.1 in C-P-C-V and 77.6 in C-P-C-G, which represents an increase of 32.8, 16.25, 25.3 and 11.65 per cent, respectively, over coconut mono-crop
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    ThesisItemOpen Access
    STUDIES ON NUTRIENT STATUS OF BANANA GROWING SOILS UNDER PREDOMINANT TEXTURAL CLASSES OF KADAPA AND KURNOOL DISTRICTS IN ANDHRA PRADESH
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD, 2004) MOHAN MURALI, V; RAMAVATHARAM, N
    The present investigation was carried out to study the nutrient status of soil and index leaf of banana crop grown in different villages of various mandals in Kadapa and Kurnool districts in Andhra Pradesh. For this purpose, 90 fields belonging to predominant textural classes with standing banana crop were selected and the soil samples were collected from 0 - 30 cm depth. Index leaf samples of banana were also collected from the plants in the fields from where the soil samples were drawn. The soil samples were analyzed for their physical and chemical characteristics viz., soil texture, pH, EC, organic carbon, CEC and free calcium carbonate and fertility characteristics viz., available N, P, K, Ca, Mg, S, Zn, Cu, Fe, Mn and B. Similarly, index leaf samples were also analyzed for their N, P, K, Ca, Mg, S, Zn, Cu, Fe, Mn and B. Based on the soil texture of surface soil samples, all the ninety samples were grouped into three textural classes viz., clayey, clay loam and sandy clay loams with 30 samples under each textural class. The soils were slightly acidic to moderately alkaline in reaction, non saline and low to medium in organic carbon. The CEC of banana grown soils varied from 9.36 to 61.30 cmol(p+)kg-1 soil and high CEC was recorded in clayey soils. All the surface soils are non calcareous in nature. Regarding the available nutrients status, the banana grown soils were low to medium in available nitrogen, low to high in available phosphorus and potassium. All the banana grown soils were sufficient in Ca, Mg and S. Available Cu, Fe, and Mn were above their respective critical limits while 42.22 and 28.88 per cent of soil samples were deficient in available zinc and boron respectively. Available N and K were positively and significantly correlated with clay content, pH, EC, CEC and CaCO3 while phosphorus showed inverse relationship with clay content and CEC of soil. Available nitrogen was positively and significantly correlated with organic carbon. Available Ca, Mg and S were positively and significantly correlated with clay content, pH, EC, CEC and CaCO3 and negatively and significantly correlated with sand content. Available Fe, Mn and B were positively and significantly correlated with sand content whereas available copper was negatively and significantly correlated with sand content. The positive significant correlation was registered between available Cu, Mn, B and clay content. Available Cu was positively and significantly correlated with pH, EC, OC and CEC. Available Fe was negatively and significantly correlated with EC. The available Mn was negatively and significantly correlated to pH, EC and CaCO3 and positively and significantly correlated with EC. The available boron was positively and significantly correlated with pH, EC, OC, CEC and CaCO3. The index leaf nitrogen phosphorus and potassium were above their respective lower limits. The leaf N, P and K were significantly and positively correlated with their respective soil nutrients. The leaf Ca, Mg and S contents were found to be sufficient and showed positive significant correlation with their respective soil nutrients. The leaf Cu, Fe, Mn were found to be above their respective critical limits. However 25.55 and 36.60 per cent of leaf samples were deficient in zinc and boron. The leaf Zn, Cu, Fe, Mn and B contents were positively and significantly correlated with their respective soil nutrients.
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    ThesisItemOpen Access
    EFFECT OF NUTRIENT MANAGEMENT PRACTICES ON YIELD AND QUALITY OF SPINACH (Beta vulgaris L.) GROWN ON ALFISOL
    (ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD, 2005) RAMAKRISHNA, M; SITARAMAYYA, M
    A field experiment entitled “Effect of nutrient management practices on yield and quality of spinach (Beta vulgaris L.) grown on Alfisol” was conducted at Student’s Farm, College of Agriculture, Rajendranagar, Hyderabad during rabi 2004-05. Different nutrient combinations with N, P, K and FYM constituted the treatments. The effect of these treatments on yield, dry matter production, nutrient composition and quality parameters of the crop was studied. The experiment was laid out in a randomized block design (RBD) with twelve treatments, each replicated thrice. Spinach var. ‘All green’ was grown as test crop. The results indicated that the yield of spinach has significantly increased (16.16 t ha-1) with the application of recommended fertilizer dose @25 : 25 : 50 N, P2O5 and K2O kg ha-1. An yield advantage of 60 per cent over control was obtained with recommended dose of fertilizer application. Application of zinc or gypsum coupled with recommended fertilizer dose to the crop did not improve yields. All the four quality parameters viz., total carotene, vitamin C, protein and chlorophyll were the highest under recommended dose of fertilizers application. In general, nutrient concentrations of all nutrients were maximum with recommended dose of fertilizer application. Application of FYM was found to be beneficial in sustaining quality as well as nutrient composition of crop rather than yield. The role of nitrogen and potassium in maintaining quality of spinach was conspicuous. These observations clearly indicated the need for balanced fertilization for higher productivity and quality of spinach grown in Alfisols.
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    ThesisItemOpen Access
    STUDIES ON USE OF NEEM PRODUCTS FOR IMPROVING NITROGEN USE EFFICIENCY BY MAIZE AND DISTRIBUTION OF NITROGEN INTO DIFFERENT FRACTIONS IN SOIL
    (ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD, 2004) SHARADHA, S; UMA DEVI, M
    A field experiment and laboratory incubation studies were conducted at College Farm, College of Agriculture, Rajendranagar, Hyderabad on a sandy clay loam soil (Inceptisol), during rabi 2003-04 to study the effect of coating of different neem products viz., neem cake and neem oil at varying levels of nitrogen viz., 90, 120 and 150 kg N ha-1 on maize under irrigated conditions. The control plot received no nitrogen. The design was randomized block design with ten treatments and replicated thrice. Nitrogen was applied in three equal splits at basal, 25 and 55 DAS and coated with neem oil (0.5% w/w) and neem cake (20% w/w) as per the treatments. All the plots received uniform doses of 60 kg P2O5 and 40 kg K2O ha-1. Simultaneously a laboratory incubation study was conducted by taking two kg of soil with seven treatments. For incubation study a common dose of 120 kg N ha-1 was used. The treatments include control (N0), application of prilled urea in single dose, and in splits and treating with neem oil / neem cake. Neem cake coated urea at 150 kg N ha-1 has recorded highest dry matter (138.09 1 ha-1), grain yield (53.34 q ha-1), stover yield (84.74 q ha-1), N (145.75 kg ha-1), P (59.61 kg ha-1), K (152.42 kg ha-1) uptake by crop at harvest and available N (238.7 kg N ha-1), P (10.0 kg P ha-1) and K (504.3 kg K ha-1), urease activity (8.4 g NH4 + g-1 hr-1) and N fractions like ammoniacal nitrogen (NH4-N) (19.5 kg ha-1), nitrate nitrogen (NO3-N) (23.39 kg ha-1), hydrolysable ammoniacal nitrogen (HAN) (112.7 kg ha-1). The next best treatments were neem cake coated urea @ 120 kg N ha-1 followed by neem oil coated urea at 150 kg N ha-1. The apparent recovery of nitrogen was higher with neem cake coated urea application (64.5 to 67.8%) followed by neem oil coated urea (48.1 to 53.8%) when compared to prilled urea (35.5 to 36.0%). There was a decrease in the urease activity in the initial stage (60 DAS) with use of neem cake / neem oil and the reverse trend was noticed at harvest. In incubation studies, split application of neem cake coated urea followed by neem oil coated urea recorded higher amounts of urease activity NH4-N, NO3-N and HAN when compared to prilled urea. Benefit cost ratios were high and quite favourable for the farmer with all the neem treatments studied. Highest benefit cost ratio was observed with neem cake coated urea treatments @ 150 kg N ha-1 (4.71) followed by neem cake coated urea @ 120 kg N ha-1 (4.67) and neem cake coated urea @ 90 kg N ha-1 (3.60). Application of neem coated urea even at lower N levels was found to be quite beneficial to the farmer, because grain yields with neem cake coated urea at N90 (41.89 q ha-1) was found to be on par with neem oil coated urea at N120 (40.42 q ha-1) and prilled urea at N150 (41.28 q ha-1), thus saving 30 to 60 kg N ha-1. Similarly neem cake coated urea at 120 kg N ha-1 (49.67 q ha-1) was significantly higher than neem oil coated urea at N150 (42.59 q ha-1) thus saving 30 kg N ha-1. Thus, taking into consideration of grain yield, benefit cost ratio and soil fertility maintenance, application of neem cake coated urea was found to be the best at all levels of N ranging from 90 to 150 kg N ha-1. Finally application of neem cake (20% w/w) coated urea @ 150 kg N ha-1 is recommended for maximising the maize yields and to realise maximum returns from sandy clay loam soils under Rajendranagar conditions.