Browsing by Author "Jose, A I"

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Carbon - nitrogen relationship in laterite soils of Kerala
(Kerala Agricultural University, 1983) Usha, P B; Jose, A I
Surface soil samples from 490 sites representing upland laterite areas of the different districts of Kerala were analysed in order to establish precise relationships between organic carbon and total as well as available nitrogen in these soils. As the acidity increased, the content of organic carbon, total nitrogen and available nitrogen (aN) in soils also increased. The content of organic carbon in soil was found to be significantly and positively correlated with the clay content (r=0.i282*). Organic carbon content had positive and significant correlation with total nitrogen (r=0.4008*) of soil. The C N ratio for low, medium and high organic carbon soils were 8.1 9. 9.63 and 1 1 .26 respectively. Simple linear equation for calculating total nitrogen based on organic carbon content of soil was worked out as N %=0.0803 C% + 0.03 8- C/aN ratio had positive and significant correlation with organic carbon (r —0,6128**) and total nitrogen (r=0.32Q9**). On an average, 10.82 percent ^ftotal nitrogen in soil was retained in available form. The N/aN ratio increased with increase in organic carbon, but not in linear proportion.
Changes in organic carbon and different forms of nitrogen under first and second rotation (coppiced) eucalypt plantations
(Kerala Agricultural University, 1983) Balagopalan, M; Jose, A I
Characterisation and classification of wetland soils of north Kuttanad
(Kerala Agricultural University, 1997) Manorama Thampatti, K C; Jose, A I
Fifteen profiles representing acid saline soils of North Kuttanad were studied for their characterisation and classification. Soils were light grey to dark brown / black in colour, sticky and plastic, subangular blocky in structure, and sandy to clayey it) texture, with random deposits of lime shells and organic matter. Faint to prominent reddish yellow or brown mottles were observed from surface downwards. Soils were highly acidic (pH 4.0-5.0) and mildly saline (EC 0.33-1.39 dS m'). Both acidity and salinity increased with depth. The soils were high in organic carbon, CEC and ECEC, but base saturation was less than 50 per cent. Taxonomically, 93 per cent of North Kuttanad belongs to the soil order Entisol and seven per cent to Inceptisol. At subgroup level, 78 per cent of the area is occupied by Typic Sulfaquent and seven per cent each by Fluventic Dystropept, Typic Tropofluvent, Typic Fluvaquent and Typic Tropopsamment.
Characterisation of soil organic matter in different soil types of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1982) Usha, P B; Jose, A I
Large number of surface soils representing the different districts of the state were analysed in order to work out precise relationships between organic carbon, total nitrogen and available nitrogen in these soils. The soils were categorized into different groups based on soil texture and content of organic matter. Relationships between different soil properties applicable to the different categories of soil were then examined. Fractionation of soil organic matter was carried out in a limited number of soils. Also the distribution of elemental components of soil organic matter was studied in soils selected for the fractionation of organic matter. Observations on the general characteristics of soil revealed that the content of organic carbon, total nitrogen and available nitrogen showed an increasing trend with increase in acidity of soil. In general more organic carbon was seen in fine textured soils. The total and available nitrogen content of soil increased with increase in content of organic matter. The content of available nitrogen showed significant and positive correlation with total nitrogen. Since the C/N ratio increased with increase in content of organic carbon it was necessary to predict the total and available nitrogen content of soil based on precise regression equations rather than depending on a conversion factor. On an average 10.82 per cent of the nitrogen in soil was extracted as available nitrogen. The C/aN ratio was positively and significantly correlated with organic carbon and total nitrogen while it was negatively correlated with available nitrogen. On an average the percentage of humic acid, fulvic acid and humin in soil organic matter were 28.28, 36.51 and 35.21 respectively. Of the 28.28 per cent humic acid, 9.60 per cent (of organic matter) was represented by hymatomelanic acid and the remaining 18.68 per cent by the insoluble fraction of humic acid. Humic acid was found to be significantly and positively correlated with total organic carbon, total nitrogen, clay and fulvic acid. Of the total fulvic acid 12.35 per cent (of organic matter) was represented by beta humus and the remaining by the soluble fraction of fulvic acid. Fulvic acid was positively and significantly correlated with organic carbon, total nitrogen, humic acid and clay. Humic acid and fulvic acid maintained a constant proportion irrespective of the variation in content of total organic matter. Humin was also positively and significantly correlated with organic carbon and total nitrogen. The mean phosphorus, sulphur and potassium content of organic matter were 0.051, 6.96 and 0.32 per cent respectively. The C/org.P, C/org.K, C/org.S, N/org.P, N/org.K, N/org.S, Org.P/org.K, Org.P/org.S and Org.K/org.S ratios were 1672.8, 94.1, 19.23, 205.81, 9.77, 2.91, 0.07, 0.008 and 0.0073 respectively.
Characterisation of soils under reed (Ochlandra travancorica Benth.) in the western ghats
(Department Of Soil Science And Agricultural Chemistry,College Of Horticulture,Vellanikkara, 1999) Sujatha, M P; Jose, A I
Characterization of Kerala soils into fertility classes with respect to available P and K extracted by a common extractant
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1988) Kamalam, P V; Jose, A I
A laboratory study was undertaken to evaluate the suitability of Mathew’s triacid extractant (0.06 N H2SO4 + 0.06 N HCI + 0.05 N oxalic acid) for the combined extraction of available P and available K in soil. The suitability of this triacid extractant was confirmed on a large number of soil samples. Precise relationships between triacid K and NH4OAc K were established. The ten fertility classes for available P and K currently followed in the soil testing laboratories are based on Bray-1 P and NH4OAc K. By making use of suitable regression equations the class intervals in terms of triacid P and triacid K values have to be formulated for the purpose of fertilizer recommendation. The use of this extractant can simplify the work in soil testing procedures thus enabling considerable savings of time and labour. A large number of soil samples was collected representing the entire state of Kerala. The available phosphorus of soil was extracted by Bray No.1 solution (1:10 soil solution ratio with an equilibration period of 5 min) and by Mathew’s triacid extractant (1:10 soil solution ratio with an equilibration period of 30 min). Phosphorus in the extract was then determined colorimetrically by the chlorostannous reduced molybdophosphoric blue colour method in HCI system. The available potassium of the soil was determined by neutral N NH4OAc with a soil solution ratio of 1:5 and an equilibration period of 5 min as well as by the triacid acid method. Potassium in the extract was determined flame photometrically. Soils were also analysed for organic carbon, pH and EC. Suitable correlation was worked out between Bray-1 P and triacid P. A linear regression equation was fitted to predict triacid P values from Bray-1 P values. Suitable relationship was also established between NH4OAc K and triacid K. The linear regression model worked out between NH4OAc K and triacid K was used to predict triacid K values from NH4OAc K. Most of the soils were acidic and non-saline. The pH showed a negative correlation with Ec and organic carbon content of soil. Soils varied in the content of organic carbon from 0.04 per cent to 4.41 per cent but in general was rich with a mean organic carbon content of 1.14 per cent. Electrical conductivity was positively correlated with organic carbon content of soil. A positive correlation was observed between organic carbon and available K. Mineralisation of organic matter contributed significantly to the increasing acidity of soil. The available P estimated by Bray-1 was found to range from 0.46 to 370.30 ppm whereas triacid P ranged from 1.73 to 462.50 ppm. The triacid extracted larger amounts of available P than the Bray-1. A significant correlation was observed between triacid P and Bray-1 P (r = 0.9575**). By fitting the regression equation y = 1.15x, where y represented triacid P and x represented Bray-1 P, the triacid P values of the ten fertility classes have been worked out. The available K as estimated by neutral N NH4OAc ranged from 10.0 to 425.0 ppm whereas triacid K ranged from 4.0 to 154.0 ppm. Triacid extracted lower amounts of available K (42.38 ppm) than the neutral N NH4OAc K (105.23 ppm). Although triacid showed less efficiency for releasing K from soil it was found to have high correlation with neutral N NH4OAc (r = 0.9235**). The linear regression equation of the form y = 0.44x was worked out where y represented triacid K and x represented NH4OAc K. This was employed to redefine the ten fertility classes in terms of triacid K values. The increase in precision obtained by the relationship between P estimated by Bray 1 and triacid as well as K estimated by neutral N NH4OAc and triacid by grouping the soils into separate textural classes was only marginal. The present study therefore confirmed the suitability of the triacid for estimation of both available P and K in the soil of Kerala. The revised class intervals for the ten fertility classes followed in the soil testing laboratories of Kerala have been formulated in terms of triacid P and triacid K values which will serve as a guide for giving fertilizer recommendations for various crops.
Comparative study on the properties of soils in relation to vegetational types
(Kerala Agricultural University, 1993) Balagopalan, M; Jose, A I
Soil properties under six types of vegetative covers, evergreen, semi-evergreen and moist deciduous forests, and plantations of teak, eucalypt and rubber showed that they differed significantly. Soils in the natural forests have higher water holding capacity, cation exchange capacity, organic carbon, N, PzOs, K2O and CaO and MgO. Soils in the plantations, on the other hand, possess greater accumulation of gravel, contain highest amounts of FezOs and AhCb. Organic carbon and N contents up to an appreciable depth were considerable in soils under natural forests. It was found that growing eucalypt after clearfelling natural forests has deleterious effect on soil properties.
Direct and residual effect of different forms and levels of magnesium on yield and magnesium uptake in rice
(Kerala Agricultural University, 1993) Susan Varughese; Jose, A I
A potculture experiment was conducted using rice as the test crop grown continuously for two seasons to study the direct and residual effect of added Mg under rice culture in waterlogged condition. The performance of the rice plant with respect to yield and Mg uptake was better in karappadam soil during the first crop season; while in the second crop season, it was higher in laterite soil. Different sources and levels of Mg applied did not have any significant influence on yield and Mg uptake of the rice plant. There was no marked difference in total Mg uptake between the two seasons, indicating a substantial release of Mgfrom added sources during the second crop season also.
Distribution of organic carbon and forms of nitrogen in soil under mahogany and teak
(Kerala Agricultural University, 1982) Balagopalan, M; Jose, A I
A study was made on the influence of mahogany and teak vegetation on soil characteristics, namely, pH, organic carbon and different forms of nitrogen. Soils under teak were more acidic than those under mahogany. The content of organic matter decreased with depth. Accumulation of organic matter was more under mahogany vegetation. This was true in the case of total nitrogen also. The C:N ratio of the soil was little influenced either by depth or by the type of vegetation. The ratios of total N to available N, total N to ammoniacal N and total N to nitrate N increased with increase in depth of the profile under both type of vegetation.
Distribution of organic carbon, nitrogen, organic phosphorus and organic sulphur in the tropical and subtropical forest soils and their inter-relationships
(Kerala Agricultural University, 1995) Balagopalan, M; Jose, A I
Dynamics of organic carbon and different forms of nitrogen under first and second rotation teak plantations of Kerala
(Kerala Agricultural University, 1982) Balagopalan, M; Jose, A I
Dynamics of potassium, magnesium and sulphur in plant and soil with special reference to the application of langbeinite
(Department Of Soil Science And Agricultural Chemistry,College Of Horticulture, Vellanikkara, 2000) Rani, B; Jose, A I
Effect of application of magnesium and sulphur on the growth, yield and uptake in rice
(Kerala Agricultural University, 1993) Muralidharan, P; Jose, A I
A field experiment was conducted to study the response of rice to application of magnesium and sulphur in a typical laterite soil, using rice (variety Jyothi) continuously for two seasons. Application of Mg had no influence either on the yield or uptake by the crop. Treatment receiving the application of sulphurbiologically activated by inoculation with Thiobacillus sp. and Aspergillus avomerii gave the maximum straw yield in both seasons of crop and thus a higher total dry matter yield, indicating its influence on the vegetative growth of the crop. While lack of influence of Mg application on the con tent of exchangeable Mg in soil was revealed, application of biologically activated sulphur was found to ensure continued availability of S throughout crop growth.
Effect of boron and molybdenum on yield and uptake of nutrients in rice
(Kerala Agricultural University, 1994) Muralidharan, P; Jose, A I
Effect of micronutrients on the uptake of N, P and K in rice
(Kerala Agricultural University, 1994) Muralidharan, P; Jose, A I
A field experiment was conducted to study the effect of application of secondary and micronutrients on the uptake of N, P and K by rice continuously for two seasons in 1991. The total N uptake was significantly enhanced by the application of B, Cu and Mo. Application of B had a consistent influence on the uptake of P and K also. Phosphorus and Zn interacted negatively in the soil influencing the uptake of each other by the crop and the decreased P uptake as result of application of Zn indirectly reduced the yield. Antagonism was observed between K and Mg.
Effect of potassium chloride and sodium chloride on the performance of coconut in a laterite soil
(Kerala Agricultural University, 1992) Prema, D; Jose, A I; Narayanan Nambiar, P K
A field experiment was conducted to study the effect of Nad on the performance of young coconut palms grown in a laterite soil at the Regional Agricultural Research Station, Pilicode. The treatments were the substitution of K2O (applied as KC1) by Na2O (applied as Nad) to the extent of 100, 75, 50, 25 and 0 per cent. The palms receiving 50 per cent substitution of toO by Na2O retained maximum number of functioning leaves. The treatments differed significantly in their influence on nutrient uptake of the palms in the case of K, Na and Cl. Palms receiving higher amount of K or Na retained higher amount of these elements. Palms receiving neither KG nor Nad registered significantly lower uptake of Cl than palms receiving other treatments. The available K and available Na increased with increased application of K and Na respectively while the other characteristics of the soil were not affected.
Effect of sodium chloride on growth and yield of coconut palms in a laterite soil
(Kerala Agricultural University, 1987) Prema, D; Jose, A I; Narayanan nambiar, P K
An investigation was carried out drawing soil and leaf samples from coconut palms of a sodium chloride trial conducted at the Regional Agricultural Research Station, Pilicode, Kasaragod, Kerala, in order to evaluate the effect of sodium chloride on growth, yield and uptake of nutrients by coconut palms grown in laterite soil. The treatments were superimposed on 24 year old palms in 1976 and samples for the study were drawn in 1986. The palms were receiving substitution of KCI by NaCI in various proportions for the last 10 years. The study revealed that there was no significant difference in yield of nuts by substitution of KCI by NaCI. However, treatments receiving 100% recommended dose of K20 and that receiving 50% substitution of K20 by Na20 appeared superior to other treatments- There was no significant difference between treatments in the case of other growth characteristics, and the nutrient uptake by the palms except K and Na. Palms receiving higher amount of K or Na retained higher amount of these elements. The available nutrient status of the soil except available K and basic chemical properties of the soil like, pH, EC and CEC remained the same. The available K content in soil increased with increased application of K to the soil.
Effect of submergence on inorganic phosphorus fractions and available phosphorus in two acid rice soils of Kerala
(Kerala Agricultural University, 1984) Regi P Mathew; Jose, A I
Flooding the soil resulted in an increase in the content of available P, Fe-P, AI-P and saloid P, while the concentration of reductant sDluble P, occluded P and Ca-P showed a gradual decrease. The levels of Fe-P, AI-P, reductant soluble P, occluded P and available P were high in laterite soil compared to kari soil. The mean values of saloid P and Ca-P were relatively high in kari soil.
Effect of zinc and molybdenum on root (Wilt) affected coconut palms
(Kerala Agricultural University, 1986) Mathew, A S; Jose, A I; Jose Abraham; Robert Cecil, S; Kamalakshi Amma, P G
A micronutrient trial using Zn and Mo as foliar and soil application was conducted on root (wilt) disease affected palms under different stages of disease for a period of four years. The study indicated that applications were not effective either in reducing the intensity of disease or in increasing the yield of palms.
Evaluation of available phosphate reserve of soil by chemical methodes
(Department of soil science and agricultural chemistry, College of Horticulture, Vellanikkara, 1979) Mathew Jacob, K; Jose, A I
A laboratory study including a pot culture experiment was carried out using 18 lateritic soil to evolve a suitable laboratory chemical method as an index for the estimation of available phosphate reserve (Ra-value). The total plant removable phosphorus of the soils was determined growing rice (variety IR-8) continuously in soils taken in pots, till the content of phosphorus in plants became below the critical level. The pot culture experiment was designed in completely randomized design with 18 treatments (soils) and 3 replications. To evolve a suitable extractant for the estimation of “Ra-value” H2SO4 and HCI at different concentrations and combinations were tried. Out of the 29 extractants employed, 17 were selected based on their consistence in the pattern of phosphorus release and the amount of phosphorous extracted. From a pilot study, in which different organic acids at different concentrations were screened, oxalic acid at the strength of 0.05 N was selected as the best chelating agent to be employed with the 17 mineral acid combinations. The results showed that compared to Bray No.1, the performance of HCI was very poor and had only a little pronounced influence on the extraction of phosphorus. Sulphuric acid at analogous concentrations extracted higher quantities of phosphorus and obtained better correlations with phosphorus uptake values at the end of 6th crop. Combinations of mineral acids extracted higher quantities of phosphorus from soil than the individual acids, with a pronounced influence at lower concentrations. The pattern of release of phosphorus fluctuated widely when the mineral acids were used individually, but the degree of fluctuation was considerably less when employed in combination. In all the above cases the major part of phosphorus was extracted within 30 minutes and thereafter the release was very slow. The pilot study employed in the selection of organic acids for chelated system, to prevent the resorption of phosphorus into the soil from the solution, revealed that resorption of phosphorus from the solution can be effectively prevented by employing organic acids; the amount of phosphorus extracted by the mineral acids can be increased by the presence of organic acids notably oxalic acid and acids at the strengths of 0.05 N were as good as 0.10 N in their effects on the extraction of soil phosphorus. A period of equilibration not less than 30 minutes was considered critical and optimum. The extractant No.10 (0.06 N H2SO4 & 0.06 N HCI in 0.05 N oxalic acid) was found to be superior to the remaining combinations and gave better correlation with “Ra-value” of the soil. Phosphorus extracted by Bray No.1 failed to correlate significantly with phosphorus uptake by crops in soil groups in which the percentage phosphorus content of plants were below 0.025, 0.05 and 0.2 showing that Bray No.1 is not an efficient extractant for the estimation of “Ra-value” of the soil. Thus the present study recommend the extractant 0.06 N H2SO4 and 0.06 N HCI in 0.05 N oxalic acid with an equilibration period of 30 minutes and soil solution ratio 1 : 10 as a better method for estimating the “Ra-value”. Regression equation between phosphorus extracted by this method and “Ra-value” of the soils selected was rather narrow, the application of this equation in predicting the possibility of skipping phosphorus application in soils appeared very much limited.