Browsing by Author "Alice Abraham"

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Comparative efficiency of foliar and soil application of complex fertilizers on paddy
(Kerala Agricultural University, 1978) Alice Abraham; Koshy, M M
Effect of submergence on the soil testing parameters of paddy soils
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1986) Usha Mathew; Alice Abraham
Laboratory incubation studies were conducted to quantify the changes in pH, EC, lime requirement and availability of important nutrients such as N, P, K, Ca & Mg due to submergence of alluvial, acid saline acid sulphate and saline rice soils of Kerala, The study has revealed that pH of all the soil types increased Immediately after flooding of the air dried soils, reached a maximum and remained more or less steady throughout the period of three months submergence. Consequent to the increase in pH, a corresponding decrease in lime requirement was observed in all the soils. Maximum reduction in lime requirement was noticed for the saline and acid saline soils. A rise in EC was observed in all the soil types due to submergence during the first four to six weeks. It showed a decreasing tendency afterwards. All the soils showed a progressive increase in available nitrogen content with increase in the period of flooding. The increase was in the range of 75 - 395$ for the various soil types. Maximum increase was recorded by saline soils (395$) and minimum by alluvial soils (75%). The levels of available phosphorus recorded for the four soil types in the air dried state were in The low to medium range for rice. Submerging of these soils has resulted in a manifold increase in the content of available phosphorus. The increase was maximum for acid saline soils (700$) and minimum (55$) for alluvial soils. The availability of exchangeable cations like potassium, calcium and magnesium, however, showed a periodical increase and decrease on flooding in all the four soil types. The results of the study have clearly brought out the magnitude of the changes that result in the status of each nutrient upon flooding of soils for wetland paddy cultivation. The manifold increase in the status of major nutrients like N and P upon flooding of soils indicates that addition of fertilizer N and P under such conditions is not likely to produce any significant effect on rice unless the rice varieties are highly responsive to these nutrients. The feasibility of reducing The quantity of fertilizers to be applied or even skipping of fertilizers for one or two seasons may be considered taking into account the responsiveness of the rice variety as well as other economic factors.
Exchangeable aluminium as an index of liming for the acidic upland soils of Kerala
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1987) Meena, K; Alice Abraham
Aluminium toxicity is the major factor limiting crop production in the acidic soils and the usual practice of alleviating aluminium toxicity is liming* / The present investigation was carried out to find out the distribution of water s dluhle and exchangeable aluminium in the acidic upland soils of Kerala and to test the suitability of exchangeable aluminium as an index for liming them* It was further programmed to find out the growth, yield and nutrient uptake pattern of two acid sensitive crops namely cowpea and fodder maize in soils under different levels of exchangeable aluminium brought out by the use of different levels of lime* Chemical analysis of eighty soil samples representing the five major upland soil types of Kerala viz* laterlte, alluvial, red loam, sandy and forest a oil have indicated the highest amount of exchangeable aluminium and percentage aluminium saturation in the laterite soils* The soil with 3 high level of exchangeable aluminium and percentage aluminium saturation was selected for conducting a pot culture experiment to test the suitability of using exchangeable aluminium as an index of liming* The exchangeable aluminium content of this soil was maintained at different levels by applying different levels of lime and the performance of these crops in this soil was compared by making biometric observations and by chemically analysing plant and soil samples* From the results of the study it was seen that higher levels of exchangeable aluminium adversely affected the growth, yield and nutrient uptake In cowpea and fodder maize* Maintenance of exchangeable aluminium at 1*26 me/100 g with a corresponding percentage aluminium saturation valua of around 30, by the use of 500 kg lime/ha appeared to be the optimum for maximising the yield of cowpea* But in fodder maize this level of lime was found to be insufficient and complete elimination of aluminium toxicity appeared to be essential for maximising production* Since the critical levels of exchangeable aiuainiua appears to be different for different crop3, it is desirable that lias levels to reduce exchangeable aluminium to such a critical level alono be applied. The results of the present study thus point to the advantage in adopting the exchangeable aluminium level of soil as a better index of liming for various crops grown in the upland acidic soils of Kerala.
Extractable aluminium in the rice soils of Kerala
(Kerala Agricultural University, 1979) Karthika Kutty Amma, M; Alice Abraham; Aiyer, R S
Twenty surface soils representing four major rice soil types of Keraia viz., the Kari, Karapadom, Kayal and low level laterites were extracted with different extractants viz.. one normal potasium chloride at different soil solution ratios, one normal ammonium acetate adjusted to different pH values and water and the alluminium estimated. Based on the results, one normal potasium chloride with a soil solution ratio of 1 :10and water were adjudged to be good for predicting toxic levels of Al in this soils. The result obtained further indicate that most of the Al extracted is of the exchangeable type in the case of Kayal and low level laterite soils, while it is not so in the case of Kari and Karapadom soils. The results of the present investigation thus project the need for a very systematic evaluation of the extractable Al content of the highly acid rice soils of Kerala in relation to the existence of Al toxicity to the rice crop.
Fertility investigations on the soils of South Kerala in relation to their physiographic positions
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1986) Wilfred Godwin, G; Alice Abraham
A study of the soils of South Kerala has been undertaken to investigate the variation in fertility status in relation to their physiographic position. Twelve locations from the districts of Trivandrum and Quilon were selected and from each location soil samples from upper, middle and lower reaches were collected from depths of 0 to 20 cm and 20 to 40 cm. The elevation of the location varied from 20 to 150 meters and the degree of slope from 6 to 27. The lower reaches of all the location were or less level paddy fields. The middle reaches were cultivated to banana, pepper, coconut and tapioca and the upper reaches in addition to the above crop perennials like coconut and rubber.
Increasing phosphours use efficiency in banana cv. nendran
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1997) Shehana, R S; Alice Abraham
Influence of soluble aluminium on the yield and growth characters of the rice plant
(Kerala Agricultural University, 1979) Alice Abraham; Koshy, M M; Aiyer, R S
The effect of 0, 10, 20, 30, 40 and 50 ppm aluminium on the yield and growth characters of the rice plant grown in solution culture was studied, Toxicity symptoms of aluminium were not manifested on the tops while root growth was progressively decreased in 20, 30, 40 and 50 ppm aluminium containing pots. Decrease in root growth was associated with a tendency for root branching and the formation of mere vascular traces in the root cortex. The reduced root growth did not suppress the yield.
Interrelations of humans with the fertility components of wetland soils
(. Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1996) Sreedevi, K; Alice Abraham
Surface soil samples from the major wetland soil types of Kerala were studied to establish the relationship between soil organic matter and its fractions with the total and available nutrients and other physicochemical characters. Destruction of organic matter has resulted in a substantial drop in the status of almost all nutrients and an appreciable change in soil properties. The SOM separated from the soils were fractionated and the correlation between soil characters and the SOM and its fractions were determined. Regression equations relating soil properties which were significantly correlated with SOM and its fractions were also derived in each soil type. The study has revealed that CEC,WHC,SOM, lime requirement, buffering capacity as well as total and available nutrients in all the four soil types showed considerable degree of variability between samples in each soil type. The content of SOM was highest in Kayal soils (8.03%) and lowest in lateritic alluvial (2.24%) soils with Kari and Karappadam soils with intermediate values of 7.58 and 6.81% respectively. Fractionation of organic matter has shown that humification of SOM was maximum in Karappadam soils, followed by Kayal, Kari and lateritic alluvial soils. The degree of degradation of humified organic matter was high in all the soil types except Kari soils, as evidenced from the HA/FA ratios. The SOM in Kayal soils may probably exist as a stable clay humus complex which has resulted in its lower contribution to CEC, lime requirement and nutrient status. All the four soil types were acidic and the contribution of SOM to free acidity was maximum in Karappadam soils (18.4%) followed by Kayal (17.2%) and lateritic alluvial soils (4.2%). Inspite of the high content of SOM, its contribution to free acidity in Kari soils was only 7.1%, probably due to the low deprotonation of SOM at low pH values. pH in all soil types is negatively correlated to SOM and its fractions. The Kari, Karappadam and Kayal soils are highly buffered when compared to lateritic alluvial soils and the slope of the buffer curves for these soils showed a drastic drop due to the destruction of organic matter. The contribution of SOM to lime requirement ranged from 13.9 to 25.5% which is evident from the drastic drop in lime requirement values consequent to the destruction of organic matter. Maximum contribution of SOM to WHC was shown by lateritic alluvial soils (49.8%). In Kari, Karappadam and kayal soils, the contribution was 24.7, 29.4 and 25.3% respectively.WHC is positively related to SOM and its fractions in all the soils. CEC was highest in Kari soils and lowest lateritic alluvial soils. The contribution of SOM to CEC was maximum in Kari soils (27.2%) and least in Kayal soils (9.7%). CEC of all soils except Kayal soil showed significant positive and linear relationship with SOM as well as with its components. The lack of such a relationship in Kayal soil is attributed to the existence of stable clay-humus complexes. Karappadam soils showed the highest content of total nitrogen and lateritic alluvial soils the lowest. Available nitrogen was highest in Kari soils and lowest in Karappadam soils. In all the four soil types, SOM contributed to more than 90% of total and available nitrogen and it is positively correlated to total and available nitrogen. Total phosphorous was highest in Kayal soils and lowest in Kari soils. Inspite of the lowest content of SOM in Kari soils, it made the maximum contribution to total phosphorous (35.2%). In the Kayal soils the contribution of SOM to total phosphorus was minimum and representing only 5.4%. The available phosphorous in all the soil types showed maximum degree of variability (85.1 to 160.8%) between samples and the contribution of SOM to available phosphorus was also very low. It showed a negative correlation with SOM and its fractions in Kari, Karappadam and Kayal soils probably due to the strong linkage of phosphorus to humus via iron and aluminium bridges. In lateritic alluvial soils, the relationship between SOM and available phosphorus was positive. The total and exchangeable potassium, calcium and magnesium are positively correlated to SOM and its fractions. However these are influenced only to a very low degree by the SOM content. The pattern of relationship of each soil property with SOM is the same as that with its fractions and hence, in studies on soil organic matter, the derivation of relationship between soil properties and soil organic matter alone is sufficient to bring out the interaction between soil organic matter and components of soil fertility.
Microbial mobilization and immobilisation of nutrients in red loam soils
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1989) Susan John, K; Alice Abraham
Nitrogen fixation by cowpea as influenced by the stage of growth and duration of crop
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1985) Indira, M; Alice Abraham
A field experiment was conducted in the College of Agriculture, Vellayani to study the quantity of nitrogen fixed by, cowpea at various stages of growth and also to find its residual effect on a succeeding crop of fodder maize The field trial was laid out as RBD and split plot design with six replications. The study revealed that the growth characters and dry matter production of cowpea increased with increasing age of the crop. The content of plant nitrogen decreased with advancing age eventhough the total uptake of nitrogen » showed an increasing trend from 579 g/plot at the maximum flowering to 657 g/plot at the maturity stage of the crop. Uptake of other nutrients like phosphorus, potassium, calcium and magnesium also showed an increasing trend towards the maturity stage of the crop. The ratios of these nutrients with respect to nitrogen narrowed with increase in the duration of the crop. The total residual nitrogen status of the soil recorded a gradual increase towards the maturity stage of the crop. The value increased from 0.0514 per cent at the maximum flowering stage to 0.0553 per cent at the maturity stage. The available nitrogen status of the soil at various stages of growth of cowpea remained unaltered. The quantity of nitrogen fixed by cowpea was found to be 23, 67 and 112 kg/ha at the maximum flowering, mid pod filling and maturity stages of the crop respectively. All these indicate that nitrogen fixing processes in cowpea are active during its entire growth period gaining pace after the maximum flowering stage of the plant. The highest residual effect due to nitrogen fixed by oowpea was obtained from plots where It was grown upto maturity as seen from the general growth characters and fodder production of maize. Uptake of the nutrients such as nitrogen, phosphorus and potassium in fodder maize was also highest in plots where oowpea was grown upto maturity.The nitrogen made available from the decomposition of plant residues at any of the three stages of cowpea was always lower than that obtained from the addition of 30 kg M/ha.The highest fodder yield (20.7 t/ha) was obtained from plots which. received an additional amount of 60 kg U/ha over and above the residual nitrogen in.the soil where cowpea was grown upto maturity. The residual effect of nitrogen in the soil where cowpea was grown .upto maturity was reckoned on equivalent to the effect of 60 kg N/ha. The study has brought out the fact that maximum nitrogen gain through fixation, by growing legume crops can be achieved only if the plant is allowed to complete its full growth period.
Nutrient fixation in the poonthalpadam soils of Kerala
(Kerala Agricultural University, 1986) Sumam George; Alice Abraham
Nutrient recycling under monoculture conditions in the tropical forest ecosystems
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1987) Prema Kumari, S; Alice Abraham
A study has been made on the forest soils of the Kulathupuzha range in Kerala State with a view to determine the extent to which the morphological, physical and chemical characters of these soils are affected by eucalyptus, teak and rubber plantations. The soils collected from several locations and from adjacent natural forests were studied for their physico-chemical properties including profile description and root disribution . Plant and leaf litter samples were also collected from these locations and subjected to detailed chemical analysis to estimate the quantity of nutrients available for recirculation and to follow the effect of each vegetation on the nutrient status of the soil.
Nutritional status of soil and plant in relation to the incidence of chenthal disease of cardamom
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1983) Dileep Kumar, K N; Alice Abraham
An investigation was carried out at the College of Agriculture, Vellayani, to study the nutritional status of soil and plant in relation to the incidence of chenthal disease in three major cultivars of cardomom viz., Vazhukka, Malabar and Mysore. Soil and plant samples for the study were collected from the cardamom plantations in the High Ranges of Idukki district of Kearala State during March, 1982 (Pre-monsoon period) and September, 1982 (Post-monsoon period)
Physico-chemical and biological properties of high evaluation soils with reference to tea (Camellia sinensis)
(Department of Agricultural Chemistry, College of Agriculture, Vellayani, 1988) Elizabeth Chacko; Alice Abraham
A study has been made on the Tea plantations in Ponmudi in Kerala State with a view to determine the extent to which the physical, chemical and biological characters of these soils are affected by the plantation. Samples for the study were collected from soil profiles exposed at different locations in the tea and adjacent non – tea areas. Plant samples were also collected from these locations and subjected to detail chemical analysis. The mechanical composition of the soils of tea plantations did not depict any significant difference when compared to non – tea soils. In both these soils, the sand and silt content decreased, and clay content increased with depth in the profile. However, a higher content of clay observed in the tea soils indicates a greater degree of weathering and clay formation. The bulk density and particle density of the tea and non – tea soils increased with depth. The surface soil of the profile which contained a greater amount of organic matter recorded a higher water holding capacity. The CEC of soils was found to be low and is likely to be influenced by the predominance of kaolinitic clay minerals. The soils of the tea plantations were highly acidic. Exchangeable aluminium and hydrogen which are the factors contributing to soil acidity were more or less similar in the tea and non – tea soils. The tea plantation recorded a highercontent of total and available nitrogen compared to non – tea areas. The soils cultivated to tea, though contained only a lower amount of total phosphorous, registered a higher content of available phosphorous. The high content of phosphorous is apparently due to the annual application of heavy doses of phosphatic fertilizers. Total acidity, sesquioxides and clay content were higher in the tea soils and contributed to a greater P fixing capacity. The contents of total and exchangeable potassium as well as exchangeable calcium and magnesium in soils cultivated to tea were higher than the adjacent non – tea soils. Lack of fixation sites for potassium in the tea soils might have probably lead to a higher status of exchangeable potassium. The total microbial count including that of bacteria, fungi and actinomyctes in the tea and non – tea areas was appreciable. The tea soils possesed a higher capacity for solubilisation of insoluble inorganic phosphates which was related to the total acidity. These soils did not show any capacity for nitrogen fixation and urease activity was comparatively low. Chemical analysis of the tea leaves showed a higher content of nitrogen and phosphorous than other nutrient elements. The annual application of fertilizers and a lesser removal of nutrients through processed tea has resulted in a rather high fertility status of the tea soils.
Preliminary note on the root nodule bacteria of Indigofera teysmannida
(Kerala Agricultural University, Vellanikara, 1963) N. S. Money; Alice Abraham
Release of soluble aluminium in soils under submerged conditions and its effect on rice
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1984) Alice Abraham; Koshy, M M
A study has been made of the extent of aluminium toxicity in relation to other important characters in the acid Rice soils of Kerala with a view to evolving suitable ameliorative measures. The submerged wet-land rice soils of Kerala showing a pH value of less than 6.0 were found to contain appreciable amounts of exchangeable aluminium. The aluminium saturation of the total and effective CEC of these soils were also very high and above the critical limits for rice. Flooding of these soils in water resulted in a rise in pH and EC, as well as water soluble and exchangeable iron. Peak values for these parameters were obtained by 20-30 days of flooding, after which the pH remained steady while EC and iron showed a decreasing trend . Water soluble and exchangeable aluminium, on the other hand, registered a significantly lower content after the 6th day and the trend continued till the 30th day.
Status and impact of heavy metals in selected soils and crops of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1999) Usha Mathew; Alice Abraham
Status of Cu, Zn, Ni, Pb and Cd in samples of selected soils, fertilizers, manures and crops were estimated. A critical analysis of the total content of these heavy metals in the soils studied here revealed that Cu arid Cd are existing beyond the critical level in the some of the samples. In the wetland soils, content of all heavy metals was lowest for phytotoxicity and food safety in samples from absolute control plots of rice PME at Pattambi, Moncompu and Kayamkulam and highest in samples from plots receiving maximum quantity of organic manures and inorganic fertilizers. The DTPA extractable form is only a very minor part of their total content. The heavy metal load of the commonly used P fertilizers in Kerala is found to be highly variable. Zn is the highest contaminant followed by Pb, Ni, Cd and Cu. With respect to manures commonly used in Kerala, Zn is the most abundant among the five elements studied followed by Cu. Retention of heavy metals was found to be more in the roots of all plants compared to the above ground portions except Zn in amaranthus. The grain, straw and root of rice plants collected from PME plots which were receiving organic manures and inorganic fertilizers continuously for several years had a distinctly higher content of all heavy metals compared to the samples obtained from absolute control plots. The content of Cu in rice samples and that of Zn and Cu in the fodder samples from sewage farm exceeded the critical level to express phytotoxicity. In some of the samples of amaranthus and cowpea, content of Zn, Pb and Cd exceeded the food safety standards prescribed in Germany. Studies on the pattern of retention of applied Cd and Ni in undisturbed soil columns of important soil types of Kerala showed that retention of Cd and Ni was more in the top than in the bottom layers. Higher retention and lower leaching loss of applied Cd and Ni was observed in the columns not treated with FYM. Pot culture studies have shown a significant reduction in yield of rice, sesame and cowpea at various levels of Cd and Ni with and without FYM. Nutrient content of seed, shoot and root showed variations but did not reveal any specific pattern in various crops. In cowpea, low levels of Cd and Ni in the absence of FYM stimulated nodulation and nitrogen content. Intake of Cd and Ni in various plant parts of rice, sesame and cowpea was in the order root> shoot> seed. It was more in the presence of FYM than in its absence. The toxic effects of Ni on growth and yield parameters were of lesser magnitude compared to Cd especially in rice and cowpea. Maximum accumulation of Cd in edible portions was recorded by sesame with no ill effect on germination. However a moqerate accumulation of Cd in rice seeds resulted in significant reduction in germination. An alarming observation obtained from the study was that almost all samples of rice grains exceeded the food safety standard of 1 mg Cd kg-1 indicating that rice, the staple food of the people of Kerala is contaminated with Cd, the most hazardous heavy metal for human health. This pioneer study on the heavy metal status of selected soils and crop plants of Kerala has brought out the need for conducting detailed studies on these aspects.