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Author: search.filters.author.Jose, A IStart date: 1990

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Now showing 1 - 10 of 16
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    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.
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    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.
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    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.
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    Soil humic fractions of red ferrallitic soils as influenced by vegetational types
    (Kerala Agricultural University, 1993) Balagopalan, M; Jose, A I
    Humic and fulvic acids (HA and FA) extracted from evergreen, semi-evergreen and moist deciduous forests, and plantations of teak, eucalypt and rubber soils belonging to red ferrallitic type of Kerala were quantified and characterised by UV and IR spectroscopies. The HA and FA conlenis were relatively higher in the natural forests. They differed significantly between vegetational types and varied in chemical composition. The IR spectra of HA and FA were very weak and their aliphatic groups were lower in eucalypt soils.
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    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.
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    Forms of magnesium in soil as influenced by added magnesium sources under submerged condition
    (Kerala Agricultural University, 1993) Susan Varughese; Jose, A I
    A laboratory incubation study was carried out using two acid rice soils of Kerala under submerged condition for 180 days. The soil samples drawn at regular intervals were analysed for chemical forms of Mg. The insoluble Mg fractions dominated over the soluble ones. Acid soluble Mg and mineral Mg together constituted about 74.03 per cent of the total Mg content. Ammonium acetate extractable Mg of the soils was 19.09 per cent. The content of organic complexed Mg was very low and that of water soluble Mg was practically nil. Total Mg content as well as the content of various Mg fractions was higher in karappadam soil than in the laterite soil. The soluble Mg fractions were higher in samples supplied with magnesium sulphate while the insoluble fractions were higher in samples supplied with carbonate forms of Mg. The difference between the Mg levels tried in this experiment became conspicuous only under conditions of prolonged submergence.
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    Influence of added magnesium sources on soil characteristics under submerged condition
    (Kerala Agricultural University, 1994) Susan Varughese; Jose, A I
    An incubation study and a potculture experiment were conducted with two acid rice soils of Kerala, using three Mg sources, viz., magnesite, dolomite and magnesium sulphate tried at two levels of Mg (25 and 50 kg MgO ha ) to study the influence of added Mg on soil characteristics. Available Mg of the karappadam soil was significantly higher than that of the laterite soil. There was no significant difference between the three Mg sources with regard to their contribution to available Mg in the soil. But the Mg availability increased with raised levels of Mg application. A negative relationship was noticed between available K and Mg fractions in the soil. Different sources and levels of applied Mg did not have any significant influence on NILjOAc extractable Ca. Magnesium application raised the pH of the soils. Efficiency of the different Mg sources in correcting the acidic soil reaction was in the order of magnesite dolomite magnesium sulphate.
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    Effect of boron and molybdenum on yield and uptake of nutrients in rice
    (Kerala Agricultural University, 1994) Muralidharan, P; Jose, A I
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    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.
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    Magnesium status of soils
    (Kerala Agricultural University, 1994) Prema, D; Jose, A I
    The magnesium status of the soils of Kerala was studied. In general, they were deficient in total Mg reserves (61 per cent of the soils studied). Altogether, 17 per cent of the soils were deficient in available Mg and 25 per cent deficient in exchangeable Mg. Black soils were rather rich in total Mg, available Mg and exchangeable Mg. The most deficient were the sandy loam soils of coastal alluvium. The laterite group was in between. The inter-relati onships among total, available and exchangeable Mg were found to be significant and positive. Exchangeable Mg correlated positively with other exchangeable cations. About 24 per cent of the total Mg reserve in the soils under study is considered available and 11 per cent exchangeable. The total Mg reserves in Kerala soils are found to be poor and Mg can be considered as a critical element in these acid soils