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Theses

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19843
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Subject: Soil Science and Agriculture Chemistry Ɨ Author: KAU Ɨ End date: 1984 Ɨ Start date: 1984 Ɨ
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    ThesisItemOpen Access
    Release of soluble aluminum in soils under submerged conditions and its effect on rice
    (Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1984) Alice Abraham; KAU; 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.
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    Evaluation of the role of elements Ca, Mg, S and B in the nutrition of groundnut with reference to monovalent (K) to divalent (Ca + Mg) catonic ratios
    (Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1984) Suresh Kumar, P; KAU; Aiyer, R S
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    ThesisItemOpen Access
    Effect of lime and different forms of phosphorus on the growth
    (Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1984) Latha, R; KAU; Koshy, M M
    A field experiment was conducted in the College of Agriculture, Vellayanl on a sandy clay loam soil (Alfisol) of pH 4.9 to study the effect of three levels of lime,0, 500 and 1000 kg per hectare and three levels of phosphorus, 50, 100 and 150 kg PgĀ°5 Per hectare in two different forms, on the growth, yield and chemical composition of cowpea. The field trial was laid out as a (3x7) factorial RBD with two replications. The study revealed that lime application significantly increased some of the- growth characters of cowpea. Application of lime at 1000 kg per hectare significantly increased the number of branches on the 60th day of sowing. The highest application rate of 1000 kg per hectare increased the length and dry weight of root on the 30th day, fresh weight of nodules on the 60th day and the number of leaves at all the stages of growth. Liming at 500 kg per hectare increased the yield and yield components of cowpea significantly, such as the dry weight of the pods per plot, weight of seeds per plot and the hundred seed weight. The highest grain yield of 408.3 g per plot (1418.0 kg per hectare) v/as obtained for lime applied at this rate as compared to the control (1172.0 kg per hectare). Lime application at 500 kg per hectare significantly increased the phosphorus content of the plant on the 60th day and the calcium content on the 30th day. The calcium content was Increased on the 45th day also by the highest level of lime application. Lime application at 1000 kg per hectare significantly reduced the potassium content of the plant on the 30th day. Application of lime at 500 kg per hectare significantly increased the phosphorus and calcium contents of the seed. But the magnesium content of the seed was reduced significantly by lime at both levels.