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ThesisItem Open Access Studies on the fractionation of soil phosphorus and the absorption and retention of ammonium nitrogen in Kerala soils(Division of agricultural Chemistry, Agricultural College & Research institute Vellayani, Trivandrum, 1963) Narayanan Nambiar, P K; KAU; Money, N SA study was undertaken with the object of finding o u t t h e retention of ammonium nitrogen in different soils of Kerala when applied in the form of ammonium sulphate and leached after one day or one week contact. Eight soils differing in texture were taken and treated with ammonium sulphate solution of three different concentrations, viz., 52.50, 10500 and 21000 ,ug.N/lOO g. of soil under the laboratory conditions. The unadsorbed nitrogen was found out by estimating nitrogen in the supernatent liquid. The ammonium nitrogen retained by the soil was estimated after leaching the soil with known volume of water. The statistical evaluation of the relation between the textural separates and the ammonium nitrogen retained was also made.ThesisItem Open Access The utility of an indigenous source of magnesium silicate for rice in Kuttanad soils(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1980) Karunakara Panicker, N; Gopalaswami, VA field experiment was conducted at Kavalikari padom, Changanacherry, Kuttanad tract, to investigate the effect of 'Steatite' (Magnesium silicate) on the growth and yield characters of rice in Kuttanad soils. The samples of grain and straw from the experiment were analysed for the contents of N, P, K, Ca, Mg and Si; and the uptake of nutrients per plot computed. The influence of the treatments on the grain shattering character of Jyothi variety; incidence of pests and diseases etc., were also studied. The following results were obtained. Steatite application increased tillering and plant height. The yield of grain and straw showed increase. The increase was statistically significant at five per cent level in the case of 400 kg/ha treatment. The thousand grain weight increased significantly in all the four levels of treatments over control. The treatments resulted in decreasing the N. P. K and Ca content of grain and straw , while Mg and S1 content increased with increasing levels of the treatment.ThesisItem Open Access Studies on foliar diagnosis, yield and quality of tapioca (Manihot utilissima Pohl.) in relation to nitrogen and phosphorus(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1968) Vijayan, M R; KAU; Subramonia Aiyer, NAn investigation was carried out at the Agricultural College and Research Institute, Vellayani during the year 1966-68 to evolve a suitable diagnostic technique for the nutritional status of nitrogen and phosphorus in two varieties of tapioca (M-4 and H-105) by foliar analysis. The response of the two varieties to graded doses of nitrogen (0.75 and 150 kg. N/ha.) and phosphorus (0.50 and 100 kg. P2O5/ha.) and their interaction in relation to the pattern of uptake, yield and quality of tubers were also investigated. Potassium and calcium were kept constant at 250 kg and 1200 kg. per hectare respectively. A split - plot experiment in R.B.D. with three levels each of nitrogen and phosphorus in factorial combinations as major treatments and with the two varieties as minor treatments, was laid out. Leaf leminae and peticles each grouped into three morphological categories. were used for testing the suitability for the diagnostic analysis. The plant part thus standardised (reflect) was analysed at three stages of growth for nutrient content. Biometric observations were recorded at three stages of growth. Yield components and quality factors of tuber were assessed in relation to nutrition of the plants.ThesisItem Open Access Estimation of loss of nitrogen from different nitrogenous fertilizers when applied to different soils under water-logged condition(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1968) Krishnakumari, M; KAU; Subramoney, NThe investigation envisaged the study of the loss of nitrogen due to leaching from different nitrogenous fertilizers applied to different types of soil and their comparative efficiency on the performance of rice variety I.R .8. The study has enabled the following conclusions to be drawn. 1. The loss of nitrogen by leaching is not reduced even when nitrogen is applied in the water insoluble form. 2. That the loss of nitrogen through leaching even from the fertilizer containing insoluble form of nitrogen might be due to the reaction between fertilizer and soil solution. 3. The loss of nitrogen depends on the texture of soil receiving nitrogenous fertilizers, maximum loss occurring in sandy soil and minimum in clayey soil. 4. The maximum loss of nitrogen through leaching occurs between 12 and 24 hours after the application of fertilizers.ThesisItem Open Access Effect of different forms and levels of phosphorus on the growth, yield and composition of three yielding varieties of rice (IR 8, Taichung Native I and Culture 28)(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1968) Jagadeeschandran Nair, M P; KAU; Koshy, M MTo study the effect of different forms and levels of phosphorus on the growth, yield and composition of three high yielding varieties of rice, a pot culture experiment was carried out in the Agricultural College and Research Institute, Vellayani, in a randomised block design with 39 treatments and 3 replications. The different forms of phosphorus used were superphosphate, ultrafos, defluorinated rock phosphate and Thomas phosphate. The levels of application were 0,25, 50 and 75 kg P2O5/ha. The rice varieties studied were Culture 28, IR 8 and Taichung Naive 1. The main findings of the experiment are summarised below: 1) The height of plants was a maximum for IR 8. This growth character was not influenced by the form of phosphorus used, but it increased significantly with increase in the rate of phosphorus application, 2) In the matter of tillers, Taichung Native 1 was superior to IR8 and Culture 28. Of the different forms of phosphorus applied, superphosphate and deflurinated rock phosphate produced the maximum number of tillers. As regards the effect of level, the number of tillers increased with increase in the level of phosphorus application.ThesisItem Open Access Sulphur status of Kerala soils(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1966) Jacob, C I; KAU; Subramoney, NA study was made of the forms and distribution of the sulphur in fourteen wet land and six dry land profiles. Relationship between different forms of sulphur and organic carbon was worked out. The main findings are as follows:- 1. Kerala soils in general are rich in total sulphur 2. Wet land soils contain more sulphur than dry land soils. 3. Total sulphur is significantly and positively correlated with organic carbon for all the three layers. 4. Maximum reserves of sulphur are found in the Kari soil of Kuttanad. 5. Excepting the Kari soils, in general the total sulphur decreases with an increase in the depth of the profile.ThesisItem Open Access Influence of salinity on the germination and growth characteristics of rice(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1963) Remani, B; KAU; Money, N SA study was made of the influence of salinity on the germination, growth and yield of different varieties of rice. Germination was studied in the laboratory for five varieties using nine salts at different concentrations. Growth and yield characteristics were observed for two varieties in a pot culture experiment by flooding the soil with sea water for twenty four hours at different stages in the growth period of the plants. The percentage germination was reduced in all the varieties with increase in the concentration of the salt. For the same concentration the adverse effects of salts on germination increased in the order ammonium chloride ammonium sulphate < sodium chloride < sodium sulphate < potassium chloride < potassium sulphate < magnesium sulphate < calcium chloride. Chlorides were generally more toxic than sulphates. Among the cations, ammonium and potassium were the least toxic, sodium and magnesium were more so, while calcium was the most injurious.ThesisItem Open Access Studies on the effect of zinc in combination with lime on the growth, yield and absorption of nutrients by rice(Division of Agricultural Chemistry, College of Agriculture, Vellayani, 1975) Mariam, K A; KAU; Koshy, M MA pot culture experiment was carried out to assess the effect of different levels of zinc and lime on the growth, yield and chemical composition of rice, variety Annapurna. The soil used was collected from the kayal land attached to The College Farm, Vellayani. The levels of zinc and lime applied in the study were 0,10,20 and 40 kg/ha of zinc sulphate and 0, 250, 500 and 1000 kg/ha of 'Geolime' respectively. A randomised Block Design with 16 treatment combinations and 3 replications were used in the experiment.ThesisItem Open Access Morphological and Physico-chemical properties of the kayal soils of Kuttanad, Kerala State(Division of Agricultural Chemistry, College of Agriculture, Vellayani, 1975) Gangadhara Menon, P K; KAU; Aiyer, R SA study made on the morphological and physico-chemical characteristics of the kayal profiles of the Kuttanad region of Kerala revealed the following salient features. (1) These soils are classified under the order- ENTISOL, Sub order- Aquent and great group- Hydraquent according to the seventh Approximation. (2) Texturally they are classified mostly as silty loan or sandyclay loan, fine sand being the dominating fraction in all the profiles and layers. Only the surface soil of the Chithira kayal profile is clayey in texture with a maximum of 36.5 per cent clay. (3) The physical characteristics of the two profiles from the Rani kayal vary widely. While the profile 1 shows a decrease in clay content with increase in depth, the second profile shows a reverse trend for clay as well as fine sand. Fine sand is maximum in the middle layer of profile 1.
