Browsing by Author "Sudharmai Devi, C R"

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Evaluation of a customised organic fertilizer in relation to labile carbon dynamics nutrient release characteristics and productivity of banana
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Naveen Leno; Sudharmai Devi, C R
Inter-relationship between organic carbon, nitrogen, organic phosphorus and organic sulphur in two red loam soil series of South Kerala
(Kerala Agricultural University, 1991) Korah, P A; Usha, P B; Sudharmai Devi, C R
Nature of acidity in upland and rice fallows in relation to response of pulse crop to liming
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1983) Sudharmai Devi, C R; Aiyer, R S
Soils over vast areas of uplands and rice lands in Kerala are acidic in nature. High concentrations of Al and Mn often limit the productivity of pulses when grown in these areas. The present investigation was aimed at detecting the toxic factors causing acidity and locating suitable varieties of cowpea and blackgram suited to these soil situations. It was further programmed to find out the optimum levels of lime that would be required to arrive at a low input management programme for pulses. For this purpose a large number of soil samples were analysed. Several pulse varieties were screened in respect of their tolerance and a pot culture study was conducted to assess their productivity, the results of which are summarised and appropriate conclusions drawn. The collected soils were acidic in nature, the factors causing toxicity being high concentration of Al and Mn. The soils require large amount of lime as amendment. Cation exchange capacity of these soils is very low and to some extent contributed by Al and Mn. Screening experiments were conducted to select varieties which are tolerant to Al and Mn toxicity. As a result S-488, a cowpea variety and Velloor, a blackgram variety were selected as tolerant ones. Comparative assessment of the yielding ability of the selected varieties, with the recommended varieties New Era (cowpea) and T9 (Blackgram) revealed that they could yield as much as or even better than the recommended varieties. The recommended varieties require high doses of lime for a substantial yield whereas the selected varieties could give economic yield with practically no liming. The observations on number of pods, grain yield, haulm yield and number of nodules revealed that the two selected varieties could excel the others in these aspects Uptake studies indicated that the increased yield in the case of the selected varieties is mainly due to the enhanced uptake and fixation of N and uptake of P and K. From the results of the study, it was concluded that the cowpea variety S-488 and the blackgram variety Velloor can be cultivated successfully under acid soil conditions. They possess the ability to give economic yields with little or no liming. These results have to be tested in farmers 'fields to evolve a low input management strategy for pulse cultivation in garden lands as a vegetable in kharif season and in the rice fallows in summer season.
Nutrient management in coconut based cropping system utilizing products from rapid conversion technology of biowastes
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Priya, U K; Sudharmai Devi, C R
Partial substitution of muriate of potash by common salt for cassava (Manihot esculenta crantz) in oxisols of Kerala
(Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani, 1995) Sudharmai Devi, C R; Padmaja, P
Field experiments were carried out in the College of Agriculture, Vellayani during 1991 to 1994 to study the possibility and extent of substitution of K of Muriate of Potash with the Na of common salt in Cassava variety M4 used as the test crop. Substitution of K was tried at 4 levels viz. 25, 50, 75 and 100 per cent of the recommended dose. Muriate of potash, replaced by wood ash and a combination of KHCO3 and NaHCO3 (eliminating chlorine source) also were included in the experiment. Plant growth characteristics like plant height and number of leaves did not vary significantly as a result of substitution. The maximum LAI was observed in the case of 50% K as MOP + 50% Na as CS treatment at all the growth stages. An increase in chlorophyll content was observed with NaCl substitution. In the early growth stages there was no significant variation in the production of roots, but at the later stages there was significant difference in this aspect. The root volume at 2 MAP varied significantly between treatments. In general, there was an increase in total weight of plant with NaCI substitution upto 50% and thereafter a decrease with higher levels of substitution, at all growth stages. Significant treatment difference could be observed in tuber yield in both the years of the experiment. T3 (50% MOP +50% CS) registered the highest tuber yield and T5 the lowest. The bulking rate and Utilisation Index also differed significantly among treatments. The cooking quality of the tubers from T3 was as good as that of T1. Significant differences could be observed in total sugars, reducing sugars and sucrose content of fresh tubers under different treatments. With increasing levels of substitution, the content of total sugars increased. Sucrose content was found to increase with Na application upto 75% substitution of K by Na. Significant variation was observed in the crude protein, total amino acid and free amino acid content of tubers. Hydrocyanic acid, total phenols and crude fibre also differed significantly between treatments. The keeping quality studies revealed that tubers from T3 could be stored fresh up to 35th day in moist soil, whereas tubers from T1 could be stored only upto 12th day, without deterioration. Enzyme studies revealed significant difference in the activity of starch synthesising enzymes, but NRA at 6 MAP was not affected by different treatments. The uptake of N was highest in T1 and P and K in T3. Na uptake by T1 which received no Na was generally higher than other treatments receiving Na. Ca and Mg uptake also differed significantly between treatments. Changes in soil organic carbon, available P, available K and available Mg were statistically significant between treatments but that of Ca was significant only from 4 MAP onwards. Yield of tubers was positively and significantly correlated to the uptake of N, P, K, Na, Ca and Mg. Yield at harvest was positively and significantly correlated to the root weight and root volume and also to the bulking rate at 2 MAP. Path coefficient Analysis revealed that the maximum direct effect on yield was contributed by the drymatter of roots at 2 MAP. From the results, it can be concluded that in soils having low to medium status of K, the K of MOP can be substituted up to 50% by Na of commonsalt in cassava without affecting the quality and quantity of tubers.
Rhizosphere priming effects of conventional and non conventional organic manures on c and n dynamics
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2018) Geethu Jacob; Sudharmai Devi, C R
Site specific nutrient management for bitter gourd (Momordica charantia L)
(Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani, 2013) Neenu, S; Sudharmai Devi, C R
A study entitled ‘Site specific nutrient management for bitter gourd (Momordica charantia L.) was conducted in College of Agriculture, Vellayani during 2007-12 with the objective of formulating a site specific nutrient recommendation for enhancing the bitter gourd production in Kalliyur village of Kerala. The experiment set up included three steps namely Omission trial, SSNM field study and validation of results. All the experiments were conducted in farmer’s fields of Kalliyur village. Kalliyur village, located in Thiruvananthapuram district with an area of 17.23 km is one of the major vegetable growing tracts and bitter gourd is a popular vegetable in the locality. Spatial variability studies conducted revealed that remarkable variations existed in the soil properties across the village. Data on irrigation water analysis showed that the water used for irrigation was slightly acidic but safe for irrigation as it did not contain significant amount of soluble salts and other elements. Nutrient omission trial conducted in a farmer’s field at selected location showed that the indigenous supply of major nutrients in the locality is limited. The growth and yield parameters were the highest in (+) NPK treatment. Though the highest yield was recorded in (+) NPK plots, yield reduction in P omission plot was less compared to N and K omission owing to the higher supply of indigenous P in soil. The SSNM experiment revealed that site specific nutrient recommendations for high yield target with soil application of micronutrients recorded the highest values for all the growth and yield attributes of bitter gourd. Nutrient uptake and harvest index were also the highest in this treatment. The lowest value of harvest index was recorded by absolute control. In the case of nutrient balance sheet the highest value of N and K balance sheet was obtained in site specific nutrient recommendations for high yield target with soil application of micronutrients while the highest value of P balance sheet was obtained in farmer’s practice II. The correlation study revealed that bitter gourd yield was highly correlated with nutrient uptake as well as dry matter production and harvest index. Economic analysis showed that the SSNM practice is beneficial to farmers as it is able to provide more income than the usual farmer’s practice. The validation trial of the best treatments SSNM treatments with high yield target showed that the yield increase was consistent and hence can be prescribed to other farmers in Kalliyur village. The study thus conclusively proved that the present rates of fertiliser recommendation are not at all sufficient for getting maximum yield and profit to farmers. A site-specific nutrient prescription of 123: 59: 160: 30: 40: 25: 10 kg N P K Ca Mg Zn B ha -1 was found to produce 24 t of fruits ha -1 and a dose of 123: 59: 160: 30: 40 kg N P K Ca Mg + 1 per cent Zn foliar + 0.5 per cent B foliar ha were found to yield 22 t fruits ha -1 . The farmers in the area could get a monetary benefit of 601604/- and 542104/- ha -1 respectively by adopting these recommendations. Adoption of SSNM prescriptions is advantageous not only from the point of view of increasing profitability to farmers but also minimizing environmental degradation.
Site specific nutrient management for chilli (Capsicum annum.L) in kalliyoor panchayath of kerala
(Department of Soil Science and Agricultural Chemistry,College of Agriculture,Vellayani, 2011) Priya, U K; Sudharmai Devi, C R
Substitution of muriate of potash by common salt in banana Musa (AAA group CAVENDISH subgroup) ‘Robusta’
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2001) Sunu, S; Sudharmai Devi, C R
A field experiment was conducted III the College of Agriculture, Vellayani during August 1999 to June 2000 to study the extent of substitution of K of muriate of potash by Na of common salt in banana cv. Robusta. Four treatments involving four levels of K at 25, 50, 75 and 100 per cent of recommended dose and four treatments substituting K with N a at 25, 50, 75 and 100 per cent were tried in RBD with three replications. The plant growth parameters like plant height, pseudostem girth, number of functional leaves and LAI varied significantly due to treatments at all growth stages. These parameters in the 100 per cent K and 50 per cent K plus 50 per cent Na treatments were on par at all growth stages. Chlorophyll content and RLWC showed an increase with the addition of Na along with K. Highest bunch yield was recorded in the 50 per cent K plus 50 per cent N a treatment followed by the yield in the lOO per cent K treatment. The yield attributes like length of bunch, number of hands per bunch, number of fingers per bunch, length and girth of fingers reflected similar trends. The quality of fruits as reflected in the total soluble solid content, total sugar content and acidity was as good in 50 per cent K plus 50 per cent N a treatment as in 100 per cent K treatment. With increase in the levels of substitution above 50 per cent there was reduction in total soluble solids and sugar content. Shelf life of fruits did not vary significantly due to treatments. Pulp/peel ratio in the 100 per cent K and 50 per cent K plus 50 per cent N a treatments were on par. Pulp/peel ratio decreased significantly with increase 10 substitution of K by Na above 50 per cent level. The uptake of nutrients except N a was higher at the 50 per cent K plus 50 per cent N a treatment and decreased with increase in substitution of K by Na above this level. Na uptake increased upto 75 per cent substitution of K by N a and decreased at 100 per cent substitution. The treatments did not have any influence on the soil physical and chemical p-roperties. Bunch yield was positively and significantly correlated to plant girth (2MAP), chlorophyll content and LA!. It can thus be concluded that upto fifty per cent of the K requirement of Robusta banana, grown in soils of low K status, can be replaced by Na of common salt.
Synerigistic effect of Na and K on yield and nutrient uptake in Coleus (Coleus praviflorus L)
(Department of Soil Science & Agricultural chemistry, College of Agriculture, Vellayani, 2004) Neenu, S; Sudharmai Devi, C R
A field experiment was carried out in College of Agriculture, Vellayani during September 2003 to January 2004 to study the “Synergistic effect of Na and K on yield and nutrient uptake in coleus (Coleus parviflorus L.)”. The treatments included were 50 and 100 per cent of the recommended dose of K alone and in combination with 50, 75 and 100 per cent of Na of common salt to equalize the same amount of recommended dose of K. The experiment was conducted in Randomized Block Design. The plant growth characteristics like plant spread, number of functional leaves and LAI showed significant variation due to treatments. The highest values for these parameters were registered by K and Na at 50:50 proportions, showing the synergistic interaction of the two elements at this combination. Leaf water content varied significantly due to treatments. The 50 per cent K plus 75 per cent Na treated plants showed highest value of RLWC. Even though the chlorophyll content did not show significant difference between treatments, it increased with Na application along with 50 per cent K, revealing a role of Na in chlorophyll biosynthesis Tuber yield did not show any significant difference due to treatments. Even then the 50:50 combinations of Na and K treatment gave the highest tuber yield followed by 100 per cent K plus 50 per cent Na treated plants. The yield attributes like number of tubers, weight of tubers and tuber index did not vary significantly. Among the quality attributes, starch content varied significantly due to treatments. The treatment with 100 per cent K plus 75 per cent Na gave the highest value of starch followed by the 50:50 combinations of Na and K. The cooking quality of treatments T3 (100 per cent K alone), T4 (50 per cent K plus 50 per cent Na) and T5 (50 per cent K plus 75 per cent Na) were similar. The shelf life of 100 per cent K plus 100 per cent Na treated tubers were found to be the highest. There was an increase in the content of N, K, Ca and Mg in the plants when Na was also supplied as treatment. Consequently the uptake of nutrients increased with the application of different levels of Na along with 50 per cent K. This shows that Na has a stimulative effect on uptake of nutrients. Application of Na did not affect any soil properties like pH, EC and organic carbon. The available nutrients like N, P, Ca and Mg increased in Na treated plots Yield of tuber was positively and significantly correlated with the dry matter production and uptake of Ca. Yield was positively correlated with the uptake of all nutrients under study. From the above points, it can be concluded that a combination of 50 per cent K and 50 per cent Na is optimum for getting the maximum yield. From the present study it also became evident that the efficiency of nutrient uptake increased at this combination. By adopting this practice, it was seen that the quality of coleus tubers improved and they became nutritionally more rich. This practice was found to be economically more feasible. Considering all these aspects, this fertilizer practice can be recommended to the farmers for getting a higher profit. From this investigation we can clearly establish a synergistic interaction of the two monovalent nutrient ions, K and Na on the growth and yield of coleus.