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Open Access
Sulphur and boron nutrition and their foliar diagnosis in sesame
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 2010) Jeena, Mathew; KAU; Sumam, George
A laboratory cum field experiment was conducted to study the effect of S and B on the growth, yield and quality of sesame var. Thilarani and to standardize the foliar diagnosis of these elements in Onattukara sandy loam soil. The study included an incubation study and two field experiments. The treatments comprising the different levels of S and B laid out in 42factorial RBD. The treatments were T1(S0B0), T2(S0B1), T3(S0B2), T4(S0B3), T5(S1B0), T6(S1B1), T7(S1B2), T8(S1B3), T9(S2B0), T10(S2B1), T11(S2B2), T12(S2B3), T13(S3B0), T14(S3B1), T15(S3B2), T16(S3B3). The different levels of S were S0 (0 kg ha-1), S1 (7.5 kg ha-1), S2, (15 kg ha-1) and S3 (30 kg ha-1) and B0 (0 kg ha-1), B1(2.5 kg ha- 1), B2 (5 kg ha-1) and B3 (7.5 kg ha-1). The incubation study was conducted at College of Agriculture, Vellayani to understand the dissolution and release pattern of S and B from their sources gypsum and borax respectively in Onattukara sandy soil. The results revealed that the release of S and B was maximum at the 30th DOI. Increasing levels of S and B has a positive influence on the S content of the soil. T16 (S3B3) recorded the highest value at all the sampling stages for S whereas in the case of B, the treatment combinations which received B at the highest levels in combination with S3 or S2 showed the highest value. The field experiments were laid out at ORARS, Kayamkulam in 42 factorial RBD having two replications using Thilarani as the test crop. It was observed that application of S and B favourably influenced the yield and yield attributes of sesame. T16 was found to be the treatment which gave the highest grain yield and oil yield in both the years and was found to be on par with T14 (S3B1). S3 was the superior S level. As for the different levels of B, B1 can be inferred as the best level. The content of saturated fatty acids such as palmatic and stearic acid showed a decreasing trend with increasing levels of S and B whereas the content of the unsaturated fatty acids showed an increasing trend. The quality attributes of oil such as acid value, iodine value and saponification value was also studied and it was found that there is a decreasing trend with regard to acid and saponification value and an increasing trend for iodine number. The grain protein content also showed an increasing trend with the increase in rate of application of S and B. Regarding the content and uptake of N, P, K, S, B, Fe, Mn, Cu and Zn, a favourable influence for the different levels of S and B was recorded. Results regarding the S and B use efficiency and their apparent recovery showed that with increase in levels of S, an increasing trend was observed for S. In the case of B, increase was noticed up to B1 (2.5 kg ha-1) and there after showed a decreasing trend. This positive influence was also reflected on the available nutrient status of the soil such as organic carbon content, available N, P, K, S, B and DTPA extractable micronutrients. Correlation studies conducted to standardize the part and stage of sampling for the foliar diagnosis of sesame showed petiole at 30 DAS and 20 DAS in the case of S and B respectively. The same stages were found for the soil sampling also for both the nutrients. The critical nutrient level in the part standardised for these two nutrients were standardized using the graphical method proposed by Cate and Nelson (1965). In the case of S, it had been standardized as 0.088 per cent and for B, it had been found to be 28 mg kg-1. The critical nutrient level in soil was also estimated using the scatter diagram technique and was found to be 23 kg ha-1 at 30 DAS for S and 1.4 ppm at 20 DAS for B. Hence the application of S @ 30 kg ha-1 and B @ 2.5 kg ha-1 could faourably enhance growth of sesame with regard to the growth characters, yield and yield attributes and the quality aspects. Moreover, analysis of the plant and soil samples at the critical stages fixed for the respective nutrients will provide the necessary data for the sustainable management of the crop in Onattukara sandy loam soil.
Open Access
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; KAU; Sudharmai Devi C R
Site Specific Nutrient management is a technology in precision fanning that offers chance for farmers to achieve the targeted yield taking into consideration the potential yield of the crop by application of apt amount of fertilizers. The technology is farmers' friendly, eco-friendly and also consumer friendly. In Indian scenario wherein farmers are suffering from yield losses up to 40% due to micronutrient deficiency of soils mainly zinc and boron deficiencies are the yield limiting factors of production. Kerala the soils are low in basic ions that are posing serious threat to crop production. The Judicious application of chemical fertilizers along with micronutrients is necessary for sustainable crop production. The present study "Site Specific Nutrient Management in" Chilli (Capsicum annuum.L.) in Kalliyoor Panchayath Of .Kerala" was carried out to satisfy the objectives viz. study the spatial variability of area, to find outtheindigenous nutrient supply via omission trials, fix a target yield based on the potential yield of the crop and formulate a site specific nutrient recommendation to obtain the targeted yield. In order to understand the spatial variability survey was conducted at 25 sites of Kalliyoor panchayath. The results of survey showed that the soils showed wide variation in terms of soil physical and chemical properties. Soil phosphorus status , was high in all cases other nutrient concentration ranged from low to high. The spatial variability necessitated carrying out the omission trials at four different sites that were ranked according to the nutrient status into high, medium first level, medium second level and low fertility soils. From the omission trials the recovery fraction and, indigenous nutrient supply were calculated. Utilising all these parameters in QUEFT model SSNJ\:1.--tre tments were fixed. /' / / - :l.33- The high yield target was fixed at 16 t ha that was 50% of the potential yield. The nutrient recommendation generated for HYT was 104.8: 13.6: 201 kg N, P205 and K20 ha-I. Medium yield target was fixed at 168:51: 230 kg N, P205 and K20 ha- I. Taking into account micronutrient and secondary nutrient deficiencies in the soil. In high yield target soil application of micro nutrients and secondary nutrients along with application of 1 % foliar spray of boron was recommended. Micronutrients for soil application were boron @ 5 kg ha-I in form of borax, zinc @ 20 kg ha-I in form of zinc sulphate. Secondary nutrients applied were calcium @ 30 kg ha-I in form of CaS04, magnesium @ 7.5 kg ha-I in form of MgS04. The requirement of sulphur was met from soil applied zinc sulphate, calcium sulphate and magnesium sulphate. In medium yield target only soil application of micro and secondary nutrients along with the application of QUEFT generated recommendations for the crop; POP + micronutrient recommendations were evaluated. Simultaneously an absolute control was also carried out. Soil analysis was carried out for all the physical and chemical properties of the soil initially before the crop was raised, and after each harvest. So that change in soil properties as a result of application of treatments could be evaluated, since the application of fertilizer coincided with each harvest. The results derived from the experiment proved the superiority of SSNM over other treatments with respect to the yield major nutrient and micronutrient uptake. , Where high yield target registered a cumulative yield of 17. 32 tons, medium yield target registered a cumulative yield of 11.75 tons this was _much superior to POP+SNMN that registered an yield of 9.83 tons, or the package of practice recommendation that registered an yield of only 8.3 tons . Farmers practice registered inferior yield data of only 5.2 tons. The study revealed that the site specific nutrient management is an efficient technology to increase the yield of crops and hence provide additional income to the farmers; this technique also provides a -134 - scope of increasing the yield without over application of fertilizers that would result in deterioration of the soil physical and chemical properties in long run.
Open Access
Nitrogen and sulphur interaction on their release pattern and use efficiency in ferralitic soils.
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 2011) Mariya Dainy, M S; KAU; Usha, P B
An experiment was carried out at College of Agriculture, Vellayani to investigate the interactive effect of nitrogen and sulphur on their release pattern and use efficiency in ferralitic soils with bhindi as the test crop. The experiment consisted of an incubation study and a field experiment. The incubation study was carried out to understand the release pattern of N and S from their sources viz. urea and gypsum in the soil at different sampling stages (30 and 100 days of incubation) using ferralitic soil kept at field capacity. The treatments consisted of M1N1S1, MINIS2 , M1N1S3 , M1N2S1 , M1N2S2 ,M1N2S3 ,M1N3S1 , M1N3S2 , M1N3S3 , M2N1S1 , M2N1S2 , M2N1S3 , M2N2S1 , M2N2S2 , M2N2S3 , M2N3S1 , M2N3S2 and M2N3S3 and M0N0S0 . Levels of N include N1 (50 kg ha-1), N2 (80 kg ha-1) and N3 (110 kg ha-1). M1 include P2O5 @ 8 kg ha-1+ K2O @ 25kg ha-1 (current POP) and M2 include P2O5 @ 35 kgha-1 + K2O @ 70 kg ha-1(modified POP). Different levels of S are S1 (10 kg ha-1), S2 (15 kg ha-1) and S3 (20 kg ha-1). Soil samples were collected and analyzed for pH, available N and available S content. There was increase in pH value to the neutral range at fifty per cent flowering stage (30 Days of Incubation) and all the treatments showed a decreasing trend in the pH value at 100 Days of Incubation. Available N and available S content increased to some extent at fifty per cent flowering and decreased at the final harvest stage. Application of N up to 110 kg ha-1 significantly increased the available N status of soil and S application up to 20 kg ha-1 increased the soil S status during incubation. The field experiment was laid out in 2×3×3+1 factorial RBD having three replications using bhindi variety Varsha Uphar as the test crop. The treatments were similar to that of the incubation study. S application @15 kg ha-1 significantly reduced the internodal length. N and S interaction N @ 80 kg ha-1 and S @ 15 kg ha-1 showed significant influence on fruit length. The maximum number of fruits and highest yield was obtained when the nutrients were applied @ 80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1. Considering the N and S interaction effects, combined application of N @ 80 kg ha-1 and S @ 20 kg ha-1 increased the number of fruits and yield. Application of N up to 80 kg ha-1 increased the crop yield and above this level, there was reduction in yield. The increase in number of fruits per plant by the application of N and S may be due to the highest uptake and efficient utilization of nutrients. N @ 110 kg ha-1 and S @ 20 kg ha-1 recorded the highest dry matter content. S application @ 15 kg ha-1 showed significant influence on N Use Efficiency (NUE) in bhindi. Application of 80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1 resulted in highest NUE. By the application of urea and gypsum, there was slight increase in the soil pH. After N and S application, there was increase in organic carbon content of the soil. At fifty per cent flowering all the nutrients showed an increase in availability and there was a decrease at the final harvest stage because of crop uptake and various losses. N application @ 110 kg ha-1 significantly increased the available N status in the soil. S application up to 20 kg ha-1 significantly increased the available P K and S content in soil. As the levels S increased, there was increase in the exchangeable calcium in soil. Higher levels of application of N recorded higher N content in both plant and fruit. Application of P and K at M2 (35 kg P2O5 ha-1 + 70 kg K2O ha-1) level significantly increased the content of P, K and Ca in plant and fruit. Increased S application increased the Ca content in plant since gypsum was used as the source of S. S application up to 20 kg ha-1 had significant influence on the fruit Ca and Mg concentration. The interactive effect of N and S was not significant in the case of S content in plant. But, N2S3 (N @ 80 kg ha-1 and S @ 20 kg ha-1) recorded the superior value. N application had got positive influence on the content of P, K, Ca, Mg and S in plant and fruit. By progressive increase in S application up to 20 kg ha-1and N application up to 80 kg ha-1, there was significant reduction in N: S ratio. N and S fertilization had significant influence on leaf chlorophyll content and application of 80 kg N ha-1, 35 kg P2O5 ha-1, 70 kg K2O ha-1 and 15 kg S ha-1 showed the superior value for chlorophyll content. An increasing trend was noticed with higher levels of N up to 80 kg ha-1 and S up to 20 kg ha-1. N and S application significantly enhanced the uptake of nutrients. Uptake of phosphorus, potassium, calcium, magnesium and S were highest when N, P, K and S were applied @ 80 kg N ha-1+ 35 kg P2O5 ha-1+ 70 kg K2O ha-1+ 20 kg S ha-1. N application @ 80 kg ha-1 significantly influenced the B: C ratio. Among the treatments M1N2S2 (80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1) which gave the highest yield showed the highest B: C ratio. Maximum B: C ratio was obtained when N and S were applied @ 80 kg ha-1 and 15 kg ha-1 respectively. As the levels of S increased, B: C ratio also increased. Fertilization of N, P, K and S @ 80 kg ha-1, 35 kg ha-1, 70 kg ha-1 and 15 kg ha-1 respectively recorded the minimum Percentage Disease Incidence (yellow vein mosaic). Among the treatments, yield, number of fruits per plant, N Use Efficiency and B: C ratio were highest for M1N2S2 (80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1) and it can be considered as the best treatment combination. Application of N significantly increased the yield and the yield was highest at N2 level (80 kg N ha-1). There was reduction in yield if we apply N @ 110 kg ha-1. By the application of S along with N increased the NUE and we can reduce the dose of N to 80 kg ha-1 instead of 110 kg N ha-1 for bhindi.
Open Access
Physico-chemical properties of rain water harvested under different situations in lateritic
(Department of soil science and agricultural chemistry, College of horticulture,Vellanikara, 2014) Ibrahim Hassen, Abdu; KAU; Betty Bastin
Rain water harvesting is universally accepted as an important measure of water conservation throughout the world. The quality of irrigation water has become a more serious problem than quantity in different parts of the world. The characterization of quality of water is crucial for assessing the suitability for i rrigation. Hence a study was taken up on “Physico-chemical properties of rain water harvested under different situations in lateritic soil’’ in the main campus of Kerala Agricultural University, Vellanikkara during September, 2012 to August 2013. The objective of the study was to compare the physico-chemical properties of rain water from different water sources in lateritic soil. Water was collected from five sources viz, rainfall (RF), rain water harvesting pond (RWH) , Kotteppadom pond (KP), well water (W) and surface runoff (SR). The experiment for surface runoff study was laid out in an area with a gentle slope between 5 – 10 per cent . Four rain pits were dug in this area with dimensions of 0.5 m x 0.5 m x 0.5 m and lined by polyethene sheet. Water samples were taken from these water sources for one year at monthly intervals and they were analyzed for various physicochemical parameters such as colour, turbidity, pH, EC, TDS, COD, BOD, SAR, RSC, NO 3 - , Cl - and Fe. The amount and distribution of rainfall received as well as the inflow to the rain water harvesting pond were also studied. Soil samples were collected from around rain-pits before and after rains and analyzed for the content of nutrients. The total quantity of rainfall during the study period was 2872.0 mm. The maximum amount of rainfall was observed in June and the minimum in January, 2013. The amount of rain water harvested in pond during the study period was 625.48 m which comes to 63 per cent of its storage capacity. The quality of water from different sources was compared based on the results of physico-chemical analysis. It was found that pH was highest (6.69) for water from Kotteppadom pond during summer and lowest (5.54) for water from rainfall during post monsoon season. The EC and TDS values were maximum for well water during pre- monsoon season and there was significant difference among the different sources. There was no significant difference among the sources of water as regards the content of Cl and NO 3 - over the different seasons. The values for BOD and COD varied significantly over the different sources as also the seasons. Significant difference was observed for SAR and RSC values among the different sources and seasons. Loss of nutrients from soil via surface runoff from a sloppy area was studied. Soil samples were analyzed for various physico-chemical parameters such as pH, EC, OC, 3 available N, P, K, Ca, Mg, Fe, BD, PD and WHC. The different parameters were estimated both before and after receipt of rainfall. The mean values of these parameters and percent changes along with t-value were found out. During summer, after the rains, there were significant changes for the parameters like pH, OC, as well as available nutrients like K, Ca, Mg, Fe, and the percentages of decrease were 1.67, 0.67, 37.94, 25.46, 5.62 and 8.85 respectively. The water holding capacity was also decreased by 4.80 per cent. During monsoon, available nutrients like N, P, K, and WHC decreased to the extent of 23.68, 26.24, 49.32 and 7.29 per cent respectively. In general, it was found that the rainfall and rain water harvested in the water harvesting pond were superior to well water, KP pond water and surface run off water. Salinity was low for water from all the sources. Surface run off in an area with moderate slope (5-10 %) resulted in loss of nutrients like K, P, Mg and Ca. -
Open Access
Silicon and boron nutrition of rice (Oryza sativa L.) in wet land soils
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padannakkad, 2014) Sainath Nagula, KAU; Biju Joseph
The experiment entitled “Silicon and boron nutrition of rice (Oryza sativa L.) in wet land soils of northern Kerala” was carried out to standardize the dose and method of application of silicon and boron to rice crop in paddy soils, to evaluate its effect on available nutrient status and yield and to study the effect of silicon in alleviating the toxicity of Fe, Mn and Al in laterite derived paddy soils. The treatments were a combination of boron source as borax (soil and foliar application) and silicon sources as calcium silicate (soil application) and potassium silicate (foliar application). Two experiments, a pot culture and a field experiment were conducted with rice variety Aishwarya as the test crop. Application of silicon and boron fertilizers improved the availability of silicon and boron in soil. Soil application of calcium silicate along with borax was superior in maintaining the available silicon and boron status of soil than foliar application of potassium silicate and borax. The study revealed that the application of silicon and boron as soil and foliar application had a synergistic effect on the availability of N, P, K, Ca, Mg, S, Zn and Cu in the soil. Application of silicon as foliar application of potassium silicate 0.5 % along with borax 0.5 % spray was effective in reducing iron toxicity in the soil while the use of calcium silicate 100 kg Si ha-1 and borax 10 kg ha-1 proved to be more effective in reducing manganese and aluminium toxicity in the soil. The content and uptake of N, P, K, Ca, Mg, and S in rice were significantly improved by the application of potassium silicate 0.5 % foliar spray along with borax 0.5 % spray 3 rounds. Foliar application of silicon and boron as potassium silicate 0.5 % spray and borax 0.5 % spray was more efficient on improving the content and uptake of silicon and boron compared to soil application of calcium silicate and borax. 141 Application of potassium silicate @ 0.5 % spray + borax 0.5 % spray 3 rounds was significantly superior with respect to yield and yield attributes of rice. In a nutshell, both the pot and field experiments clearly indicated that application of Si and B significantly improves the available nutrient status of soil, nutrient uptake, grain and straw yield of rice. Foliar application of potassium silicate and borax (0.5 % each) 3 rounds at 15 days interval significantly improved the available nutrient status of soil, yield and yield attributes of rice. It was also effective on alleviating toxicity of Fe, Mn and Al in laterite derived paddy soils
Open Access
Long term effect of field management on soil quality in ultisol
(Department of soil science and agricultural chemistry, College of Horticulture,Vellanikkara, 2013) Nithya, A M; KAU; Betty Bastin
Soil quality is directly related to agricultural sustainability. Assessment of soil quality is essential for determining the sustainability of land management systems. It is generally accepted that intensive agricultural production leads to a decline in soil quality. For this reason, it is highly essential to monitor soil quality to avoid soil degradation and in doing so, preserve the production capabilities of the land and protect environment. The response of soils to management and input depends on soil quality. It is therefore important to identify the soil characteristics responsible for changes in soil quality, which may eventually be considered as soil quality indicators for assessing agricultural sustainability. The present investigation has been undertaken to study the “Long term effect of field management on soil quality in Ultisol”. It was conducted in the main campus of Kerala Agricultural University, Vellanikkara during December, 2012 to June, 2013. The objective of the study was to evaluate the soil quality under different long term field management conditions in an Ultisol (Vellanikkara series) based on physical, chemical and biological indicators. Here, an attempt has been made to evaluate the physical, chemical and biological properties of soil using available soil quality indicators. Five different fields were selected namely, natural forest, rubber plantation, cocoa garden, STCR experimental field and tapioca fields. Soil samples were collected from three depths namely 0-15 cm, 15-30 cm and 30-60 cm. The different sampling sites within each field were selected based on slope percentage. The samples were characterized for soil texture, aggregate size distribution, soil temperature, water holding capacity, single value constants, pH, EC CEC, AEC, SiO2/R2O3, organic carbon , lime requirement, available macronutrients, secondary nutrients, micronutrients, counts of bacteria, fungi and actinomycetes and enzyme activity. The sampling areas were also surveyed and documented for the presence of earthworms and termites. The physical characteristics like water holding capacity, soil aggregate stability and soil temperature showed a decreasing trend with depth in the different fields. Forest ecosystem showed the most conducive physical characteristics followed by cocoa and rubber. The contents of available nutrients, secondary nutrients and micronutrients were found to be the highest in surface samples. The forest ecosystem showed relatively high values for organic carbon, and available nutrients like nitrogen, sulphur, boron, iron, manganese, zinc and copper. Microbial activity was found to be the highest in surface soils in almost all fields. The highest counts of bacteria and actinomycetes were reported in forest ecosystem and lowest in tapioca field. Fungal activity was found to be the highest in cocoa field followed by forest ecosystem. Enzyme activity was also found to be the highest in surface soils in the different fields. Soil quality was evaluated using available soil quality indicators. Based on scoring with the soil quality parameters, the highest scoring was observed for natural forest followed by cocoa field. Correlations between various soil quality parameters of different fields were also worked out. .
Open Access
Substrate impact on biogas production and manurial value of slurry
(Department of Soli Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2015) Anooja, C Lonappan; KAU; Beena, V I
The growing population of the world increases energy demand and waste generation. Due to lack of proper recycling technology, large quantities of biodegradable wastes are being produced. Biogas production is a good technology for mitigating both the problems. The slurry produced after biomethanation is a good manure which provides balanced nutrition for crops and improves soil quality. There are large varieties of biodegradable wastes which can be used as feed stock for biogas production. The quality and quantity of biogas and slurry generated are based on the nature and composition of feed stock. In order to find out an efficient substrate from the available substrates in Kerala and to determine manurial value of different types of slurry, the present study was undertaken at College of Horticulture, Vellanikkara during 2012 – 2014. To elucidate the impact of different substrates on biogas production, an experiment was laid out with three replications and six treatments viz., cow dung alone and co digestion of cow dung with poultry manure, goat manure, biodegradable house hold waste, elephant dung, and pulse residue in 1:1 ratio with equal quantity of water. The biogas generated from different treatments were analysed for CH 4 and CO 2 . The highest CH 4 production was recorded for the treatment combination of pulse residue with cow dung which was on par with cow dung and elephant dung combination, while the highest CO 2 was recorded in the biogas produced from poultry manure and cow dung combination. The hydraulic retention time recorded was lowest for elephant dung and cow dung combination. The highest organic carbon content was recorded in the slurry generated from cow dung alone, which was on par with the combination of goat manure with cowdung. The highest ammoniacal nitrogen content was recorded for biodegradable house hold waste - cow dung combination followed by pulse residue - cow dung combination. The highest total nitrogen content was observed for cow dung - poultry manure combination and cow dung - goat manure combination.157 A pot culture experiment was conducted to find out the manurial value of the slurry obtained from the treatments for biogas production with three replications and six treatments. This experiment was done by irrigating the pots with the slurry obtained from the treatments along with absolute control, as per Package of Practices and Recommendations of KAU (both were irrigated with fresh water) and with fresh undigested cow dung slurry with cowpea (var. Bhagyalakshmy) as test crop. The highest number of pods per plant and the highest yield were obtained from the plants which were irrigated with biogas slurry produced from pulse residue and cow dung combination. After harvest, the highest organic carbon content was noted in soil which was irrigated with biogas slurry produced from elephant dung and cow dung combination. The highest available nitrogen and available phosphorus content was recorded for soil irrigated with slurry produced from cow dung alone and cow dung - pulse residue combination. Available potassium content in soil was highest for in the soil which was irrigated with slurry produced from poultry manure and cowdung combination which was on par with slurry produced from elephant dung- cow dung combination. The plants irrigated with the slurry produced from cow dung-pulse residue combination and cow dung-elephant dung combination had recorded highest uptake of total nitrogen. Plants raised from the seeds obtained from these treatments showed greater shoot length, seedling length and vigour index. However elaborate studies are necessary to monitor the hormones present in different types of slurry generated from different substrates.
Open Access
Silicon, boron and zinc nutrition of bitter gourd (Momordica charantia L.) var. preethi
(Department of plant soil science and agricultural chemistry, Padannakkad, 2015) Mohammed, Shahid Salam C H; KAU; Suresh, P R
The experiment entitled “Silicon, boron and zinc nutrition in bitter gourd (Momordica charantia L.) var.Preethi” was carried out with the objective to standardize the dose and method of application of silicon, boron and zinc red loam soils. The investigation was carried out at College of Agriculture (COA), Padannakkad and RARS farm at Nileswar during April 2014 to August 2014. The whole study consisted of two parts- pot culture and field experiments. The pot culture study was conducted at COA, padanakkad. The experiment was carried out in RBD taking into consideration of varying light intensity at the site of pot culture area. The treatments applied with three levels each of zinc and boron (0.2, 0.4 and 0.6%) respectively and two levels of silicon (20 and 40 ppm) on soil basis. There were eighteen treatment combinations and one control with three replications. The soil taken from the field of RARS, Nileswar and uniformly filled in pots arranged in three blocks and then plants was raised in that. Five seed were sown in each pot then thinned to single plant. Silicon is applied as calcium silicate to soil at the time of planting. Boron and zinc are applied as foliar with borax and zinc sulphate respectively, biomtric yield data were collected. Significant differences among the treatments were observed in the biometrics characteristics of plants and for yield. T14 (B-0.6% foliar + Zn-0.2% foliar + Si-40 ppm in soil) recorded highest fruit length, breadth, weight and vitamin C content. Another experiment with same treatments was also carried in RARS farm, Nileswar in RBD with nineteen treatment and three replications. Three plants were maintained in each pit and each of the plot have four such pits. Majour nutrients viz, N, P, K application and other cultural practices were uniformly followed for all plants as Package of practices, KAU (2011). Method of application and level of application of silicon, boron and zinc were same as that of pot culture experiment. Foliar application are done at 30th , 40th , 60th days after planting. Soil application of silicon at two levels was done at the time of planting. The result of field experiment revealed that, yield and quality parameters differed significantly with the application of varied levels of Si, B and Zn. Highest vitamin C was found in T14 (B-0.6% foliar + Zn-0.2% foliar + Si-40 ppm in soil). It also showed highest fruit 107 length, breadth, weight and yield. While in the case of Fe content of fruits T9(B-0.4% foliar + Zn-0.4% foliar + Si- 20 ppm in soil) recorded highest concentration in fruits. After the harvest, the effect of these treatments on soil nutrient availability was studied. The results showed that available N, P, K, Ca, Mg, S, Si, B and Zn status in treated plot were improved significantly when compared to control. Similarly, leaf nutrient analysis at the time of harvest revealed that N, P, K, Si, B and Zn were showed significant differences among treatments. Both pot culture and field experiment indicated th effect of silicon and boron are more important than zinc in bitter gourd. T14 (B-0.6% foliar + Zn-0.2% foliar + Si-40 ppm in soil) found to be performing well under pot culture and field conditions respectively.
Open Access
Decomposition of leaf litter by oriculture
(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 2015) Nithya, Jose; KAU; Sushama, P K
Oriculture involves the use of macrophytophagous oribatid mites to bring about biodegradation of plant litter, converting the same into nutrient rich humus which can be utilized as a bio-fertilizer.In oriculture, the oribatid mite species with a proven role in bio processing of plant litter are mass cultured and released into the soil. Success of oriculture lies in the right choice of oribatid mite species based on the particular type of plant litter. Oriculture can thus be treated as the modern method of agriculture with minimum cost of production and maximum yield in a most suitable ecofriendly atmosphere. So the proposed study entitled “Decomposition of leaf litter by Oriculture” was conducted during the period 2014-2015 to envisage the standardization of the methodology for mass multiplication of selected oribatid mites, and to assess the degrading efficiency of soil dwelling oribatid mites on various types of leaf litter and also to evaluate the manurial value of bio processed litter. Standardization of the methodology for oriculture based on the procedure suggested by Xavier and Haq (2006) was conducted in Completely Randomised Design with six treatments and three replications. For that soil samples were collected from different tree growing areas like cashew, rubber, jack, cocoa, teak and mixed forest plantation. Isolation of mites from soil and litter samples was carried out. It was not possible to extract mites from soil samples but isolation and mass culturing of mites using jack litter was made possible by using Berlese tulgren apparatus. The potential of isolated mites to infest the crop plant okra was studied by releasing a known number of mites by adopting standard procedure. Since the mites being soil habituated, it could not survive on the plant. The isolation of symbiotic microflora associated with mites recorded fungal populations of 3×10-1 cfu/g of sample and bacterial population 11×10-1 cfu /g of sample. Among that most predominant microflora, four bacteria and three fungi were selected for further studies, of which one belonged to Aspergillus sp. and other one was Penicillium sp. Invitro screening of symbiotic microflora for lignin,tannin,and cellulose degrading ability revealed that lignin and tannin degrading microorganisms were present. Antagonistic activity of isolated microflora against the five major soil borne pathogen revealed that the isolate bacteria 8 and fungi 3 can control all the tested one. The experiment to assess the manurial value of decomposed litter was done by factorial CRD with different combinations of two factors, leaf litter of varying C:N ratio and different modes of biotic enrichment (Litter alone, litter+ cow dung , litter+ mites , litter+ cow dung+ mites ) as treatments and three replications. The percentage of litter decomposed was assessed and found that jack litter with the biotic enrichment litter+ mite + cow dung found to be the best combination showing the highest percentage irrespective of the litter type. Maximum percentage of litter decomposed was observed for jack litter with the biotic enrichment, litter+ cowdung+ mite and minimum decomposition rate was for cocoa with biotic enrichment litter alone. Effect of different modes of biotic enrichments on the contents of macro and micro nutrients observed to be highest in the treatment combination litter + cow dung+ mites.Influence of litter types on nutrient content of decomposed litter revealed that highest carbon content (51.26 %) was in cashew litte, N content was in jack litter (3.20 %), P content (0.31 %) was in teak litter and highest K content (0.24%) in cocoa litter. Influence of litter type and biotic enrichment on N, P,K content of the decomposed litter showed that jack litter +cow dung +mites was highest in N content (3.46 %) and teak litter + cow dung +mites was highest in P (0.47 %) and mixed litter + cow dung + mites had highest K(0.21%) content.

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