1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Soil phosphorus dynamics and its interactions in red sandy loam soils(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padannakkad, 2025-06-19) Shiv Prasad, T; Nideesh, PThe study entitled “Soil phosphorus dynamics and its interactions in red sandy loam soils” was carried out at the instructional farm II, College of Agriculture, Padannakkad, to assess the short-term dynamics of phosphorus in the sandy loam soils cultivated with cowpea as modified by different amendments and to study its impact on growth and yield parameters of cowpea. The study was carried out in two parts; an incubation experiment and a field experiment. Soil samples collected from the instructional farm II were incubated at field capacity for three months, and analysis was done after the incubation period. Treatment combinations were T1 (Control), T2 (Soil test-based P fertilizer), T3 (T2 + ZnSO4 @ 20 kg ha-1), T4 (T2 + Borax @ 10 kg ha-1), and T5 (T2 + Lime @ 250 kg ha-1). Analysis of the soil samples before incubation experiment showed that the soil is very strongly acidic, non saline and high in organic carbon. Soil sample analysis after incubation showed a significant effect of lime application on the soil pH. Available P was also significantly affected by treatments and was highest in T4 (T2 + borax) and T5 (T2 + lime) treatments. Treatments have significant effect on the Phosphorus activity coefficient (PAC) also having higher values of 15.82% and 15.79% in T4 and T5 treatments respectively, indicating better conversion of total P to available P in those treatments. On analysing the different P pools, Ca-P and Fe-P pools were found at significantly higher levels in treatment T5 (T2 + lime), whereas the Al-P, loosely bound P, and reductant P were significantly higher in T4 (T2+ borax). The incubation study revealed that boron and lime application could help in enhancing the available P content in the soil. The application of borax has a significant effect on the soil P pools also indicating its role in enhancing the reserve soil P pools. The field experiment was laid out in a randomized block design with eight treatments and three replications. The treatment combinations were T1 (KAU POP based lime and fertilizers), T2 (Soil test-based fertilizers and lime), T3 (KAU organic POP ), T4 (T2 + ZnSO4 @ 20kg ha-1), T5 (T2 + Borax @ 10 kg ha-1), T6 (T2 + PSB), T7 (T3 + PSB) and T8 (T2 excluding P + Nano P @ 10ml L-1). The cowpea variety Kanakamony was used as a test crop for the field experiment. Results of the field experiment showed significant changes in the soil chemical properties and phosphorus pools. At flowering, T3 ( KAU organic POP) treatment showed significantly higher soil pH which was on par with T1 (KAU POP) treatment. Phosphorus pools were significantly affected by treatments. Available P content was significantly higher in T1 (KAU POP) and T2 (KAU organic POP) treatments, Fe bound P and Al bound P were significantly higher in T4 ( T2 + ZnSO4) treatment. Ca bound P and reductant P were significantly higher in T2 (Soil test-based fertilizer and lime) and T3 (KAU organic POP) treatments respectively. Loosely bound P was significantly higher in T1 (KAU POP) and Organic P content was higher in T3 (KAU organic POP) treatment. Total P was significantly higher in T7 (T3 + KAU organic POP) treatment. At post-harvest, there was no significant change in the soil pH, EC and OC. Available P was significantly higher in T1 (KAU POP) treatment which was on par with T2, T3 and T4 treatments. Fe bound P and Al bound P were significantly higher in T4 (T2 + ZnSO4) treatment, whereas Ca bound P and Reductant P were significantly higher in T3 (KAU organic POP) treatment. Organic P was significantly higher in T1 (KAU POP) and T3 (KAU organic POP) treatments. Loosely bound P was significantly higher in T7 ( T3 + KAU organic POP) and total P was highest in T3 and T7 treatments. Treatment T2 (soil test based fertilizer and lime) had significantly higher PAC (Phosphorus activation coefficient) values at flowering and post-harvest stages (14.977 and 11.443% respectively) than the other treatments. The plant analysis results revealed that higher N and P were recorded in treatment T8 and K content was highest in treatment T1. Total Ca, Mg and Fe were highest in treatment T2. Total S was highest in treatments T1 and T7. Total Cu and Mn were highest in treatment T3. Total Zn was highest in T4 and T7 treatments, whereas B was highest in T5. Application of amendments had no significant effect on the growth parameters of cowpea, while yield parameters like pod weight per plant, pod yield and grain weight were significantly affected by treatments. Pod weight per plant was highest in T3, T7 and T8 treatments while pod yield was maximum in T8. Grain yield was significantly higher in T7 and T8 treatments compared to other treatments. The study results revealed a change in the dynamics of phosphorus pools and soil properties with the application of different amendments. Application of lime helps in increasing available P in the soil. The synergistic and antagonistic behaviour of added amendments such as B and Zn were also seen affecting different pools and hence the available P. Even though the available P is very high in the coastal sandy soils, a small amount of fertilizer addition is necessary to ensure the sustainable release of phosphorus from the reserve pools, as is evident from the PAC values. The addition of amendments such as Borax, ZnSO4, etc., could help in fixing excess P in the soil and can thus reduce the negative impact on the environment and soil. Borax can also help in the sustainable release of fixed P from the reserve pools. Foliar application of nano P fertilizer (DAP) was found to increase the yield parameters and is an alternate option for ensuring P supply to plants without adding P to the soils.Item Nutrient optimization for grain cowpea (vigna unguiculata (L.) walp.) in high phosphorus soils(Department of Agronomy College of Agriculture, Vellayani, 2018) Anjaly, V; Sheeba Rebecca IsaacItem Soil erosion risk assessment in Kunthippuzha sub-watershed using remote sensing and gis(Department of Soil and Water Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology Tavanur, 2018) Shaheemath Suhara, K K; Abdul Hakkim, V MItem Crop weather modelling of cocoa production in humid tropics under the purview of climate change(Academy of Climate Change Education and Research, Vellanikkara, 2018) Vishnu, R P; Sunil, K MItem Understorey productivity of selected fodder grasses in mature coconut and rubber plantations(Department of Silviculture and Agroforestry, Vellanikkara, 2018) Rose Mary Jose; Jamaludheen, VItem Control of cashew stem borer (Plocaederus ferrugineus L.) by the DD. 136 nematode (Nevaplectana earpocapsae Weiser 1955)(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1989) Madhu, S; Venkitesan, T SItem Response of upland rice(Oryza sativa L.) to NK ratios and S under partial shade(Department of Agronomy, College of Agriculture, Vellayani, 2005) Mini Gopalakrishnan; Jayakrishnakumar, VA field experiment was conducted at the Instructional Farm of the College of Agriculture, Vellayani during the first crop season of 2004 to study the response of upland rice to NK ratios and S nutrition under partial shade of coconut garden. The treatments included six levels of N and K in 2 : 1 and 2 : 1.5 ratio (T1 – 80 kg N : 40 kg K2O, T2 – 80 kg N : 60 kg K2O,T3 – 100 kg N : 50 kg K2O, T4 – 100 kg N : 75 kg K2O, T5 – 120 kg N : 60 kg K2O, T6 – 120 kg N : 90 kg K2O) and two levels of sulphur (S0 – 0 kg ha-1, S1 – 15 kg ha-1). Farmyard manure @ 5 t ha-1, P @ 30 kg P2O ha-1 were applied uniformly to all the treatments. Experiment was laid out in 6 x 2 randomized block design with three replications. Results of the experiment revealed that NK ratio and S application had significant influence on most of the yield attributing characters and yield of upland rice. Fertilizing the crop with 100 kg N ha-1, 50 kg K2O ha-1 and 15 kg S along with 30 kg P2O5 was found to significantly influence the growth characters, yield attributes and yield of rice. The physiological characters like chlorophyll content and relative leaf water contents were significantly influenced by NK ratio of (100 kg N : 50 kg K2O). Application of S significantly increased the physiological parameters. Application of 15 kg S in combination with 100 kg N and 50 kg K2O ha-1 significantly influenced the physiological parameters over control. Quality attributes like protein content of grain was significantly influenced by the application of 100 kg N and 50 kg K2O in combination with 15 kg S ha-1. The uptake of nutrients was profoundly influenced by the treatments and their interactions. Increased uptake of nutrients was recorded at an NK ratio of 100 kg N : 50 kg K2O. Application of S @ 15 kg ha-1 in combination with 100 kg N and 50 kg K2O ha-1 had a significant influence on uptake of nutrients. Increasing the levels of nitrogen, potassium and sulphur increased the soil available nutrients. Application of N at 120 kg, K at 90 kg K2O ha-1 and S at 15 kg ha-1 significantly improved the available nutrient status of soil. The results of the economic analysis revealed that benefit cost ratio was maximum in plots supplied with 100 kg N, 50 kg K2O and 15 kg S ha-1. Based on this investigation, it can be concluded that application of 100 kg N, 50 kg K2O and 15 kg S ha-1 along with 30 kg P2O5 ha-1 is necessary for obtaining economic yield of upland rice variety Harsha under partial shade.Item Agrotechniques for safed musli (Chlorophytum borivilianum Sandaou and Fernandes) in Kerala(Department of Agronomy, College of Agriculture, Vellayani, 2005) Suma, V K; Girija Devi, LA field experiment was conducted at the Instructional Farm attached to the College of Agriculture, Vellayani during the year 2004-2005, to study the adaptability and performance of safed musli under different sources of organic manures. Standardization of agro techniques such as planting weight of tuber and doses of nutrients were also undertaken. The experiment was laid out in factorial randomised block design with three replications. The treatments consisted of five sources of organic manures - M1 – FYM @ 30 t ha-1 (farmers’ practice), M2 – vermicompost, M3 – 50 per cent FYM + 50 per cent vermicompost, M4 – 50 per cent FYM + 50 per cent groundnut cake, M5 – 50 per cent FYM + 50 per cent neem cake and M6 (control), viz., FYM @ 10 t ha-1 as basal + NPK @ 100 : 80 : 80 kg ha-1 and two different planting weight of tubers such as 10 g unit-1 (P1) and 15 g unit-1 (P2). Organic manure and planting weight of tuber had significant influence on most of the growth and yield attributing characters of safed musli. The fresh and dry tuber yield of safed musli as well as saponin content were also influenced by treatments. Results of the study revealed that application of organic manure as 50 per cent FYM + 50 per cent groundnut cake significantly improved the growth characters like plant spread, number of suckers hill-1 and number of leaves plant-1 and physiological parameters like LAI, LAD and TBR. Similar trend was also observed for yield and yield attributing characters like length, diameter and number of tubers. Among the quality parameters, fresh and dry weight of tuber after peeling and saponin content were highest in the treatment where 50 per cent FYM + 50 per cent groundnut cake was applied as organic source. The N, P and K uptake were maximum in 50 per cent FYM + 50 per cent groundnut cake applied plots. The available N and K content in soil were the highest in 50 per cent FYM + 50 per cent neem cake treated plots where as P availability was maximum in plots that received nutrients as 50 per cent FYM + 50 per cent groundnut cake. Planting weight of tuber also significantly influenced the various growth and yield attributing characters. The growth characters like plant spread, number of suckers hill-1 and number of leaves plant-1 and physiological parameters like LAI, LAD and TBR were the highest in treatments where 15 g unit–1 weight of tuber was used as planting material. The yield, yield attributing characters and quality parameters were also the maximum in the same treatment. The uptake and availability of nutrients were also the maximum in the treatment where higher planting weight of tuber was used (15 g unit–1). Economic analysis revealed that planting safed musli @ 15 g unit-1 weight of tuber and applying nutrients as 50 per cent FYM + 50 per cent groundnut cake could fetch maximum net return whereas for getting the highest BCR, it is wise to use 10 g unit-1 weight of planting material along with 50 per cent FYM + 50 per cent groundnut cake.Item Effect of seal formation due to cattle manure application on infiltration and runoff(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2003) Rakesh, K NThe application of soil amendment is one of the major management practices in farming operations. Nowadays, the importance of manure application as a soil amendment is increasing due to the increased concern for the ecology and environment its abundance in availability and low cost. The manures are rich in organic matter content and other nutrients. It changes the physical properties of the soil. But the excess application of organic manure may lead to detrimental results due to the surface seal formation. Hence, the present study attempts to assess the effect of seal formation due to cattle manure application on infiltration and runoff. In the coarse textured soils, like sandy loam soil the infiltration rate will be reduced and runoff will be increased. But in the fine textured soils, like clay loam soil, the infiltration rate will be increased and runoff will be reduced. The contents of the nutrients like nitrogen, organic matter and total solids in the runoff water and the physical properties like bulk density will increase with the increase in manure application and rainfall intensity. Hence it was concluded that, while applying manure on the field, the rate of application of the manure can be determined only after determining the soil texture and rainfall intensity. Otherwise, the manure application will be results in pollution of nearby water bodies.Item Effect of seed soaking and foliar spray of growth regulators on rice (Oryza sativa L.)(Department of Agronomy, College of Agriculture, Vellayani, 2001) Poornima Yadav, P I; Babu Mathew, PA field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani during the rabi 2000, to study the effect of seed soaking and foliar spray of growth and yield of rice. To assess the influence of different seed soaking chemicals on seed germination and seedling characters, a nursery study was conducted in CRD with four treatments and four replications (T1 –water soaking, T2 – soaking in Azospirillum, T3 – soaking in Penshibao, T4 – soaking in Azospirillum + Penshibao). The main field experiment was laid out in split split plot design with three replications. The treatments included four types of seed soaking (T1 – water soaking, T2 – soaking in Azospirillum, T3 – soaking in Penshibao, T4 – soaking in Azospirillum + Penshibao) in the main plots, five types of growth regulators as foliar spray (F1 – triacontanol, F2-GA3, F3-kinetin, F4-Penshibao and F5-water spray) in sub plots and two stages of application (S1-20 DAT and S2-20 and 30 DAT) in sub sub plots. Observations on nursey study revealed that soaking rice seeds in Azospirillum or Penshibao alone or in combination improved the germination percentage and all other seedling characters. Results of the main field experiment indicated that seed soaking, foliar spray, stages of application and their combinations had a significant influence on most of the growth characters, growth analysis parameters, yield attributing characters, yield, nutrient uptake and BCR. Soaking seeds in Penshibao + Azospirillum (T4), foliar spray with Penshibao (F4) and spraying at 20 and 30 DAT (S2) improved almost all growth characters, growth analysis parameters and chlorophyll content. These treatments also recorded the highest grain yield while straw yield was comparable for soaking in Penshibao alone and its combination with Azospririllum. Among the foliar sprays, Penshibao registered the highest grain and straw yield when applied at two stages compared to single application. In treatment combinations, soaking seeds in Azospirillum and Penshibao followed by foliar spray of Penshibao, soaking seeds in Penshibao followed by its foliar spray and soaking in Penshibao and Azospirillum followed by foliar spray of GA3 were found to be on par and significantly superior to other combinations. Nutrient uptake was also influenced by the three factors studied (seed soaking, foliar spray and stage of application). Nitrogen uptake was the highest for soaking seeds in Penshibao and Azospirillum and it was on par with soaking in Penshibao alone. Similarly foliar spray with Penshibao at 20 and 30 DAT registered the highest N uptake at harvest. The different chemicals used for seed soaking were found to have a comparable effect and superior to water soaking on P uptake. Among the combinations, soaking in Penshibao and Azospirillum with foliar spray of Penshibao at 20 and 30 DAT registered the highest values for N,P and K uptake. The economic analysis showed that the individual effect of combind soaking in Azospirillum (600 g ha-1) and Penshibao (100 ppm), foliar spray of Penshibao (100 ppm) and spraying at 20 and 30 DAT were superior to other treatments. Among the interactions, the treatment combination of soaking seeds in Penshibao + Azospirillum followed by foliar application of Penshibao at 20 and 30 DAT, recorded the highest BCR.