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2007 - 20097
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Subject: Agronomy × Author: KAU × End date: 2009 × Start date: 2007 × Type: Thesis ×
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    ThesisItemOpen Access
    Concurrent growing of green manure crops in dry and wet seeded rice
    (Department of Agronomy, College of Horticulture, Vellanikkara, 2008) Anitha, S; KAU; Jose, Mathew
    An investigation entitled ‘Concurrent growing of green manure crops in dry and wet seeded rice’ was conducted at Agricultural Research Station, Mannuthy to develop a comprehensive technology package for the system of concurrent growing of green manure crops in direct seeded rice. The investigation consisted of four experiments viz., Experiment Ia - Concurrent growing of green manure crops in dry seeded rice, Experiment Ib - Residual effect of concurrent growing of green manure crops in dry seeded rice, Experiment IIa - Concurrent growing of daincha in wet seeded rice and Experiment IIb - Residual effect of concurrent growing of daincha in wet seeded rice. The experiment on concurrent growing of green manure crops in dry seeded rice consisted of two green manure crops (horse gram and cowpea), three methods of incorporation (Incorporation by cono weeder, desiccation by 2,4 - D spray @1.0 kg ha-1 and allowing for self decomposition) and two levels of nitrogen (100 and 75% of recommended N) and a control without green manure crops . Among the two green manure crops, cowpea was the best in supplying the required quantity of green matter with 25 per cent savings of N fertilizer and a substantial reduction in weed incidence. All the three methods of incorporation were found to be equally effective. Hence in places where there is a difficulty in self decomposition, cowpea can be effectively incorporated by conoweeder or by spraying 2, 4-D. The cowpea variety used in this study was a short duration bush type variety facilitating additional pod yield from cowpea before it was incorporated. Concurrent growing of cowpea along with dry seeded rice is a viable system as it resulted in increased productivity, profitability and sustainability dry seeded rice. In the experiment to study the residual effect of concurrent growing of green manure crops in dry seeded rice, the main plots of dry seeded rice crop during the 1st crop season were divided into two sub plots and applied 100 and 75 per cent N to the subplots. The results revealed that concurrent growing of green manure crops were effective in increasing the yield and sustaining soil fertility status compared to pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. But there was no savings of N fertilizer to the succeeding transplanted rice crop as the highest yield of succeeding rice was achieved only when it received 100 per cent of the recommended N. The profitability of the rice- rice cropping system was the highest with concurrent growing of cowpea in dry seeded rice. The experiment on concurrent growing of daincha in wet seeded rice consisted of two stages of incorporation of daincha (20 DAS and 30DAS), three methods of incorporation (Incorporation by cono weeder, desiccation by 2, 4 - D spray @1.0kg ha-1 and Desiccation by Chlorimuron ethyl+ met sulfuron methyl spray @ 4.0 g ha-1 met sulfuron methyl spray @ 5 g ha-1) and two levels of nitrogen (100 and 75% of recommended N) and a control without daincha. Results indicated that concurrent growing of daincha can be successfully practiced in wet seeded rice with improved productivity. Incorporation of 30 days old daincha employing any of the three methods of incorporation was equally effective in increasing the productivity and profitability of wet seeded rice. Incorporation of daincha at 30 DAS could add about 14 t ha-1 of green matter with minimum investment and resulted in 70 per cent weed suppression. Concurrent growing of daincha receiving both 100 and 75 per cent of recommended N produced significantly higher yield than pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. Hence there was a saving of 25 per cent N without affecting the yield. The highest yield was obtained when 100 per cent of recommended N was applied to the system. The treatments for the experiment to study the residual effect of concurrent growing of daincha in wet seeded rice were similar to that of dry seeded rice. The results showed that concurrent growing of daincha and its incorporation at 30 DAS was effective in increasing the yield of succeeding rice and sustaining soil fertility status compared to pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. The highest yield of succeeding rice was achieved only when it received 100 per cent of the recommended N hence there was no savings of N fertilizer to the succeeding transplanted rice crop. Concurrent growing of daincha in wet seeded rice increased the profitability of the rice- rice cropping system. Concurrent growing of green manure crops in dry and wet seeded rice is a management alternative to reduce the production cost and to increase the yield of rice and is a practical model for sustainable rice production.
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    ThesisItemOpen Access
    Impact of long term integrated nutrient supply system on soil health and rice productivity
    (Department of Agronomy, College of Agriculture, Vellayani, 2007) Raji S, Prasad; KAU; Babu Mathew, T
    A field experiment was carried out in both kharif and rabi seasons during 2004-2005 at Cropping System Research station, Karamana to find out the effect of long term integrated nutrient supply system on soil health and productivity of rice ( Oryza sativa L) –rice sequential cropping system. The experiment was laid out in RBD with 12 treatments in 4 replications and treatments in kharif and rabi together form one set of treatment. The treatments included control , 50% ,75% and 100% levels of RDF in kharif and rabi and 50% or 25% substitution of recommended dose of nitrogen in kharif substituted by organic manure viz. FYM , crop residues and green manure. The treatments exerted profound influence in majority of growth characters and yield attributes. Application of 25% or 50% substitution of RDF through organic manure along with 75% or 100% RDF in rabi through chemicals produced remarkable influence in growth and yield attributes. In grain and straw yield of rabi and kharif , the highest values were given by those treatments which supplied either 50% or 25% of RDF through FYM or crop residues in kharif and 100% or 75% of RDF through inorganic fertilizers in rabi .Since these treatments were on par with each other, the best treatment is that which supply 25% RDF through organic manure in kharif and 75% of RDF through inorganic fertilizers in rabi since25% of the chemical fertilizers are saved there. The highest NPK contents in grain and straw in both kharif and rabi were recorded and mostly in those treatments with 50% or 25% of RDF through organic manures in kharif along with 100% or 75% of RDF through in organics in rabi The highest NPK uptake in all the crop stages in both kharif and rabi were also higher observed in plots those receive 50% or 25% of RDF through organic manures in kharif along with 100% or 75% of RDF through in organics in rabi The soil available P and K values did not vary remarkably in both Kharif and rabi .However soil available nitrogen in soil varied profoundly before and after rabi seasons and the maximum available nitrogen was observed before rabi in those plots which supply 25% RDF through crop residues in kharif and 100% RDF through chemical fertilizers in rabi and 50% RDF through green manure in kharif and 100% RDF through chemical fertilizers in rabi. The physical properties like bulk density and water holding capacity were also significantly influenced by the treatments before and after the experiment in which lower bulk density values were exhibited by organics applied plots in kharif and they also showed significantly higher water holding capacity compared to those treatments which were supplied with organic matter in kharif . Soil chemical properties like organic carbon and CEC remarkably improved in organic manure applied plots along with inorganics in rabi. The population count studies of bacteria, fungi, and actinomycetes revealed the positive influence of the collective application of organic matter and inorganic fertilizers on soil biological properties and its subsequent influence on soil health when compared with control. As per the economic analysis of the cultivation the maximum benefit cost ratio was exhibited by the treatment which received 25% of RDF in kharif through crop residues and 75% of RDF through in organics in rabi .
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    ThesisItemOpen Access
    Sulphur-zinc interaction in integrated nutrient supply system of wetland rice ( Oryza sativa L.)
    (Department of Agronomy, College of Agriculture, Vellayani, 2007) Vipin, K S; KAU; Shahul Hammed, S M
    An experiment was conducted at Cropping Systems Research Centre (CSRC), Karamana, Thiruvananthapuram during rabi season of 2005-06 to study the response of wetland rice to sulphur and zinc under integrated nutrient condition using the variety Aiswarya. The experiment was laid out in factorial randomized block design with three replications. The treatments consist of combinations of two levels of nitrogen (N), three levels of sulphur (S) and two levels of ZnSO4 (Z) along with two controls (zero level of fertilizer treatment and Package of Practice recommendation treatment). Recommended dose of nitrogen applied as 100 per cent inorganic (N1) and 50 per cent N applied equally as organic-inorganic integration (N2) constitutes the N levels. Sulphur applied @ 10 kg ha-1 (S1), 20 kg ha-1 (S2) and 30 kg ha-1 (S3) were the three sulphur levels. The two ZnSO4 fertilizer levels are10 kg ZnSO4 ha-1 (Z1) and 20 kg ZnSO4 ha-1 (Z2) and farmyard manure @ 5 t ha-1 was applied uniformly to all treatments. Results of the experiment revealed that the main effects of nitrogen, sulphur and ZnSO4 as well as their combinations exerted positive significant influence on the growth and yield attributing characters of rice. Organic- inorganic integration (N1) significantly influenced growth characters like plant height, tiller number hill-1, leaf area index and dry matter production and yield character like number of panicles hill-1 and yield while higher sulphur (S3) level upto 30 kg ha-1 were found significantly superior in influencing all growth, yield attributing characters and yield of rice to lower level (S1). ZnSO4 @ 20 kg ha-1 (Z1) recorded significantly higher plant height, tiller number hill-1 leaf area index, number of panicles hill-1, weight of panicle, filled grains panicle-1 and yield of rice. Treatment combinations also significantly influenced most of the growth, yield attributing characters and yield of rice compared to controls. Chlorophyll content was significantly influenced by S application only. Nutrient uptake was also influenced by treatments and their combinations. Organic- inorganic integration (N1) significantly favoured the uptake of N, P, K, S and Zn while S application at higher levels contributed significantly to uptake of N, S and Zn. Uptake of N, S and Zn was significantly influenced with higher level of ZnSO4 @ 20 kg ha-1 (Z2). Combination of S @ 30 kg ha-1 along with ZnSO4 @ 20 kg ha-1 produced highest uptake of Zn. Available N and K exhibited significant variation with combined use of both organic and inorganic source of nitrogen. Available nutrient status of N, K, S and Zn was significantly increased by S application at higher levels. Again, there was increase in availability of S and Zn content of the soil with higher level of ZnSO4 (20 kg ha-1) application. N X S and S X Zn interactions also played significant role in increasing available N and S content of soil. Treatment combinations recorded significantly better results in uptake and availability of nutrients compared to control treatments. Highest benefit cost ratio was recorded by a combination of S @ 30 kg ha-1 + ZnSO4 @ 20 kg ha-1 along with full recommended dose of N as inorganic fertilizer.
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    ThesisItemOpen Access
    Evaluation of potha grass (Themeda cymbaria (Roxb) Hack) for fodder production and quality
    (Department of Agronomy, College of Horticulture, Vellanikkara, 2007) Praveen, A; KAU; George Thomas, T
    Potha grass (Themeda cymbaria (Roxb.) Hack.) is a native fodder grass grown in parts of central Kerala. The present investigation was undertaken to have an understanding on the phenology, growth characteristics, fodder production potential and nutritive quality of T.cymbaria. Comparisons were made with Guinea grass (Panicum maximum) cv. Makueni. The experiments were conducted at the Agronomy Research Farm of College of Horticulture, Kerala Agricultural University Vellanikkara during 2006– 2007. The phenological and growth characteristics were noted during the year 2006-07. P.maximum started flowering at the beginning of January and continued up to July 2007. It took one month from flowering to seed maturity. However, no phenological events related to flowering were observed in T.cymbaria during the experimental period. Growth was comparatively fast in P.maximum than T.cymbaria. Plant height, number of leaves, leaf area, leaf weight, stem weight and dry matter production per plant were the highest in P.maximum during all the growth stages. Similarly, growth indices like leaf area ratio (LAR), specific leaf area (SLA), leaf area duration (LAD), relative growth rate (RGR), absolute growth rate (AGR) and net assimilation rate (NAR) showed higher values in P.maximum than T.cymbaria. However, the value of leaf weight ratio (LWR) was higher in T.cymbaria than P.maximum. Both grasses showed a decline in growth during summer season. However, with the onset of monsoon, both grasses performed well. The fodder production potential of T.cymbaria was compared with Guinea grass cv. Makueni under irrigated and rainfed conditions by harvesting the herbage at 30, 45, and 60 days intervals. Growth characters like plant height, number of leaves, leaf weight, stem weight and leaf area index (LAI) were found to be higher in P.maximum than T.cymbaria. The green and dry fodder yields at the end of the experimental period of 10 months from planting indicated a clear yield advantage for Guinea grass over Potha grass. Between irrigated and rainfed grasses, although there were yield differences at some stages of cutting, total yields showed no significant difference. The highest green and dry fodder yields were recorded in irrigated Guinea grass. Regarding cutting intervals, 45 days cutting interval performed better compared to 30 and 60 days intervals. From yield point of view, Poth grass may not be comparable with Guinea grass. However, Potha grass could be recommended as a soil conservation grass as it did not show any flowering and seed formation. Growth during the dry period was also normal. It could be an ideal alternative as a soil conservation grass for farmers who also rear livestock, instead of the usually recommended non-edible Vetiver (Vetiveria zizanioides). Nutrient aspects like crude protein, ether extract, nitrogen free extract, ash, phosphorus, magnesium, and oxalate contents of both grasses were found to be similar under irrigated and rainfed conditions at different cutting intervals. However, crude fibre content was higher in Potha grass, while potassium and calcium contents were higher in Guinea grass. From nutrient point of view, there is hardly any difference between the two grasses. Potha grass can replace Guinea grass in feeding with the same quality.
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    ThesisItemOpen Access
    Performance of summer crops in rice fallows and its effect on succeeding transplanted rice
    (Department of Agronomy, College of Agriculture, Vellayani, 2009) Shrikant P, Golabhavi; KAU; Latif, P H
    A field experiment entitled “Performance of summer crops in rice fallows and its effect on succeeding transplanted rice” was taken up at the Cropping systems research station, Karamana, Thiruvananthapuram during February 2008 to October 2008 that covered the summer (third crop) and virippu (the first crop) seasons of rice cultivation. The main objectives of the experiment was study the performance of different upland crops in the summer rice fallows of southern Kerala in terms of resource utilisation, yield, soil health and carry over effect on succeeding rice crop, and to arrive at a sound practice of summer rice fallow utilization. The experiment was laid out in a randomised block design with three replication and seven treatments (T1 - Control or summer rice fallow, T2 - Sweet potato, T3 - Pumpkin, T4 - Sesamum, T5 - Amaranthus, T6 – Cowpea and T7 - Daincha) which were followed by rice crop in the virippu season. Al the crops were raised as par the KAU package of practices recommendations. Results of the study revealed that there was a significant variation in the composition of weed flora of summer crops and the succeeding rice crop. The associated weed species of summer crop also varied significantly. Cowpea (T6) being grown on pandal had no weed separation effect and hence had the higher WDMP and SDR. Amaranthus (T5) recorded the highest economic yield and rice yield equivalent, water productivity, net profit and B:C ratio. However, sweet potato (T2) recorded the highest energy yield per unit area and highest nutrient uptake of macro and micro nutrients. The nutrient balance sheet showed a general negative balance for N and P except for sweet potato (T2) and Daincha (T7) where as K showed a negative balance for all treatments. The succeeding rice crop was not significantly influenced by the summer crops with respect to yield and yield attributes. The post rice soil was left less acidic by pumpkin-rice sequence, where as Daincha-rice significantly increased the soil acidity. The post rice soil significantly varied in the available P and K with the highest value noted in Amaranthus-rice (T5). Significantly higher quantity of Zn was recorded in Daincha-rice (T7).
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    ThesisItemOpen Access
    Standardisation of organic manures and effect of microbial inoculants on growth, yield and quality of kasthuri turmeric(Curcuma aromatica Salisb.)
    (Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 2009) Nirmalatha, J D; KAU; Sulekha, G R
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    ThesisItemOpen Access
    Ecofriendly management of weeds in rice
    (Department of Agronomy, College of Horticulture, Kerala Agricultural University, Vellanikkara, 2008) Sindhu, P V; KAU; George Thomas, C