List of ants in various agricultural lands of Vietnam is presented based on the surveys in 2009. The samplings by pitfall trapping and time unit sampling were carried out in four different cropping fields: paddy, vegetable, sugarcane farms and citrus orchards in Hanoi City, Hung Yen Province, Thanh Hoa Province, and Binh Duong Province. In total, 49 species of ants belonging to 26 genera of 6 subfamilies were collected from 496 samples of 12 agricultural fields. Among them, the most species rich genera were Tetramorium which included 7 species, followed by Monomorium (6 species), Camponotus (4 species) and Pheidole (4 species).
Field experiment was conducted in coastal soil (Barisal silt) of Bangladesh during July 2007 to May 2009 for determining the effect of organic manuring on soil organic matter and rice yield under tidal flooded ecosystem.Two rice crops of T. Aman (wet season; July - November) and Boro (dry season; December - May) were grown in the experimental fields in each year. Six treatments consisting of poultry liter application (2.0 t ha-1) before Boro crop (T1), Sesbania incorporation before T. Aman (T2), Lathyrus sativas (L) incorporation after T. Aman (T3), red clover (Melilotus alba, L.) incorporation before T. Aman (T4), Chemical fertilizers (T5 = 84-14- 48- 8 kg N, P, K & S ha-1) and absolute control (T6) were compared in randomized complete block design. Each treatment was replicated for three times. Test rice varieties in T. Aman and Boro season were BRRI dhan44 and BRRI dhan29, respectively.The first T. Aman crop was damaged due to SIDR before harvest. The second T. Aman crop gave 3.96 to 4.39 t ha-1 grain yield across the treatments and their treatment effect was not significant (P > 0.05). Boro crop in both the years showed consistently significant response to fertilizer and manure application. Means of two years results show that the absolute control plot yielded 3.66 t ha-1, which increased to 6.09 t ha-1 receiving chemical fertilizer alone (T5). Application of organic residues increased rice yield compared with chemical fertilizer alone. The highest yield at the value of 6.71 t ha-1 was obtained with T1 followed by 6.56 t ha-1 in T3. After two years, soil analysis showed an insignificant increase in soil organic matter (SOM) due to the application of organic residues. However,long-term application of organic residues is expected to increase SOM in tidal flooded soil and which may contribute to soil health as well as rice yields.
A laboratory experiment was carried out in the Seed Technology Laboratory, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur from August-September in 2004 and 2005 to study the effects of different botanicals on the seed quality of lentils during storage. After processing and drying, seeds were preserved with different botanicals and stored in earthen pots. The seeds were divided into four parts including a part considered as a control. For botanical treatments, three botanicals of whole leaf powders of neem, dholkalmi and bishkatali were used at the doses of 5% w/w i.e., 25 g/500 g of lentil grains. The lentil seeds were stored till the next planting time and the seed quality data on moisture (%), germination (%), dry weight of seedlings and vigor index were observed during the storage period. Germination percentage of the initial seed lot was on average 90%, and average moisture content of the seeds before storage was 9%. Significant influences of the botanicals were observed in germination percentage, dry weight and vigor of the lentils. The highest values for almost all of these characteristics were observed for the seeds preserved with neem leaf powder. Bishkatali showed the same performance as neem.Among the three botanicals, dholkalmi showed the least effect. Neem treated seeds were found to have the highest germination percentage (86.0% in 2004 and 87.2% in 2005), dry weight (0.72 g in 2004 and 0.78 g in 2005) and vigor (62.3 in 2004 and 68.0 in 2005), which were somewhat similar to bishkatali but significantly higher othan the control. No significant difference among the seeds with botanicals on moisture percentage was observed.
A pot experiment was conducted to study the growth and mycorrhizal dependence (MD) of eight selected pulses (blackgram, bushbean, chickpea, cowpea, gardenpea, grasspea, lentil, and mungbean), and two oil seeds (groundnut and soybean). Soil was collected from the research farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh. The arbuscular mycorrhizal (AM) dependence of the crops was evaluated based on growth parameters, spore population and root colonization. A positive growth response to AM was observed in all the crops. The shoot dry weight and number of pods of the inoculated crops were increased by 48 and 141%, respectively, at 50% flowering stage compared to the uninoculated control. Mycorrhizal colonization differed among the crops ranging from 46.6 to 83.3% along with spore abundance in the rhizosphere soil ranging from 15.0 to 314.0 100g-1soil. The mycorrhizal dependence (MD) varied from 25.27 to 50.79%. Two groups of plants were marked according to their MD: (i) the highly dependent plants with an MD>30% (bushbean, chickpea, cowpea, gardenpea, grasspea, groundnut, lentil and mungbean) and (ii) the intermediate group plants with an MD between 10-30% (blackgram and soybean).
A pot experiment was carried out in a vinyl house with treatments of three organic materials and one fertilizer to assess the biodynamics of microbial biomass nitrogen and sulfur in organic matter amended and fertilizer treated soils. The organic materials were dustbin waste, poultry litter and rice straw. The organic materials were added at a rate of 2% of the dry weight of the soil. In the fertilizer treatment, nitrogen was applied at a rate of 200 μg N g-1 soil as NH4NO3 and sulfur were applied at a rate of 15 μg S g-1 soil as MgSO4.7H2O. A basal dressing of 150 μg P and 188μg K g-1 soil as KH2PO4 and 10 μg Zn g-1 soil as ZnO was added to each pot. The wheat variety Shatabdi was planted in the pots where necessary. The data was recorded periodically up to 128 days of crop growing. Organic matter amended soils induced higher amount of biomass-C, -N and -S formation than that of the fertilizer treated unplanted soils. Higher amounts of biomass-C, -N and -S were found in the planted soils from day 30 and onwards compared to the unplanted soils. Rice straw showed higher contribution to biomass-C, -N and -S formation than that of poultry litter and dustbin waste. Fertilizer contributed the highest amount of inorganic N, which was significantly higher than that of dustbin waste and poultry litter. Dustbin waste induced the highest amount of SO4-S which was significantly higher than that of fertilizer treated and poultry litter amended soils. In rice straw amended soils, inorganic N and SO4-S rapidly decreased by day 5 due to N and S immobilization and then remained constant.
A pot experiment was carried out in a vinyl house with treatments of three organic materials and one fertilizer to assess the biodynamics of microbial biomass nitrogen and sulfur in organic matter amended soils and their roles in the yield of wheat cv. Shatabdi. The organic materials were dustbin waste, poultry litter and rice straw. The organic materials were added at a rate of 2% of the soil. In the fertilizer treatment, nitrogen was applied at a rate of 200 μg N g-1 soil as NH4NO3 and sulfur was applied at a rate of 15 μg S g-1 soil as MgSO4.7H2O. A basal dressing of 150 μg P and 188 μg K g-1 soil as KH2PO4 and 10 μg Zn g-1 soil as ZnO was added to each pot. The crops were harvested 30, 60 and 128 days after sowing. The organic matter amended soils induced higher amounts of biomass-C formation than that of the fertilizer treated unplanted soils. Higher amounts of biomass-C, -N and -S were found in the planted soils from day 30 and onwards compared to the unplanted soils. The fertilizer contributed the highest amount of inorganic N, which was significantly higher than that of the dustbin waste and poultry litter. The dustbin waste induced the highest amount of SO4-S, which was significantly higher than that of the fertilizer treated and poultry litter amended soils. In the soil amended with rice straw, inorganic N and SO4-S rapidly decreased by day 5 due to N and S immobilization. At the time of harvest, the highest amount of shoot dry weight of 34.4 g pot-1 was observed in the soils treated with fertilizer, which was significantly higher than that of 24.69, 22.64 and 3.26 g pot-1 in the dustbin waste, poultry litter and rice straw amended soils, respectively. A positive correlation was observed between the decrease in biomass-N or -S, N or S uptake and dry matter (shoot) yield of wheat. The critical shoot N and S concentrations in the wheat were 1.46 and 0.138%, respectively.
A pattern based experiment was carried out from the rabi season of 1999 to the kharif-II season of 2002 at the Bangladesh Agricultural University Farm, Mymensingh, Bangladesh in the Old Brahmaputra Floodplain Soils (Agroecological Zone 9, Aeric Haplaquept) to find out the integrated use of organic and inorganic fertilizers on the yield of T. Aus and mungbean in a Wheat-T. Aus/mungbean-T. Aman cropping sequence. There were four treatments for wheat (1st crop of the pattern) in the Wheat-T. Aus/Mungbean-T. Aman rice cropping pattern experiments: T1, Control; T2, NPKSZnB for Moderate Yield Goal (MYG); T3, NPKSZnB for High Yield Goal (HYG); T4, NPKSZnB for MYG + Cowdung (CD). The nutrient rates for four treatments (T1-T4) of wheat were: N0P0K0S0Zn0B0 kg ha-1 for T1, N80P20K50S10Zn1B1 kg ha-1 for T2, N120P30K75S15Zn2B2 kg ha-1 for T3 and N80P20K50S10Zn1B1 kg ha-1 + CD for T4. In T. Aus/mungbean (second crop of the pattern), one-third of the plot of each treatment was cultivated by T. Aus rice and the remaining two-third was plotted by mungbean. The rates of N, P, K and S for T. Aus rice were 60, 12, 32 and 5 kg ha-1 for MYG, and 90, 18, 48 and 7.5 kg ha-1 for HYG, respectively. The corresponding rates of P, K and S for mungbean were 10, 13 and 5 kg ha-1 for average yield goal (AYG), respectively. The variety BR 26 for T. Aus rice and BARI Mung-2 for mungbean was planted in all three years. The results showed that grain yields (3.46 t ha-1) and straw yields (5.19 t ha-1) of T. Aus rice (mean of three years) was increased significantly by the application of fertilizers. The application of chemical fertilizers, NPKS (HYG) remarkably increased the crop yields. The highest mean mungbean seed yield of 0.56 t ha-1 (mean of three years) and stover yield of 1.99 t ha-1 were obtained from the PKS plus inoculum plus residual NPKSZnB for HYG treatment, while the lowest mean grain yields of 1.48 t ha-1 for T. Aus and 0.42 t ha-1 for mungbean were recorded in the unfertilized control plots.
This field experiment was conducted to find out the effect of the different levels of fertilizers on the growth parameters of mustard varieties of BARI sharisa-9 (V1), BARI sharisa-12 (V2) and BARI sharisa-15 (V3), and to find out the optimum and economically viable fertilizer dose. A total of 5 treatments, including one control comprising of a different package of chemical fertilizers, were used in this study. The treatments were F1 (N120+P35+K50+S25+Zn4+B2), F2 (N90+P30+K40+S20+Zn3+B1.5), F3 (N60+P25+K30+S15+Zn2+B1), F4 (N30+P20+K20+S10+Zn1+B0.05) and F5 (Native nutrient). The data revealed that leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR) and plant dry matter accumulation were affected by different fertilizer applications. The present result revealed that N120, P35, K50 , S25, Zn4 and B2 kg/ha would be the most suitable fertilizer doses for production of the mustard variety BARI sharisa-9.
Growing concerns over sustainability between human activity, natural resources and ecosystems have been widely recognized in the world. Due to the complex systems and processes involved, it is quite difficult to quantify and find an optimal strategy for sustainable development and management. Artificial neural networks (ANNs) have widely been applied to modelling complex systems such as the relationship between habitat conditions and the distribution of target species. Since such relationships are strongly affected by the uncertainties originating from errors in data and modelling processes, fuzzy neural networks (FNNs), a fuzzified version of ANNs, have been applied to habitat prediction. Despite the high predictive ability of FNNs, they suffer from problems such as variances in model structure and overfitting to given data. The present study, therefore, aims to evaluate the effect of a weight decay backpropagation on the accuracy and model structure of the FNNs that evaluate the spatial distribution and habitat preference of Japanese medaka (Oryzias latipes). As a result, weight decay improved the generalization ability of the FNNs with a small deterioration of predictive accuracy. The habitat preference curves derived from the FNNs could represent the trends of habitat preference of the fish, of which the variance was markedly reduced. This case study of Japanese medaka supports the applicability of FNNs with weight decay, which can retrieve consistent information from the field observation data.