Effect of tillage and residue retention on maize productivity

In Bangladesh, maize is generally sown after extensive tilth and minimum residue retention. Conservation agriculture (CA) systems reduce the input costs, machinery use, CO2 emissions; and improve soil health (Raper et al., 1994). Crop residues are known to affect soil physical properties (Hulugalle et al., 1986), availability of nutrients (Wade and Sanchez, 1983; Asghar et al., 2006) and soil biological activity (Tian et al., 1993). Crop residue retention has been suggested to improve overall soil fertility and to support sustainable crop production. Crop residue retention under no tillage system reduce soil erosion, increase soil organic matter (SOM), and reduce requirement of labour and fuel under cereal grain and row crop culture (Salinas-Garcia et al., 1997). Kumar and Goh (2000) reported that incorporation of crop residues is essential for sustaining soil productivity through replenishing SOM that not only a key indicator of soil quality, but it also supplies essential nutrients upon mineralization (N, P, and S) and improves soil physical, chemical, and biological properties (Kumar et al., 2001). In our country, the crop residue is used mostly for cattle feed (Saadullah et al., 1991), fuel for stove and some cases burning. It is essential to estimate the amount of crop residue that should be retained in field to get the benefits. Therefore, the present research investigated to find out the minimum tillage with residue retention could be an effective element for maize production

Effect of low cost feed on the production of walking catfish, Clarias batrachus in farmer's ponds

A feeding trial was conducted for six months in farmer's ponds to assess the performance of BFRI formulated catfish feed on the growth and survival of Clarias batrachus (L.). Nine interested farmers and their ponds (size range: 10-15 dec) in the Barera union of Mymensingh Sadar were selected. The ponds were divided into 3 treatments each with 3 replications. Among the three treatment diets, two diets - traditional (F1) and BFRI formulated (F3) were prepared by using low cost agro-based locally available ingredients and the commercial diets was Saudi-Bangla Grower-1 (F2). The diets were designed as F1, F2 and F3 for traditional (20.40% protein), Commercial (31% protein) and BFRI formulated (30.44% protein) diets respectively. The fingerlings of catfish (7.3 g) were collected from local fish vendors and stocked at the rate of 100/dec. Feeding rates were adjusted by weight after fortnightly sampling of fish. Feeding rate were 10 and 8% of the total body weight respectively for 1st, 2nd month and 5% for the rest of the experimental period. The range of some selected water quality parameters were as follows: dissolved oxygen 4.0 - 7.4 mg/l, temperature 24.0°- 33.9°C, pH 6.8 - 8.00, and transparency 17.0 - 32.00 cm. Which showed suitability of the ponds for rearing fish. At the end of the experiment, significantly highest gain (p0.05) was observed in fish fed on commercial diet (F2) and BFRI formulated diet (F3). The FCR value ranged between 2.00 and 2.80 with the traditional diet (F1) showing significantly lower FCR. The total production of fish ranged between 1398.08 and 2145.34 kg/ha with F3 diet resulting in the highest production and net profit. A simple economic analysis showed that fish fed with BFRI formulated (F3) diet resulted in the highest net profit in farmer's pond

Impact of Versatile Multi-crop Planter on service providers’ livelihood in some selected areas of Bangladesh

The cropping intensity of Bangladesh is increasing year after year because most small holders start growing three or more crops in a year. Over a 5-year cycle due to changing profitability of crops, farmers cultivate 4-6 crops with diverse seed sizes, seed rate, row spacing, fertilizer rates, and seed depth. Hence a planter for such diverse cropping systems needs to have multi-functional capabilities. Service providers also need to be able to hire out their planter for business all year round to justify the investment cost. There are a number of other criteria and challenges that would need to be satisfied by potential purchasers of a planter. The VMP (Versatile Multi-crop Planter) is such a unique machine for two-wheel tractor which can meet the above criteria and successfully establish a diverse range of crops since 2008 (Haque et al., 2011). It has designed with capability for seeding and fertilizing with fluted roller or vertical plate meters in lines for single-pass shallow-tillage, strip planting, zero tillage and bed planting. The service providers remove seeding unit from VMP and convert only for high speed rotary tiller (HSRT). Most of the grain seeds like wheat, paddy, maize, jute, pulses, oilseeds etc. can be sown in line using VMP. It owners are using this device for their own land cultivation and earning cash income through custom hiring to other farmers and could improve their livelihood through this machine. Therefore, an attempt was made to assess the profitability of VMP operations at farm level and the impacts of its operations on service providers’ livelihood

Modeling irrigation water delivery schedule for rice cultivation in East Coast Malaysia

An irrigation water delivery-scheduling model has been developed to increase irrigation efficiency for a large-scale rice irrigation project in Malaysia. The study focused on modeling irrigation water delivery schedules during the main season and off-season of the rice-based project. The procedure used a water balance approach in which rainfall was considered as a stochastic variable. Rainfall and evapotranspiration values were used to estimate weekly irrigation water deliveries through the water balance equation. Comparison of the observed and computed irrigation delivery values for the main season and off-season showed that the observed values were higher than the computed values, indicating excess water supply in the field. With the application of this model, it was observed that a modification of the existing irrigation water delivery schedules would save a considerable amount of irrigation water during the main season and off-season. The computed irrigation schedules could save 19% and 11% of irrigation water in the main season and off-season, respectively when compared with the traditional irrigation schedules

Development and validation of unpuddled riding-type rice transplanter for wet land rice establishment

Manual transplanting is tedious and time consuming which often the causes of delayed planting resulting yield loss of rice in Bangladesh. Mechanized rice transplanting is seen as a solution of labor problems. Likewise, using mechanized rice transplanting ensures uniform plant spacing as well as fast and efficient planting that contributes to high productivity (Manjunatha et al., 2009). Transplanters have been developed for rice seedling planting into puddled soils to alleviate labour shortages and reduce costs of rice establishment (Adhikari et al., 2006). Although, tillage for rice establishment has significantly mechanized in Bangladesh, 16-18 % of total production cost are involved in tillage and land leveling (BRRI, 2013). Development of a rice transplanter suitable for unpuddled transplanting under minimum tillage conditions could further minimize the land preparation cost, which will be of interest to the farmers. No significant work to date has been conducted in Bangladesh to develop a rice transplanter for minimum tillage unpuddled soil conditions. Therefore, the following development and validation study was conducted during 2013-15 with modifying and evaluating a riding-type, 6-row mechanical rice transplanter for unpuddled soil conditions

Population dynamics of the ribbon fish, Lepturacanthus savala (Cuvier 1829) from the north-eastern part of the Bay of Bengal

Population parameters of Lepturacanthus savala from the trawl catches in the north-eastern part of the Bay of Bengal, Bangladesh were investigated based on length frequency data, using complete ELEFAN computer program. The asymptotic length (Lα) and growth constant (K) were estimated to be 106.50 cm (total length) and 0.80/year respectively. Based on these growth parameters, the total mortality (Z) was estimated to be 1.89. The estimated values for natural mortality (M) and fishing mortality (F) were 1.08 and 0.81 respectively. The estimated value for the exploitation rate (E) using the length converted catch curve was 0.43. The recruitment pattern showed two peaks per year. The estimated sizes of L. savala at 25, 50 and 75% probabilities of capture were 57.49, 60.39 and 63.28 cm respectively. The estimated length weight relationship for combined sex was W=0.00093 TL(super)2.9

Post impoundment changes in the fish fauna of Kaptai reservoir, Bangladesh

Based on the present investigation and reviewing the published and unpublished documents critically, this communication considers the post impoundment changes in the fish fauna of Kaptai reservoir. Investigation reveals that a total of 73 species of fish belongs to 47 genera, 25 families and 2 species of prawn are present in the reservoir. Of them, 31 are commercially important, 6 and 9 species are newly identified

Screening of promising biofortified short duration lentil cultivars for conservation agriculture in North-west Bangladesh

In Bangladesh, lentil (Lens culinaris Medikus subsp.culinaris) production was 0.26 million tons from 0.20 million hectares (average yield 1.3 t ha-1) which is 29 % of the total national pulse production (AIS, 2016). Globally, it is cultivated as a rainfed crop on 3.85 million hectares (m ha) with a yield of only 1.1 t ha-1 (Erskine et al., 2011). In rice based cropping patterns, after harvesting of t.aman rice maximum land remains fallow for about 90 days until establishment of the boro rice. Presently, this rice land cannot be used to grow lentil since varieties have 110-115 days duration (AIS, 2017). Promising biofortified short duration (83-90 days) lentil varieties can play an important role to expand its cultivation through establishing lentil by relay sowing into t.aman rice and harvesting before boro rice. The relay cultivation method involves no tillage and residue retention, and establishes the lentil before t.aman rice is harvested. The selection of promising biofortified short duration lentil genotypes under relay cultivation method is therefore important to accommodate in fallow between t.aman and boro rice

Effects of inundation period and tillage option on field performance of self-propelled rice transplanter

Mechanized transplanting of rice could decrease costs and use of labor in the peak of transplanting periods. Self-propelled rice transplanter requires an ideal field condition as well as optimal inundation of non-puddled soil before transplanting. Hence, self-propelled rice transplanters (four rows walking type, model DP480 except clay loam soil during the Boro season in 2013-2014 where six rows riding type rice transplanter, model S3-680) was evaluated in clay loam, loam and sandy loam soil during the irrigated dry season (Boro) in 2012-2013 and 2013-2014. Tillage treatments in a strip plot design were stripped, zero and conventional tillage and irrigation treatments as inundation periods before transplanting as sub-plots were 12, 18 and 24 hours (hrs). Soil penetration resistance decreased with the increased of inundation period in both the seasons and three soil types. Field capacity of both the walking (0.11 to 0.14 ha hr-1) and the riding type rice transplanter (0.21 to 0.22 ha hr-1) had not varied significantly with the tillage options. Averaged of two seasons, strip tillage gave higher field capacity for 12 hrs inundation period in clay loam soil and 18 hrs inundation period in loam and sandy loam soil whereas zero and conventional tillage gave higher for 24, 18 and 24 hrs inundation period and 18, 12 and 18 hrs inundation period in clay loam, loam and sandy loam soil, respectively. The non-puddled strip and zero tillage reduced fuel consumption by 22% to 13% and 8% to 13% for transplanting in clay loam and sandy loam soil compared to conventional tillage, respectively. However, strip tillage reduced the percentage of missing hills (9.7%) compared to zero (13.0%) and conventional tillage (10.7%) while percentage of missing hills, averaged of two seasons and three soil types, decreased 13.7% to 9.2% with the increased of inundation periods 12 to 24 hrs. The highest percentage of picker missing hills was observed in zero tillage irrespective of seasons and soil types. However, zero tillage also gave higher percentage of damage hills compared to conventional and strip tillage. Floating hills decreased with the increased of inundation periods in non-puddled strip and zero tillage. Conventional tillage increased the buried hills significantly in both the seasons. Strip tillage gave higher grain yield compared to zero and conventional tillage in both the seasons except clay loam soil during the Boro season in 2012-13 where zero tillage gave a higher grain yield. However, 18 hrs inundation periods for strip (6.1 t ha-1), 24 hrs for zero (6.0 t ha-1) and conventional (5.9 t ha-1) tillage gave the highest grain yields. Finally, it can be stated that non-puddled minimum tillage (strip and zero) is a resource saving technique while 18 hrs inundation prior to transplant for strip and 24 hrs inundation for zero tillage showed more benefited for rice production

Impacts of Thai silver barb (Puntius gonionotus Bleeker) inclusion in the polyculture of carps

The impact of inclusion of Thai silver barb, Puntius gonionotus (Bleeker) in the polyculture with two major Indian carps viz., Labeo rohita, Catla catla and common carp Cyprinus carpio has been studied in seasonal ponds for 115 days. The presence of silver barb decreased the growth of Indian carps while increased that of common carp. A significantly higher (P<0.05) fish yield (1793.65 Kg/ha/yr) was observed in the four species polyculture system containing silver barb when the combined yield of all species was compared