Bed planting method for rice production systems is very new and research on it is still at an introductory phase. A field experiment was conducted to determine the effect of different agronomic aspects of bed planting on the growth and yield of transplanted aman rice (both irrigated and rain fed). This study also evaluates the water and fertilizer application efficiency of rice cropping system under bed planting method. Results showed that the bed planting method increased grain yield of rice up to 16% than the conventional method. Bed planting also increased the number of panicle m−2, number of grains panicle−1, and 1000-grain weight of rice than conventional method. Sterility percentage and weed infestation were lower in bed planting than conventional method. About 42% of the irrigation water and time for application could be saved through bed planting in transplanted aman rice cropping system. Water use efficiency and crop productivity for grain production were higher in bed planting over conventional method. This study concluded that bed planting method is a new approach for optimum fertilizer and water use efficiency as well as higher yield compared to conventional flat method.
Rice is the major staple food in Bangladesh and the majority of its food grain comes from paddy rice. About 80% of the cropped area of this country is used for rice production, with annual production of 43.50 million metric tons in total acreage of 11.20 million ha. The average yield of rice in Bangladesh is 3.90 t ha−1 [
Rice production is currently in stagnant condition because farmers do not fully follow the improved techniques in an integrated way, which creates a yield gap. In this situation, farmers, researchers, and scientists are looking for new methods or technologies to get higher rice yield. To meet the increasing food demand, rice production must be increased and continued. Bed planting rice production systems may be a technique for improving the yield. In this system, the land is prepared conventionally and raised bed as well as furrows are prepared manually or using a raised bed planting machine. Crops are planted in rows on top of the raised beds, and irrigation water is applied in the furrows between the beds. Water moves horizontally from the furrows into the beds. This system is often considered for growing high-value crops that are more sensitive to temporary water logging stress. In conventional tillage system for transplanting rice, land is prepared by puddling the soil. For direct seeding of pregerminated rice seed, land is also prepared by puddling. Puddling and continuing inundation until maturity have significant effects on the physical, chemical, and biological status of soils that influence the growing conditions for all crops in the system [
Preliminary research on bed planting at the Bangladesh Rice Research Institute [
The experiment was conducted at the farmer’s field in Chuadanga during August to November/2011. The soil of the experiment plot was silt loam with pH 7.30.
The aman rice variety SORNO was used as an experimental plant. Because, this variety is widely used by the farmers in the Chuadanga district of Bangladesh.
The experiment was laid out in a randomized complete block design with three replications. The combination of treatments was randomly distributed in the plots within a block. The unit plot size was 8 m2 (4 m
The land was prepared conventionally. The final land preparation was done by ploughing and cross ploughing by two wheel power tiller with two laddering before two days of transplanting. One day before transplanting the plots was laid out as per experimental design.
Raised bed and furrows were made manually by spade following the conventional land preparation. According to the treatments 60 cm (centre to centre of furrows) width bed were made. For the 60 cm bed, the top of the raised bed were 35 cm and furrow between beds were 25 cm. The beds were made one day before transplanting the plots according to lay out of the experiment. The heights of beds were 15 cm.
The crop was fertilized with N, P, K, S, and Zn at the rates of 100, 20, 35, 10, and 4 kg ha−1, respectively. The sources of N, P, K, S, and Zn were urea, TSP, MP, gypsum, and ZnSO4, respectively. The all of TSP, MP, gypsum, and ZnSO4 were applied at the time of final land preparation as basal dose in the plots with conventional treatment. In the plots with bed planting treatments, the basal doses were applied before transplanting on the top of the beds. The urea was top dressed in three equal splits at 15, 30, and 50 days after transplanting (DAT).
Thirty day old seedlings were uprooted from the seedbed without making any injury to them and transplanted on the same day. Two to three seedlings hill−1 were transplanted maintaining row spacing at 25 cm and plant to plant spacing of 15 cm. Irrigation water was applied one day before transplanting between the furrows of bed to make the soil soft.
Though transplant aman rice was a rain fed crop, supplemental irrigation was needed for preparation of the plots with conventional treatment and for the bed planting of all plots. Another supplemental irrigation was done for all plots at flowering stage of rice.
Manual weeding was done twice in the transplant aman rice field during growth period. The plots were weeded at 15 and 30 DAT. Weed samples from each plot were collected at the time of weeding for comparing weed population and dry biomass yield of different treatments.
The rice was infested by stem borer at tillering stage and by rice bug at grain filling stage. Furadan 5 G at the rate of 10 kg ha−1 was applied at 40 DAS and Malathion 57 EC 5 G at the rate of 1 L ha−1 was applied at grain filling stage to control stem borer and rice bug, respectively.
Rice was harvested and threshed by using pedal thresher.
The experiment was conducted with randomized complete block design replicated three times. All statistical analysis was conducted by
The yield increase by bed planting over conventional method was 16%. A similar finding was also found in panicles; grains per panicle and 1000 gm grain wt. Raised bed planting had more 50 panicle number m−2, 21 grain number per panicle and 0.19 gm in 1000 grain wt than conventional method. Likewise, grain yield and yield components significantly (
Grain yield and yield components with respect to fertilizer application.
Method of fertilizer application | Yield and yield components | |||
---|---|---|---|---|
Grain yield |
Panicles m−2 (no) | Grains panicle−1 (no) | 1000 grain wt (gm) | |
Fertilizer broadcasting in |
5.83a | 417a | 161a | 23.01a |
Fertilizer broadcasting in conventional plot | 4.90b | 367b | 140b | 22.82b |
Coefficient of variation CV (%) | 5.31 | 4.10 | 4.59 | 5.30 |
Level of significance | ** | ** | ** | ** |
Where **represent probability of ≤0.01. Values were means of three replicates. In a column figures with same letter do not differ significantly whereas figures with dissimilar letter differ significantly (
Planting method affected plant height, panicle length, nonbearing tillers m−2, sterility percentage, straw yield, and harvest index of transplanted aman rice. Plant height, panicle length, and harvest index were higher in bed planting than conventional method. On the contrary, nonbearing tillers m−2 and sterility percentage were higher in conventional method than bed planting. Likewise, lower number of nonbearing tillers m−2 was recorded in bed planting treatments than conventional method. Bed planting significantly (
Plant biomass with respect to raised bed and conventional method.
Method of fertilizer application | Plant height |
Panicle |
Nonbearing tiller |
Sterility (%) | Straw yield |
Harvest index |
---|---|---|---|---|---|---|
Fertilizer broadcasting in raised bed | 87.23a | 24.88a | 67b | 10.16b | 5.60a | 0.51a |
Fertilizer broadcasting in conventional plot | 86.38b | 24.30b | 78a | 12.41a | 4.92b | 0.49b |
Coefficient of variation CV (%) | 3.25 | 3.47 | 4.25 | 6.14 | 4.52 | 5.30 |
Level of significance | ** | ** | ** | ** | ** | ** |
Where **represents probability of ≤0.01. Values were means of three replicates. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
Transplanting of aman rice under different planting method affected the number of tillers m−2 of rice. The increasing trend of tillers m−2 was continued to 50 DAT. At 50 DAT both planting methods attained the highest number of tiller m−2 and then started declining up to 100 DAT. Interestingly, tiller number did not differ significantly up to 40 days after transplanting in both raised bed and transplanting method. However, both methods differ significantly (
Effect of tiller production in both raised bed and conventional method.
|
Tiller (no.m−2) at days after transplanting | ||||||||
---|---|---|---|---|---|---|---|---|---|
20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | |
Fertilizer broadcasting in raised bed | 235a | 543a | 588a | 626a | 514a | 502a | 595a | 489a | 484a |
Fertilizer broadcasting in conventional plot | 196a | 367a | 441a | 522b | 490b | 470b | 462b | 450b | 445b |
Coefficient of variation CV (%) | 6.58 | 6.95 | 7.10 | 4.55 | 5.37 | 6.45 | 7.25 | 6.48 | 5.17 |
Level of significance | n.s. | n.s. | n.s. | ** | * | ** | ** | ** | ** |
Where n.s. * and **represent probability of >0.05, ≤0.05, and ≤0.01, respectively. Values were means of three replicates. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
Planting method affected the leaf area index of transplant aman rice recorded at different DAT. Plant-to-plant distance in rows also influenced the leaf area index measured at different stages of crop growth. The highest leaf area index (LAI) was achieved at flowering stage (80 DAT) by planting method. It was also revealed that at early stage of crop growth the leaf area index of bed planting treatments was lower than conventional method and at maximum tillering stage to next stages. Result showed that LAI did not differ significantly between two methods at 20 days after transplanting. However, LAI differs significantly (
Effect of leaf area index in both raised bed and conventional method.
Method of fertilizer application | LAI at different DAT | ||||
---|---|---|---|---|---|
20 | 40 | 60 | 80 | 100 | |
Fertilizer broadcasting in raised bed | 0.60a | 4.96b | 6.57b | 8.35b | 6.26b |
Fertilizer broadcasting in conventional plot | 1.32a | 6.23a | 12.47a | 12.62a | 9.47a |
Coefficient of variation CV (%) | 4.52 | 6.28 | 7.45 | 8.25 | 5.17 |
Level of significance | n.s. | ** | ** | n.s. | * |
Where n.s. * and **represent probability of >0.05, ≤0.05, and ≤0.01, respectively. Values were means of three replicates. In a column figures with same letter do not differ significantly whereas figures with dissimilar letter differ significantly (
Planting method affected the dry matter production of transplanted aman rice recorded at different days after transplanting (DAT). In the first date of measurement (20 DAT) it was observed that the conventional method produced higher dry matter yield than bed planting. Likewise, at the final date (100 DAT) highest dry matter production was also recorded in conventional method than bed planting method. However, dry matter production differs significantly (
Effect of dry matter production in both raised bed and conventional method.
Method of fertilizer application | Dry matter production (g m−2) at different days after transplanting (DAT) | ||||||||
---|---|---|---|---|---|---|---|---|---|
20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | |
Fertilizer broadcasting in raised bed | 75b | 218b | 617b | 734b | 1162a | 1450a | 1765b | 2083b | 2250b |
Fertilizer broadcasting in conventional plot | 107a | 317a | 835a | 1160a | 2282a | 2825a | 3970a | 4724a | 5101a |
Coefficient of variation CV (%) | 6.45 | 7.45 | 6.33 | 8.45 | 7.10 | 4.58 | 5.29 | 7.11 | 4.56 |
Level of significance | ** | ** | ** | ** | n.s. | n.s. | * | ** | ** |
Where n.s. * and **represent probability of >0.05, ≤0.05, and ≤0.01, respectively. Values were means of three replicates. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
At the initial stage (20 to 40 DAT), the crop growth rate in bed planting was lower than conventional method. The greatest crop growth was observed at 50 to 60 DAT in both planting method. However, crop growth rate significantly (
Effect of crop growth rate in both raised bed and conventional method.
Method of fertilizer application | Crop growth rate (g m−2 day−1) at different days after transplanting (DAT) | |||||||
---|---|---|---|---|---|---|---|---|
20–30 | 30–40 | 40–50 | 50–60 | 60–70 | 70–80 | 80–90 | 90–100 | |
Fertilizer broadcasting in raised bed | 14.3b | 39.9b | 11.8b | 42.8b | 28.8b | 31.5b | 31.80b | 16.70b |
Fertilizer broadcasting in conventional plot | 21a | 51.8a | 2.5a | 111.2a | 54.3a | 4.5a | 75.4a | 37.7a |
Coefficient of variation CV (%) | 5.26 | 5.78 | 6.10 | 4.88 | 6.49 | 6.70 | 8.20 | 4.91 |
Level of significance | ** | ** | ** | ** | ** | ** | ** | ** |
Where **represents probability of ≤0.01. Values were means of three replicates. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
Weed population and dry biomass were greatly influenced by different planting methods of transplanted aman rice. The bed planting method reduced weed population resulting in lower dry biomass than the conventional method. The conventional method had significantly (
Effect of weed growth in both raised bed and conventional method.
|
Weed vegetation | |
---|---|---|
Weed vegetation population (no.m−2) | Dry biomass (kg ha−1) | |
Fertilizer broadcasting in raised bed | 123b | 113.3b |
Fertilizer broadcasting in conventional plot | 380a | 337a |
Coefficient of variation CV (%) | 8.14 | 6.47 |
Level of significance | ** | ** |
Where **represents probability of ≤0.01. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
Amount of water required for different irrigations differed remarkably between the conventional and bed planting methods. The conventional method received the higher amount of water at every irrigation and total amount was 142.66 cm. In bed planting method total amount received was 100.47 cm. Result showed that total water savings by bed over conventional method were 42%. At transplanting and reproductive stage, conventional method required significantly (
Irrigation water savings by bed planting of rice production over conventional method.
Method of fertilizer application | Water required at different times of irrigation (cm) | Water saved over conventional method (%) | ||||
---|---|---|---|---|---|---|
Land preparation | Transplanting | Reproductive stage | Rainfall | Total | ||
Fertilizer broadcasting in raised bed | — | 6.35a | 41.62b | 52.50a | 100.47b |
|
Fertilizer broadcasting in conventional plot | 13.06 | 6.20b | 70.90a | 52.50a | 142.66a | |
Coefficient of variation CV (%) | — | 3.54 | 7.25 | 6.33 | 4.37 | |
Level of significance | — | ** | ** | n.s. | ** |
Where n.s. and **represent probability of >0.05 and ≤0.01, respectively. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
Water use efficiency for grain production and biomass production in bed planting was 51 kg ha−1cm−1 and 114 kg ha−1cm−1, respectively. In contrast, water use efficiency for grain production and biomass production in conventional planting was 29 and 69 kg ha−1cm−1, respectively. However, water used efficiency for grain production and biomass production by bed planting over conventional was 57% and 61%, respectively (Table
Water use efficiency in both raised bed and conventional method.
Method of fertilizer application | Water use efficiency savings by bed planting of rice over conventional method | |
---|---|---|
Water use efficiency for grain production |
Water use efficiency for biomass production | |
Fertilizer broadcasting in raised bed | 51a | 114a |
Fertilizer broadcasting in conventional plot | 29b | 69b |
Coefficient of variation CV (%) | 5.12 | 3.99 |
Level of significance | ** | * |
Where * and **represent probability of ≤0.05 and ≤0.01, respectively. Values were means of three replicates. In a column figures with same letter do not differ significantly, whereas figures with dissimilar letter differ significantly (
Agronomic efficiency (AE) of nitrogen fertilizer in raised bed was 32.15%. On the other hand AE for conventional plot was 27%. So, AE in raised bed was 20% higher than conventional plot (Table
Agronomic efficiency of fertilizer in both bed and conventional plot.
Method of Fertilizer application | Agronomic efficiency of fertilizer (%) |
---|---|
Fertilizer application broadcasting in raised bed | 32.15 |
Fertilizer application broadcasting in conventional plot | 27 |
The number of panicles m−2 was significantly (
Tiller production in raised bed was significantly (
Weight of 1000 grain was also significantly higher in bed planting than conventional method (Table
Raised bed planting method had 0.93 t ha−1 higher rice production than conventional method (Table
Weed production was significantly (
The differences in total water use between these two methods were 42% higher in conventional over bed planting method for the entire cropping period (Table
This study concludes that raised beds increased rice yield 16% than by the conventional tillage on the flat. Raised bed also reduced irrigation water requirement by 42% and so increased irrigation efficiency. This findings conclude that water and fertilizer use efficiency for grain production and crop productivity were higher in bed planting than conventional method. The potential gains from growing rice production on raised beds are considered to be associated with better agronomic management than conventional method. Also, the crust problem on the soil surface was eliminated and soil physical status was greatly improved in bed planting plot over conventional flat system.
Based on the findings of this single season experiment, high yielding aman rice (depends on both irrigation and rainfall) crops have been successfully grown on raised bed; however, this research needs further validation. In this perspective, further study is under way to investigate yield and growth response of transplanted boro rice (completely depends on irrigation) under conventional and bed planting method. Therefore, further research about raised bed over conventional method will be focused on water and fertilizer use efficiency for boro rice (irrigated) production.
The authors are thankful to the farmer who leases his land for this experiment. The author also thanks the pump operator for his kind help to irrigate the land. The authors are deeply indebted to the authorities of Bangladesh Rice research institute (BRRI), Local weather office, Chuadanga and seed processing unit, and Bangladesh Agricultural Development Corporation (BADC), Chuadanaga for their assistance and constructive suggestion.