In irrigated agricultural systems, nitrogen (N) and water are the vital resources for sustainability of the crop production in the modern era of climate change. The current study aimed to assess the impact of water and N management on the productivity of irrigated rice cultivars. In the context, a field observation was done at the research farm of Bangladesh Agricultural University, Mymensingh, during dry seasons in consecutive two years (2018–2019 and 2019–2020). The experiments were set up following split-plot design assigning water management in the main plots, nitrogen management in the sub-plots, and the cultivars were approved in the split-split plot with three replications. After two years observation, it was revealed that rice cultivar Binadhan-8 gave the maximum value of leaf area index, number effective tillers hill-1 and grains panicle-1 which lead to the higher grain yield (GY). Substantial relationships were observed among the concentration of N, growth, total dry matter (TDM) and N content, N uptake, N utilization effectiveness, and GY. However, with little exception, the Combined effect of water and N, cultivars and water management were varied significantly for all parameters. Finally, the results of the current study concluded that application of irrigation at 8 days after the disappearance of ponded water and source of 105 kg N ha-1 from PU + Poultry manure are the best management approach for the excellent performance of rice cultivar Binadhan-8.
Increasing population is one of the significant encounters for food and environmental security across the globe. On the other hand, due to the changing climate, water and N shortage has created a big challenge particularly in the rice growing world. The main restrictive factors for irrigated rice farming are also water and nitrogen. Proficient water and nitrogen management has remained significant for sustainable rice cultivation in irrigated rice farming system. Future rice production will depend greatly on developing approaches and practices that use water and nitrogen efficiently under climate change condition [
Proper management of N fertilizer is vital to improving rice crop development and yields. This is likewise the most restrictive supplement for rice production throughout the planet [
For improvement of water productivity and water use efficiency in irrigated rice, various water management systems have been anticipated [
We conducted the field experiment during dry seasons of 2018–2019. The experiment was also repeated in the next season of 2019–2020. The site of experimental was the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh, Bangladesh. Geographically the site lies at the latitude of 24°42′55″N, longitude of 90°25′47″E, and the elevation of 19 m above the sea level. The experimental place experiences the subtropical monsoon climate with humid nature. Before starting the trial the physicochemical properties of the field soils were analyzed and are displayed in
Soil characteristics | Values |
---|---|
Soil texture | Clay loam |
Soil pH | 6.13 |
Electric conductivity (µs/cm) | 649 |
Organic carbon (%) | 1.294 |
Total nitrogen (N) (%) | 0.115 |
Available form of phosphorus (P) (ppm) | 28.2 |
Available form of potassium (K) (ppm) | 83.64 |
Available form of sulphur (S) (ppm) | 25.90 |
Treatments were: (a) three rice cultivars viz., BRRI dhan-28, Binadhan-8 and Binadhan-10; (b) three water management systems, viz., application of irrigation at 8 and 10 days after the disappearance of ponded water (DAD) and Bangladesh Rice Research Institute (BRRI) recommended water application systems (AWD) and (c) three sources of N viz., Prilled Urea (PU) (140 kg N ha-1), Urea Super Granule (USG) (83 kg N ha-1), PU + 3 t ha-1 poultry manure (POM) (105 kg N ha-1). All treatments were arranged in a split-plot design where water management treatments were assigned in the main plots and nitrogen management as the sub-plots, and the cultivars were arranged in the split-split plot and all treatments were replicated thrice.
The field was prepared by 4-5 ploughing followed by laddering. Except N sources, other fertilizers such as P-K-S-Zn were applied at 20-65-18-1.3 kg ha-1. Nitrogen was applied as per treatments. The source of the nutrients was applied for N as PU (140 kg N ha-1), USG (83 kg N ha-1), PU + 3 t ha-1POM (105 kg N ha-1); for P as triple super phosphate (TSP), for K as muriate of potash (MOP), for S as Gypsum and for Zn as Zinc sulphate fertilizers. Calculation of nutrients was accomplished based on IPNS, and only the required amount was added from the fertilizers. During the final land preparation, entire amounts of P, K, S, Zn fertilizers and poultry manure were applied as basal dose. Two seedlings were transplanted hill-1 maintain spacing of 25 cm × 15 cm. USG was applied among every four hills in an alternate row after one week of the transplanting of rice seedling. Urea was used in three equal installments after 15, 40, and 70 days after the crops were transplanted. The unit plot size was 4.0 m × 2.5 m. At the time transplanting the field was with 4 cm of standing water, and the three irrigation treatments were imposed after the disappearance of this ponded water-traditional irrigation at 8, and 10 days after DAD, and BRRI recommended AWD. Free flooding method was used for application of irrigation except AWD. Irrigation water was measured using volumetric method. For AWD method, a 20 cm deep hole was dug in treated plot and a perforated plastic pipe was installed to monitor the level of the water table after irrigation. The practice was continued until flowering starts. 2–4 cm standing water was kept from flowering to dough stage. Polythene sheet was used beneath the soil to prevent seepage from one plot to another.
The plants were sampled from each pot at active tillering stage, panicle initiation stage, flowering stage, and physiological maturity for the measurement of growth parameters includingplant height, leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), and net assimilation rate (NAR). For LAI, the leaf blades were isolated from the leaf sheath immediately after sampling the plants then the area of the leaf blades was estimated by using a digital leaf area meter (LI 3100, Licor, Inc., Lincoln NE, USA). After assessing the leaf area, the plant sampled, including leaves used for determining its area, was dried in an electric oven at 65°C for 72 h. Different parameters of growth analysis viz., RGR, CGR, LAI, and NAR were calculated from the dry mass and leaf areas by using the following the standard formulae reported by Radford [
Water productivity in rice was calculated as follows [
where, Y, grain yield (t ha-1), WR, total amount of water used (cm).
Relative water content (RWC) was calculated after collection of leaf in turgid condition accordingly [
where, FW, fresh leaf weight, TW, turgid leaf weight, and DW, leaf dry weight. For determining the FW, the fresh leaf was cut into small pieces, and afterwards, weighed. the leaf sample (cut pieces) was drenched in distilled water for 4 h in the dim, and afterwards, the turgid leaf weight was determined to measure the TW. The small pieces of leaves were then oven dried at 80°C in an electric oven for 24 h and were weighed to estimate the DW.
The following formula calculates the internal N use efficiency of GY (INUEY):
It is expressed as kg GY/kg N uptake.
Internal N use efficiency of dry biomass (INUEDM) was calculated by the following formula:
It is expressed as kg biomass/kg N uptake.
All recorded data were statistically analyzed by using analysis of variance (ANOVA) and mean separation test was done by following Duncan’s multiple range test (DMRT) at 5% level of probability [
The weather data were recorded Department of Irrigation and Water Management, Bangladesh Agricultural University, Mymensingh, Bangladesh which are presented in
In both seasons, the maximum temperatures were varied from 21.0°C to 35.3°C with an average value of 29.1°C, however the minimum temperature ranged from 8.7°C to 29.4°C having a mean value of 18.7°C. Considering the months of observation, March to May was the hottest time, while January to February was the coolest period in both seasons. Daily rainfall ranged from 0 to 82 mm with monthly recorded values (January to May) of 0.0, 0.2, 163.7, 329.5, and 350.2 mm, respectively. No rainfall was happened up to the end of February. Though, rainfall was more regular and steady from the first week of March to onwards. During growth crop stages, 15.3 mm of rainfall was recorded up to panicle initiation (PI) (17 January–08 March), 155.6 mm during PI to flowering (FL) (09 March to 03 April), and 672.7 mm from FL (04 April) to harvest (02 May).
The vegetative growth of plants was completely in fully irrigated condition. On the opposing, they were subjected to equally irrigation and rainfall at PI stage and almost completely grown under rainfed conditions from FL to harvesting stages. From FL to harvest stages the crop received the maximum rainfall. The cultivar and environment had an influence on the duration of crop life cycle. Outline for three cultivars with their phenology are shown in
A significant dissimilarity for plant height was recorded at different growth stages of all rice cultivars, water and nitrogen treatments (
Treatments | PH | LAI | ||||||
---|---|---|---|---|---|---|---|---|
AT | PI | FL | PM | AT | PI | FL | PM | |
Cultivars | ||||||||
BRRI dhan28 | 28.85b | 56.63b | 86.68b | 87.22b | 0.056c | 0.97b | 3.32c | 2.70b |
Binadhan-8 | 29.62a | 57.16ab | 87.62b | 88.16b | 0.062a | 1.01a | 3.51a | 2.86a |
Binadhan-10 | 30.24a | 57.91a | 89.17a | 89.72a | 0.059b | 0.98ab | 3.43b | 2.74b |
CV (%) | 4.22 | 2.81 | 2.17 | 2.05 | 8.35 | 4.52 | 4.03 | 4.98 |
Water management | ||||||||
8-DAD | 34.84a | 62.37a | 96.80a | 97.40a | 0.082a | 1.15a | 4.21a | 3.46a |
10-DAD | 28.94b | 57.53b | 87.01b | 87.55b | 0.057b | 0.99b | 3.38b | 2.62b |
AWD | 24.94c | 51.80c | 79.65c | 80.14c | 0.038c | 0.82c | 2.67c | 2.21c |
CV (%) | 6.93 | 2.45 | 3.63 | 3.40 | 8.45 | 4.52 | 4.03 | 4.57 |
Nitrogen management | ||||||||
140 kg N ha-1 from PU | 27.41c | 55.64c | 84.42c | 84.96c | 0.052c | 0.93c | 3.14c | 2.49c |
83 kg N ha-1 from USG | 29.45b | 57.16b | 87.91b | 88.46b | 0.059b | 0.98b | 3.40b | 2.77b |
105 kg N ha-1from PU + 3 t ha-1 POM | 31.86a | 58.90a | 91.14a | 91.68a | 0.067a | 1.05a | 3.72a | 3.04a |
CV (%) | 8.67 | 3.41 | 1.59 | 1.50 | 7.48 | 4.52 | 3.92 | 4.71 |
ANOVA | ||||||||
Cultivars (V) | ** | ** | ** | ** | ** | ** | ** | ** |
Water management (W) | ** | ** | ** | ** | ** | ** | ** | ** |
Nitrogen management (N) | ** | ** | ** | ** | ** | ** | ** | ** |
V × W × N | NS | NS | NS | NS | NS | NS | NS | NS |
CV (%) | 4.22 | 2.81 | 2.17 | 2.05 | 8.35 | 4.52 | 4.03 | 4.98 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
Plant height augmented progressively over time reaching the peak level at PM. Binadhan-10 at PM showed longest plant (89.72 cm) height. The longest plant was observed at 8-DAD treatment in view of water management system. The influence of nitrogen management on plant height was also documented (
Elevated LAI was registered with the application of 105 kg N from PU + 3 t ha-1 POM as compared to 83 kg N ha-1 from USG and 140 kg N ha-1 from PU.
CGR improved similarly with the upsurge in leaf area over the time until FL and then declined irrespective of cultivar, water and nitrogen management (
Treatments | CGR (g cm-2day-1) | RGR (g-1g-1day) | ||||
---|---|---|---|---|---|---|
AT-PI | PI-FL | FL-PM | AT-PI | PI-FL | FL-PM | |
Cultivars | ||||||
BRRI dhan-28 | 9.71b | 10.49c | 5.17b | 40.13 | 11.66 | 4.08a |
Binadhan-8 | 10.75a | 11.56a | 5.37a | 40.07 | 11.56 | 3.89c |
Binadhan-10 | 10.04b | 10.98b | 5.37a | 39.79 | 11.68 | 3.99b |
CV (%) | 7.91 | 7.05 | 2.46 | 1.69 | 2.24 | 1.77 |
Water management | ||||||
8-DAD | 14.05a | 17.16a | 6.38a | 39.37b | 12.81a | 3.22c |
10-DAD | 10.21b | 9.24b | 5.29b | 40.20a | 10.37c | 3.99b |
AWD | 6.24c | 6.62c | 4.24c | 40.42a | 11.72b | 4.75a |
CV (%) | 11.40 | 7.28 | 3.72 | 1.19 | 3.22 | 3.36 |
Nitrogen management | ||||||
140 kg N ha-1 from PU | 8.97c | 9.37c | 4.80c | 40.42a | 11.51b | 4.22a |
83 kg N ha-1 from USG | 10.23b | 10.86b | 5.38b | 40.02b | 11.55b | 3.99b |
105 kg N ha-1from PU + 3 t ha-1 POM | 11.30a | 12.79a | 5.73a | 39.56c | 11.84a | 3.75c |
CV (%) | 3.85 | 9.85 | 1.68 | 1.43 | 2.62 | 2.38 |
ANOVA | ||||||
Cultivars (V) | ** | ** | ** | NS | NS | ** |
Water management (W) | ** | ** | ** | ** | ** | ** |
Nitrogen management (N) | ** | ** | ** | ** | ** | ** |
V × W × N | NS | NS | ** | NS | ** | NS |
CV (%) | 7.91 | 7.05 | 2.46 | 1.69 | 2.24 | 1.77 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
Treatments | NAR (mg cm-2day-1) | RWC (%) | |||||
---|---|---|---|---|---|---|---|
AT-PI | PI-FL | FL-PM | AT | PI | FL | PM | |
Cultivars | |||||||
BRRI dhan28 | 1.279 | 0.2289c | 0.1079a | 38.37c | 49.84c | 64.22b | 72.83b |
Binadhan-8 | 1.336 | 0.2391a | 0.0651c | 39.76a | 51.21a | 65.97a | 75.20a |
Binadhan-10 | 1.294 | 0.2334b | 0.0874b | 39.09b | 50.30b | 64.86b | 73.94b |
CV (%) | 7.30 | 11.31 | 12.59 | 2.75 | 1.60 | 2.73 | 2.75 |
Water management | |||||||
8-DAD | 1.500a | 0.3133a | 0.0998a | 44.86a | 57.49a | 75.40a | 87.88a |
10-DAD | 1.348b | 0.2050b | 0.0790c | 39.40b | 51.40b | 64.61b | 72.81b |
AWD | 1.060c | 0.1832c | 0.0815b | 32.96c | 42.46c | 55.03c | 61.27c |
CV (%) | 10.88 | 12.09 | 10.28 | 2.39 | 1.60 | 2.18 | 3.64 |
Nitrogen management | |||||||
140 kg N ha-1 from PU | 1.245b | 0.2166c | 0.0940b | 37.22c | 48.33c | 62.59c | 70.70c |
83 kg N ha-1 from USG | 1.315a | 0.2336b | 0.0978a | 39.00b | 50.53b | 64.80b | 73.82b |
105 kg N ha-1 from PU + 3 t ha-1 POM | 1.348a | 0.2512a | 0.0686c | 41.00a | 52.49a | 67.66a | 77.44a |
CV (%) | 6.44 | 14.17 | 11.49 | 2.85 | 1.64 | 2.17 | 3.44 |
ANOVA | |||||||
Cultivars (V) | NS | ** | ** | ** | ** | ** | ** |
Water management (W) | ** | ** | ** | ** | ** | ** | ** |
Nitrogen management (N) | ** | ** | ** | ** | ** | ** | ** |
V × W × N | NS | ** | ** | NS | NS | NS | NS |
CV (%) | 7.30 | 11.31 | 12.59 | 2.75 | 1.60 | 2.73 | 2.75 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
Water management | Nitrogen management | CGR (g cm-2day-1) | RGR (g-1g-1day) | ||||
---|---|---|---|---|---|---|---|
AT-PI | PI-FL | FL-PM | AT-PI | PI-FL | FL-PM | ||
8-DAD | 140 kg N ha-1 from PU | 12.72c | 14.23c | 5.66d | 39.47c | 12.17c | 3.50g |
83 kg N ha-1 from USG | 14.29b | 16.74b | 6.59b | 39.87bc | 12.48b | 3.21h | |
105 kg N ha-1 |
15.15a | 20.51a | 6.91a | 38.78d | 13.78a | 2.94i | |
10-DAD | 140 kg N ha-1 from PU | 8.63f | 7.84f | 4.68f | 40.09bc | 10.41e | 4.14d |
83 kg N ha-1 from USG | 10.34e | 9.19e | 5.30 e | 40.38b | 10.23e | 3.97e | |
105 kg N ha-1 |
11.65d | 10.70d | 5.90c | 40.13b | 10.46e | 3.87f | |
AWD | 140 kg N ha-1 from PU | 5.56i | 6.03g | 4.08i | 41.69a | 11.95c | 5.02a |
83 kg N ha-1 from USG | 6.06h | 6.64g | 4.25h | 39.81bc | 11.94c | 4.79b | |
105 kg N ha-1 |
7.09g | 7.17fg | 4.39g | 39.78bc | 11.27d | 4.44c | |
ANOVA | |||||||
Water Management (W) | ** | ** | ** | ** | ** | ** | |
Nitrogen |
** | ** | ** | ** | ** | ** | |
W × N | ** | ** | ** | ** | ** | ** | |
CV (%) | 3.85 | 9.85 | 1.68 | 1.43 | 2.62 | 2.38 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
Water management | Nitrogen management | NAR (mg cm-2day-1) | RWC (%) | |||||
---|---|---|---|---|---|---|---|---|
AT-PI | PI-FL | FL-PM | AT | PI | FL | PM | ||
8-DAD | 140 kg N ha-1 from PU | 1.44 | 0.2814c | 0.1089a | 43.88 b | 55.49 | 73.64b | 85.77b |
83 kg N ha-1 from USG | 1.54 | 0.3117b | 0.1107a | 44.40 b | 57.37 | 75.74a | 88.30ab | |
105 kg N ha-1 |
1.50 | 0.3467a | 0.0798d | 46.30a | 59.62 | 76.84a | 89.56a | |
10-DAD | 140 kg N ha-1 from PU | 1.25 | 0.1909f | 0.0862c | 36.76e | 49.13 | 61.75e | 67.48e |
83 kg N ha-1 from USG | 1.36 | 0.2027e | 0.0810d | 39.32d | 51.67 | 63.39d | 71.90d | |
105 kg N ha-1 |
1.42 | 0.2213d | 0.0700e | 42.11c | 53.39 | 68.68c | 79.06c | |
AWD | 140 kg N ha-1 from PU | 1.03 | 0.1776h | 0.0868c | 31.01h | 40.37 | 52.38h | 58.86g |
83 kg N ha-1 from USG | 1.03 | 0.1863g | 0.1019b | 33.29g | 42.54 | 55.26g | 61.27fg | |
105 kg N ha-1 |
1.11 | 0.1857g | 0.0560f | 34.58f | 44.48 | 57.47f | 63.70f | |
ANOVA | ||||||||
Water Management (W) | ** | ** | ** | ** | ** | ** | ** | |
Nitrogen |
** | ** | ** | ** | ** | ** | ** | |
W × N | NS | ** | ** | ** | NS | ** | ** | |
CV (%) | 6.44 | 14.17 | 11.49 | 2.85 | 1.64 | 2.17 | 3.44 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
Water management | Cultivars | CGR (g cm-2day-1) | RGR (g-1g-1day) | ||||
---|---|---|---|---|---|---|---|
AT-PI | PI-FL | FL-PM | AT-PI | PI-FL | FL-PM | ||
8-DAD | BRRI dhan28 | 13.46 | 16.24c | 6.16c | 39.32cd | 12.67b | 3.31 |
Binadhan-8 | 15.03 | 18.20a | 6.39b | 39.88bc | 12.75b | 3.09 | |
Binadhan-10 | 13.67 | 17.04b | 6.61a | 38.91d | 13.01a | 3.25 | |
10-DAD | BRRI dhan28 | 9.71 | 8.69e | 5.16e | 40.18b | 10.33e | 4.09 |
Binadhan-8 | 10.71 | 9.73d | 5.45d | 40.25ab | 10.38e | 3.92 | |
Binadhan-10 | 10.20 | 9.30de | 5.27e | 40.18b | 10.40e | 3.97 | |
AWD | BRRI dhan28 | 5.97 | 6.52f | 4.20f | 40.90a | 11.98c | 4.84 |
Binadhan-8 | 6.49 | 6.74f | 4.27f | 40.09b | 11.54d | 4.65 | |
Binadhan-10 | 6.25 | 6.59f | 4.25f | 40.29ab | 11.64d | 4.76 | |
ANOVA | |||||||
Water Management (W) | ** | ** | ** | ** | ** | ** | |
Cultivar (V) | ** | ** | ** | NS | NS | ** | |
W × V | NS | * | ** | * | ** | NS | |
CV (%) | 7.91 | 7.05 | 2.46 | 1.69 | 2.24 | 1.77 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
Water management | Cultivars | NAR (mg cm-2day-1) | RWC (%) | |||||
---|---|---|---|---|---|---|---|---|
AT-PI | PI-FL | FL-PM | AT | PI | FL | PM | ||
8-DAD | BRRI dhan28 | 1.47 | 0.3039c | 0.1337a | 44.20 | 56.79 | 74.70 | 87.04 |
Binadhan-8 | 1.56 | 0.3242a | 0.0588g | 45.47 | 58.11 | 76.30 | 88.72 | |
Binadhan-10 | 1.46 | 0.3117b | 0.1069b | 44.90 | 57.57 | 75.21 | 87.87 | |
10-DAD | BRRI dhan28 | 1.31 | 0.1982f | 0.0858c | 38.54 | 50.83 | 63.69 | 70.96 |
Binadhan-8 | 1.37 | 0.2103d | 0.0693f | 40.17 | 52.19 | 65.67 | 74.82 | |
Binadhan-10 | 1.35 | 0.2063e | 0.0820d | 39.48 | 51.17 | 64.47 | 72.66 | |
AWD | BRRI dhan28 | 1.04 | 0.1847g | 0.1040b | 32.36 | 41.90 | 54.27 | 60.50 |
Binadhan-8 | 1.07 | 0.1827g | 0.0672f | 33.64 | 43.34 | 55.94 | 62.04 | |
Binadhan-10 | 1.06 | 0.1822g | 0.0735e | 32.88 | 42.15 | 54.89 | 61.28 | |
ANOVA | ||||||||
Water Management (W) | ** | ** | ** | ** | ** | ** | ** | |
Cultivar (V) | NS | ** | ** | ** | ** | ** | ** | |
W × V | NS | ** | ** | NS | NS | NS | NS | |
CV (%) | 7.30 | 11.31 | 12.59 | 2.75 | 1.60 | 2.73 | 2.75 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance.
The movement in NAR was descending based on treatments (
RWC was significantly influenced by cultivars, water and nitrogen management. The tolerance levels of cultivars were higher to drought conditions having elevated RWC (%). At FL, the maximum RWC (65.97%) was exhibited by Binadhan-8. Most of the cultivars had a slight change in RWC at FL and PM and related patterns of RWC as before were documented. The interaction effect of water and nitrogen management was significant for RWC. The highest RWC (76.84%) at FL was recorded from 105 kg N from PU + 3 t ha-1 POM with 8-DAD which is statistically similar to 83 kg N ha-1 from USG and 8-DAD.
TDM increased significantly from AT to PM (TDM at FL only presented,
Treatments | Effective tillers hill-1 | Grains panicle-1 | 1000 grain weight (g) | TDM at FL (g plant-1) | Grain yield |
Straw yield |
Harvest index (%) |
---|---|---|---|---|---|---|---|
Cultivars | |||||||
BRRI dhan28 | 12.22b | 76.78c | 21.13 | 19.96c | 5.12c | 5.63c | 47.59 |
Binadhan-8 | 13.22a | 80.24a | 21.57 | 22.03a | 5.34a | 5.88a | 47.63 |
Binadhan-10 | 12.64b | 78.24b | 21.32 | 20.78b | 5.20b | 5.75b | 47.60 |
CV (%) | 6.12 | 2.03 | 4.29 | 2.24 | 1.48 | 1.10 | 1.19 |
Water management | |||||||
8-DAD | 16.41a | 95.49a | 23.68a | 30.78a | 6.13a | 6.87a | 47.20b |
10-DAD | 12.20b | 76.53b | 20.87b | 19.29b | 5.14b | 5.61b | 47.71a |
AWD | 9.47c | 63.24c | 19.46c | 12.70c | 4.40c | 4.78c | 47.91a |
CV (%) | 5.23 | 1.56 | 4.32 | 2.51 | 1.48 | 1.23 | 0.86 |
Nitrogen management | |||||||
140 kg N ha-1 from PU | 11.45c | 73.14c | 20.64c | 18.12c | 4.93c | 5.39c | 47.70 |
83 kg N ha-1 from USG | 12.64b | 78.23b | 21.34b | 20.84b | 5.19b | 5.76b | 47.53 |
105 kg N ha-1from PU + 3 t ha-1 POM | 13.99a | 83.89a | 22.04a | 23.81a | 5.54a | 6.11a | 47.59 |
CV (%) | 5.85 | 2.72 | 3.75 | 2.34 | 1.21 | 1.10 | 1.18 |
ANOVA | |||||||
Cultivars (V) | ** | ** | NS | ** | ** | ** | NS |
Water management (W) | ** | ** | ** | ** | ** | ** | ** |
Nitrogen management (N) | ** | ** | ** | ** | ** | ** | NS |
V × W × N | NS | NS | NS | NS | * | NS | NS |
CV (%) | 6.12 | 2.03 | 4.29 | 2.24 | 1.48 | 1.10 | 1.19 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability, aGrain yield and straw yield with the moisture content of 14%.
Water management | Nitrogen management | Effective tillers hill-1 | No. of grains panicle-1 | 1000 grain weight (g) | TDM at FL |
Grain yield |
Straw yield |
Harvest index (%) |
---|---|---|---|---|---|---|---|---|
8-DAD | 140 kg N ha-1 from PU | 14.39c | 88.61c | 22.62 | 26.63c | 5.72c | 6.35c | 47.44 |
83 kg N ha-1 from USG | 16.35b | 95.73b | 23.67 | 30.60b | 6.06b | 6.91b | 46.84 | |
105 kg N ha-1 |
18.50a | 102.1a | 24.77 | 35.13a | 6.61a | 7.35a | 47.33 | |
10-DAD | 140 kg N ha-1 from PU | 11.06f | 70.84f | 20.26 | 16.34f | 4.88 f | 5.26f | 47.77 |
83 kg N ha-1 from USG | 12.12e | 76.14e | 20.84 | 19.37e | 5.09e | 5.60e | 47.79 | |
105 kg N ha-1 |
13.41d | 82.59d | 21.52 | 22.16d | 5.44d | 5.98d | 47.56 | |
AWD | 140 kg N ha-1 from PU | 8.91h | 59.97i | 19.05 | 11.40i | 4.19i | 4.56i | 47.88 |
83 kg N ha-1 from USG | 9.45gh | 62.82h | 19.50 | 12.56h | 4.42h | 4.78h | 47.97 | |
105 kg N ha-1 |
10.07g | 66.94g | 19.84 | 14.13g | 4.57g | 5.00g | 47.87 | |
ANOVA | ||||||||
Water Management (W) | ** | ** | ** | ** | ** | ** | ** | |
Nitrogen |
** | ** | ** | ** | ** | ** | NS | |
W × N | ** | ** | NS | ** | ** | ** | NS | |
CV (%) | 5.85 | 2.72 | 3.75 | 2.34 | 1.21 | 1.10 | 1.18 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; a Grain yield and straw yield with the moisture content of 14%.
Water management | Cultivar | Effective tillers hill-1 | Grains panicle-1 | 1000 grain weight (g) | TDM at FL |
Grain yield |
Straw yield |
Harvest index (%) |
---|---|---|---|---|---|---|---|---|
8-DAD | BRRI dhan28 | 15.65 | 93.17 | 23.37 | 29.31c | 6.01b | 6.71c | 47.23 |
Binadhan-8 | 17.17 | 97.74 | 24.02 | 32.73a | 6.31a | 7.02a | 47.22 | |
Binadhan-10 | 16.42 | 95.56 | 23.67 | 30.32b | 6.08b | 6.87b | 47.16 | |
10-DAD | BRRI dhan28 | 11.76 | 74.94 | 20.67 | 18.25f | 5.03e | 5.49f | 47.65 |
Binadhan-8 | 12.73 | 78.48 | 21.11 | 20.27d | 5.24c | 5.75d | 47.77 | |
Binadhan-10 | 12.09 | 76.16 | 20.84 | 19.33e | 5.14d | 5.59e | 47.70 | |
AWD | BRRI dhan28 | 9.260 | 62.24 | 19.34 | 12.31h | 4.31h | 4.70i | 47.89 |
Binadhan-8 | 9.766 | 64.49 | 19.59 | 13.08g | 4.47f | 4.86g | 47.89 | |
Binadhan-10 | 9.406 | 63.00 | 19.47 | 12.70gh | 4.40g | 4.79h | 47.94 | |
ANOVA | ||||||||
Water Management (W) | ** | ** | ** | ** | ** | ** | ** | |
Cultivar (V) | ** | ** | NS | ** | ** | ** | NS | |
W × V | NS | NS | NS | ** | * | ** | NS | |
CV (%) | 6.12 | 2.03 | 4.29 | 2.24 | 1.48 | 1.10 | 1.19 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance, aGrain yield and straw yield with the moisture content of 14%.
The highest TDM (32.73 g plant-1) was recorded in Binadhan-8 and 8-DAD treatment. TDM was greatly responsible for GY variations among cultivars (R2 = 0.98,
Treatments | Irrigations (number) | Frequency of water application (DAT) | Water used for crop establishment (cm) | Irrigation water applied |
Rain water |
Total water use |
Grain yield |
Water productivity (t ha-1 cm-1) | % yield |
---|---|---|---|---|---|---|---|---|---|
8-DAD | 6 | 30,40,50,60,70,80 | 4 | 24 | 84.4 | 108.4 | 6.13a | 0.057 | 39.32 |
10-DAD | 5 | 30,42,54, 66,78 | 4 | 20 | 84.4 | 104.4 | 5.14b | 0.049 | 16.82 |
AWD | 5 | 30,43,56,69, 82 | 4 | 20 | 84.4 | 104.4 | 4.40c | 0.042 | – |
** | |||||||||
CV (%) | 1.48 |
Note: Within a column, the means with different alphabets were varied significantly at 5 % level of probability; ** Significant at 1% level of significance.
Three water management systems had distinct amount of water. Full water under 10-DAD and AWD was lesser than that of 8-DAD. The amount of water was 108.4 cm for 8-DAD and 104.4 cm for that of 10-DAD and AWD. Water productivity was the maximum (0.057 t ha-1 cm-1) in 8-DAD due to higher yield and was found to be least (0.042 t ha-1 cm-1) in AWD.
N content (%) and uptake of grain and straw were influenced by cultivar, water and nitrogen management (
Cultivars | N content in grain (%) | N uptake in grain |
N content in straw (%) | N uptake in straw |
Internal N use efficiency of grain yield (kg grain yield/kg N uptake) | Internal N use efficiency of dry biomass (kg biomass/kg N uptake) |
---|---|---|---|---|---|---|
Cultivars | ||||||
BRRI dhan28 | 1.26b | 65.71b | 0.941b | 55.27c | 45.37a | 49.51 |
Binadhan-8 | 1.30a | 71.06a | 1.007a | 61.53a | 43.00c | 48.57 |
Binadhan-10 | 1.28ab | 67.91b | 0.973ab | 58.30b | 44.16b | 48.98 |
CV (%) | 3.49 | 5.99 | 6.49 | 4.20 | 3.98 | 4.63 |
Water management | ||||||
8-DAD | 1.46a | 90.37a | 1.263a | 87.10a | 34.75c | 49.40a |
10-DAD | 1.27b | 65.91b | 0.985b | 55.66b | 42.65b | 47.04b |
AWD | 1.09c | 48.40c | 0.672c | 32.34c | 55.13a | 50.63a |
CV (%) | 4.28 | 4.12 | 9.18 | 6.49 | 4.10 | 5.59 |
Nitrogen management | ||||||
140 kg N ha-1 from PU | 1.21c | 60.83c | 0.881c | 49.44c | 47.85a | 50.10a |
83 kg N ha-1 from USG | 1.27b | 67.35b | 0.965b | 57.79b | 44.21b | 49.28a |
105 kg N ha-1from PU + 3 t ha-1 POM | 1.35a | 76.50a | 1.075a | 67.89a | 40.47c | 47.68b |
CV (%) | 2.47 | 5.89 | 6.49 | 4.30 | 3.16 | 4.45 |
ANOVA | ||||||
Cultivars (V) | ** | ** | ** | ** | ** | NS |
Water management (W) | ** | ** | ** | ** | ** | * |
Nitrogen management (N) | ** | ** | ** | ** | ** | ** |
V × W × N | NS | NS | NS | NS | NS | NS |
CV (%) | 3.49 | 5.99 | 6.49 | 4.20 | 3.98 | 4.63 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability; ** Significant at 1% level of significance, *Significant at 5% level of significance.
The grain N content (%) in cultivar ranged from 1.26% to 1.30%. Binadhan-8 had the highest N content (%) whereas that content was superior in 8-DAD and 105 kg N from PU + 3 t ha-1 POM. Increment of rice GY is the outcome of superior grain N content (%) and uptake. In respect of straw, N content (%) varied from 0.941% to 1.007% for cultivar, 0.672% to 1.263% for water management and 0.881% to 1.075% for nitrogen management. Irrespective of treatments, N uptake in straw varied from 32.34 to 87.10 kg ha-1. Straw N uptake was also inferior to that of grain. A well significant positive association was observed between grain N content and GY (R2 = 0.98,
The analyzed data of internal N use efficiency was presented in
Water management | Nitrogen management | N content in grain (%) | N uptake in grain |
N content in straw (%) | N uptake in straw |
Internal N use efficiency of grain yield (kg grain yield/kg N uptake) | Internal N use efficiency of dry biomass (kg biomass/kg N uptake) |
---|---|---|---|---|---|---|---|
8-DAD | 140 kg N ha-1 from PU | 1.38 | 79.58c | 1.190 | 75.96c | 36.81g | 49.62bc |
83 kg N ha-1 from USG | 1.46 | 88.78b | 1.250 | 86.87b | 34.57h | 49.50bc | |
105 kg N ha-1 from PU + 3 t ha-1 POM | 1.55 | 102.7a | 1.330 | 98.47a | 32.88i | 49.07bcd | |
10-DAD | 140 kg N ha-1 from PU | 1.21 | 59.44f | 0.881 | 46.42f | 46.13d | 46.52e |
83 kg N ha-1 from USG | 1.27 | 64.92e | 0.978 | 54.92e | 42.60e | 47.82cde | |
105 kg N ha-1 from PU + 3 t ha-1 POM | 1.34 | 73.36d | 1.090 | 65.65d | 39.21f | 46.77de | |
AWD | 140 kg N ha-1 from PU | 1.03 | 43.46i | 0.567 | 25.92i | 60.62a | 54.14a |
83 kg N ha-1 from USG | 1.09 | 48.35h | 0.660 | 31.56h | 55.45b | 50.52b | |
105 kg N ha-1 from PU + 3 t ha-1 POM | 1.16 | 53.38g | 0.790 | 39.55g | 49.32c | 47.21cde | |
ANOVA | |||||||
Water Management (W) | ** | ** | ** | ** | ** | * | |
Nitrogen |
** | ** | ** | ** | ** | ** | |
W × N | NS | NS | ** | ** | ** | ** | |
CV (%) | 2.47 | 5.89 | 6.49 | 4.30 | 3.16 | 4.45 |
Note: Within a column, the means with different alphabets were varied significantly at 5% level of probability;** Significant difference at
Study on individual effect of cultivar, irrigation scheduling and nitrogen management on diverse interference in rice is well recognized in the literature. Studies on physiological development, yield, water productivity and NUE of exclusively high yielding cultivars in relation to different water and nitrogen management are still inadequate. In fact, the effect of water and N source on high yielding rice subsisted in production. According to association between water and nitrogen management, appropriate rate of water and source of N use aiming at improving water productivity, NUE could be increased by N utilization and amplify rice GY. In our study, cultivars varied in respect of performance under different water and nitrogen management. The dissimilarity in the performance may be connected to crop length, growth, TDM and NUE indicators variation.
In our study grain filling time influenced GY. The involvement of grain filling period to rice GY exhibited that GY of diverse cultivars was fixed by grain-filling period [
Our study revealed that plant height, LAI, CGR, RGR and NAR improved distinctly in crop grown at 8-DAD and 10-DAD over those of severe AWD. Moisture insufficiency raised from severe AWD and rice plant suffered from water stress in dry season. Thus it declined maximum growth attributes at different developmental stages. It specified that rice crop desires optimal saturation rather than AWD for its optimum growth in dry season. For improving growth parameters of summer rice, use of irrigation at saturation might produce positive condition compared to AWD [
In our study, the growth variables of
Effective tillers plant-1, grains panicle-1 and TDM were higher in Binadhan-8 contrasted to Binadhan-10 and BRRI dhan28. Binadhan-8 finally created higher GY over those of Binadhan-10 and BRRI dhan28. Differential production potentiality is accountable for differences in productivity of rice cultivars [
The crop grown at 8-DAD treatment results in more effective tillers plant-1, grains panicle-1, TDM, 1000 grain weight that these attributes produced influential role in producing higher grain and straw yield. 8-DAD increased GY by 39.32% over AWD. Decline in tillering at AWD directed to decrease panicle fabrication, grain formation and development which ultimately reduced crop yield under dry condition.
Our study reflected significant variation on growth, yields attributes and yield due to combined application of water and N source. In the highest irrigation treatment (8-DAD), using 105 kg N from PU + 3 t ha-1 POM provided significantly higher yield. However, use of 105 kg N from PU + 3 t ha-1 POM with the lower irrigation treatments 10-DAD and AWD gave significantly lower yield. The considerable and reliable interactions between irrigation and N might be due to the little variation among the water management treatments and the low level of soil moisture stress [
The levels of internal crop N use-efficiency for high-yielding irrigated rice were determined by our study. The use of N fertilizer must be optimized to maximize economic returns although farmers are struggling for higher N use-efficiency. Hence, use of 140 kg N ha-1 fertilizer produced a INUEY level of 47.85 kg grain/kg crop N uptake and INUEDM level of 50.10 kg biomass/kg crop N uptake. It was reported INUEY of 46 kg rice grain/kg crop N uptake was found [
Results from the research exposed that
Active tillering
Anthesis
Alternate wetting and drying
Bangladesh Rice Research Institute
Crop growth rate
days
Days after the disappearance of ponded water
Emergence
Flowering
Grain yield
Leaf area index
Nitrogen
Net assimilation rate
Non-significant
Plant height
Panicle Initiation
Physiological Maturity
Poultry manure
Prilled Urea
Relative growth rate
Relative water content
Total dry matter
Urea super granule
The authors would like to thank Department of Agronomy, Bangladesh Agricultural University and Bangladesh Agricultural Research Council (BARC), Bangladesh. The authors also extend their appreciation to the Taif University Researchers Supporting Project number (TURSP-2020/85), Taif University, Taif, Saudi Arabia for funding.