1. Mandana Tayefe, Ebrahim Amiri, and Azin Nasrollah Zade
In The Name Of GOD
Effect of nitrogen management on nitrogen uptake, dry matter production and some yield parameters
Mandana Tayefe, Ebrahim Amiri, and Azin Nasrollah Zade

2. Islamic Azad University – Lahijan Branch
Introduction
RICE (Oryza sativa L.) is one of the most important cereal crops of the world, grown in wide range of climatic zones.
Nitrogen (N) is the most important nutrient in irrigated rice production.
It is the most yield-limiting nutrient in irrigated rice production around the world.
Islamic Azad University – Lahijan Branch

3. Islamic Azad University – Lahijan Branch
Introduction
Nitrogen contributes to spikelet production during early panicle formation stage, and contributes to sink size during the late panicle formation stage. Nitrogen also plays a role in grain filling, improving the photosynthetic capacity, and promoting carbohydrate accumulation in culms and leaf sheaths
Use of N fertilizers in adequate amount, form and methods of application are important management strategies of this element.
Nitrogen use efficiency has been defined in various ways, but these definitions generally take into account quantity of N accumulated in the plant, known as uptake efficiency and quantity of N utilized in grain production known as utilization efficiency.
Islamic Azad University – Lahijan Branch

4. Islamic Azad University – Lahijan Branch
Introduction
The present investigation was undertaken to have a detailed account of the effect of commercially-available nitrogenous (N) fertilizers (Urea) on the nitrogen uptake, dry matter production, yield and some yield components of commercial rice varieties in Iran.
Islamic Azad University – Lahijan Branch

5. Islamic Azad University – Lahijan Branch
Materials and Methods
The field experiment was conducted at Rice Research Institute, Rasht, Guilan, Iran, during the growing season.
The experiment was laid out in randomized complete block design with three replications.
4 nitrogen fertilizers levels: (N1: without fertilizer, N2: 30 kilogram per hectare in one division during transmission of seedling from nursery to the main field, N3: 60 kilogram per hectare in two divisions during relocation of seedling from nursery to the main field and tillering(30 days after transmission), and N4: 90 kilogram fertilizer per hectare in two divisions at the time of transferring seedlings from nursery to the main field and in clawing stage).
Islamic Azad University – Lahijan Branch

6. Islamic Azad University – Lahijan Branch
Materials and Methods
Three different varieties were examined (Hashemi: v1, Alikazemi: v2 and khazar: v3).
The N fertilization was applied as single incorporated application of urea (46% N).
Three hills in each plot were randomly selected and tagged for recording plant height(cm), tillers/m2, punicle/m2 at harvest (95 days after transplanting).
The net plots area were harvested and dried for 2 days at 70o c.Grain weight, adjusted to 14% moisture content, was used as estimates of grain yield (kg/ha).
Islamic Azad University – Lahijan Branch

7. Islamic Azad University – Lahijan Branch
Materials and Methods
The net plots area (6 m2) were harvested and dried for 2 days at 70o C.
Grain weight, adjusted to 14% moisture content, was used as estimates of grain yield (kg ha-1).
Grain nitrogen concentration was determined by the methods of micro-Kjeldal digestion, distillation, and titration.
The data were analyzed statistically with MSTATC and SAS software were used in variance analysis and comparison of average.
Islamic Azad University – Lahijan Branch

8. Results and Discussion
Nitrogen fertilization and variety had significant effects on grain yield.
Source df
Grain yield (kg/ha)
Year 1 ns R 4 N 3 ** V 2 *
N*V 6
Error 44 - cv
Islamic Azad University – Lahijan Branch

9. Results and Discussion
Maximum yield (3662 kg/ha) was obtained with the higher N rate (90kgN/kg) with detecting yield decrease in the range of rates tested .
Islamic Azad University – Lahijan Branch

10. Results and Discussion
In his research presented that dry matter accumulation increased significantly with N fertilizer application in rice at all the growth stages of the crop. Also total biomass due to Khazar variety was higher than other varieties (7734 kg ha-1).
Findings showed that N4 (90kgN/ha) caused higher panicle density (235.8/m2) (table2) .Also variety had significant effects on panicles m-2.As Hashemi variety had the highest panicles m-2 (235.9 m2).
Differences between N rates due to total grains per panicle were not significant .Also variety had significant effect on total grains per panicle .As Khazar variety had the highest total grains per panicle (161) .
Islamic Azad University – Lahijan Branch
Variable
total biomass (kg/ha)
Yield (kg/ha)
panicle/m2
Total grains per panicle
2008
7504a
3069a
217.66a
110.27a
2009
5860b
2911a
194.97a
102.63b N1
5032d
2194c
179.33c
108.6a N2
6241c
2749b bc
107a N3
7169b
3356a ab
106.2a N4
8386a
3662a a
103.8a V1
5973b
2663b a
78.25b V2
6339b
2893b b
80.04b V3
7734a
3414a c
161a

11. Results and Discussion
Results could also explain the lower yields for Hashemi variety, considering the high correlation between total dry matter production and grain yield (R2 = 0.73 and 0.91 and 0.99 (first year) and R2 = 0.90 and 0.95 and 0.99 (second year) for Khazar, Kazemi, Hashemi respectively.
Islamic Azad University – Lahijan Branch

12. Results and Discussion
Grain N-uptake increased significantly with N .In the other hand, the highest grain N-uptake was due to Khazar variety. Khazar variety accumulated maximum N (52.41 kgha−1) in the grain.
N4 (90kg N ha-1) caused the highest content of straw N uptake (57.16 kg ha-1). In N4 treatment (90 kg N ha-1), the highest straw-N uptake was observed (22.16 kg ha-1) and the lowest content (12.61 kg ha-1) belonged to N1 (0 kg N ha-1). Straw N-uptake increased with nitrogen increasing, significantly. But result of variance analysis at 1% confidence level revealed that nitrogen uptake in straw had no significant response to variety .
Result of variance analysis at 1% confidence level revealed that nitrogen uptake in total had a significant response to N fertilization. N4 treatment (90 kg N ha-1) caused the highest total-N uptake was observed (79.38 kg ha-1) and the lowest content (45.77 kg ha-1) belonged to N1 (0 kg N ha-1). Total N-uptake increased, as nitrogen fertilizer increased, significantly. Result of variance analysis at 1% confidence level revealed that total nitrogen uptake had significant response to variety .As Khazar variety produced highest nitrogen-N uptake (71.54 kg ha-1), Also the lowest content of total-N uptake belonged to Hashemi variety (57.37 kg.ha-1).

13. Islamic Azad University – Lahijan Branch
CONCLUSIONS
Total biomass (8386 kg/ha), grain yield (3662 kg/ha), panicles m-2 (235.8) and total grain per panicle (103.8) were reached the highest value at high nitrogen level.
Among the varieties the highest total biomass (7734 kg/ha), grain yield (3414 kg/ha) and total grain per panicle (78.2) belonged to Khazar. Dry matter, total N uptake was varied in different cultivars significantly and Khazar variety had the highest contents. Total biomass and total N uptake was varied significantly with the increasement of the amount of nitrogen applied. As total biomass and total N uptake increased with increasing in N fertilizing.
This information could be useful for genetic improvement programs under development, and to select management practices that increase yield and N use of applied fertilizer.
Islamic Azad University – Lahijan Branch

14. Thanks for your attention
Islamic Azad University – Lahijan Branch