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Effect of basal and tiller nitrogen rates on population dynamics, nitrogen uptake and utilization, and yield formation of direct-seeding early rice
基蘖肥氮不同比例对直播早稻群体动态、氮素吸收利用及产量形成的影响

XUE Li-hong,QIN Xi,LI Gang-hu,YANG Lin-zhang,
薛利红
,覃 夏,李刚华,杨林章

土壤 , 2010,
Abstract: A field experiment was carried out to study the effects of different basal and tiller nitrogen rates on the population dynamics, nitrogen uptake and utilization, yield formation and economic benefit of direct seeding early rice (Zhongxuan 181) in 2008 at Yujiang City, Jiangxi Province. Under the same seeding rate, total N rate and panicle N rate, the increase of basal nitrogen rate decreased the seedling emergence ratio and the tiller emergence rate at 38 days after seeding (DAS=38). The highest tillers (DAS=54) and effect panicles decreased under the lower and higher N rate, while first increased then decreased with the increasing basal N rate under the optimum N rate. Leaf N concentration and LAI of top three leaves at and after heading reduced by the increase of basal N rate, thus the plant N accumulation and the ratio of N allocation to panicle at maturity decreased, and N agronomic use efficiency and recovery use efficiency decreased significantly. The increase of basal N rate decreased the rice yield and net economic benefit. The optimum yield and economic benefit was achieved at the N rate of 180 kg/hm2 and the ratio of basal, tiller and panicle N of 35:40:25.
Logistic rice model for dry matter and nutrient uptake
García y García, Axel;Dourado-Neto, Durval;Basanta, Maria del Valle;López Ovejero, Ramiro Fernando;Favarin, José Laércio;
Scientia Agricola , 2003, DOI: 10.1590/S0103-90162003000300011
Abstract: the temporal variation of cumulative dry matter can be represented by a sigmoidal curve and the temporal variation of nutrient uptake follows this characteristic shape. therefore, modeling the temporal variation of cumulative dry matter allows estimating nutrient uptake along the crop cycle. the objective of this study was to propose a sine model to estimate dry matter and macronutrient uptake, and to estimate the moments of maximum n and k uptake rates for the rice crop. the field experiment was carried out on a wetland area of piracicaba, sp, brazil, consisting of an humic haplaquept. the chosen rice variety was iac 103, a middle season cycle and high yield. observed variables were dry matter of different plant parts (root, leaf and stem, and panicle) and macronutrient contents per unit dry matter. a sine model was proposed for the cumulative variation of these variables, based on biological events that occurred during the crop cycle. the temporal variation of nutrient uptake was estimated and a lower accuracy was observed for k uptake. the maximum absorption rate for n and k was found at 56% of the relative development of the crop, corresponding to 60 days after emergence in this experiment. the proposed model presented a satisfactory behavior to define the order of magnitude of estimated dry matter and macronutrient uptake by the rice crop and maximum n and k uptake rates.
Logistic rice model for dry matter and nutrient uptake  [cached]
García y García Axel,Dourado-Neto Durval,Basanta Maria del Valle,López Ovejero Ramiro Fernando
Scientia Agricola , 2003,
Abstract: The temporal variation of cumulative dry matter can be represented by a sigmoidal curve and the temporal variation of nutrient uptake follows this characteristic shape. Therefore, modeling the temporal variation of cumulative dry matter allows estimating nutrient uptake along the crop cycle. The objective of this study was to propose a sine model to estimate dry matter and macronutrient uptake, and to estimate the moments of maximum N and K uptake rates for the rice crop. The field experiment was carried out on a wetland area of Piracicaba, SP, Brazil, consisting of an Humic Haplaquept. The chosen rice variety was IAC 103, a middle season cycle and high yield. Observed variables were dry matter of different plant parts (root, leaf and stem, and panicle) and macronutrient contents per unit dry matter. A sine model was proposed for the cumulative variation of these variables, based on biological events that occurred during the crop cycle. The temporal variation of nutrient uptake was estimated and a lower accuracy was observed for K uptake. The maximum absorption rate for N and K was found at 56% of the relative development of the crop, corresponding to 60 days after emergence in this experiment. The proposed model presented a satisfactory behavior to define the order of magnitude of estimated dry matter and macronutrient uptake by the rice crop and maximum N and K uptake rates.
Effect of Nitrogen Supplied from Manure and Fertilizer on the Growth, Yield and Nutrient Uptake of Rice  [PDF]
S. Begum,M.M. Rahman,M.J. Abedin Mian,M.R. Islam
Journal of Biological Sciences , 2001,
Abstract: An investigation was undertaken to see the effect of added nitrogen supplied from poultry manure and urea-N on the growth, yield and nutrient uptake of BRRI Dhan 29 rice. There were eight treatments consisting of T0 (control), T1 (N100), T2 (PM5.0), T3 (N75 + PM1.25), T4 (N50 + PM2.5), T5 (N25 + PM3.75), T6 (PM7.5) and T7 (N120). Application of poultry manure alone or in combination with urea-N significantly increased the plant height, number of effective tillers hill-1, panicle length, number of grains panicle-1 and filled grains panicle-1 whereas 1000-grain weight varied insignificantly. The grain and straw yields increased significantly with different treatments and the highest yield was obtained with T6 treatment which was statistically at par with T5. The NPKS uptake was positively influenced by different treatments. Poultry manure was found the best source of N for rice. Application of poultry manure considerably increased the organic matter content, total N, available P, exchangeable K, available S and CEC of the post harvest soil and thus improved soil health.
Comparative Study of Nitrogen, Phosphorus and Potassium Fertilizers on Yield and Nutrient Uptake by Rice  [PDF]
M. Uddin,M. M. Rahman,M. A. Hoque,S. Begum
Journal of Biological Sciences , 2001,
Abstract: The field experiment was conducted in a silt loam soil to compare the effect of N, P and K fertilizers on the yield and nutrient uptake by rice and post-harvest soil properties. Seven treatments were T0 (control), T1 (Urea + Triple superphosphate + Muriate of potash), T2 (Urea + Diammonium phosphate + Muriate of potash), T3 (Urea + Triple superphosphate + Ash), T4 (Urea + Single superphosphate + Muriate of potash), T5 (Urea + Single superphosphate + Ash) and T6 (Urea + Diammonium phosphate + Ash). Application of fertilizers significantly increased the grain and straw yields of rice. Panicle length, effective tillers hill-1 and filled grains panicle-1 were also increased significantly due to application of fertilizers but the increase of 1000-grain weight was insignificant. Grain yield was highest with T3 (Urea + Triple superphosphate + Ash) treatment (5.46 t ha-1) which was followed by T1 (Urea + Triple superphosphate + Muriate of potash) treatment (5.30 t ha-1), while the lowest was in control. The grain yields were increased by 47.0 to 68.0% over control due to application of fertilizers. The results on straw yield reflected similar trend as in grain yield. Application of fertilizers caused a significant increase during NPKS uptake by rice. The application of fertilizers had a negligible influence on pH, CEC, organic matter, total N, available P, exchangeable K, and available S content of the post-harvest soils compared to their initial status.
Comparison of two models in the estimation of nitrogen uptake rates using data from 15-N incubation experiments  [cached]
Clavery Tungaraza,Natacha Brion,Willy Baeyens
Oceanologia , 2005,
Abstract: This paper compares two uptake rate models, Dugdale & Goering's (D&G) model and Elskens' model. The aim is to provide an insight into how estimates of uptake processes, i.e. regeneration and loss rates from both dissolved and particulate nitrogen pools, influence the total uptake rates when the two models are compared. The uptake rates of three nitrogenous nutrients (nitrate, ammonium and urea) from 15-N incubation experimental data were compared. The comparison indicated that the D&G model underestimated nitrate uptake rates by about 34%, implying a significant regeneration and loss rates of the nutrient. Elskens' model further showed that the loss rates from the dissolved phase were about 40% and 25% for the ammonium and urea pools, respectively, indicating that the D&G model underestimated the experimental uptake rates of the nutrients. On average, nitrification made up about 30% of the total ammonium uptake flux, whereas the sinks from particulate nitrogen and dissolved nitrogen were estimated at 36% and 56%, respectively. The D&G model sometimes overestimated the f-ratio values to about 60% and higher as a result of ammonium and urea uptake rates underestimation. This paper also shows that detritus adsorption, bacterial uptake and cell lysis are equally important processes.
Effect of incubation time and substrate concentration on N-uptake rates by phytoplankton in the Bay of Bengal  [PDF]
S. Kumar,R. Ramesh,S. Sardesai,M. S. Sheshshayee
Biogeosciences Discussions , 2005,
Abstract: We report here the results of three experiments, which are slight variations of the 15N method (JGOFS protocol) for determination of new production. The first two test the effect of (i) duration of incubation time and (ii) concentration of tracer added on the uptake rates of various N-species (nitrate, ammonium and urea) by marine phytoplankton; while the third compares in situ and deck incubations from dawn to dusk. Results indicate that nitrate uptake can be underestimated by experiments where incubation times shorter than 4h or when more than 10% of the ambient concentration of nitrate is added prior to incubation. The f-ratio increases from 0.28 to 0.42 when the incubation time increases from two to four hours. This may be due to the observed increase in the uptake rate of nitrate and decrease in the urea uptake rate. Unlike ammonium [y{=}2.07x{-}0.002, (r2=0.55)] and urea uptakes [y{=}1.88x{+}0.004 (r2=0.88)], the nitrate uptake decreases as the concentration of the substrate (x) increases, showing a negative correlation [y{=}-0.76x+0.05 (r2=0.86)], possibly due to production of glutamine, which might suppress nitrate uptake. This leads to decline in the f-ratio from 0.47 to 0.10, when concentration of tracer varies from 0.01 to 0.04μ M. The column integrated total productions are 519 mg C m-2 d-1 and 251 mg C m-2 d-1 for in situ and deck incubations, respectively. The 14C based production at the same location is ~200 mg C m-2 d-1, which is in closer agreement to the 15N based total production measured by deck incubation.
Effect of Real Time N Management on Biomass Production, Nutrient Uptake and Soil Nutrient Status of Direct Seeded Rice (Oryza sativa L.)
Gunasekhar Nachimuthu,V. Velu,P. Malarvizhi,S. Ramasamy
American Journal of Plant Physiology , 2007,
Abstract: A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, in deep clay soil (Vertic ustochrept) to study the effect of real time N management using Leaf Color Chart (LCC) on biomass production, nutrient uptake and soil available nutrient status in short duration rice (Var. CO 47) under direct wet (drum) seeded condition. The study was conducted in factorial randomized block design with three replications. The treatments included maintaining three LCC critical values (cv.) viz., LCC 3, 4 and 5 with different rates of N application (20, 25, 30 and 35 kg N ha-1 each time, besides absolute control (Zero-N), Blanket N (120 kg N ha-1in four equal splits from 21 Days After Sowing (DAS) and Manage N practices (120 kg N ha-1 in four unequal splits). The results of the experiment suggest that rate of biomass production and NPK uptake were highest during panicle initiation to first flowering stages for the tested variety CO 47 and LCC based N management have effectively saved the N fertilizer. The lack of difference in soil available nutrient between LCC based treatments and conventional blanket N treatment suggest that LCC based N management could be best option for farmers to save fertilizer N besides maintaining soil fertility. The results suggest further scope to standardise the LCC based N management for different intensively cultivated cultivars at specific location and season.
Absorción de nitrógeno y rendimiento de arroz con diferentes formas de nitrógeno aplicado previo al riego
Quintero,César Eugenio; Prats,Fabio; Zamero,María de los ángeles; Arévalo,Edgardo Santiago; Spinelli,Nicolás Blas; Boschetti,Graciela Norma;
Ciencia del suelo , 2011,
Abstract: in argentina, rice is mechanically sowed on dry soil and is then flooded from early tillering to maturity. this practice gives rise to conditions that promote nitrogen losses by volatilization and denitrification. the most recommended n fertilizers for rice have n in the form of ammonium or amides; however, nitric sources have shown advantages. a field trial was conducted to evaluate the responsiveness and absorption efficiency of different sources and forms of nitrogen. urea, ammonium sulfate (as), calcium nitrate (cn), solution of urea-ammonium nitrate-thiosulfate (uan + ats) and calcium ammonium nitrate (can) were tested. a fertilizer rate of 60 kg n/ha was applied before irrigation and a control treatment with no n was included. rice n uptake and yield was measured. the control treatment yielded 9756 kg/ha and total n uptake was 137 kg/ha, while the fertilized treatments absorbed from 164 to 185 kg n/ha. pure fertilizer sources (urea, sa, cn) showed a high rate of initial n uptake, with an 80 to 100% apparent recovery of n fertilizer at the panicle differentiation stage. surprisingly, the greatest response was observed in the treatment with cn, presenting a high fertilizer use efficiency. the mixed sources (uan+ats, can) showed a lower n uptake and fertilizer recovery. the results of this field trial indicate that denitrification losses were not significant and nitric sources could be used in rice fertilization.
The correlation between panicle angle and rice quality and genetic analysis on rice quality in japonica rice (Oryza sativa L.)
粳稻穗角与稻米品质的相关性及稻米品质遗传分析

JIANG Jian-Hua,GUO Yuan,CHEN Xian-Gong,XU Hong-Mei,HOU Yi-Jia,HONG De-Lin,
江建华
,郭媛,陈献功,徐红梅,侯一甲,洪德林

遗传 , 2007,
Abstract: Linear correlation between panicle angle and 10 quality traits were studied by using P1, P2 and 349 lines of the RIL population in a cross of Bing 8979(erect panicle)/C bao (curve panicle) in japonica rice. We found that, there were no linear correlation between panicle angle and brown rice rate , head rice rate, chalky grain rate, chalkiness area, gelatinization temperature, gel consistency and apparent amylose content. The correlation coefficients between panicle angle and milled rice rate, between panicle angle and grain length, and between panicle angle and grain length/width ratio were 0.124*, 0.470** and 0.241** , respectively. By using major gene-polygene mixed inheritance models, genetic analyses showed that brown rice rate, milled rice rate and apparent amylose content were controlled by two major genes plus polygenes. The two major genes expressed additive effect and additive x additive effects. Head rice rate, grain length, grain length/width ratio and gel consistency were controlled by two major genes with additive-epistatic effects plus polygenes. Chalky grain rate, chalkiness area and gelatinization temperature were controlled by three major genes with additive-epistatic effects plus polygenes. Brown rice rate, milled rice rate, head rice rate, chalky grain rate, chalkiness area and gelatinization temperature traits were mainly governed by major genes. Grain length, grain length/width ratio, gel consistency and apparent amylose content traits were mainly governed by polygenes.
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