UPTAKE AND UTILIZATION OF 5-SPLIT NITROGEN TOPDRESSING IN AN IMPROVED AND A TRADITIONAL RICE CULTIVAR IN THE BHUTAN HIGHLANDS

2012 ◽  
Vol 48 (4) ◽  
pp. 536-550 ◽  
Author(s):  
BHIM BAHADUR GHALEY

SUMMARYThe uptake of urea fertilizer (NDFF), applied with 150 kg nitrogen (N) ha−1, topdressed in five splits of 30 kg N ha−1 (30 N) each at 7, 26, 45, 70 and 83 days after transplanting (DAT) of rice (Oryza sativa L.), was investigated in an improved (Khangma Maap, KM) and a traditional (Janam, JN) cultivar in Bhutan highlands, using enriched 15N stable isotope. The treatments were arranged in a split–split plot design, with N fertilizer levels as main plots, cultivars as subplots and topdressing treatments as sub-subplots, with all the sub-subplots receiving the same dose except different timing of one split of enriched 15N to determine partial N fertilize use efficiency at each split dose. Although cultivar differences were not recorded in soil N accumulation and in total dry matter N, KM produced 21% higher grain yields compared to JN due to higher grain harvest index and partial factor productivity of N. Irrespective of the cultivars, topdressing timing had significant effects on NDFF, with highest mean N recovery (REN) of 29% of applied 30 N at 45 DAT during active tillering stage, resulting in mean NDFF total (grain + straw) uptake of 8.71 kg N ha−1 compared to least effective topdressing timing at 7 DAT with mean REN of 12% and NDFF total of 3.51 kg N ha−1. In similarity to topdressing at 45 DAT, topdressing at 70 DAT (panicle initiation stage) was equally effective with mean REN of 27% across the cultivars. Hence, fertilizer N topdressing recommendations that combine use of improved cultivars with N applications timed to coincide with maximum crop demand at 45 and 70 DAT, could enhance N fertilizer use efficiency for increased rice yields as well as reduce N losses downstream, which can cause adverse off-site environmental effects.

2008 ◽  
Vol 88 (5) ◽  
pp. 849-857 ◽  
Author(s):  
P. A. Barbieri ◽  
H. S. Rozas ◽  
H. E. Echeverría

Nitrogen (N) fertilization is an important management practice to increased grain yield; however, it is imperative to increase nitrogen use efficiency (NUE) in order to diminish risks of environmental pollution. The objective of this study was to determine the effect of fertilization times on wheat grain yield, grain N accumulation and grain N recovery efficiency (RE) in different sites and years at the south-eastern wheat belt of the Pampas. The experiments were a factorial combination of N rates and fertilization times (sowing and tillering). Grain yield ranged from 1600 to 7900 kg ha-1 and fertilization at tillering increased grain yield compared with fertilization at sowing (5465 vs. 5110 kg ha-1), similar behavior was observed for grain N accumulation (95 vs. 86 kg ha-1) and RE (0.41 vs. 0.32). Predicted grain yield by CERES-Wheat model for different N rates and fertilization times was correlated with observed grain yield (r2 = 0.71). While fertilization at tillering significantly increased grain yield, CERES-Wheat model estimated nitrate leaching losses that ranged from 12 to 62 kg N ha-1 and from 7 to 16 kg N ha-1 for fertilization at sowing and tillering, respectively. However, denitrification losses ranged from 1.2 to 3.9 and from 0.5 to 2.4 kg N ha-1 for fertilization at sowing and tillering, respectively. Leaching losses for fertilization at sowing are a consequence of water excess early in the growing season and would be the main N loss factor. Therefore, N application at tillering is an appropriate strategy to improve NUE in the south-eastern wheat belt of the Pampas. Key words: Wheat, fertilization time, nitrogen use efficiency, N losses, CERES-Wheat


1994 ◽  
Vol 119 (3) ◽  
pp. 427-433 ◽  
Author(s):  
C.A. Sanchez ◽  
R.L. Roth ◽  
B.R. Gardner

Six field studies were conducted from 1980-88 to evaluate the response of cabbage (Brassica oleracea L., Capitata group) to sprinkler irrigation and sprinkler-applied N fertilizer on a coarse-textured soil. The plots were irrigated using a modified self-moving lateral sprinkler irrigation system that applied five levels of water and five levels of N (liquid NH4NO3) in specified combinations of central composite rotatable design. Cabbage yields were significantly increased by water and N applications in all experiments. The N rates predicted for maximum yield exceeded typical cabbage N fertilizer recommendations. However, the above-average plant populations used in these studies resulted in above-average yields and plant N accumulation. Deficit and excess irrigation produced negative results. Generally, cabbage production was optimized and N losses to the environment were minimized when crops were irrigated for evapotranspiration (ET) replacement. However, even when irrigated for ET replacement, these data demonstrate the potential for N leaching at high N rates, presumably as a result of rainfall.


HortScience ◽  
2009 ◽  
Vol 44 (6) ◽  
pp. 1712-1718 ◽  
Author(s):  
Laura L. Van Eerd ◽  
Kelsey A. O'Reilly

The increase in fertilizer costs as well as environmental concerns has stimulated growers to re-evaluate their fertilizer applications to optimize nitrogen use efficiency (NUE) while maintaining crop yields and minimizing N losses. With these objectives, field trials were conducted at seven sites with five N rates (0 to 220 kg N/ha) of ammonium-nitrate applied preplant broadcast and incorporated as well as a split application treatment of 65 + 45 kg N/ha. In three contrasting years (i.e., cool/wet versus warm/dry versus average), N treatment had no observable effect on grade size distribution or brine quality. Based on the zero N control treatment, the limited yield response to fertilizer N was the result of sufficient plant-available N over the growing season. In the N budget, there was no difference between N treatments in crop N removal, but there was a positive linear relationship between N applied and the quantity of N in crop residue as well as in the soil after harvest. As expected, apparent fertilizer N recovery and N uptake efficiency were lower at 220 versus 110 kg N/ha applied preplant or split. The preplant and split applications of 110 kg N/ha were not different in yield, overall N budget, or NUE. Considering the short growing season, planting into warm soils, and the generally productive, nonresponsive soils in the region, growers should consider reducing or eliminating fertilizer N applications in machine-harvested cucumber.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 765
Author(s):  
Hao Qing Zhang ◽  
Xue Qiang Zhao ◽  
Yi Ling Chen ◽  
Jia Lin Wang ◽  
Ren Fang Shen

The root is the main site of nitrogen (N) acquisition and aluminum (Al) toxicity. The objective of this study is to investigate whether liming and cultivation of an Al-tolerant rice (Oryza sativa L.) cultivar can improve root growth, thereby increasing N acquisition by rice plants in acid paddy soil. Two rice cultivars (‘B690’, Al-sensitive, and ‘Yugeng5’, Al-tolerant) were cultivated with 15N-labeled urea, and with or without lime in an acid paddy soil (pH 4.9) in pots. We examined root and shoot growth, soil pH, soil exchangeable Al, N uptake, 15N distribution in plant-soil system, and fertilizer N recovery efficiency. Results showed that liming improved the root growth of ‘B690’ by decreasing soil exchangeable Al concentrations, in both N-limited and N-fertilized soils. Liming enhanced the N uptake of ‘B690’ only in the absence of N fertilizer. The root weight of ‘Yugeng5’ was greater than that of ‘B690’ without lime, but the two cultivars showed similar N uptake. The fertilizer N recovery efficiency and N loss did not differ significantly between limed and non-limed conditions, or between the two rice cultivars. Thus, liming an Al-sensitive rice cultivar and cultivating an Al-tolerant one improves root growth, but does not enhance fertilizer N recovery efficiency in the present acid paddy soil.


1998 ◽  
Vol 131 (4) ◽  
pp. 395-407 ◽  
Author(s):  
A. G. CHALMERS ◽  
C. J. DYER ◽  
R. SYLVESTER-BRADLEY

Amounts of spring nitrogen (N) fertilizer (0–240 kg/ha), combined with three timing treatments (single, divided early or divided late), were tested at 14 sites in England and Wales between 1984 and 1988 to determine the optimum fertilizer N requirement for winter oats. The trials were superimposed on commercial crops of the cultivars Pennal (9 sites) or Peniarth (5 sites). Optimum amounts of N ranged from nil to 202 kg/ha (mean 119) and optimum yields varied between 5·8 and 9·9 t/ha (mean 7·3). Much (c. 60%) of the inter-site variation in N optimum was explained by differences in soil N supply, as indicated by N offtake in the grain at nil applied N. Mean yield differences between single and early (+0·08 t/ha) or late (−0·04 t/ha) divided dressings were slight, although significant (P<0·05) but inconsistent yield effects were obtained from early N at two sites and late N at three sites.Lodging occurred at 11 of the 12 sites where lodging scores were recorded and always increased significantly (P<0·05) with applied N. The amount of crop lodging at N optimum was, on an area basis, <50% at nine of the sites. The overall extent of site lodging was also influenced by soil N fertility and hence inversely related to N optimum. However, multiple regression, using site lodging as well as soil N supply, only accounted for slightly more (65%) of the variation in N optimum, which suggests that lodging was not a major limiting factor. Lodging was unexpectedly less from early N (mean 43%), but more from late N (53%) divided dressings, compared with a single N dressing (49%). Early N reduced lodging significantly (P<0·05) at four sites, although the actual reduction was only large at one site where early N also increased yield significantly (+0·57 t/ha).Grain N concentrations increased significantly (P<0·05) with applied N, on average by 0·12% per 40 kg/ha N increment. Timing effects on grain N concentration were very small, with mean values of 1·94, 1·91 and 1·96%N respectively from single, early and late divided dressings. Apparent recovery in grain of fertilizer N at the optimum amount ranged from 13 to 57% (mean 37), with better N recovery at the more yield-responsive sites. Changes in mean grain weight due to the amount and timing of fertilizer N were small, with an average reduction of 0·6 mg/grain per 40 kg/ha N applied. The adverse effects of N fertilizer on grain quality were slight and unlikely to have commercial significance. The agronomic implications of these results on the N fertilization of winter oats are discussed.


1994 ◽  
Vol 122 (3) ◽  
pp. 385-391 ◽  
Author(s):  
K. F. Ng Kee Kwong ◽  
J. Deville

SUMMARYThe patterns of N uptake and dry matter synthesis by sugarcane (Saccharum hybrid spp.) were studied at four locations in Mauritius with 15N–labelled ammonium sulphate (100 kg N/ha) applied either in a single dressing in September or in two split applications in September and the following February. More than 80% of the total N recovered at harvest (100–120 kgN/ha) was absorbed by the sugarcane during an active uptake period from October to January. Split application prolonged this active N uptake until April only and had no effect on dry matter accumulation. While total Nabsorbed by above-ground sugarcane showed no decline over time, 10–20 kg N/ha of the 15N–labelled N was lost from the green tops even when the N was applied on two occasions. The fertilizer N losses from above-ground sugarcane were, however, not evident when fertilizer N recovery with time was studied by the difference method. In view of the observed losses of fertilizer N from the aerial parts of sugarcane, measurement of fertilizer N recovery at harvest by the N isotope dilution technique underestimates fertilizer N uptake by sugarcane and attributes too large a fraction of N loss to denitrification/volatilization of NH3.


2004 ◽  
Vol 84 (3) ◽  
pp. 845-854 ◽  
Author(s):  
B. J. Zebarth ◽  
Y. Leclerc ◽  
G. Moreau

This study evaluated rate and timing of N fertilization effects on the N use efficiency characteristics of rain-fed Russet Burbank potato. Trials conducted in 1999–2001 included different rates of fertili zer N (0–160 kg N ha-1 in 1999 and 0–200 kg N ha-1 in 2000 and 2001) applied either at planting according to normal grower practice, or at hilling, the latest time that granular fertilizer can practically be applied. Whole-plant dry matter and N accumulation were determined at topkill. Soil inorganic N content was measured to 30-cm depth at planting and at tuber harvest. Soil N supply (plant N accumulation plus soil inorganic N content at harvest with no fertilizer N applied) varied from 77 to 146 kg N ha-1 depending on the year. Crop N supply (soil N supply plus fertilizer N applied) was a better predictor of plant N accumulation than fertilizer N rate, and was used to remove the confounding effect of variation in soil N supply when making among-year comparisons for N use efficiency characteristics. Nitrogen uptake efficiency (NUpE; plant N accumulation/crop N supply) decreased with increasing rates of N applied at hilling N rate in 1999, which was a dry year, but was not influenced by at-hilling N rate in 2000 and 2001, or by at-planting N rate in any year. Nitrogen use efficiency (NUE; dry matter accumulation/crop N supply) and N utilization efficiency (NUtE; dry matter accumulation/plant N accumulation) decreased curvilinearly with increasing crop N supply in each year. Similar relationships between NUE and crop N supply, and between NUtE and plant N accumulation, among the 3 yr of the study suggest that these relationships are largely independent of seasonal climatic variation, and are primarily genetically controlled. Timing of N fertilization had no effect on any N use efficiency parameter, with the exception of reduced NUpE associated with split N application in 1999. This suggests that under rain-fed potato production in Atlantic Canada, timing of N fertilization has no significant effect on N use efficiency of Russet Burbank potato in years of adequate soil moisture, but NUpE may be decreased by split application of N in dry years. Key words: Solanum tuberosum, soil inorganic N, apparent fertilizer N recovery


1999 ◽  
Vol 124 (6) ◽  
pp. 719-725 ◽  
Author(s):  
G.A. Picchioni ◽  
Héctor M. Quiroga-Garza

Two greenhouse studies were conducted to trace the fate of fertilizer N in hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy `Tifgreen'], and to estimate total plant N recovery and losses. The first experiment was performed during winter, with artificial light supplementing natural light to provide a photoperiod of 13.6 to 13.8 hours. The second experiment was conducted during summer and fall under only natural light conditions, with a progressively decreasing photoperiod of 13.7 to 11.1 hours. Urea (UR), ammonium sulfate (AS), and ammonium nitrate (AN) were labeled at 2 atom% 15N, and applied at N rates of 100 or 200 kg·ha-1 for 84 days (divided into six equal fractions and applied every 14 days). Fertilizer N source did not affect total dry matter (DM) accumulation by the plant components, but the high N rate increased clipping DM production under the longer photoperiod. Under the decreasing photoperiod, overall DM production was reduced, and clipping DM production was unaffected by increased N rate. Average N concentration of clippings varied between N sources, ranging from a high of 38.6 g·kg-1 DM with AS to a low of 34.7 g·kg-1 for UR. In Expt. 1, the greatest total plant N recovery [clippings, verdure (shoot material remaining after mowing), and thatch plus roots] occurred with AS (78.5%) and the lowest with UR (65.9%). In Expt. 2, these values declined to 53.0% and 38.0%, respectively. Urea fertilization resulted in the greatest N losses as a fraction of the N applied (33.6% to 61.5%) and AS fertilization the lowest (20.7% to 46.3%). In view of the greater N losses, UR may be a less suitable soluble N source for bermudagrass fertilization within the conditions of this study. In addition, late-season N fertilization may result in a significant waste of fertilizer N as bermudagrass progresses into autumnal dormancy when temperature, photoperiod, and irradiance decline and cause reduction in growth and N uptake.


1988 ◽  
Vol 68 (3) ◽  
pp. 687-703 ◽  
Author(s):  
H. UKRAINETZ ◽  
C. A. CAMPBELL ◽  
R. P. ZENTNER ◽  
M. MONREAL

A 9-yr study was conducted on a Gray Luvisolic loam at Loon Lake, Saskatchewan to determine the effect of ammonium nitrate-N (34–0–0) and urea-N (46–0–0) on bromegrass (Bromus inermis Leyss.) production and nutrient quality, N recovery, and N use efficiency when the N was applied either annually or as a single application at the start of the experiment. The effects of phosphorus (P) and sulphur (S) were also assessed. Each N source was applied at single rates of 0, 100, 200, 400 and 800 kg ha−1 N and annual rates of 0, 50, 100 and 200 kg ha−1 N. The ammonium nitrate was also applied as a single dose at rates of 600 and 1000 kg ha−1 N. Phosphorus and S were applied every second year at 224 kg ha−1 P2O5 and 45 kg ha−1 S. Forage dry matter yields were positively related to precipitation received in May and July, and April–May, but negatively related to June precipitation. Forage dry matter production was greater over the first 8-yr period for annual N applications than for a single application receiving an equivalent amount of N; but fertilizer N recovered in forage over the same period was similar (about 30%) for the two methods of application. Dry matter yields were 19% greater after 4 yr and 26% greater after 8 yr when ammonium nitrate was used compared to urea. Recovery of fertilizer N in forage also favored the ammonium nitrate source. The application of low to moderate N rates depressed forage N and P concentrations when yield response was high but concentrations were increased by the highest rates of N fertilizer and by repeated annual applications of N. Toxic concentrations of NO3-N occurred in bromegrass in the first year when N was applied at or above 400 kg ha−1 as one application and also in the second year when N was applied at 800 kg ha−1. When N was applied annually at 200 kg ha−1, NO3-toxicity became a potential problem in later years as soil mineral N accumulated. Phosphorus and S fertilizers increased dry matter yields of forage; P fertilizer increased and S decreased forage P concentration. Annual N applications resulted in more uniform year-to-year yields and N uptake response compared to a single application and provided greater dry matter production without loss of nutritive quality. It was concluded that, in contrast to reports in the literature, the response of forage grasses to N is not site specific.Key words: N source, N recovery, N application method, N use efficiency, phosphorus, sulfur


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