Late-Fall, Winter, and Spring Broadcast Applications of Urea to No-Till Winter Wheat II. Fertilizer N recovery, Yield, and Protein as Affected by NBPT

2017 ◽  
Vol 81 (2) ◽  
pp. 331-340 ◽  
Author(s):  
Carlos M. Romero ◽  
Richard E. Engel ◽  
Chengci Chen ◽  
Roseann Wallander ◽  
Clain A. Jones
1988 ◽  
Vol 68 (1) ◽  
pp. 133-142 ◽  
Author(s):  
YADVINDER SINGH ◽  
E. G. BEAUCHAMP

Three field experiments were undertaken over a 2-yr period to compare the response of winter wheat to fall-applied large urea granules containing a nitrification inhibitor (dicyandiamide, DCD) with that of commercial urea granules (prills) applied as a top dressing in the spring. The objective was to determine the effectiveness of large urea granules coupled with DCD in conserving N when applied at planting or one month after planting. Granules of 1, 2 and 3 g urea as well as 2 g urea + DCD were compared with commercial urea prills at an application rate of 80 kg N ha−1. Large urea granules, as compared with fall-incorporated commercial urea prills, were effective in conserving N over the winter period especially when applied 1 mo after planting and resulted in yields and apparent N recovery similar to those with top dressed commercial prills applied in the spring. Incorporation of DCD into 2-g granules (50 or 100 g kg−1 urea) further increased the conservation of N fertilizer as reflected by higher yields and greater apparent fertilizer N recovery. Uptake of 15N from 2-g urea granules decreased with distance from the granule. However, plants furthest from spaced large granules were able apparently to obtain sufficient N to reach the yield potential dictated by the weather and soil conditions. Yield and N recovery data indicated that N conservation increased with increasing granule size. Crop response and fertilizer N availability decreased as depth of placement exceeded 10 cm. Placement between the 5 and 10 cm depths appeared to maximize fertilizer N availability. It was concluded that a combination of large urea granules and a nitrification inhibitor (such as DCD) can effectively conserve fall-applied N and result in yield responses and N uptake by winter wheat similar to that with commercial urea prills applied as a top dressing in the spring. Key words: Time of application, yield, 15N recovery, apparent fertilizer N recovery


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.


2020 ◽  
Vol 23 (4) ◽  
pp. 417-426
Author(s):  
Chisaka Arisede ◽  
Zaman-Allah Mainassara ◽  
Cairns Jill ◽  
Tarekegne Amsal ◽  
Magorokosho Cosmos ◽  
...  

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.


1992 ◽  
Vol 72 (4) ◽  
pp. 1075-1089 ◽  
Author(s):  
A. M. Johnston ◽  
D. B. Fowler

The yield of recrop winter wheat (Triticum aestivum L.) is a function of the interaction between agronomic management and the prevailing environment. Eight field trials were conducted over 2 yr on Dark Brown and Black Chernozemic soils in Saskatchewan to determine the influence of fertilizer-N rate and time of application on the early-season crop development and water use of no-till seeded winter wheat. Ammonium nitrate was surface broadcast on one of three schedules: as early as possible (early); 67% early and 33% at the beginning of stem elongation (split): or 3 wk after early (late), at rates of 0, 67, 134 and 202 kg N ha−1. In 1987, N fertilization resulted in the development and maintenance of a larger leaf-area index (LAI) and increased leaf conductance, leading to higher dry matter (DM) yield at anthesis and harvest. High air temperatures increased evaporative demand in 1988 and hastened crop development. Early-season response of both LAI and tiller number to fertilizer-N were abruptly terminated, followed by rapid pre-anthesis senescence in 1988. On average, 43% of harvest DM had accumulated by anthesis in 1987, compared with 78% in 1988. Although early N application increased and maintained LAI over late N in three of the eight trials, tiller responses to early N application were lost before anthesis under the environmental stress encountered. Increases in water-use efficiency of DM production with added N were a reflection of DM responses and not water use. Most of the soil water was extracted pre-anthesis, with on average 98% of post-anthesis evapotranspiration (ET) coming from rainfall. Maximum ET was associated with periods of high rainfall. Pre-anthesis DM yield increases associated with fertilizer-N, and dependence of post-anthesis ET on rainfall, resulted in increased plant stress and reduced leaf conductance during grain filling with fertilizer-N additions. Early correction of N deficiencies were required to efficiently utilize rainfall and stored soil water for biomass production under the recrop conditions used to produce no-till winter wheat in Saskatchewan’s semi-arid environment.Key words: Winter wheat, N application time, drought, water-use efficiency


2009 ◽  
Vol 89 (4) ◽  
pp. 403-411 ◽  
Author(s):  
S S Malhi ◽  
Y K Soon ◽  
S Brandt

Growing season rainfall affects fertilizer N recovery, particularly in semi-arid environments. However, the influence of rainfall distribution during the growing season is not well-understood. We conducted a 7-yr study (from 1997 to 2006) to assess this effect, and that of no-till (NT) vs. conventional tillage (CT), on fertilizer N recovery by spring wheat (Triticum aestivum L.) fertilized with 15N-labelled urea at 40 kg N ha–1 and grown on stubble on a Dark Brown Chernozem soil in Saskatchewan, Canada. Two of the seven experimental years had growing season rainfall close to normal, one was above normal and four were below normal. Tillage treatment did not affect 15N recovery by wheat; however, 15N recovery in the top 15 cm of soil averaged 47% under NT vs. 39% under CT (P = 0.02). Total N and 15N uptakes were most affected by "year" due to variation in growing season rainfall distribution. Excluding an ultra-low value of 3.8% (or 1.5 kg N ha–1) in 2002, due to extreme drought, 15N recovery by wheat averaged 47.5% (range 30–57%), and percent N derived from fertilizer was 12–20%. Rainfall in May correlated significantly with 15N and total N uptake (r = 0.605 and 0.699, respectively). The recovery of 15N in wheat head correlated negatively with June rainfall (r = –0.624), probably because more moisture increased soil N mineralization, which diluted the 15N pool. During grain filling, soil N uptake was 12–30 kg ha–1, compared with negligible amounts (< 7%) of 15N; however, about 15 kg ha–1 of 15N were remobilized vs. 34–74 kg ha–1 of soil N. It is concluded that, in this semi-arid region, fertilizer N uptake is influenced more by rainfall in May than other months of the growth period.Key words: 15N-labelled urea, fertilizer N recovery, N uptake, rainfall, remobilized N, tillage


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