Effect of timing of application on the recovery of fertilizer N applied to irrigated soft white wheat

1993 ◽  
Vol 73 (4) ◽  
pp. 503-513
Author(s):  
J. M. Carefoot ◽  
R. L. Conner ◽  
J. B. Bole

The effect of timing of application on the recovery of fertilizer N applied to irrigated soft white wheat (Triticum aestivum L.) was investigated in a 3-yr field study and a 1-yr lysimeter study using 15N-labelled urea and ammonium nitrate. Fertilizer N treatments consisted of a check and 90 kg ha−1 applied as preplant N, postplant N or combinations. Under a controlled watering regime in the lysimeter experiment, timing of N application had no effect on plant growth parameters. In the field studies, although grain yield was not affected by N timing, grain N concentration increased from 17.9 to 19.6 g kg−1 as the proportion of postplant N was increased from 0 to 100%. Plant N uptake was greater when all of the N was applied postplant than preplant (means = 124.5 and 114.2 kg ha−1, respectively) in the field studies. Plant recovery of fertilizer N (FNR) by the difference method was greater when all of the fertilizer N was applied postplant (43.7%) man preplant (28.6%) in the field experiments. With a negative apparent added N interaction (ANI), the FNR was less by the difference method than by the 15N method. However, with a positive ANI, FNR was less by the 15N method than by the difference method. There was a greater difference between methods as the proportion of N applied as postplant N increased. Key words: Fertilizer N timing, irrigation, soft white wheat, nitrogation, fertilizer N recovery

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.


2020 ◽  
Vol 56 (5) ◽  
pp. 688-698
Author(s):  
Ali M. Ali

AbstractProximal plant sensing with active canopy sensors offers a leap in the non-destructive assessment of crop agronomic information. For managing fertilizer nitrogen (N), sensor readings must be translated using functional models or algorithms to fertilizer amounts. Six field experiments were conducted in three wheat seasons in the West Nile Delta in Egypt to develop and validate an algorithm based on GreenSeeker canopy reflectance sensor for field-specific fertilizer N management in wheat, which takes into account both spatial and temporal variability of N during the crop growth season. The proposed algorithm is based on the prediction of total N uptake and response index of N uptake determined from normalized difference vegetation index measured by the sensor from plots differing in yield potential as established by applying a range of fertilizer N levels in the four experiments conducted in the first two wheat seasons. The treatments in the two experiments conducted in the third wheat season were designed to define appropriate fertilizer N management prior to applying a sensor-based dose at Feekes 6 stage (jointing stage). The application of 40 and 60 kg N ha−1 at 10 and 30 days after sowing of wheat and a sensor-guided dose of N estimated by using the algorithm developed in this study resulted in yields similar to those obtained by following the general recommendation, but with an average of 66 kg N ha−1 less fertilizer N. These results were also reflected in a substantial increase in N recovery (21.9%) and agronomic (7.7 kg grain kg−1 N) efficiencies compared with the general recommendation, thereby proving the usefulness of the sensor-based algorithm in optimizing fertilizer N management in wheat.


1982 ◽  
Vol 18 (1) ◽  
pp. 73-78
Author(s):  
W. Y. Chew ◽  
K. Ramli ◽  
A. B. A. Majid

SUMMARYTwo field experiments studied the nitrogen fertilizer requirements of guinea and napier grass on peat. Plants in the control plots, though optimally limed and fertilized with other nutrients, absorbed only 1.7 and 2.4% of total peat N in a year and N fertilization improved DM yield, with an optimum at 900 kg/ha/yr. Further positive response was not observed, probably because of a reduced ratio of N to other nutrients. Optimum N uptake, and N concentration in the DM, were achieved at 600 kg/ha/yr N but N recovery decreased linearly with increasing fertilizer N at the rate of about 2–4% per 100 kg/ha/yr N.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 891E-892
Author(s):  
David R. Sandrock* ◽  
Timothy L. Righetti ◽  
Anita N. Azarenko

Accurate methods for determining the fate and recovery of nitrogen (N) fertilizer applied to container-grown nursery crops are essential to comply with regulations and develop innovative fertilizer programs. The objectives of this study were (i) to use 15N techniques to determine the fate of fertilizer N, (ii) to compare nonisotopic and isotopic methods of determining N recovery, and (iii) to determine the relative importance of fertilizer and non-fertilizer N at rates of 25, 50, 100, 200, and 300 mg·L-1 in container-grown Euonymus alatus (Thunb.) Sieb., Cornus sericea L., and Weigela florida (Bunge) A. DC. In all species, root and shoot N increased with N rate, and at each rate more N was stored in the roots than in the shoots. Estimation of N recovery determined by the total N method (Kjeldahl N/applied N) was significantly higher for all species and at each N rate than estimation of N recovery determined by the labeled fertilizer N method (labeled N/total applied N). Increasing fertilizer rates up to 100 mg·L-1 resulted in increased uptake of N derived from other sources (NDFO). NDFO at low N concentrations was a significant portion of the total N in the plant. As a result, the difference in estimation of percent N recovery between each method was larger at lower N concentrations for all species. The nonisotopic total N method produces higher fertilizer N uptake estimates, as much as three to four times the isotopic based estimates, in container-grown plants at N concentrations of 25 mg·L-1. Actual fertilizer N loss increases dramatically from 25 to 300 mg·L-1 (due to dramatic increases in N applied), despite small gains in fertilizer N recovery efficiency.


2002 ◽  
Vol 51 (1-2) ◽  
pp. 147-156 ◽  
Author(s):  
Erika Nótás ◽  
K. Debreczeni ◽  
K. Fischl ◽  

The primary (1 st year) and the after-effects (2 nd , 3 rd year) of N fertilizers (KNO 3 , NH 4 Cl) on the soil-plant-atmosphere system were studied in a three-year greenhouse pot experiment with and without maize plants. The two- and three-year balances of the fertilizer N uptake and gaseous N losses were also analyzed. The cumulative values of the gaseous losses showed a similar trend in all years, significant differences were not obtained. On the basis of the three-year balance, the gaseous loss in the planted and unplanted pots was 18-22% and about 37-39%, respectively. Consequently, there was a 50% decrease in denitrificated gaseous losses of fertilizer N due to plant N uptake. The cumulative gaseous loss, calculated by the difference method, was significantly higher in cases of KNO 3 applications than in NH 4 Cl treatments, as an assumed  consequence of the intensive denitrification. It was found that the gaseous loss was not influenced by soil moisture.  In contrast to the gaseous losses, the values of plant N uptake and soil mineral N content showed significant differences in the years studied, as a result of the quick transformation of mineral N to organic N, the non-complete homogenization of the total soil amount, the seasonal climatic differences in the greenhouse during the years studied, and consequently the different microbiological activity. The plant N uptake was found to depend significantly on the fertilizer N form. Results obtained by the difference method and the 15 N-tracer technique were very similar. In the case of KNO 3 treatment and higher soil moisture (WHC = 80%) plant N uptake was more intensive, ranging between 48-57% (calculated by the difference method), and 35-51% (calculated by the 15 N- tracer method) in the first year (1993). It can be concluded that 60-100% of the fertilizer N was used from the soil by plant uptake and gaseous losses, which depends mainly on the treatments and the soil moisture during the first year. These values changed between 7-17% in the 1 st year after-effect and between 1-5% in the 2 nd year after-effect.


2019 ◽  
Vol 99 (3) ◽  
pp. 345-355
Author(s):  
Richard E. Engel ◽  
Carlos M. Romero ◽  
Patrick Carr ◽  
Jessica A. Torrion

Fertilizer NO3-N may represent a benefit over NH4-N containing sources in semiarid regions where rainfall is often not sufficient to leach fertilizer-N out of crop rooting zones, denitrification concerns are not great, and when NH3 volatilization concerns exist. The objective of our study was to contrast plant-N derived from fertilizer-15N (15Ndff), fertilizer-15N recovery (F15NR), total N uptake, grain yield, and protein of wheat (Triticum aestivum L.) from spring-applied NaNO3 relative to urea and urea augmented with urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT). We established six fertilizer-N field trials widespread within the state of Montana between 2012 and 2017. The trials incorporated different experimental designs and 15N-labeled fertilizer-N sources, including NaNO3, NH4NO3, urea, and urea + NBPT. Overall, F15NR and 15Ndff in mature crop biomass were significantly greater for NaNO3 than urea or urea + NBPT (P < 0.05). Crop 15Ndff averaged 53.8%, 43.9%, and 44.7% across locations for NaNO3, urea, and urea + NBPT, respectively. Likewise, crop F15NR averaged 52.2%, 35.8%, and 38.6% for NaNO3, urea, and urea + NBPT, respectively. Soil 15N recovered in the surface layer (0–15 cm) was lower for NaNO3 compared with urea and urea + NBPT. Wheat grain yield and protein were generally not sensitive to improvements in 15Ndff, F15NR, or total N uptake. Our study hypothesis that NaNO3 would result in similar or better performance than urea or urea + NBPT was confirmed. Use of NO3-N fertilizer might be an alternative strategy to mitigate fertilizer-N induced soil acidity in semiarid regions of the northern Great Plains.


1984 ◽  
Vol 64 (4) ◽  
pp. 563-570 ◽  
Author(s):  
M. R. CARTER ◽  
D. A. RENNIE

Growth chamber and field studies were conducted to assess the relative utilization of placed and broadcast 15N-urea by spring wheat. The field studies were conducted on zero and conventional (shallow) tillage systems, of 4-yr duration, located on Chernozemic soils at two locations in Saskatchewan. Placement below the seeding depth in comparison to broadcast application, generally reduced fertilizer N immobilization and increased fertilizer N uptake, recovery, and efficiency. Under moisture stress, placed applications were effective in enhancing dry matter yield and total N uptake. It is concluded that fertilizer N placement for these two contrasting tillage systems should be identical, thus some soil disturbance under zero tillage may be necessary to achieve optimum crop use of applied fertilizer N. The dominant N transformation processes and possible tillage induced differences, in regard to methods of N application, are discussed. Key words: Placed and broadcast N application, N efficiency, N utilization, 15N-urea, zero tillage, soil moisture


1997 ◽  
Vol 77 (4) ◽  
pp. 543-551 ◽  
Author(s):  
F. S. Rembon ◽  
A. F. MacKenzie

Soybean (Glycine max L. Merill) can produce high-N residues that may benefit subsequent corn (Zea mays L.) production, but the degree of benefit is often unpredictable and may be related to tillage methods. This study investigated the effects of conventional-tillage (CT) and no-tillage (NT) on fertilizer replacement values for corn in a corn-soybean rotation. Field experiments were conducted for two growing seasons on two soils, a Ste. Rosalie clay (Humic Gleysol), and an Ormstown silty clay (Humic Gleysol). Continuous corn, corn following soybean, soybean following corn, continuous soybean, and three levels of fertilizer N (0, 90, 180 and 0, 20, and 40 kg N ha−1 for corn and soybean, respectively) were compared. Tillage did not effect yield or N uptake consistently. Corn grain yields and N uptake were greater following soybean than following corn. Soybean provided N fertilizer credits ranging from 40 to 150 kg N ha−1, which was greater than the residual NO3 in the soil prior to planting. Credits were greater in the year with higher corn yields and lower previous winter precipitation resulting in greater NO3 carryover. Tillage effects on N credits from soybean differed between the sites. Consequently, N contributions of soybean to corn could not be related to tillage method or soil type. Key words:Zea mays L., Glycine max L. Merill, rotations, grain yield, N uptake, tillage, fertilizer N


1995 ◽  
Vol 125 (1) ◽  
pp. 25-37 ◽  
Author(s):  
J. Webb ◽  
R. Sylvester-Bradley ◽  
J. D. Wafford

SUMMARYAt 14 sites in the UK, spring wheat (Triticum aestivum) cv. Tonic, was sown on three or four dates at each site between October and March in the 1988/89, 1989/90 and 1990/91 seasons. Responses to spring-applied fertilizer N over the range 0–320 kg/ha were determined. Earlier sowing did not increase uptake of soil N by the crop. Fertilizer N increased grain N offtake by between 25 and 140 kg/ha and yield by between 0·3 and 5·5 t/ha, although grain yield was less responsive to fertilizer N at later sowing dates. Apparent recovery of fertilizer N (AFR) also decreased as sowing was delayed but there was no effect of delayed sowing on the amount of grain produced from each kg of fertilizer N recovered. Because fertilizer N recovery decreased with later sowing, the amount of fertilizer N needed to produce the optimum economic grain yield was not reduced. Neither AFR nor optimum fertilizer (Nopt) was related to optimum yield. Regression of Nopt on the difference between optimum yield and yield without fertilizer N (△y) explained 77% of the variance in Nopt. There was an inverse relationship between △y and soil mineral N (SMN) in spring; regression of △y, on SMN in spring accounted for 29% of the variance in △y Current advisory systems which adjust economic fertilizer N recommendations according to anticipated yield are not justified by these results. Moreover the adjustments made, based on yield expectation, appear about three times as large as those needed to minimize residues of fertilizer N left unrecovered by the crop and to reduce the risk of nitrate leaching in the following winter.


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