Isotopic and Nonisotopic Estimations of Fertilizer Nitrogen Uptake by Sudangrass in Field Experiments

1974 ◽  
Vol 38 (1) ◽  
pp. 107-109 ◽  
Author(s):  
R. L. Westerman ◽  
L. T. Kurtz
Keyword(s):  
Nitrogen Uptake ◽  
Field Experiments ◽  
Fertilizer Nitrogen

Nitrogen Fertilization of Sugarcane in an Intercropping System with Maize and Potato in the Humid Tropical Climate of Mauritius

1996 ◽  
Vol 32 (2) ◽  
pp. 213-218 ◽  
Author(s):  
K. F. Ng Kee Kwong ◽  
G. Umrit ◽  
J. Deville
Keyword(s):  
Nitrogen Uptake ◽  
Nitrogen Fertilization ◽  
Field Experiments ◽  
Nitrogen Recovery ◽  
Food Crops ◽  
Pure Stand ◽  
Nitrogen Application ◽  
Fertilizer Nitrogen ◽  
Labelled Nitrogen ◽  
Companion Crop

SUMMARYThe competition for fertilizer nitrogen between sugarcane and a companion crop (maize or potato) grown between the sugarcane rows was studied using nitrogen-15 labelled nitrogen in three field experiments in Mauritius. The effect of the timing of nitrogen application on nitrogen recovery by sugarcane was also investigated. Not more than 15 kg ha−1 of the 120 kg ha−1 nitrogen applied to the sugarcane was taken up by the companion crop but this was compensated for by the uptake of 8 kg ha−1 nitrogen applied to maize or potato. The present recommendations for nitrogen fertilization of pure stand sugarcane were found to be applicable to sugarcane intercropped with non-leguminous food crops. Though fertilizer nitrogen uptake by sugarcane was increased by delaying nitrogen application until after the harvest of the maize and potato, this was not accompanied by an increase in sugarcane yields.

Comparisons of liquid and solid fertilizers and anhydrous ammonia for sugar beet

1970 ◽  
Vol 74 (1) ◽  
pp. 139-145
Author(s):  
A. P. Draycott ◽  
R. Holliday
Keyword(s):  
Sugar Beet ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Field Experiments ◽  
Surface Soil ◽  
Early Spring ◽  
Seed Plants ◽  
Deep Placement ◽  
Side Band ◽  
Anhydrous Ammonia

SUMMARYSix field experiments (1963–8) in eastern England compared solid fertilizer with liquid fertilizer or anhydrous ammonia for sugar beet. Two glasshouse experiments investigated the interaction between depth of placement of fertilizer and soil moisture.Yields of sugar were the same from broadcast solid and sprayed liquid in all the experiments, but nitrogen uptake by the crop was less from liquid than from solid. Three experiments tested placement of liquid 4 in to the side and either 2 or 6 in below the seed. Plants with deep-placed fertilizer consistently out-yielded those with shallowplaced fertilizer, but yields were never significantly different from broadcast solid fertilizer. Dry-matter yields of sugar beet grown in containers indoors showed that the crop responded to deep placement when the surface soil was watered infrequently.With anhydrous ammonia injected during seed-bed preparation, sugar yield and nitrogen uptake were the same as with solid fertilizer in the seed bed, and were greater than with anhydrous ammonia injected in the ploughed land during early spring. A side-band injection of anhydrous ammonia before singling gave a crop containing as much nitrogen at harvest as, but less sugar than, nitrogen applied in the seed bed.

Isotopic studies on the uptake of nitrogen by pasture grasses. II. Uptake of fertilizer nitrogen by Rhodes grass in posts

1964 ◽  
Vol 15 (6) ◽  
pp. 876 ◽  
Author(s):  
EF Henzell ◽  
AE Martin ◽  
PJ Ross ◽  
KP Haydock
Keyword(s):  
Linear Function ◽  
Total Nitrogen ◽  
Nitrogen Uptake ◽  
Nitrogen Fertilizer ◽  
Rhodes Grass ◽  
Fertilizer Nitrogen ◽  
Pasture Grasses ◽  
Isotopic Studies ◽  
Pretreatment Phase

Nitrogen uptake by Rhodes grass was a linear function of the quantity of 15NH4N03 applied for rates up to the equivalent of 400 lb N/ac, but the proportion of fertilizer nitrogen recovered in the plants fell significantly when the rate was increased to 800 lb N/ac. A nitrogen pretreatment equivalent to 200 lb N/ac had relatively little effect on the uptake of 15NH4N03 by the grass, despite the fact that it almost doubled the weight of roots in the pots when the 15NH4N03 was first applied. Over the range 0–400 lb N/ac, 84.1%% of added total nitrogen and 75.5% of added 15N was taken up by plants that received no nitrogen fertilizer during the pretreatment phase, and 80.3% of added total nitrogen and 71.9% of added 15N was taken up by plants that received a pretreatment of 200 lb N/ac. Fertilizer nitrogen was distributed between tops and roots in the ratio (averaged for the two pretreatments) of 5.2 : 1 for total nitrogen and 4.5 : 1 for 15N; these ratios were constant over the range 0–400 lb N/ac and were not significantly different.

Fertilizer nitrogen uptake efficiencies for potato as influenced by application timing

2016 ◽  
Vol 104 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Libby Rens ◽  
Lincoln Zotarelli ◽  
Ashok Alva ◽  
Diane Rowland ◽  
Guodong Liu ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Application Timing ◽  
Fertilizer Nitrogen

Furrow irrigation of grain sorghum in a tropical environment. II. Influence of period of inundation on the utilization of soil and fertilizer nitrogen by the crop

1985 ◽  
Vol 36 (1) ◽  
pp. 83 ◽  
Author(s):  
GC Wright
Keyword(s):  
Nitrogen Uptake ◽  
Plant Uptake ◽  
Surface Soil ◽  
Grain Sorghum ◽  
Furrow Irrigation ◽  
Tropical Environment ◽  
Soil Layers ◽  
Fertilizer Nitrogen ◽  
Crop Maturity ◽  
Applied Nitrogen

Grain sorghum was grown in plots that had been fertilized, before sowing, with either 0, 80 or 170 kg Ha-1 nitrogen (N), and furrow irrigated for periods of 0 (sprinkler irrigated control), 3, 6, 12 or 24 h. The apparent uptake of fertilizer nitrogen declined from 63 to 7% as the period of inundation increased from 0 to 24 h. Large quantities of nitrate (up to 82 kg N ha-1) remained in the surface soil layers of all furrow irrigated ridges at crop maturity, in contrast to the sprinkler irrigated ridges (up to 4 kg N ha-1). At all inundation periods a constant proportion of the applied nitrogen was moved to the ridge tops, where it was unavailable for plant uptake. The differences in the recovery of applied nitrogen between the crops given 0 (sprinkler) and 3 h irrigation was mainly attributed to the surface accumulation of nitrate in the latter. Further reduction of nitrogen uptake with longer periods of inundation are attributed to differential rates of loss of nitrogen from the soil by denitrification and leaching.

Monitoring wheat fields by RapidScan: accuracy and limitations

2017 ◽  
Vol 8 (2) ◽  
pp. 333-337 ◽  
Author(s):  
D. J. Bonfil
Keyword(s):  
Grain Yield ◽  
Nitrogen Uptake ◽  
Field Experiments ◽  
Yield Loss ◽  
Assessment Tool ◽  
Growth Period ◽  
Biomass Estimation ◽  
Proximal Sensing ◽  
Crop Monitoring ◽  
Emergence Date

Simple active radiometer sensors, such as RapidScan, enable agronomic decision-making and phenotyping within commercial wheat fields and experiments. The objectives of this study were: 1 - to evaluate the accuracy of quantitative biomass and nitrogen uptake estimation by the RapidScan, and 2 - to evaluate yield loss estimation based on NDVI. The RapidScan sensor was used as an assessment tool in the following studies: (i) over 3 years, 518 wheat samples were monitored during the vegetative growth period for biomass and aboveground nitrogen uptake and (ii) wheat cultivars were tested in an additional 4 field experiments, which were scanned weekly and correlated with grain yield. Results showed that accurate biomass estimation is limited up to about 100 g DM m−2. Grain yield, actual and potential, estimation is highly affected by the emergence date. The results showed that the use of a proximal-sensing technique allows for rapid and accurate crop monitoring and yield estimation, but emphasizing limitations in future use as well.

Sign in / Sign up

Export Citation Format

Share Document