scholarly journals Optical crop sensor for variable-rate nitrogen fertilization in corn: II - indices of fertilizer efficiency and corn yield

2013 ◽  
Vol 37 (5) ◽  
pp. 1299-1309 ◽  
Author(s):  
Jardes Bragagnolo ◽  
Telmo Jorge Carneiro Amado ◽  
Rodrigo da Silveira Nicoloso ◽  
Antônio Luis Santi ◽  
Jackson Ernani Fiorin ◽  
...  

Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N) fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF), based on optical spectrometry crop sensors, could increase the N use efficiency (NUE). The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF). With this purpose, three experiments with no-tillage corn were carried out in the 2008/09 and 2010/11 growing seasons on a Hapludox in South Brazil, in a completely randomized design, at three different sites that were analyzed separately. The following crop properties were evaluated: aboveground dry matter production and quantity of N uptake at corn flowering, grain yield, and vegetation index determined by an N-Sensor® ALS optical sensor. Across the sites, the corn N fertilizer had a positive effect on corn N uptake, resulting in increased corn dry matter and grain yield. However, N fertilization induced lower increases of corn grain yield at site 2, where there was a severe drought during the growing period. The VRF defined by the optical crop sensor increased the apparent N recovery (NRE) and agronomic efficiency of N (NAE) compared to the traditional fertilizer strategy. In the average of sites 1 and 3, which were not affected by drought, VRF promoted an increase of 28.0 and 41.3 % in NAE and NRE, respectively. Despite these results, no increases in corn grain yield were observed by the use of VRF compared to TSF.

1995 ◽  
Vol 5 (1-2) ◽  
pp. 85-99 ◽  
Author(s):  
L. M. Dwyer ◽  
B. L. Ma ◽  
H. N. Hayhoe ◽  
J.L.B. Culley

2004 ◽  
Vol 84 (4) ◽  
pp. 481-490 ◽  
Author(s):  
Terence P. McGonigle ◽  
Eric G. Beauchamp

We investigated corn grain yield responses to early-season soil mineral N and plant N content following application of a variety of manures in Eastern Canada. Liquid cattle, liquid swine, straw-bedded poultry, wood-bedded poultry, and solid cattle manures were each applied at 100, 200, and 300 kg N ha-1 prior to planting corn in a field experiment repeated 3 consecutive years. Additional treatments were urea applied at 50, 100, and 150 kg N ha-1, and liquid cattle and solid cattle manures at 200 kg N ha-1 with bedding amendments added to the field before manure spreading. Control plots received no manure, no urea, and no bedding amendment. Part of the ammonium-N applied in manures and a portion of that added as urea was volatilized or immobilized shortly after application and was not recovered as soil mineral N at planting. Across all treatments, soil mineral N in the top 30 cm on Jun. 10 in each year gave a better relationship to corn grain yield than soil mineral N measured at planting or on Jul. 10. Inclusion of data for plant N content on Jun. 10 or Jul. 10 did not improve the regressions. With remarkable consistency across all manure types, across manure rates, and over the three years, similar values for soil mineral N on Jun. 10 in plots given manure at planting had yields typically 0.5-1.0 t ha-1 greater than those in plots given urea at planting. This result indicates that mineralization of N from manure after the time of sidedress N and undetected as soil mineral N on Jun. 10 can contribute to yield increases of corn. Recent manure history should be considered when using soil tests for mineral N that are taken 3-4 wk after planting to calculate sidedress N fertilization. Key words: Sidedress, soil test, slurry, solid, cattle, swine, poultry


Crop Science ◽  
2004 ◽  
Vol 44 (3) ◽  
pp. 847 ◽  
Author(s):  
Weidong Liu ◽  
Matthijs Tollenaar ◽  
Greg Stewart ◽  
William Deen

2021 ◽  
Vol 208 ◽  
pp. 104880
Author(s):  
Sami Khanal ◽  
Andrew Klopfenstein ◽  
Kushal KC ◽  
Venkatesh Ramarao ◽  
John Fulton ◽  
...  

1985 ◽  
Vol 65 (3) ◽  
pp. 481-485 ◽  
Author(s):  
G. J. HOEKSTRA ◽  
L. W. KANNENBERG ◽  
B. R. CHRISTIE

The objective of this study was to determine the effects on grain yield of growing cultivars in mixtures of different proportions. Two maize (Zea mays L.) hybrids, Pride 116 and United 106, were grown for 2 yr in pure stand and in seven mixtures of different proportions (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, 1:7) at plant densities of 61 500, 99 400, and 136 000 plants per hectare. The total number of mixture combinations was 42, i.e. 2 years × three densities × seven proportions. All but one mixture yielded as expected based on the yield of component hybrids in pure stand. The higher yielding hybrid (United 106) yielded significantly less grain per plant in mixtures than in pure stand. The lower yielding hybrid (Pride 116) yielded more in mixtures than in pure stand, although the difference was not significant. These data support previous observations that the ability of a hybrid to yield in pure stands is not necessarily related to its ability to yield in mixtures. High plant densities appear to enhance the likelihood of interactions occurring among hybrids. For United 106, the number of proportions yielding less grain per plant than in pure stand was highly significant at the two higher plant densities. For Pride 116, the number of proportions yielding more than in pure stand was highly significant at the highest plant density.Key words: Corn, grain yield, mixtures of different proportions, high plant densities, Zea mays


1990 ◽  
Vol 70 (1) ◽  
pp. 51-60 ◽  
Author(s):  
D. T. GEHL ◽  
L. D. BAILEY ◽  
C. A. GRANT ◽  
J. M. SADLER

A 3-yr study was conducted on three Orthic Black Chernozemic soils to determine the effects of incremental N fertilization on grain yield and dry matter accumulation and distribution of six spring wheat (Triticum aestivum L.) cultivars. Urea (46–0–0) was sidebanded at seeding in 40 kg N ha−1 increments from 0 to 240 kg ha−1 in the first year and from 0 to 200 kg ha−1 in the 2 subsequent years. Nitrogen fertilization increased the grain and straw yields of all cultivars in each experiment. The predominant factor affecting the N response and harvest index of each cultivar was available moisture. At two of the three sites, 91% of the interexperiment variability in mean maximum grain yield was explained by variation in root zone moisture at seeding. Mean maximum total dry matter varied by less than 12% among cultivars, but mean maximum grain yield varied by more than 30%. Three semidwarf cultivars, HY 320, Marshall and Solar, had consistently higher grain yield and grain yield response to N than Glenlea and Katepwa, two standard height cultivars, and Len, a semidwarf. The mean maximum grain yield of HY 320 was the highest of the cultivars on test and those of Katepwa and Len the lowest. Len produced the least straw and total dry matter. The level of N fertilization at maximum grain yield varied among cultivars, sites and years. Marshall and Solar required the highest and Len the lowest N rates to achieve maximum grain yield. The year-to-year variation in rates of N fertilization needed to produce maximum grain yield on a specific soil type revealed the limitations of N fertility recommendations based on "average" amounts and temporal distribution of available moisture.Key words: Wheat (spring), N response, standard height, semidwarf, grain yield


2017 ◽  
Vol 30 (3) ◽  
pp. 670-678 ◽  
Author(s):  
ROGÉRIO PERES SORATTO ◽  
TIAGO ARANDA CATUCHI ◽  
EMERSON DE FREITAS CORDOVA DE SOUZA ◽  
JADER LUIS NANTES GARCIA

ABSTRACT The objective of this work was to evaluate the effect of plant densities and sidedressed nitrogen (N) rates on nutrition and productive performance of the common bean cultivars IPR 139 and Pérola. For each cultivar, a randomized complete block experimental design was used in a split-plot arrangement, with three replicates. Plots consisted of three plant densities (5, 7, and 9 plants ha-1) and subplots of five N rates (0, 30, 60, 120, and 180 kg ha-1). Aboveground dry matter, leaf macro- and micronutrient concentrations, yield components, grain yield, and protein concentration in grains were evaluated. Lower plant densities (5 and 7 plants m-1) increased aboveground dry matter production and the number of pods per plant and did not reduce grain yield. In the absence of N fertilization, reduction of plant density decreased N concentration in common bean leaves. Nitrogen fertilization linearly increased dry matter and leaf N concentration, mainly at lower plant densities. Regardless of plant density, the N supply linearly increased grain yield of cultivars IPR 139 and Pérola by 17.3 and 52.2%, respectively.


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