scholarly journals Predicting nitrogen fertilizer requirements for corn by chlorophyll meter under different N availability conditions

2005 ◽  
Vol 85 (1) ◽  
pp. 149-159 ◽  
Author(s):  
M. T. Rashid ◽  
Paul Voroney ◽  
G. Parkin
Keyword(s):  
Management Strategies ◽  
Crop Management ◽  
Inverse Correlation ◽  
Accurate Method ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
N Availability ◽  
Corn Hybrids ◽  
Chlorophyll Meter ◽  
Application Rates

Nitrogen management strategies that enhance fertilizer use efficiency and maximize profitability in corn require a rapid and accurate method to determine the crop N needs of current hybrids. The objective of this study was to evaluate the potential of a portable chlorophyll meter for predicting N fertilizer requirements for corn grown under varying levels of N availability. Several crop management treatments were imposed in an attempt to create conditions ranging from low N availability (oily food waste application in spring and fall, application at different rates in spring) to high N availability (continuous fertilized corn, winter wheat cover crop). Different corn hybrids were sown at different sites (21 site yr) and varying N fertilizer application rates were applied. Chlorophyll meter readings (CMR) were taken at the 5th to 6th leaf stage (V6) using a SPAD-502 chlorophyll meter. The crop management treatments, corn hybrids and their interaction significantly affected the chlorophyll meter readings. A high inverse correlation between chlorophyll meter readings and maximum economic rate of nitrogen (MERN) was observed (r = −0.87). The main new and unique aspect of our research is the development of a linear model for using chlorophyll meter measurements to make N fertilizer recommendations (MERN = 348.47 − 8.5304 × CMR ) for corn production under varying degrees of N availability in Southern Ontario. Key words: Chlorophyll meter, soil organic carbon, nitrogen application

scholarly journals Modelled Quantification of Different Sources of Nitrogen Inefficiency in Semi-Arid Cropping Systems

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1222
Author(s):  
Niloufar Nasrollahi ◽  
James Hunt ◽  
Caixian Tang ◽  
David Cann
Keyword(s):  
Water Conservation ◽  
Cropping Systems ◽  
C:N Ratio ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Annual Rainfall ◽  
N Availability ◽  
Application Rates ◽  
Fertilizer Application Rate ◽  
Semi Arid

Most dryland grain growers in Australia retain all or most of their crop residues to protect the soil from erosion and to improve water conservation but retaining stubbles with a high carbon-to-nitrogen (C:N) ratio can affect N availability to crops. A simulation experiment was conducted to investigate the effects of N fertilizer application rate and residue retention on soil N dynamics. The simulation used seven N fertilizer application rates (0, 25, 50, 75, 100, 150 and 200 kg N ha−1) to wheat (Triticum aestivum) over 27 years (1990–2016) at four locations across a gradient in annual rainfall in Victoria, Australia. Nitrogen immobilization, denitrification and N leaching loss were predicted and collectively defined as sources of N inefficiency. When residues were retained, immobilization was predicted to be the biggest source of inefficiency at all simulated sites at N application rates currently used by growers. Leaching became a bigger source of inefficiency at one site with low soil water-holding capacity, but only at N rates much higher than would currently be commercially applied, resulting in high levels of nitrate (NO3−) accumulating in the soil. Denitrification was an appreciable source of inefficiency at higher rainfall sites. Further research is necessary to evaluate strategies to minimize immobilization of N in semi-arid cropping systems.

scholarly journals Nutrient Management Programs, Nitrogen Fertilizer Practices, and Groundwater Quality in Nebraska’s Central Platte Valley (U.S.), 1989–1998

2001 ◽  
Vol 1 ◽  
pp. 750-757 ◽  
Author(s):  
Stan Daberkow ◽  
Harold Taylor ◽  
Noel Gollehon ◽  
Milt Moravek
Keyword(s):  
Irrigation Water ◽  
Fertilizer Application ◽  
Management Program ◽  
N Fertilizer ◽  
N Availability ◽  
Modest Improvement ◽  
Total N ◽  
Drinking Water Standard ◽  
Irrigation Water Use ◽  
Farmer Behavior

Given the societal concern about groundwater pollution from agricultural sources, public programs have been proposed or implemented to change farmer behavior with respect to nutrient use and management. However, few of these programs designed to change farmer behavior have been evaluated due to the lack of detailed data over an appropriate time frame. The Central Platte Natural Resources District (CPNRD) in Nebraska has identified an intensively cultivated, irrigated area with average groundwater nitrate-nitrogen (N) levels about double the EPA’s safe drinking water standard. The CPNRD implemented a joint education and regulatory N management program in the mid-1980s to reduce groundwater N. This analysis reports N use and management, yield, and groundwater nitrate trends in the CPNRD for nearly 3000 continuous-corn fields from 1989 to 1998, where producers faced limits on the timing of N fertilizer application but no limits on amounts. Groundwater nitrate levels showed modest improvement over the 10 years of this analysis, falling from the 1989–1993 average of 18.9 to 18.1 mg/l during 1994–1998. The availability of N in excess of crop needs was clearly documented by the CPNRD data and was related to optimistic yield goals, irrigation water use above expected levels, and lack of adherence to commercial fertilizer application guidelines. Over the 10-year period of this analysis, producers reported harvesting an annual average of 9729 kg/ha, 1569 kg/ha (14%) below the average yield goal. During 1989�1998, producers reported annually applying an average of 162.5 kg/ha of commercial N fertilizer, 15.7 kg/ha (10%) above the guideline level. Including the N contribution from irrigation water, the potential N contribution to the environment (total N available less estimated crop use) was estimated at 71.7 kg/ha. This is an estimate of the nitrates available for denitrification, volatilization, runoff, future soil N, and leaching to groundwater. On average, between 1989–1993 and 1994–1998, producers more closely followed CPNRD N fertilizer recommendations and increased their use of postemerge N applications � an indication of improved synchrony between N availability and crop uptake.

Carbon footprint of crop production in China: an analysis of National Statistics data

2014 ◽  
Vol 153 (3) ◽  
pp. 422-431 ◽  
Author(s):  
K. CHENG ◽  
M. YAN ◽  
D. NAYAK ◽  
G. X. PAN ◽  
P. SMITH ◽  
...  
Keyword(s):  
Carbon Footprint ◽  
Crop Production ◽  
Management Practices ◽  
Fertilizer Application ◽  
N Fertilization ◽  
Paddy Rice ◽  
N Fertilizer ◽  
Carbon Equivalent ◽  
Ghg Mitigation ◽  
Application Rates

SUMMARYAssessing carbon footprint (CF) of crop production in a whole crop life-cycle could provide insights into the contribution of crop production to climate change and help to identify possible greenhouse gas (GHG) mitigation options. In the current study, data for the major crops of China were collected from the national statistical archive on cultivation area, yield, application rates of fertilizer, pesticide, diesel, plastic film, irrigated water, etc. The CF of direct and indirect carbon emissions associated with or caused by these agricultural inputs was quantified with published emission factors. In general, paddy rice, wheat, maize and soybean of China had mean CFs of 2472, 794, 781 and 222 kg carbon equivalent (CE)/ha, and 0·37, 0·14, 0·12 and 0·10 kg CE/kg product, respectively. For dry crops (i.e. those grown without flooding the fields: wheat, maize and soybean), 0·78 of the total CFs was contributed by nitrogen (N) fertilizer use, including both direct soil nitrous oxide (N2O) emission and indirect emissions from N fertilizer manufacture. Meanwhile, direct methane (CH4) emissions contributed 0·69 on average to the total CFs of flooded paddy rice. Moreover, the difference in N fertilizer application rates explained 0·86–0·93 of the provincial variations of dry crop CFs while that in CH4 emissions could explain 0·85 of the provincial variation of paddy rice CFs. When a 30% reduction in N fertilization was considered, a potential reduction in GHGs of 60 megatonne (Mt) carbon dioxide equivalent from production of these crops was projected. The current work highlights opportunities to gain GHG emission reduction in production of crops associated with good management practices in China.

Impact of mineral N fertilizer application rates on N2O emissions from arable soils under winter wheat

2014 ◽  
Vol 100 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Ulrike Lebender ◽  
Mehmet Senbayram ◽  
Joachim Lammel ◽  
Hermann Kuhlmann
Keyword(s):  
Winter Wheat ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
N2o Emissions ◽  
Arable Soils ◽  
Mineral N ◽  
Application Rates

scholarly journals Phosphorus Budget for a Forested-Agricultural Watershed in Korea

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 4 ◽  
Author(s):  
Arif Reza ◽  
Jaesung Eum ◽  
Sungmin Jung ◽  
Youngsoon Choi ◽  
Changwon Jang ◽  
...  
Keyword(s):  
Management Strategies ◽  
Sewage Treatment ◽  
Agricultural Practices ◽  
Fertilizer Application ◽  
Drainage Water ◽  
Agricultural Watershed ◽  
Application Rates ◽  
P Balance ◽  
Agriculture Fertilizer ◽  
Total P

Despite increased attention to the need for sustainable agriculture, fertilizer application rates above crop requirements remain common agricultural practices in South Korea, causing eutrophication of freshwater and coastal ecosystems. The aim of this study is to quantify phosphorus (P) inputs, outputs, and retention in a forested-agricultural watershed. The P budget showed that the combined use of chemical fertilizer and organic compost was the largest source of P (97.6% of the total) followed by atmospheric wet deposition (2.1% of the total P), whereas forest export (0.2% of the total) and sewage treatment plants (STPs) (0.1% of the total) were negligible. The P outputs were crop harvesting and hydrologic export to surface water. The P balance showed that P inputs are higher than the P outputs; approximately 87% of the total P input was retained in the soils within the watershed. However, P concentrations in drainage water were still high enough to cause eutrophication of downstream reservoirs. The results provide important details on the proportion of P export and retention in the watershed. This will help efforts to improve water quality and design better management strategies for agricultural nonpoint source pollution.

Effect of fertilizer rate and form on the recovery of 15N-labelled fertilizer applied to wheat in Syria

1997 ◽  
Vol 128 (4) ◽  
pp. 415-424 ◽  
Author(s):  
C. J. PILBEAM ◽  
A.M. McNEILL ◽  
H. C. HARRIS ◽  
R. S. SWIFT
Keyword(s):  
Fertilizer Application ◽  
Application Rate ◽  
N Fertilization ◽  
N Fertilizer ◽  
Organic N ◽  
Inorganic N ◽  
Fertilizer Rate ◽  
Application Rates ◽  
Dry Conditions ◽  
Added Nitrogen Interaction

15N-labelled fertilizer was applied at different rates (0, 30, 60, 90 kg N ha−1) and in different forms (urea or ammonium sulphate) to wheat grown in Syria in three seasons (1991/92, 1992/93 and 1994/95).Recovery of 15N-labelled fertilizer in the above-ground crop at harvest was low (8–22%), with the amount of 15N-labelled fertilizer recovered in the crop increasing as the rate of application increased. Fertilizer application caused a significant increase in the amount of unlabelled soil N in the crop, suggesting that the application of N fertilizer caused a ‘real’ added nitrogen interaction. Recovery of 15N-labelled fertilizer in the crop was unaffected by the form of the fertilizer.On average 31% (14–54%) of the 15N-labelled fertilizer remained in the soil at harvest, mostly in the 0–20 cm layer. At the lowest application rate (30 kg N ha−1) most of the residual fertilizer was as organic N, but at the higher application rates (60 and 90 kg N ha−1), a greater proportion of the 15N-labelled fertilizer was recovered as inorganic N, presumably as the result of top-dressing N in dry conditions in the spring. The amount of 15N-labelled fertilizer remaining in the soil increased as the fertilizer rate increased, but was unaffected by the form of fertilizer applied.Losses of 15N-labelled fertilizer were large (>35%), probably caused by gaseous losses, either through volatilization of N from the calcareous soil, or through denitrification from wet soils rich in organic residues.N fertilization strategies in the West Asia/North Africa (WANA) region should take note of the low recovery of N fertilizer by the crop in the season of application, and the resultant large quantities of residual fertilizer.

Dry matter production by a subtropical grass (Makarikari grass) grown in association with a temperate annual legume (barrel medic) and nitrogen fertilizer in southern Queensland

1985 ◽  
Vol 25 (1) ◽  
pp. 54 ◽  
Author(s):  
DL Lloyd ◽  
TB Hilder
Keyword(s):  
Dry Matter ◽  
N Uptake ◽  
Winter Season ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Pasture Grass ◽  
Barrel Medic ◽  
Application Rates ◽  
Matter Production ◽  
Cutting Experiment

The effects of a temperate annual legume, barrel medic (Medicago truncatula) cv. Cyprus, and five levels of fertilizer nitrogen (N), from 0 to 400 kg/ha.year, on the dry matter (DM) production and N economy of Makarikari grass (Panicum coloratum var. makarikariense) cv. Pollock, were investigated in a cutting experiment between 1973 and 1979. Each year, N fertilizer on grass alone increased both DM production and N uptake, up to N application rates of 200 and 400 kg/ha.year respectively. The mean annual effect of medic was to increase DM production and N uptake of associated grass each year by 90 and 130% respectively, and of the grass-medic system by 230 and 530%, respectively, for fertilizer rates between 0 and 100 kg N/ha.year. The increased DM production of associated grass occurred in summer and autumn; grass DM production was suppressed in spring, probably by competition with the medic. A trend for the DM yield of grass grown without medic to decline with time was most evident in the treatment without N fertilizer; in the comparable grass-medic pasture, grass DM production was as great in the sixth year as in the first. Medic DM yield varied with winter season rainfall. When the study concluded, the amount of N in the soil (0-10 cm depth) was higher after grassmedic than grass alone, except at the highest level of N fertilizer application. It was estimated that medic had fixed about 71 kg N/ha.year.

ECONOMICS OF N-FERTILIZATION OF DRYLAND GRASSES FOR HAY PRODUCTION IN SOUTHWESTERN MANITOBA

1990 ◽  
Vol 70 (2) ◽  
pp. 559-563 ◽  
Author(s):  
W. P. McCAUGHEY ◽  
E. G. SMITH ◽  
A. T. H. GROSS
Keyword(s):  
Sandy Loam ◽  
Fertilizer Application ◽  
N Fertilization ◽  
N Fertilizer ◽  
Grass Species ◽  
Fertilizer Response ◽  
Intermediate Wheatgrass ◽  
Response Data ◽  
N Supply ◽  
Application Rates

An economic analysis was conducted on N fertilizer response data of four dryland grass species on two soil types. Clay-loam soils were more productive than sandy-loam soils. The N supply required to obtain optimum economic yield was determined and results showed that producers must increase N fertilizer application rates over current rates of application in order to maximize profit.Key words: Bromegrass, crested wheatgrass, intermediate wheatgrass, Russian wild ryegrass, nitrogen fertilizer, economics

Sugar cane crop management by N-fertilizer application affects the aromaticity of humic acid structures in the superficial layer in soil

2018 ◽  
Vol 34 (4) ◽  
pp. 510-514
Author(s):  
S. A. Assunção ◽  
L. H. C. dos Anjos ◽  
M. G. Pereira ◽  
E. Lima ◽  
A. Paz González ◽  
...  
Keyword(s):  
Humic Acid ◽  
Sugar Cane ◽  
Crop Management ◽  
Fertilizer Application ◽  
Superficial Layer ◽  
N Fertilizer
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