Economics
of Variable Rate Lime In Indiana (Look
this paper in the category: Ensayos a Campo)
Abstract:
“In Indiana, variable rate application (VRA) of lime is often
considered a good place to start site-specific management (SSM).
This is because soil pH is one of the most variable of
manageable soil characteristics in the state, the availability
of essential nutrients is closely related to soil pH, and
because spreaders can be retrofitted relatively inexpensively to
do VRA. The objective of this study is to evaluate the
profitability of VRA for lime as a standalone activity. The
methodology involves a spreadsheet model using corn and soybean
pH response functions estimated with small plot data. The
overall results indicate increased annual returns to corn and
soybean production with site-specific pH management strategies.
On average, SSM with agronomic recommendations provides
an increased annual return of $7.24 per hectare (ha) (+1.78%).
SSM with the economic decision rule provides an average increase
in annual return of $19.55 ha-1 (+4.82%). Information strategy,
which uses sitespecific information to determine the
economically optimal uniform rate of lime, provides an average
increase in annual return of $14.38 ha-1 (+3.54%)”.
Authors:
Rodolfo Bongiovanni (Proyecto Agricultura de Precisión, INTA
Manfredi), J. Lowenberg-DeBoer (Universidad de Purdue). Source:
Agricultura de Precisión,
Manfredi,
Córdoba, Argentina. Consult other works in Spanish of the same institution in:
INDICE
AGRARIO: AGRICULTURA DE PRECISION.
Economics
of Variable Rate Planting for Corn (Look
this paper in the category: Ensayos a Campo)
Abstract:
“This analysis works out the economic implications for
variable rate seeding of the corn population response curves
estimated by Pioneer Hi-Bred agronomists. Examples are developed
for various mixes of low, medium and high yield potential soil,
as well as for a range of seed costs and variable rate equipment
costs. The strategies analyzed were: variable rate planting
using agronomic recommendations for each yield potential zone,
variable rate planting using an economic decision rule for each
yield potential zone, an information strategy which sets the
uniform planting rate at the highest population indicated by
agronomic recommendations for any part of the field and a second
information strategy which uses an economic decision rule for
the whole field based on potential in each yield zone. The
economic decision rule sets the value of additional yield
produced by adding a few more plants equal to the cost of
planting a few extra seeds.
Major assumptions of the analysis include: only corn is
considered for variable rate planting, 1000 acres of corn are
planted annually, the yield potential zones are small,
irregularly shaped and interspersed so that changing population
by field is ineffective, the zones are accurately mapped and
corn price at harvest is $3/bu. The analysis does not include
risk, alternative uses for low yield potential soil or the
benefits of variable rate planting other than seed cost savings
and matching population to the yield potential of the soil.
The general conclusion is that variable rate seeding has
profit potential only for farmers with some low yield potential
land(<100 bu./a). Farmers with mix of medium and high
potential land are better off with uniform rate seeding. The
surprise is that variable rate seeding is potentially profitable
when the proportion of low yield land is small. In the example,
the farm with 10% low yield potential soil shows positive
returns to variable rate planting. The results are not
particularly sensitive to seed cost or variable rate investment
cost”.
Author:
J. Lowenberg-DeBoer, Universidad de Purdue. Source:
Agricultura de Precisión,
Manfredi,
Córdoba, Argentina. Consult other works in Spanish of the same institution in:
INDICE
AGRARIO: AGRICULTURA DE PRECISION.
Nitrogen
Management in Corn Using Site-Specific Crop Response Estimates
from a Spatial Regression Model (Look
this paper in the category: Ensayos a Campo)
Abstract:
“Adapting variable rate technology (VRT) to Argentine
conditions requires methods that use inexpensive information and
that focus on the inputs and variability common to Argentine
maize and soybean growing areas. The goal of this study is to
determine if spatial regression analysis of yield monitor data
can be used to estimate the site-specific crop Nitrogen (N)
response needed to fine tune variable rate fertilizer
strategies. N has been chosen as the focus of this study because
it is the most commonly used fertilizer by corn farmers in
Argentina. The methodology uses yield monitor data from on-farm
trials to estimate site-specific crop response functions. The
design involves a strip trial with a uniform N rate along the
strip and a randomized complete block design, with regression
estimation of N response curves by landscape position. Spatial
autocorrelation and spatial heterogeneity are taken into account
using a spatial error model and a groupwise heteroskedasticity
model. A partial budget is used to calculate uniform rate and
VRT returns. First year data indicate that N response differs
significantly by landscape position, and that VRA for N may be
modestly profitable on some locations depending on the VRT fee
level, compared to a uniform rate of urea of 80kg ha-1. A more
complete analysis will pool data over many farms and several
years to determine if reliable differences exist in N response
by landscape position or other type of management zone. The
study is planned for four years. The purpose of this preliminary
analysis is to show how spatial regression analysis of yield
data could be used to fine tune input use”.
Authors:
Rodolfo Bongiovanni (Proyecto Agricultura de Precisión, INTA
Manfredi), J. Lowenberg-DeBoer (Departamento de Economía Agrícola
- Universidad de Purdue). Source:
Agricultura de Precisión,
Manfredi,
Córdoba, Argentina. Consult other works in Spanish of the same institution in:
INDICE
AGRARIO: AGRICULTURA DE PRECISION.
Precision
Agriculture in Argentina – 2001 (Look
this paper in the category: Presente y Futuro)
Abstract:
“Argentine farm managers see precision agriculture as a
means as a means to reduce costs in grain production, to
increase productivity and make input use more efficient. Yield
monitors, Global Positioning Systems (GPS) guidance and
satellite images are increasingly used in large operations,
while variable rate application (VRA) is rare. Factors
discouraging precision agriculture adoption are: high investment
cost, high risk, low management-induced soil variability, and
the widespread use of custom operators. Factors that encourage
its adoption include: large farm operations with relatively high
capital per worker, highly educated farm management, technology
available from abroad, need for yield information, and ease of
pooling data. The objective of this article is to present
Argentina as a case study in the adoption of precision
agriculture”.
Authors:
Rodolfo Bongiovanni y James Lowenberg-DeBoer. Source:
Agricultura de Precisión,
Manfredi,
Córdoba, Argentina. Consult other works in Spanish of the same institution in:
INDICE
AGRARIO: AGRICULTURA DE PRECISION.
Precision Agriculture in the 21st
Century. Geospatial and Information Technologies in Crop
Management
Description:
"Sensors, satellite photography, and multispectral imaging
are associated with futuristic space and communications science.
Increasingly, however, they are considered part of the future of
agriculture. The use of advanced technologies for crop
production is known as precision agriculture, and its rapid
emergence means the potential for revolutionary change
throughout the agricultural sector. Precision Agriculture in the
21st Century provides an overview of the specific technologies
and practices under the umbrella of precision agriculture,
exploring the full implications of their adoption by farmers and
agricultural managers. The volume discusses how precision
agriculture could dramatically affect decisionmaking in
irrigation, crop selection, pest management, environmental
issues, and pricing and market conditions. It also examines the
geographical dimensions--farm, regional, national--of precision
agriculture and looks at how quickly and how widely the
agricultural community can be expected to adopt the new
information technologies. Precision Agriculture in the 21st
Century highlights both the uncertainties and the exciting
possibilities of this emerging approach to farming. This book
will be important to anyone concerned about the future of
agriculture: policymakers, regulators, scientists, farmers,
educators, students, and suppliers to the agricultural
industry".
Contents:
1. Dimensions of Precision Agriculture. 2. A New Way to Practice Agriculture. 3. Adoption of Precision Agriculture. 4. Public Policy and Precision Agriculture. References. Glossary.
Authors:
Steven
T. Sonka, Marvin E. Bauer and Edward T. Cherry. Committee
on Assessing Crop Yield: Site-Specific Farming, Information
Systems, and Research Opportunities, National Research Council
(USA). 1998, 168 pages.
Publisher:
National Academy Press.
Value
of pH Soil Sensor Information (Look
this paper in the category: Ensayos a Campo)
Abstract:
“The
economic trade off between grid soil sampling and laboratory
tests, or soil sensor data is the choice between relatively
accurate information at a few points, or less accurate
information a many points. Estimates indicate that the value of
yield lost due to sensor measurement error is small”.
Authors:
J. Lowenberg-DeBoer - Alan Hallman (Departamento de Economía
Agrícola - Universidad de Purdue).
Source:
Agricultura de Precisión,
Manfredi,
Córdoba, Argentina. Consult other works in Spanish of the same institution in:
INDICE
AGRARIO: AGRICULTURA DE PRECISION.
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