Dr. Mohammed Sa’id Berigari, Senior Soil and Environmental Scientist, USA, June
Agronomy is a highly integrative group of sciences using several
disciplines of crop and soil sciences including plant breeding, physiology,
transgenic crop improvement, soil chemistry, fertility, physics, microbiology,
and other related genetic and environmental aspects of crop and soil managements. The primary objective of such integrated disciplines
is to develop improved varieties of agronomic, turf, and forage crops to
continuously produce sufficient food, feed, fuel, and fiber for the growing
In spite of great scientific achievements in these areas, the
world today faces growing challenges of large scale food insecurity and
malnutrition, adverse impacts of climate change, environmental degradation, and
heavy reliance on fossil fuel energy. Solutions
to these challenges will be found with sustained investments globally from both
public and private sectors at all levels to address such challenges. The agronomists will provide the tools,
essential technologies, and solutions required to address these challenges.
Crop Adaptation to Climate Change: Drought is number one limitation to crop productivity
worldwide. With climate change, the
incidence and duration of drought and other abiotic and biotic stresses on
major crops will increase in many areas of the globe, adversely affecting crop
yields and food supply. Solutions to
such a complex problem can best be addressed by research teams of scientific
expertise-breeders, physiologists, molecular geneticists, and soil and
The majority of the progenitors of most crops were developed
under periodical dry conditions when drought tolerant genes already existed in
most crop germplasm or in their wild relatives.
However, these important genes have not all survived in modern cultivars
because agriculture has concentrated on breeding varieties adapted to favorable
environments and to irrigation. The need
is urgent to incorporate genes for drought tolerance with predictions of more
widespread and severe droughts. Agronomists
must produce more of “crops-per-drop” of water and develop sound strategies to
share water resources at the rural and urban interface where water can be
bought and diverted to nonagricultural sectors.
Crop Resistance to
Biotic Stresses: Organisms that cause stresses in crops
continually adjust their pathogenic mechanisms to further invade plant’s
limited defenses. The rate of adjustment
by some pathogens has accelerated with new adopted intensive management
practices and climate change that adversely affect environmental conditions. Moreover, crop uniformity can increase
genetic susceptibility to various pests.
For instance, US soybean cultivars are almost uniformly susceptible to
new biotic stresses of aphids and
The management practices that retain plant residues on the
field result in increased soil organic matter, improved soil properties, and
additional sequestered carbon; however, they also create an environment where
pathogens can prosper and cause reductions in crop yields. Examples include
pathogens like gray leaf spots of
corn whose inoculum grows on previous crop residue. And also,
aflatoxins carcinogens are produced by fungi whose proliferation increases
in stress environments of drought, high temperatures, and /or high humidity. Therefore,
there is urgent need for plant genomic tools that can identify novel resistance
genes and rapidly incorporate them into improved cultivars.
for Resource-Limited Systems: Agricultural productivity is limited
in many parts of the world by poor soil conditions and high fertilizer
prices. However, soil tilth issues
including high soil pH, Al toxicity, and salinity increases are not easily overcome
by conventional high-input practices.
Consequently, new crop varieties and management practices are needed
that reduce reliance on agricultural inputs and remedy common soil problems.
Research teams with multidiscipline will be the key to
solutions of those problems because they have the expertise to improve N
fixation in legume crops and improve nutrient uptake and use and can develop
crop varieties that are tolerant to such limitations. Research teams should focus on efficient and
reliable methods to identify desirable crop germplasm that has the right
genetic makeup to deliver these improvements.
Coupled with technology transfer, these efforts will increase yields and
quality of food crops and enhance food security and alleviate nutritional
Systems: Agriculture always adapts to change. Consider the revolutionary changes in
agriculture resulting from such practices as irrigation, fertilizer, weed,
insect, and disease control, and modern tillage systems. There is a need to make similar changes to
cropping systems as we face future changes in climate and an increased need for
efficient use of resources. Nearly
80-90% US food is produced on large scale farms, commonly operated by family
To maintain greatest advances and productivity, environmental
sustainability, and profitability new crop management information and
technology systems are required to be adopted for various farms. Such innovations should enhance integrated
pest management and water and soil conservation in ways that are practical and
convenient for large scale farms. There
are numerous tools that can make this possible, like remote sensing and other
off site-site monitoring. The synergy
between variety development and crop management research has resulted in yield
increases for the last half century. The
interplay between genetics and environment must be optimized continually to
produce food, feed, fiber and fuel worldwide.
Biofuel production from crop plants is expected to increase in the
coming years. Crops in addition of being
sources of oils and proteins, they are also, sources of various carbohydrates
including sugars, starches, and cellulose that can be converted to biofuel
ethanol. All biofuel crops should be
grown in a way that optimize biomass yield while minimizing inputs of
fertilizer, irrigation, and pesticides.
It is essential to minimize the competition between biofuel
crops and human food crops. Thus,
ethanol-based biofuel crops will be and should be grown on marginal soils and
to leave more arable soils for human food crops. Since biodiesel is produced from seed oil, biofuel
must be produced from existing seed crops.
Therefore, biofuel research needs to concentrate on oil seed crops that
are used less for feedstock but very productive such as peanuts. The composition of biofuel crops will need to
be modified to make them easy to convert to energy use, but these modifications
may make more vulnerable stresses and pests.
As a result there is a
need 1) modify crop composition relative to requirement of processing, 2) increase
yield in low-input production systems, 3)understand plant response to changes
in the environment , in tandem with changes to composition for accurate
modification, 4) understand the ecosystem services (carbon sequestration, water
quality, wild life habitat, etc.) from perennial bioenergy crop production on
arable and marginal soils, and 5) develop new production systems that thrive in
Grand Challenge of Bioresources: Germplasm Collections are excellent treasure
of genetic diversity and the foundation for all crop improvement programs. A germplasm collection for a single crop
species may contain greater than 50, 000 distinct genetic plant types, yet the
genomic profiles are not readily available, limiting application of information
contained in the collections. However,
new inexpensive technologies offer a low-cost remedy for developing detailed
genetic profile to entire collection. As
a result, new genomics information will enhance our ability to correlate plant’s
genotype with its agricultural performance for plant breeding purposes in a way
never before possible.
To translate the economically important diversity of
germplasm collections into food and other agricultural products, it is critical
to integrate the new genomics information with a series of field-breeding
positions specifically targeted at “mining” germplasm collections. Field breeders will use hybridization and selection
informed by genomics to produce novel, agronomically important genetic types
that work effectively in agriculture. As
a result, development of crops will be accelerated to avoid famines and
market-place catastrophes resulting from fluctuations in rainfall, and pests,
therefore enabling greater food security around the world.
1. Lauer, J.G.; et.al. 2012.
The scientific grand challenges of the 21st century for the
Crop Science Society of America. Crop
Sci.Soc.Amer., 52(3): 1003-1010.
2. Lauer, J.G.; et al. 2012.
Grand challenges for crop science.
CSA (Crops, Soils, Agronomy) News, Magazine, Crop Sci.Soc.Amer., Soil
Sci.Soc.Amer., and Amer. Soc. Agron.: 4-11.
Dr Berigari’s article is very interesting
as he outlines the challenges that we face today in agriculture and food
production in the face of climatic change, disease resistance etc., and
increasing population demands. To compound the problem is the all too common
loss of good agricultural land to urban and industrial development while less
fertile land, or land that had been previously used for industry and is now
waste, is ignored. Throughout the world there is a finite amount of
agricultural land and it should be safeguarded for generations to come. I have
always had an interest in genetics and in producing my own vegetables I try new
F1 varieties that have been bred to be more suited to the warmer weather we now
have. The recognition that old strains and varieties of crops offer a wealth of
genetic variation that can be utilised in the production of new crops that are
better suited to changing conditions. This valuable genetic resource can be
maintained in seed banks such as the Millenium Seed Bank Partnership, Kew
Gardens, London which works with numerous institutions throughout the world. As
Mesopotamia saw the birth of agriculture I would suggest that efforts should be
made to record the region’s domesticated and wild varieties of plants, not only
to conserve them but in order to evaluate their potential use in the breeding
of new crops that are adapted to local conditions.