Crop pest management and food security in Nigerian agriculture

Abstract

Pests damage crops at different stages of growth on the field, at harvest, during transportation and in storage. This leads to 5 – 40% crop loss yearly and has a serious effect on the food security for the ever-increasing population of the country. The management of pests in crops to obtain a better yield is paramount for food security. The resource-poor farmers who produce a large percentage of the crop for consumption cannot afford expensive management of pests in order to meet the yearly target consumption level for the country. The different methods for the management of pests—cultural, biological, indigenous knowledge systems, use of resistant varieties, use of plant extracts, use of pheromones and the minimal use of chemicals in an integrated pest management system which hitherto existed as fragmented information—are discussed. Areas for future research are also mentioned.     

Plant genetics, sustainable agriculture and global food security

The United States and the world face serious societal challenges in the areas of food, environment, energy, and health. Historically, advances in plant genetics have provided new knowledge and technologies needed to address these challenges. Plant genetics remains a key component of global food security, peace, and prosperity for the foreseeable future. Millions of lives depend upon the extent to which crop genetic improvement can keep pace with the growing global population, changing climate, and shrinking environmental resources. While there is still much to be learned about the biology of plant-environment interactions, the fundamental technologies of plant genetic improvement, including crop genetic engineering, are in place, and are expected to play crucial roles in meeting the chronic demands of global food security. However, genetically improved seed is only part of the solution. Such seed must be integrated into ecologically based farming systems and evaluated in light of their environmental, economic, and social impacts-the three pillars of sustainable agriculture. In this review, I describe some lessons learned, over the last decade, of how genetically engineered crops have been integrated into agricultural practices around the world and discuss their current and future contribution to sustainable agricultural systems.     

The use of neutron radiography in agriculture to improve the food quality.

The report presented in the 7th ONU's Conference (USA, 2001) about climatic changes that took place at the end of 2001 informs that, in less than 50 years, more than 45% of the world population will be suffering from lack of water. This fact occurs by the absence of management on water resources, mainly, in agriculture. As the excess as the lack of humidity in soil can change the harvest quality, causing physiologic anomalies in food and promoting soil diseases incidence caused by bacteria and fungus. In order to establish a larger control in the food quality, a study has been performed, through the neutron radiographic technique, that proposes the optimization of agricultural harvests in relation to the minimum quantity of water necessary for the plant to develop and, also, of the soil compactness. Thus, neutron radiographic images of the system root-soil can be produced so that each root will be evaluated for its ability to penetrate in the soil layers, having the advantage of not interfering in this system what it is not possible through the usual techniques yet. The initial tests using bean roots showed that the soil thickness, which involved the roots, resulted in low contrast images, what impeded their visualization with enough clearness so that their grow could not be observed. For this reason, it was opted to the gadolinium as a contrast agent so that we have been studying its transport through the roots.     

The role of grasslands in food security and climate change

Background

Grasslands are a major part of the global ecosystem, covering 37 % of the earth''s terrestrial area. For a variety of reasons, mostly related to overgrazing and the resulting problems of soil erosion and weed encroachment, many of the world''s natural grasslands are in poor condition and showing signs of degradation. This review examines their contribution to global food supply and to combating climate change.

Scope

Grasslands make a significant contribution to food security through providing part of the feed requirements of ruminants used for meat and milk production. Globally, this is more important in food energy terms than pig meat and poultry meat. Grasslands are considered to have the potential to play a key role in greenhouse gas mitigation, particularly in terms of global carbon storage and further carbon sequestration. It is estimated that grazing land management and pasture improvement (e.g. through managing grazing intensity, improved productivity, etc) have a global technical mitigation potential of almost 1·5 Gt CO₂ equivalent in 2030, with additional mitigation possible from restoration of degraded lands. Milk and meat production from grassland systems in temperate regions has similar emissions of carbon dioxide per kilogram of product as mixed farming systems in temperate regions, and, if carbon sinks in grasslands are taken into account, grassland-based production systems can be as efficient as high-input systems from a greenhouse gas perspective.

Conclusions

Grasslands are important for global food supply, contributing to ruminant milk and meat production. Extra food will need to come from the world''s existing agricultural land base (including grasslands) as the total area of agricultural land has remained static since 1991. Ruminants are efficient converters of grass into humanly edible energy and protein and grassland-based food production can produce food with a comparable carbon footprint as mixed systems. Grasslands are a very important store of carbon, and they are continuing to sequester carbon with considerable potential to increase this further. Grassland adaptation to climate change will be variable, with possible increases or decreases in productivity and increases or decreases in soil carbon stores.     

Meeting the challenge of food and energy security

Growing crops for bioenergy or biofuels is increasingly viewed as conflicting with food production. However, energy use continues to rise and food production requires fuel inputs, which have increased with intensification. Focussing on the question of food or fuel is thus not helpful. The bigger, more pertinent, challenge is how the increasing demands for food and energy can be met in the future, particularly when water and land availability will be limited. Energy crop production systems differ greatly in environmental impact. The use of high-input food crops for liquid transport fuels (first-generation biofuels) needs to be phased out and replaced by the use of crop residues and low-input perennial crops (second/advanced-generation biofuels) with multiple environmental benefits. More research effort is needed to improve yields of biomass crops grown on lower grade land, and maximum value should be extracted through the exploitation of co-products and integrated biorefinery systems. Policy must continually emphasize the changes needed and tie incentives to improved greenhous gas reduction and environmental performance of biofuels.     

The origins of subsistence agriculture in Oceania and the potentials for future tropical food crops

Subsistence agriculture in the Pacific Islands has a complex prehistory centered on western Melanesia. Based on an analysis of cultigen provenience, a sequential model of a three-tiered crop structure of indigenous agricultural systems has been derived: (1) The independent early domestication of endemic species in the New Guinea region; (2) introduction of species from Southeast Asia; (3) the advent of American crop plants. The temporal sequence has archaeological and linguistic confirmation of 10 000 years ago for the beginnings of agriculture, 6000 years for Southeast Asian introduction, with the sweet potato contributing in Polynesia in prehistory, and in Melanesia only in post-Columbian times. Recent research directed toward issues of domestication in New Guinea and subsistence prehistory in Australia on three genera,Canarium, Colocasia andIpomoea, exemplify under-recognized resources with quite different potentials for economic botany. Unlike past exploitation of indigenous plant resources, future users of plants such as those exemplified, and especially where commercialization is involved, cannot avoid addressing intellectual property rights that pertain to species domesticated, selected or conserved by peoples of the non-industri-alized world.     

Application of antimicrobial peptides in agriculture and food industry

Antimicrobial peptides have captured the attention of researchers in recent years because of their efficiency in fighting against pathogens. These peptides are found in nature and have been isolated from a wide range of organisms. Furthermore, analogs or synthetic derivatives have successfully been developed on the basis of natural peptide patterns. Long use of pesticides and antibiotics has led to development of resistance among pathogens and other pests as well as increase of environmental and health risks. Antimicrobial peptides are under consideration as new substitutes for conventional pesticides and antibiotics. Many plants and animals have been manipulated with antimicrobial peptide-encoding genes and several pesticides and drugs have been produced based on these peptides. Such strategies and products may still have a long way to go before being confirmed by regulatory bodies and others need to surmount technical problems before being accepted as applicable ones. In spite of these facts, several cases of successful use of antimicrobial peptides in agriculture and food industry indicate a promising future for extensive application of these peptides. In this review, we consider the developing field of antimicrobial peptide applications in various agricultural activities.     

Potential and attainable food production and food security in different regions

Growing prosperity in the South is accompanied by human diets that will claim more natural resources per capita. This reality, combined with growing populations, may raise the global demand for food crops two- to four-fold within two generations. Considering the large volume of natural resources and potential crop yields, it seems that this demand can be met smoothly. However, this is a fallacy for the following reasons. (i) Geographic regions differ widely in their potential food security: policy choices for agricultural use of natural resources are limited in Asia. For example, to ensure national self-sufficiency and food security, most of the suitable land (China) and nearly all of the surface water (India) are needed. Degradation restricts options further. (ii) The attainable level of agricultural production depends also on socio-economic conditions. Extensive poverty keeps the attainable food production too low to achieve food security, even when the yield gap is wide, as in Africa. (iii) Bio-energy, non-food crops and nature compete with food crops for natural resources. Global and regional food security are attainable, but only with major efforts. Strategies to achieve alternative aims will be discussed. <br>     

The potential for underutilized crops to improve security of food production

Staple crops face major challenges in the near future and a diversification away from over-reliance on staples will be important as part of the progress towards the goal of achieving security of food production. Underutilized or neglected crops species are often indigenous ancient crop species which are still used at some level within the local, national or even international communities, but have the potential to contribute further to the mix of food sources than they currently do. The most cost-effective and easily disseminated changes that can be made to a crop are changes to the genetics, as these are contained within the seed itself and, for many species, the seed is a pure breeding, self-replicating, resource. This article focuses on the potential of underutilized crops to contribute to food security and, in particular, whether genetics and breeding can overcome some of the constraints to the enhanced uptake of these species in the future. The focus here is on overview rather than detail and subsequent articles will examine the current evidence base.     

The role of conservation agriculture in sustainable agriculture

The paper focuses on conservation agriculture (CA), defined as minimal soil disturbance (no-till, NT) and permanent soil cover (mulch) combined with rotations, as a more sustainable cultivation system for the future. Cultivation and tillage play an important role in agriculture. The benefits of tillage in agriculture are explored before introducing conservation tillage (CT), a practice that was borne out of the American dust bowl of the 1930s. The paper then describes the benefits of CA, a suggested improvement on CT, where NT, mulch and rotations significantly improve soil properties and other biotic factors. The paper concludes that CA is a more sustainable and environmentally friendly management system for cultivating crops. Case studies from the rice-wheat areas of the Indo-Gangetic Plains of South Asia and the irrigated maize-wheat systems of Northwest Mexico are used to describe how CA practices have been used in these two environments to raise production sustainably and profitably. Benefits in terms of greenhouse gas emissions and their effect on global warming are also discussed. The paper concludes that agriculture in the next decade will have to sustainably produce more food from less land through more efficient use of natural resources and with minimal impact on the environment in order to meet growing population demands. Promoting and adopting CA management systems can help meet this goal.     

Complex agro-ecosystems for food security in a changing climate

Attempts to increase food crop yields by intensifying agricultural systems using high inputs of nonrenewable resources and chemicals frequently lead to de-gradation of natural resources, whereas most technological innovations are not accessible for smallholders that represent the majority of farmers world wide. Alternatively, cocultures consisting of assemblages of plant and animal species can support ecological processes of nutrient cycling and pest control, which may lead to increasing yields and declining susceptibility to extreme weather conditions with increasing complexity of the systems. Here we show that enhancing the complexity of a rice production system by adding combinations of compost, azolla, ducks, and fish resulted in strongly increased grain yields and revenues in a season with extremely adverse weather conditions on East Java, Indonesia. We found that azolla, duck, and fish increased plant nutrient content, tillering and leaf area expansion, and strongly reduced the density of six different pests. In the most complex system comprising all components the highest grain yield was obtained. The net revenues of this system from sales of rice grain, fish, and ducks, after correction for extra costs, were 114% higher than rice cultivation with only compost as fertilizer. These results provide more insight in the agro-ecological processes and demonstrate how complex agricultural systems can contribute to food security in a changing climate. If smallholders can be trained to manage these systems and are supported for initial investments by credits, their livelihoods can be improved while producing in an ecologically benign way.