SUSTAINABLE AGRICULTURE

Sustainability of agricultural production a desired goal to feed the rapidly increasing population

By Dr. S. M. ALAM
Dec 16 - 22, 2002

Sustainable agriculture integrates three main meaningful goals - economic profitability, environmental health, and social and economic equity A variety of philosophies, policies and practices have contributed whole heartedly to these goals. People in many different capacities, from farmers to consumers, have shared this vision and contributed to it. Despite the diversity of people and perspectives, the following themes commonly weave through definitions of sustainable agriculture. Sustainability rests on the principle that we must meet the needs of the present situation without compromising the ability of future generations to meet their own needs. Therefore, stewardship of both natural and human resources is of prime importance. Stewardship of human resources includes consideration of social responsibilities such as working and living conditions of laborers, the needs of rural communities, and consumer health and safety both in the present and the future.

Stewardship of land and natural resources involves maintaining or enhancing this vital resource base for the long term. A system perspective is essential to understanding the phenomenon of sustainability. The system is envisioned in its broadest sense, from the individual farm, to the local ecosystem, and to communities affected by this farming system both locally and globally. An emphasis on the system allows a larger and more thorough view of the consequences of farming practices on both human communities and the environment. A system approach gives us the tools to explore the interconnections between farming and other aspects of our environment. Sustainable agriculture normally requires a series of small, realistic steps. Family economics and personal goals influence how fast or how far participants can go in the transition. It is important to realize that each small decision can make a difference and contribute to advancing the entire system further on the "sustainable agriculture continuum." Finally, it is important to point out that reaching toward the goal of sustainable agriculture is the responsibility of all participants in the system, including farmers, laborers, policy makers, researchers, retailers, and consumers. Each group has its own part to play, its own unique contribution to make to strengthen the sustainable agriculture community.

Agriculture is the mainstay of Pakistan's economy and sustainability of agricultural production a desired goal to feed the rapidly increasing population. Sustainability becomes even more crucial in view of the prevailing agro-climatic conditions that are highly conducive to rapid loss of agricultural resources like soil, water and nutrients. However, the challenge of putting sustainable agricultural systems into place has perhaps seen less than desirable and necessary progress. One reason being that the concept of sustainable agriculture is difficult to deal with, particularly in the developing countries like Pakistan where farmers have few resources and limited options. In addition, sustainability in agriculture is a "moving target" and no single method of farming in any region remains sustainable without continual intervention and change.

Agro-ecosystems capable of ensuring sustained productivity require management of resources through a diversity of interdependent forms of life, recycling of plant and animal wastes, selection and rotation of crops. This approach is based on the fact that soil is living entity and that it must be fed to enable it feed its inhabitants. We need to understand and work in harmony with the natural biological systems in order to develop cultural and biological means of crop nutrition and protection that are balanced, sustainable and resilient. With this method, soil fertility is maintained as well as improved by increased biological activity that provides plants and animals with essential nutrient elements and conserves soil resources. Insects and diseases are controlled by encouraging a balanced host-predator relationship and by an increase in beneficial insect population.

Sustainability of agriculture may differ from field to field and farm to farm from one period of time to another because of dynamic biological, physical, chemical, and environmental factors. Thus, continuous investments need to make in agricultural research for evolving new knowledge, new practices/technologies, and in updating farmers knowledge and skills. This job can best be done through participatory activities of scientists, extension workers, NGOs and endusers, i.e. farmers. This workshop is intended to bring together all the players that contribute or can contribute towards making agricultural systems sustainable. The main objective will be to sift the information already available, seek new knowledge and recommend strategies for both short term and long term sustainability of agro- ecosystems.

INTRODUCTION: Four essential ingredients of an agro-ecosystem that are susceptible to human intervention to a certain extent include i) planting material, ii) soil, iii) inputs, and iv) insect/pests and weeds. Only a good balance between all these components can help sustain agricultural productivity. In addition, farm animals contribute significantly to the livelihood of farming community and hence their well-being is an essential component of a healthy farming system.

LAND PREPARATION: In ploughing of land and its leveling is the pre-requisite requirement for getting a good crop yield. Therefore, it is necessary to prepare the land smoothly and precisely in order to get a substantial crop productivity.

SEED AND CROP MANAGEMENT: In order to obtain optimum and sustained crop yields, the first pre- requisite is the quality seed that is produced and maintained under appropriate conditions, while rotations and diversification are key principles in sustainable ecological farming system. Diversity of crops in both time and space prevents insect and disease buildup, improves cycling and acquisition of nutrients and provides a hedge against poor market conditions for any one crop. Rotation must be as varied as possible and include legumes, green manuring crops and deep-rooted crops. varietal selection should therefore look beyond maximum potential yield and consider insect and disease resistance, nutritional quality, flavour and positive response to lower inputs of nutrients and water. Cover crops are used to hold the soil, improve fertility and provide habitat for beneficial insects. Weeds could be managed through rotations with competitive cover crops, timely mowing or cultivation, mulching with organic materials, and living mulches etc. In this session papers pertaining to some of these aspects will be presented.

SOIL MANAGEMENT: Important land resources problems include threat to bio-diversity, depleting fertility, deteriorating biological activity and twin menace of water-logging and salinity. Maintenance of health and biological activity of soil is possible through green manures and leguminous cover crops, composted plant and animal residues fortified with micronutrients, naturally occurring microbial inoculants, cover crops that activate K, composted manures high in P. Inputs of organic matter must be sufficient to maintain or, even better, to increase the long term humus content of the soil. Adoption of resource conservation technologies like Zero tillage, bed and furrow planting technique can help sustain productivity. For problem soils (e.g., salt- affected soils), adoption of biological approach is not only environment friendly, but economically viable as well. It is on some of these aspects that expert lectures will be delivered.

WATER MANAGEMENT: The Indus Basin Irrigation System mainly supports Pakistan's irrigated agriculture which comprises 20.6 million ha., ca 5 million ha being rainfed. Competition between the agricultural and non-agricultural uses has decreased the availability of sweet water for agriculture and the supplies are expected to decrease further. In addition, substantial losses of irrigation water occur during transport and from the site of irrigation. The water losses and its inefficient use exist in both rain-fed and irrigated tracts. In irrigated areas, there are huge conveyance losses and the efficiency of water application/use at farm level is far from satisfactory with the existing irrigation system. Therefore, to sustain agriculture in Pakistan, adoption of water management practices on a large scale are urgently required. The conservation of water is possible through adopting improved irrigation technologies and tillage practices, green manuring, and the use of mulches, etc. The brackish sub-surface water from salt-affected areas can profitably be used following treatments like gypsum, acids or acid formers. Elaborate discussions are planned on these aspects.

FERTILIZER MANAGEMENT: Soils in Pakistan are either low in nutrients or the latter are not readily available. This is because i) the entire crop is normally removed from the field resulting in mining of nutrients, and ii) the organic matter content is low because of meager replenishment as well as rapid loss; both factors contribute to a low level of biological activity that is responsible for nutrient mobilization. Use of chemical fertilizers is therefore essential to obtain desirable yields. This practice not only affects the short term economy of the agro-ecosystems but has serious environmental implications as well. Indeed, inorganic fertilization must be a supplemental source and not a substitute for recycling nutrients and the objective of any fertilization scheme must be to maintain or increase fertility and biological activity of the soil. Materials are not to be used as a primary management strategy, but rather as an aid to resolving a specific problem until the farm system is brought back into balance. Hence, strategies to economize fertilizer use and to increase its efficiency are needed for agriculture to remain sustainable, profitable, and environmental friendly. Several lectures will address these issues during the course of the workshop.

PLANT PROTECTION: One of the crop yield limiting factors is the pre- and post-harvest loss by insect/pests and microbial pathogens. Some of the strategies to avoid these losses include preventive management such as use of resistant varieties, limiting to avoid cycles of pest emergence, intercropping, rotations, balanced plant nutrition, parasitic nematodes, introduction of predators, habitat enhancement to encourage beneficial predators, sticky traps, microbial and viral diseases. Pest problem can also be minimized by proper timing of plantings and the use of trap crops to attract pests and beneficial alike. It should be appreciated, however, that pest-free and weed-free fields are neither always possible nor economically and ecologically desirable. Learning the thresholds for tolerable levels of weeds, insects, birds and rodents taken time and experience and is an ongoing process. Being an integral component of any cropping system, different aspects of plant protection will be discussed.

ANIMALS HEALTH AND NUTRITION: Farm animals are essential components of a farming system especially in countries like Pakistan and contributes significantly to the earnings of the farming community. Livestock management is based on good nutrition, animals stress reduction, and preventive medicine etc. Some recently developed, economical and efficient means to maintain animal health will be discussed.

The phenomenon of sustainable agriculture is sound and very useful for present day of agriculture. Therefore a serious thought may be given to its meaningful use in the agriculture system of the country.