Low-input technologies for increasing crop productivity and sustainability: A review

Sustainable agriculture is an important element of the overall effort to make human activities compatible with the demands of the earth's eco-system. The low external input agriculture or low input agriculture (LIA) emphasizes the use of techniques that integrate natural processes such as nutrient recycling, biological N fixation (BNF), soil regeneration and natural enemies of pests into food production processes. Efforts are made to minimize losses from the system, such as by leaching or removal of crop residues. Yields are maintained through greater emphasis on cultural practices, integrated pest management (IPM), and utilization of on-farm resources and management. The conceptual basis of low-input agriculture includes a) adaptation of plants to the constraints, rather than eliminatrion of all constraints to meet the plant's requirements, and b) maximization of output per unit of added input. The major components of LIA are selection of most appropriate lands, use of improved (stress tolerant) bio-types, low-cost technologies for better crop establishment, management of soil-water constraints with minimum inputs, BNF, efficiently managing P fertilizers including phosphate solubilizer and identifying and correcting deficiencies of other essential plant nutriments. Improved LIAs discussed in this paper are conservation tillage, seed treatments and seed production related low cost technologies, appropriate planting time and methods, biofertilizers, better intercrops, possible in-situ or ex-situ composting, suitable agroforestry, alley cropping and other alternative farming systems. Other suitable LIAs include cover crops and green manures, effective biomass transfer techniques, improved fallows, permaculture (a land use and community building movement for harmonious integration) and IRM/IPM approaches. Future research to improve LIA should focus more on developing interventions to meet farmer realities, such as increased food security, improved cash generation, reduced risk, and enhanced quality of life.