(a) Define ecology. Mention its basic concepts and relevance in crop production. (20 marks) (b) How to improve drainage of…

(a) Ecology: definition, basic concepts and relevance in crop production

Ecology is the study of the structure and function of nature (E.P. Odum): the interrelationships between organisms and their environment. Unlike biology, which studies the organism, it studies the organism in relation to its surroundings, with Tansley's ecosystem concept at its core.

Basic concepts: the ecosystem, a functional unit of living communities interacting with non-living components; habitat and ecological niche; food chains and trophic levels; unidirectional energy flow; biogeochemical nutrient cycling; population and community dynamics; ecological succession; and limiting factors, as in Liebig's law of the minimum and Shelford's law of tolerance.

Relevance to crop production: a cropped field is an agroecosystem, so ecological principles guide its management. Nutrient cycling and organic matter decomposition underpin soil fertility and justify INM, residue recycling and legume rotations. Food-web balance between pests and natural enemies underlies biological control and Integrated Pest Management. Niche and competition concepts guide intercropping, crop-weed competition and cropping systems. Pollinator biodiversity supports yield in oilseeds and fruits. Limiting-factor and tolerance laws explain crop-zone adaptation and climate risk. Organic farming and agroforestry apply these principles to sustain yields without degrading the resource base.

(b) Drainage of waterlogged areas, and drip and sprinkler irrigation

Drainage: surface drainage removes ponded water through open field drains, land grading and levelling; subsurface drainage lowers shallow water tables through perforated corrugated PVC pipe drains, as used in waterlogged saline tracts in Haryana, and mole drains in heavy clays; bio-drainage uses deep-rooted, high-transpiring trees such as eucalyptus along canals and field boundaries; and controlling canal seepage, with lining and conjunctive use of groundwater, prevents recurrence.

Drip irrigation. Advantages: application efficiency of 90-95% and water saving of 40-60%; fertigation; fewer weeds; operation on undulating land and with moderately saline water. Limitations: high initial cost, emitter clogging, need for filtration and skilled maintenance, rodent and UV damage to laterals, and unsuitability for closely sown crops.

Sprinkler irrigation. Advantages: uniform coverage on undulating or sandy soils; no land levelling; frost protection and humidity control; water saving of about 30-40%. Limitations: high energy and capital cost, spray drift and uneven distribution in wind, evaporation loss, and foliar disease and salt-injury risk with saline water.

Both are promoted under PMKSY 'Per Drop More Crop'.

(c) Extension approaches and emerging concepts in transfer of technology

Approaches: the linear 'transfer of technology' approach, top-down from research to extension to farmer, using demonstrations and training through Krishi Vigyan Kendras and the Lab-to-Land programme; the participatory approach, involving farmers through farmer groups, Farmer Field Schools and farmer-participatory action research; and the pluralistic approach, where public, private and NGO providers work together, as under ATMA (2005) and agri-clinics.

Emerging concepts: ICT-enabled e-extension through Kisan Call Centres, mKisan, KVK apps and the Kisan Sarathi platform; video-based and farmer-to-farmer extension; drone and precision-agriculture advisories; AI-based pest and weather advisories; Climate Resilient Villages under NICRA; and agri-startup and incubation support. The common shift is from one-way transfer to two-way, demand-driven, knowledge exchange.