Land optimisation for sustainable production of green leafy vegetables in Sri Lanka
Population growth has resulted in increasing pressure on arable lands. Thereby, people are moving to self-gardening as a solution to obtain quality nutritious food economically. Green leafy vegetables play a key role to supplement the micro-nutrient requirement of the diet. The cultivation systems of green leafy vegetables are diverse with the dwelling systems, preferences of age groups and type of species. However, the management of sustainable continuous production systems to supplement the family's daily demand while optimizing the available land is poorly understood. Therefore, the present study was focused on evaluation of demand for selected green leafy vegetables and design a sustainable production system for continuous supply. Consumption patterns were observed within rural, semi-urban and urban communities with reference to preferences of different age groups by means of a structured questionnaire under cluster sampling technique. Production capacity (marketable yield) was measured for five selected species; Alternanthera sessilis (mugunuwenna), Trianthema portulastrum (sarana), Centilla asiatica (gotukola), Ipomoea aquatica (kankun) and Sesbania grandiflora (kathurumurunga) in field conditions in Puttlam district, Sri Lanka (8.09°N; 80.00°E) during June to August 2015. Centella asiatica, Alternanthera sessilis and Sesbania grandiflora were the top three according to the preferences. Centella asiatica (4098±738.43 g m‑2) and Alternanthera sessilis (3749.4±566.61 g m‑2) reported higher yield than others but with longer harvesting intervals (37±7 days). Ipomoea aquatica (1785.2±480.55 g m‑2) showed medium production capacity and medium length of harvesting intervals (19±1 days). Well-trained Sesbania grandiflora (1572±414.26 g m‑2) plantation reported relatively smaller economic yield compared to Trianthema portulastrum (2341.87±86.91 g m‑2) but with the shortest harvesting interval (10±0 days). By using the above information, the area requirement of a family was estimated as the product of area requirement/meal/head, numbers of blocks and numbers of family members. Per capita area requirement per meal was estimated by per capita demand per meal and production capacity. Also a considered family can save money up to 2-3% of their income except benefit of healthy products from home gardening. This approach was used to prepare a production schedule for a family optimizing resource for sustainable green leafy production.
Karunaratne, A.S., Ekanayake, E.M.N.B. and Walker, S. (2020). Land optimisation for sustainable production of green leafy vegetables in Sri Lanka. Acta Hortic. 1278, 193-200
consumption, yield, optimum plot size, continuous production, harvesting interval