Your search found 7 records
1 Gunasena, H. P. M.; Marambe, B.. 1998. Neem in Sri Lanka: A monograph. Peradeniya, Sri Lanka: University of Peradeniya - Oxford Forestry Institute (UK), Forestry Research Link. iii, 62p.
(Location: IWMI-HQ Call no: 633.88 G744 GUN Record No: H022217)
2 Karunasena, K. G. J.; Marambe, B.; Sangakkara, U. R.; Dharmasena, P. B. 1997. Productivity of rice and chilli under village tanks of Sri Lanka in Maha season with respect to resource utilization. In Kumaragamage, D. (Ed.), Tropical agricultural research. Vol.9, 1997 Peradeniya, Sri Lanka: PGIA. pp.168-181.
Rice ; Crop production ; Cropping systems ; Labor ; Tank irrigation ; Villages ; Resource management / Sri Lanka / Ambalegoda Tank / Elapathwewa Tank
(Location: IWMI-HQ Call no: 630.72 G744 KUM Record No: H023278)
3 Marambe, B.. (Ed.) 1998. Tropical agricultural research. Vol.10, 1998. Peradeniya, Sri Lanka: University of Peradeniya. Postgraduate Institute of Agriculture (PGIA). vi, 437p.
Agricultural research ; Water stress ; Coconuts ; Soil-water-plant relationships ; Soil management ; Sugarcane ; Water management ; Hydrology ; Cropping systems ; Agricultural economics ; Erosion ; Food production ; Nitrogen ; Plant growth ; Tomatoes ; Potatoes ; Weed control ; Pests ; Diseases ; Animal husbandry ; Millets ; Beans / Sri Lanka / India
(Location: IWMI-HQ Call no: 630.72 G744 MAR Record No: H023376)
4 Marambe, B.; Sangakkara, U. R.; Haq, K. A. (Eds.) 1996. Crop diversification strategies for minor irrigation schemes: Proceedings of the workshop organized by the Irrigation Research Management Unit, Irrigation Department and the Sri Lanka National Program, International Irrigation Management Institute, held at the Irrigation Department, Colombo, Sri Lanka on 20 February 1996. Colombo, Sri Lanka: Sri Lanka. Irrigation Department. IRMU; International Irrigation Management Institute (IIMI). SLNP. xii, 78p.
Irrigation programs ; Irrigation management ; Small scale systems ; Crops ; Diversification ; Rice ; Cropping systems ; Constraints ; Social aspects ; Economic aspects ; Field crops ; Crop production ; Labor ; Farmers' attitudes ; Water management ; Groundwater / Sri Lanka
(Location: IWMI-HQ Call no: IIMI 631.7.2 G744 MAR Record No: H019767)
The last few decades Sri Lanka has made detennined efforts for crop diversification to raise farm production and improve the quality of life of the farmers. Significant progress has also been made and a large area has been brought under different crops, especially, chili and big onion, two very important cash crops. Most of these developments have occurred in medium and major schemes resulting in significant increases in the cropping intensity as well as in the participation of farmers. Minor schemes which command around 42 percent of the total irrigated area of the country, however did not benefit much from the crop diversification program and their cropping intensity to fluctuate between 80 percent and 90 percent for nearly half a century. At the same time, because of increasingly reduced return from rice farming, many farmers in these schemes are looking for off farm employment to make a living. To understand the technical and socioeconomic dynamics and develop strategies for crop diversification in minor schemes, the Irrigation Research Management Unit (IRMU) of the Irrigation Department (ID) in collaboration with the Sri Lanka National Program (SLNP) of the International Irrigation Management Institute (IIMI) organized a consultation workshop on strategies for Crop diversification in Minor Irrigation Schemes. This volume is the report of the proceedings of the above workshop held at the Irrigation Department, Colombo, Sri Lanka on 20 February, 1996. The workshop provided an opportunity to the participants from different organizations to exchange experiences and identify new approaches to crop diversification.
5 Jayasinghe, C. K.; Jayasekera, S.; Marambe, B.; Gunasena, H. P. M. 2006. Pesticide residue analysis status in Sri Lanka. Colombo, Sri Lanka: Council for Agricultural Research Policy (CARP) 14p.
(Location: IWMI HQ Call no: IWMI 668.65 G744 JAY Record No: H041522)
(0.61 MB)
6 Amarasingha, R. P. R. K.; Suriyagoda, L. D. B.; Marambe, B.; Gaydon, D. S.; Galagedara, L. W.; Punyawardena, R.; Silva, G. L. L. P.; Nidumolu, U.; Howden, M. 2015. Simulation of crop and water productivity for rice (Oryza sativa L.) using APSIM under diverse agro-climatic conditions and water management techniques in Sri Lanka. Agricultural Water Management, 160:132-143. [doi: https://doi.org/10.1016/j.agwat.2015.07.001]
Water productivity ; Water management ; Rice ; Crop management ; Agroclimatic zones ; Irrigation water ; Rain ; Water requirements ; Plant establishment ; Farmers / Sri Lanka / Maha-Illuppallama / Bathalagoda / Bombuwela / Dambadeniya / Maradankalla / Thabbowa
(Location: IWMI HQ Call no: e-copy only Record No: H047402)
(0.93 MB)
The APSIM–Oryza model has been used worldwide to evaluate the impact of diverse management practices on the growth of rice (Oryza sativa L.). Despite its importance, the crop productivity (kg ha-1) and water productivity (kg ha-1mm-1) of rice under moisture-limited (i.e. rainfed or rainfed with supplementary alternate wetting-and-drying (AWD) irrigation) farmer-field conditions in tropical South-Asia has received little attention in modelling exercises. Benefits of aligning crop establishment with the onset of rainfall to reduce dependency on supplementary irrigation and improve crop and water productivities have not yet been quantified in Sri Lanka. Therefore, we parameterised and evaluated the APSIM–Oryza model for two widely grown Sri Lankan short- and medium-duration rice varieties. The model estimated the grain yield of rice under moisture-limited farmer-field conditions with a strong fit (n = 24, R2 > 0.97, RMSE= 484 kg ha-1), across cultivation year, season, time of establishment (i.e. with rainfall onset or date-specific planting), variety and/or water management practice (i.e. totally rainfed or rainfed with supplementary irrigation). A climatic analysis indicated that the farmers regularly establish rice crops 2–4 weeks after the rainfall onset. This is a consequence of the current practice of setting the date for crop establishment at pre-season cultivation meetings without a scientifically-validated rainfall forecast. The same analysis revealed that an early onset to the rainy season resulted in longer seasons with more rain than late onset. When the onset of rainfall is delayed, crop modelling scenarios using the validated APSIM model showed an increased dependence on supplementary irrigation for rice cultivation. Alternatively, in years when an early onset was observed, late planting in the season reduced the use of rain water by 95% while increasing the irrigation water requirement by 11% compared with planting at rainfall onset. Access to supplementary with AWD irrigation increased the stability of grain yield, and crop and water productivity, irrespective of the onset of rainfall or time of crop establishment.
7 Amarasingha, R. P. R. K.; Suriyagoda, L. D. B.; Marambe, B.; Rathnayake, W. M. U. K.; Gaydon, D. S.; Galagedara, L. W.; Punyawardena, R.; Silva, G. L. L. P.; Nidumolu, U.; Howden, M. 2017. Improving water productivity in moisture-limited rice-based cropping systems through incorporation of maize and mungbean: a modelling approach. Agricultural Water Management, 189:111-122. [doi: https://doi.org/10.1016/j.agwat.2017.05.002]
Water productivity ; Cropping systems ; Intercropping ; Rice ; Maize ; Mung beans ; Water requirements ; Irrigation water ; Supplemental irrigation ; Simulation models ; Performance evaluation ; Crop yield ; Soil moisture ; Risk assessment ; Agroclimatic zones / Sri Lanka / Aralaganwila / Bathalagoda / Bombuwela / Maha-Illuppallama / Maradankalla / Vanathawilluwa / Weerawila
(Location: IWMI HQ Call no: e-copy only Record No: H048189)
(1.01 MB)
Crop and water productivities of rice-based cropping systems and cropping patterns in the irrigated lowlands of Sri Lanka have not been researched to the degree warranted given their significance as critical food sources. In order to reduce this knowledge gap, we simulated the water requirement for rice, maize, and mungbean under rice-based cropping systems in the Dry Zone of Sri Lanka. We evaluated the best combinations of crops for minimum water usage while reaching higher crop and water productivities. We also assessed the risk of cultivating mungbean as the third season/sandwich crop (i.e. rice-mungbean-rice) in different regions in Sri Lanka. In the simulation modelling exercise, APSIM-Oryza (rice), APSIM-maize and APSIM-mungbean modules were parameterised and validated for varieties grown widely in Sri Lanka. Moreover, crop productivities and supplementary irrigation requirement were tested under two management scenarios i.e. Scenario 1: irrigate when plant available water content in soil fell below 25% of maximum, and Scenario 2: irrigate at 7-day intervals (current farmer practice). The parameterised, calibrated and validated model estimated the irrigation water requirement (number of pairs of observations (n) = 14, R2 > 0.9, RMSE = 66 mm season-1 ha-1), and grain yield of maize (n = 37, R2 > 0.95, RMSE = 353 kg ha-1) and mungbean (n = 26, R2 > 0.98, RMSE = 75 kg ha-1) with a strong fit in comparison with observed data, across years, cultivating seasons, regions, management conditions and varieties. Simulated water requirement during the cropping season reduced in the order of rice (1180–1520 mm) > maize and mungbean intercrop = maize sole crop (637–672 mm) > mungbean sole crop (345 mm). The water productivity of the system (crop yield per unit water) could be increased by over 65% when maize or mungbean extent was increased. The most efficient crop combinations to maximise net return were diversification of the land extent as (i) 50% to rice and 50% to mungbean sole crops, or (ii) 25%, 25% and 50% to rice, maize and mungbean sole crops, respectively. Under situations where water availability is inadequate for rice, land extent could be cultivated to 50% maize and 50% mungbean as sole crops to ensure the maximum net return per unit irrigation water (115 Sri Lankan Rupees ha-1 mm-1). Regions with high rainfall during the preceding rice cultivating season are expected to have minimum risk when incorporating a third season mungbean crop. Moisture loss through evapotranspiration from the third season mungbean crop was similar to that of a fallowed site with weeds.
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