The experiment was conducted at the village Boyra Sesmore, Bangladesh Agricultural University, Mymensingh from December 2012 to May 2013 to study the yield and economics of SRI and farmers method of Boro rice cv.BRRIdhan29 cultivation. The experiment consisted of a) cultivation of rice only by 10 tha-1 cowdung (T1), b) recommended SRI package (T2) with 5 tha-1 of decomposed cowdung +100% of recommend fertilizer RF; this coincides with the original concept of SRI), c) SRI modification-1 (T3) with 100% of RF; SRI concept suggest to use manure), d) SRI modification-2 (T4) (with 5 t ha-1 of decomposed cowdung + 50% of RF; 50 : 50 use of manure: fertilizer), e) modification-3 (T5) with 10 t ha-1 of decomposed cowdung +50% of RF; 50% manure + 50% dose of fertilizer), f) Farmers practice of rice cultivation (T6). The experiment was laid out in a randomized complete block design (RCBD) with three replications. The effect of various cultivation methods of SRI was significant in respect of all plant characters except plant height. The tallest plant height (100.23 cm), the highest number of total tillers hill-1 (35.01), effective tillers hill-1 (28.00), grains panicle-1 (152.60), grain yield (7.50 t ha-1) and straw yield (9.41 t ha-1) were obtained with 5 t ha-1 of decomposed cowdung +100% of recommend fertilizer RF (T2); of SRI and the highest number of non-effective tillers hill-1 (6.58) was obtained from 10 t ha-1 of decomposed cowdung +50% of RF; 50% manure + 50% dose of fertilizer (T5). The shortest plant height (92.85 cm) and the lowest grain yield (3.57 t ha-1) were obtained from farmers own practice of cultivation. The lowest number of total tillers hill-1 (22.82) was obtained from only use cowdung, effective tillers hill-1 (17.00), grains panicle-1 (92.09) were recorded from cultivation of rice in T1. The highest number of total cost of production (154397.00tk) was obtained from 5 tha-1 of decomposed cowdung +100% of recommend fertilizer (T2) and lowest cost of production was (61957tk) observed from farmers own practice of rice cultivation . The lowest number of net return (27349.67tk) and the lowest BCR (1.18) was obtained from 100% of recommend fertilizer (T3). Key words: SRI, BRRI dhan29, manure, fertilizer, yields.
System of Rice Intensification (SRI) has attracted attention because of its apparent success in increasing rice yield. It is claiming to be a superior technology (Barrett et al., 2004) which can increase the yield to a fantastic level (Sheehy et al., 2004). SRI was originated in Madagascar and was first synthesized by de Laulanie (1983), a French Jesuit priest. SRI raises productivity not by relying on external inputs, e.g., new seeds and fertilizer, but by changing the way farmers manage their rice plants, soil, water and nutrients (Uphoff, 2007). The success of SRI method of rice cultivation depends on the synergistic development of both tiller and root system. The main elements of SRI are to transplant young seedlings that preserve the full genetic potential for producing more viable tillers and root growth, to give the plants wide spacing with single seedling that can reduce competition between hills and keep the soil well-aerated that can allow maximum uptake of nutrients (Uphoff, 1999). In SRI method there are some components that are to be maintained properly for obtaining the maximum return from the method. For example, under this system less than 15 day old infant seedlings are transplanted within 30 minutes of uprooting with single seedling hill-1 and having spacing not less than 25 cm x 25 cm even up to 50 cm x 50 cm in square method of planting. Rice plants can better realize their potential for tiller and root growth and for subsequent grain filling when spaced more widely rather than more densely. Yield depends on the number and size of fertile tillers cm-1 rather than per plant, but total plant performance can be enhanced with optimum spacing rather than crowding. The seedlings are transplanted so that their roots remain in `L’ shape instead of traditional 92