HomeInternational Rice Research Notesvol. 30 no. 1 (2005)

Evaluating integrated nutrient management for the biasi system of rainfed rice cultivation

A.k. Swarnkar | V.m. Victor | A.s. Rajput

Discipline: Biology, Agriculture



Biasi is a set of cultural operations traditionally practiced in direct seeded rice. In this operation, the field is plowed by an indigenous plow in standing water 30-50 d after emergence. Bullock plowing often followed planking and chalai (thinning and distribution) operations. This system is very popular in the eastern region of India; about 75% of the area (25.5 million ha) is under the biasi system. The effectiveness of the system greatly affects yield. Often, operation is delayed because there is less rain to flood the field. The post-biasi operation, which is done to redistribute seedlings, has high labor requirements and is costly. The other major drawbacks are high plant mortality (38-40%) and heavy weed intensity. It is important to evaluate a suitable integrated nutrient management system under biasi to increase yield with minimal operational cost. Use of green manure, especially Sesbania rostrata, which nodulates in roots as well as in stems, gives better performance and maintains the nutrient supply. A significant savings of 40 kg N ha-1 was recorded by incorporating 40-d-old S. rostrata in a standing rice crop under biasi (IGKV 1994). Green manure incorporation will thus improve yield.