Principal Scientist (Microbiology), OP Rupela from ICRISAT has sent a report "Economic assessment of desilted sediment in terms of plant nutrients equivalent: A case Study in the Medak district of Andhra Pradesh"
following is extracts from report

Water harvesting, storage and reutilization for crop production is an important component of research for sustainable agricultural development in the dry regions. Traditionally in southern India, water storage tanks are an integral part of villages and the water is used for recharging groundwater and irrigating fields. Over the years, the storage capacity of tanks gets reduced due to sediment deposits from erosion and runoff processes. During 2001, the Government of Andhra Pradesh undertook the ‘Neeru-Meeru’ (Water and You) initiative in Medak district, for desiltation of tanks during the dry season. We assessed the viability of desilting operations and economic value of potential utilization of sediments desilted from tanks for its nutrient value. The sediment samples collected from 21 tanks spread out in 11 mandals of the Medak district were analyzed for their plant nutrient content and microbiological properties. On an average, the B/C ratio for desilting operations from water tanks based on the economic plant nutrient value (N and P content) of the district was calculated to be 1.23 which reflects a positive benefit for the costincurred in the ‘Neeru-Meeru’ program.

Global Theme 3: Water, Soil and Agrodiversity Management for Ecosystem Resilience Report No 4 by  KV Padmajja,, SP Wanii,, Lav Agarrwall and K L Sahrrawat, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), District Water Management Agency

(Contributed by OP Rupela on 16 May 2008. for full report contact us)