Organic agricultural systems for cassava crops in upland soil of Thailand.

Summary

A study was carried out in upland soil during 2003-2005 in the central part of Thailand where the soil is classified as a sandy loam with a low inherent fertility. The design of the trial comprised of a completely randomized block design with ten treatments in three replication which were as follows; control, conventional method, the combination of using of Canavalia sp as green manure and mulching with Vigna sp Crotolaria sp as green manure, mulching with Vigna sp and Canavalia sp as green manure and mulching with Vigna sp. The another four treatments were Canavalia sp and Crotolaria sp as green manures and mulching with Vigna sp incorporated with liquid fertilizer, Crotolaria sp and Vigna sp as green manure mulching with Canavalia sp incorporated with liquid fertilizer. There was a tendency for those treatments comprising of green manure incorporate with mulching and liquid fertilizer having greater height, yield and starch of cassava than those treatments receiving just the green manure incorporated with mulching. Moreover, it was found that the combination of Crotolaria sp. incorporated with Canavalia sp and liquid fertilizer resulted in the highest, yields and starch among the application of organic fertilizer. An assessment of the economic return was on investments indicated that the combination of Crotolaria sp. incorporated with Canavalia sp and liquid fertilizer gave the greatest net profit.