Author : Niyom Boonpikum

Summary : A field experiment to determine the effects of organic amendments, drainage, and mulching on rice and sorghum yields and on some chemical properties of a salt-affected soil was conducted in Kalasin province, Thailand from September 11, 1980 to July 16, 1981. The results showed that among the four kinds of organic amendments tested, rice bull and buffalo manure at the rate of 25 tons/ha each gave significantly the highest grain yield of the rice RD7 variety. In the first crop, the grain yield in the rice hull treatments was 2.331 tons/ha while the buffalo manure was 2.120 tons/ha. In the second crop, testing the residual effect of the soil amendments, the buffalo manure gave a yield of 2.732 tons/ha and rice hull, 2.420 tons/ha. Rice RD7 variety is a medium salt-tolerant variety and was able to grow on 6.70 mmhos/cm of electrical conductivity EC. The sesbania straw treatment gave significantly higher nitrogen and potassium in rice straw, than the buffalo manure, rice straw, and rice hull treatments. Submerge significantly increased the pH and available phosphorus in the soil. The irrigation water was classified as C (subscript 3)-S (subscript 1) or C (subscript 4) - S (subscript 1), which simply means it is high in salinity hazards and low in sodium hazard. The intermittent drainage treatment before the application of tons of rice straw mulch per hectare increased the grain yield, had dry weight, total dry matter production, and harvest index of the sorghum over the control. The sorghum grain yield was highly correlated with head dry weight, 100-grain weight and harvest index, but not with plant height, panicle lenght, grain-stover ratio and total dry matter production in the intermittent drainage plot.